2 * Copyright © 2014 Red Hat
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 #include <linux/delay.h>
24 #include <linux/errno.h>
25 #include <linux/i2c.h>
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/seq_file.h>
30 #include <linux/iopoll.h>
32 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
33 #include <linux/stacktrace.h>
34 #include <linux/sort.h>
35 #include <linux/timekeeping.h>
36 #include <linux/math64.h>
39 #include <drm/drm_atomic.h>
40 #include <drm/drm_atomic_helper.h>
41 #include <drm/drm_dp_mst_helper.h>
42 #include <drm/drm_drv.h>
43 #include <drm/drm_print.h>
44 #include <drm/drm_probe_helper.h>
46 #include "drm_crtc_helper_internal.h"
47 #include "drm_dp_mst_topology_internal.h"
52 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
53 * protocol. The helpers contain a topology manager and bandwidth manager.
54 * The helpers encapsulate the sending and received of sideband msgs.
56 struct drm_dp_pending_up_req {
57 struct drm_dp_sideband_msg_hdr hdr;
58 struct drm_dp_sideband_msg_req_body msg;
59 struct list_head next;
62 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
65 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
67 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
69 struct drm_dp_payload *payload);
71 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
72 struct drm_dp_mst_port *port,
73 int offset, int size, u8 *bytes);
74 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
75 struct drm_dp_mst_port *port,
76 int offset, int size, u8 *bytes);
78 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
79 struct drm_dp_mst_branch *mstb);
82 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
83 struct drm_dp_mst_branch *mstb);
85 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
86 struct drm_dp_mst_branch *mstb,
87 struct drm_dp_mst_port *port);
88 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
91 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
92 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
93 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
95 #define DBG_PREFIX "[dp_mst]"
97 #define DP_STR(x) [DP_ ## x] = #x
99 static const char *drm_dp_mst_req_type_str(u8 req_type)
101 static const char * const req_type_str[] = {
102 DP_STR(GET_MSG_TRANSACTION_VERSION),
103 DP_STR(LINK_ADDRESS),
104 DP_STR(CONNECTION_STATUS_NOTIFY),
105 DP_STR(ENUM_PATH_RESOURCES),
106 DP_STR(ALLOCATE_PAYLOAD),
107 DP_STR(QUERY_PAYLOAD),
108 DP_STR(RESOURCE_STATUS_NOTIFY),
109 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
110 DP_STR(REMOTE_DPCD_READ),
111 DP_STR(REMOTE_DPCD_WRITE),
112 DP_STR(REMOTE_I2C_READ),
113 DP_STR(REMOTE_I2C_WRITE),
114 DP_STR(POWER_UP_PHY),
115 DP_STR(POWER_DOWN_PHY),
116 DP_STR(SINK_EVENT_NOTIFY),
117 DP_STR(QUERY_STREAM_ENC_STATUS),
120 if (req_type >= ARRAY_SIZE(req_type_str) ||
121 !req_type_str[req_type])
124 return req_type_str[req_type];
128 #define DP_STR(x) [DP_NAK_ ## x] = #x
130 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
132 static const char * const nak_reason_str[] = {
133 DP_STR(WRITE_FAILURE),
134 DP_STR(INVALID_READ),
138 DP_STR(LINK_FAILURE),
139 DP_STR(NO_RESOURCES),
142 DP_STR(ALLOCATE_FAIL),
145 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
146 !nak_reason_str[nak_reason])
149 return nak_reason_str[nak_reason];
153 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
155 static const char *drm_dp_mst_sideband_tx_state_str(int state)
157 static const char * const sideband_reason_str[] = {
165 if (state >= ARRAY_SIZE(sideband_reason_str) ||
166 !sideband_reason_str[state])
169 return sideband_reason_str[state];
173 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
178 for (i = 0; i < lct; i++) {
180 unpacked_rad[i] = rad[i / 2] >> 4;
182 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
185 /* TODO: Eventually add something to printk so we can format the rad
188 return snprintf(out, len, "%*phC", lct, unpacked_rad);
191 /* sideband msg handling */
192 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
197 int number_of_bits = num_nibbles * 4;
200 while (number_of_bits != 0) {
203 remainder |= (data[array_index] & bitmask) >> bitshift;
211 if ((remainder & 0x10) == 0x10)
216 while (number_of_bits != 0) {
219 if ((remainder & 0x10) != 0)
226 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
231 int number_of_bits = number_of_bytes * 8;
234 while (number_of_bits != 0) {
237 remainder |= (data[array_index] & bitmask) >> bitshift;
245 if ((remainder & 0x100) == 0x100)
250 while (number_of_bits != 0) {
253 if ((remainder & 0x100) != 0)
257 return remainder & 0xff;
259 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
263 size += (hdr->lct / 2);
267 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
274 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
275 for (i = 0; i < (hdr->lct / 2); i++)
276 buf[idx++] = hdr->rad[i];
277 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
278 (hdr->msg_len & 0x3f);
279 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
281 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
282 buf[idx - 1] |= (crc4 & 0xf);
287 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
288 u8 *buf, int buflen, u8 *hdrlen)
298 len += ((buf[0] & 0xf0) >> 4) / 2;
301 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
303 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
304 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
308 hdr->lct = (buf[0] & 0xf0) >> 4;
309 hdr->lcr = (buf[0] & 0xf);
311 for (i = 0; i < (hdr->lct / 2); i++)
312 hdr->rad[i] = buf[idx++];
313 hdr->broadcast = (buf[idx] >> 7) & 0x1;
314 hdr->path_msg = (buf[idx] >> 6) & 0x1;
315 hdr->msg_len = buf[idx] & 0x3f;
317 hdr->somt = (buf[idx] >> 7) & 0x1;
318 hdr->eomt = (buf[idx] >> 6) & 0x1;
319 hdr->seqno = (buf[idx] >> 4) & 0x1;
326 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
327 struct drm_dp_sideband_msg_tx *raw)
333 buf[idx++] = req->req_type & 0x7f;
335 switch (req->req_type) {
336 case DP_ENUM_PATH_RESOURCES:
337 case DP_POWER_DOWN_PHY:
338 case DP_POWER_UP_PHY:
339 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
342 case DP_ALLOCATE_PAYLOAD:
343 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
344 (req->u.allocate_payload.number_sdp_streams & 0xf);
346 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
348 buf[idx] = (req->u.allocate_payload.pbn >> 8);
350 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
352 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
353 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
354 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
357 if (req->u.allocate_payload.number_sdp_streams & 1) {
358 i = req->u.allocate_payload.number_sdp_streams - 1;
359 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
363 case DP_QUERY_PAYLOAD:
364 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
366 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
369 case DP_REMOTE_DPCD_READ:
370 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
371 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
373 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
375 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
377 buf[idx] = (req->u.dpcd_read.num_bytes);
381 case DP_REMOTE_DPCD_WRITE:
382 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
383 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
385 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
387 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
389 buf[idx] = (req->u.dpcd_write.num_bytes);
391 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
392 idx += req->u.dpcd_write.num_bytes;
394 case DP_REMOTE_I2C_READ:
395 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
396 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
398 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
399 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
401 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
403 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
404 idx += req->u.i2c_read.transactions[i].num_bytes;
406 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
407 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
410 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
412 buf[idx] = (req->u.i2c_read.num_bytes_read);
416 case DP_REMOTE_I2C_WRITE:
417 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
419 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
421 buf[idx] = (req->u.i2c_write.num_bytes);
423 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
424 idx += req->u.i2c_write.num_bytes;
429 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
431 /* Decode a sideband request we've encoded, mainly used for debugging */
433 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
434 struct drm_dp_sideband_msg_req_body *req)
436 const u8 *buf = raw->msg;
439 req->req_type = buf[idx++] & 0x7f;
440 switch (req->req_type) {
441 case DP_ENUM_PATH_RESOURCES:
442 case DP_POWER_DOWN_PHY:
443 case DP_POWER_UP_PHY:
444 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
446 case DP_ALLOCATE_PAYLOAD:
448 struct drm_dp_allocate_payload *a =
449 &req->u.allocate_payload;
451 a->number_sdp_streams = buf[idx] & 0xf;
452 a->port_number = (buf[idx] >> 4) & 0xf;
454 WARN_ON(buf[++idx] & 0x80);
455 a->vcpi = buf[idx] & 0x7f;
457 a->pbn = buf[++idx] << 8;
458 a->pbn |= buf[++idx];
461 for (i = 0; i < a->number_sdp_streams; i++) {
462 a->sdp_stream_sink[i] =
463 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
467 case DP_QUERY_PAYLOAD:
468 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
469 WARN_ON(buf[++idx] & 0x80);
470 req->u.query_payload.vcpi = buf[idx] & 0x7f;
472 case DP_REMOTE_DPCD_READ:
474 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
476 r->port_number = (buf[idx] >> 4) & 0xf;
478 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
479 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
480 r->dpcd_address |= buf[++idx] & 0xff;
482 r->num_bytes = buf[++idx];
485 case DP_REMOTE_DPCD_WRITE:
487 struct drm_dp_remote_dpcd_write *w =
490 w->port_number = (buf[idx] >> 4) & 0xf;
492 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
493 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
494 w->dpcd_address |= buf[++idx] & 0xff;
496 w->num_bytes = buf[++idx];
498 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
504 case DP_REMOTE_I2C_READ:
506 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
507 struct drm_dp_remote_i2c_read_tx *tx;
510 r->num_transactions = buf[idx] & 0x3;
511 r->port_number = (buf[idx] >> 4) & 0xf;
512 for (i = 0; i < r->num_transactions; i++) {
513 tx = &r->transactions[i];
515 tx->i2c_dev_id = buf[++idx] & 0x7f;
516 tx->num_bytes = buf[++idx];
517 tx->bytes = kmemdup(&buf[++idx],
524 idx += tx->num_bytes;
525 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
526 tx->i2c_transaction_delay = buf[idx] & 0xf;
530 for (i = 0; i < r->num_transactions; i++) {
531 tx = &r->transactions[i];
537 r->read_i2c_device_id = buf[++idx] & 0x7f;
538 r->num_bytes_read = buf[++idx];
541 case DP_REMOTE_I2C_WRITE:
543 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
545 w->port_number = (buf[idx] >> 4) & 0xf;
546 w->write_i2c_device_id = buf[++idx] & 0x7f;
547 w->num_bytes = buf[++idx];
548 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
558 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
561 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
562 int indent, struct drm_printer *printer)
566 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
567 if (req->req_type == DP_LINK_ADDRESS) {
568 /* No contents to print */
569 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
573 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
576 switch (req->req_type) {
577 case DP_ENUM_PATH_RESOURCES:
578 case DP_POWER_DOWN_PHY:
579 case DP_POWER_UP_PHY:
580 P("port=%d\n", req->u.port_num.port_number);
582 case DP_ALLOCATE_PAYLOAD:
583 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
584 req->u.allocate_payload.port_number,
585 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
586 req->u.allocate_payload.number_sdp_streams,
587 req->u.allocate_payload.number_sdp_streams,
588 req->u.allocate_payload.sdp_stream_sink);
590 case DP_QUERY_PAYLOAD:
591 P("port=%d vcpi=%d\n",
592 req->u.query_payload.port_number,
593 req->u.query_payload.vcpi);
595 case DP_REMOTE_DPCD_READ:
596 P("port=%d dpcd_addr=%05x len=%d\n",
597 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
598 req->u.dpcd_read.num_bytes);
600 case DP_REMOTE_DPCD_WRITE:
601 P("port=%d addr=%05x len=%d: %*ph\n",
602 req->u.dpcd_write.port_number,
603 req->u.dpcd_write.dpcd_address,
604 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
605 req->u.dpcd_write.bytes);
607 case DP_REMOTE_I2C_READ:
608 P("port=%d num_tx=%d id=%d size=%d:\n",
609 req->u.i2c_read.port_number,
610 req->u.i2c_read.num_transactions,
611 req->u.i2c_read.read_i2c_device_id,
612 req->u.i2c_read.num_bytes_read);
615 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
616 const struct drm_dp_remote_i2c_read_tx *rtx =
617 &req->u.i2c_read.transactions[i];
619 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
620 i, rtx->i2c_dev_id, rtx->num_bytes,
621 rtx->no_stop_bit, rtx->i2c_transaction_delay,
622 rtx->num_bytes, rtx->bytes);
625 case DP_REMOTE_I2C_WRITE:
626 P("port=%d id=%d size=%d: %*ph\n",
627 req->u.i2c_write.port_number,
628 req->u.i2c_write.write_i2c_device_id,
629 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
630 req->u.i2c_write.bytes);
638 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
641 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
642 const struct drm_dp_sideband_msg_tx *txmsg)
644 struct drm_dp_sideband_msg_req_body req;
649 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
651 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
652 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
653 drm_dp_mst_sideband_tx_state_str(txmsg->state),
654 txmsg->path_msg, buf);
656 ret = drm_dp_decode_sideband_req(txmsg, &req);
658 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
661 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
663 switch (req.req_type) {
664 case DP_REMOTE_DPCD_WRITE:
665 kfree(req.u.dpcd_write.bytes);
667 case DP_REMOTE_I2C_READ:
668 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
669 kfree(req.u.i2c_read.transactions[i].bytes);
671 case DP_REMOTE_I2C_WRITE:
672 kfree(req.u.i2c_write.bytes);
677 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
681 crc4 = drm_dp_msg_data_crc4(msg, len);
685 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
686 struct drm_dp_sideband_msg_tx *raw)
691 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
696 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
697 struct drm_dp_sideband_msg_hdr *hdr,
701 * ignore out-of-order messages or messages that are part of a
704 if (!hdr->somt && !msg->have_somt)
707 /* get length contained in this portion */
708 msg->curchunk_idx = 0;
709 msg->curchunk_len = hdr->msg_len;
710 msg->curchunk_hdrlen = hdrlen;
712 /* we have already gotten an somt - don't bother parsing */
713 if (hdr->somt && msg->have_somt)
717 memcpy(&msg->initial_hdr, hdr,
718 sizeof(struct drm_dp_sideband_msg_hdr));
719 msg->have_somt = true;
722 msg->have_eomt = true;
727 /* this adds a chunk of msg to the builder to get the final msg */
728 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
729 u8 *replybuf, u8 replybuflen)
733 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
734 msg->curchunk_idx += replybuflen;
736 if (msg->curchunk_idx >= msg->curchunk_len) {
738 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
739 if (crc4 != msg->chunk[msg->curchunk_len - 1])
740 print_hex_dump(KERN_DEBUG, "wrong crc",
741 DUMP_PREFIX_NONE, 16, 1,
742 msg->chunk, msg->curchunk_len, false);
743 /* copy chunk into bigger msg */
744 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
745 msg->curlen += msg->curchunk_len - 1;
750 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
751 struct drm_dp_sideband_msg_reply_body *repmsg)
756 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
758 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
760 if (idx > raw->curlen)
762 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
763 if (raw->msg[idx] & 0x80)
764 repmsg->u.link_addr.ports[i].input_port = 1;
766 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
767 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
770 if (idx > raw->curlen)
772 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
773 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
774 if (repmsg->u.link_addr.ports[i].input_port == 0)
775 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
777 if (idx > raw->curlen)
779 if (repmsg->u.link_addr.ports[i].input_port == 0) {
780 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
782 if (idx > raw->curlen)
784 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
786 if (idx > raw->curlen)
788 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
789 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
793 if (idx > raw->curlen)
799 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
803 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
804 struct drm_dp_sideband_msg_reply_body *repmsg)
808 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
810 if (idx > raw->curlen)
812 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
814 if (idx > raw->curlen)
817 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
820 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
824 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
825 struct drm_dp_sideband_msg_reply_body *repmsg)
829 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
831 if (idx > raw->curlen)
835 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
839 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
840 struct drm_dp_sideband_msg_reply_body *repmsg)
844 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
846 if (idx > raw->curlen)
848 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
851 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
854 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
858 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
859 struct drm_dp_sideband_msg_reply_body *repmsg)
863 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
864 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
866 if (idx > raw->curlen)
868 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
870 if (idx > raw->curlen)
872 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
874 if (idx > raw->curlen)
878 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
882 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
883 struct drm_dp_sideband_msg_reply_body *repmsg)
887 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
889 if (idx > raw->curlen)
891 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
893 if (idx > raw->curlen)
895 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
897 if (idx > raw->curlen)
901 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
905 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
906 struct drm_dp_sideband_msg_reply_body *repmsg)
910 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
912 if (idx > raw->curlen)
914 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
916 if (idx > raw->curlen)
920 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
924 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
925 struct drm_dp_sideband_msg_reply_body *repmsg)
929 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
931 if (idx > raw->curlen) {
932 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
939 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
940 struct drm_dp_sideband_msg_reply_body *msg)
942 memset(msg, 0, sizeof(*msg));
943 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
944 msg->req_type = (raw->msg[0] & 0x7f);
946 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
947 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
948 msg->u.nak.reason = raw->msg[17];
949 msg->u.nak.nak_data = raw->msg[18];
953 switch (msg->req_type) {
954 case DP_LINK_ADDRESS:
955 return drm_dp_sideband_parse_link_address(raw, msg);
956 case DP_QUERY_PAYLOAD:
957 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
958 case DP_REMOTE_DPCD_READ:
959 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
960 case DP_REMOTE_DPCD_WRITE:
961 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
962 case DP_REMOTE_I2C_READ:
963 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
964 case DP_ENUM_PATH_RESOURCES:
965 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
966 case DP_ALLOCATE_PAYLOAD:
967 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
968 case DP_POWER_DOWN_PHY:
969 case DP_POWER_UP_PHY:
970 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
971 case DP_CLEAR_PAYLOAD_ID_TABLE:
972 return true; /* since there's nothing to parse */
974 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
975 drm_dp_mst_req_type_str(msg->req_type));
980 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
981 struct drm_dp_sideband_msg_req_body *msg)
985 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
987 if (idx > raw->curlen)
990 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
992 if (idx > raw->curlen)
995 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
996 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
997 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
998 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
999 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
1003 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
1007 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
1008 struct drm_dp_sideband_msg_req_body *msg)
1012 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1014 if (idx > raw->curlen)
1017 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1019 if (idx > raw->curlen)
1022 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1026 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
1030 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
1031 struct drm_dp_sideband_msg_req_body *msg)
1033 memset(msg, 0, sizeof(*msg));
1034 msg->req_type = (raw->msg[0] & 0x7f);
1036 switch (msg->req_type) {
1037 case DP_CONNECTION_STATUS_NOTIFY:
1038 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
1039 case DP_RESOURCE_STATUS_NOTIFY:
1040 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
1042 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
1043 drm_dp_mst_req_type_str(msg->req_type));
1048 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1049 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1051 struct drm_dp_sideband_msg_req_body req;
1053 req.req_type = DP_REMOTE_DPCD_WRITE;
1054 req.u.dpcd_write.port_number = port_num;
1055 req.u.dpcd_write.dpcd_address = offset;
1056 req.u.dpcd_write.num_bytes = num_bytes;
1057 req.u.dpcd_write.bytes = bytes;
1058 drm_dp_encode_sideband_req(&req, msg);
1061 static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1063 struct drm_dp_sideband_msg_req_body req;
1065 req.req_type = DP_LINK_ADDRESS;
1066 drm_dp_encode_sideband_req(&req, msg);
1069 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1071 struct drm_dp_sideband_msg_req_body req;
1073 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1074 drm_dp_encode_sideband_req(&req, msg);
1077 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1080 struct drm_dp_sideband_msg_req_body req;
1082 req.req_type = DP_ENUM_PATH_RESOURCES;
1083 req.u.port_num.port_number = port_num;
1084 drm_dp_encode_sideband_req(&req, msg);
1085 msg->path_msg = true;
1089 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1091 u8 vcpi, uint16_t pbn,
1092 u8 number_sdp_streams,
1093 u8 *sdp_stream_sink)
1095 struct drm_dp_sideband_msg_req_body req;
1097 memset(&req, 0, sizeof(req));
1098 req.req_type = DP_ALLOCATE_PAYLOAD;
1099 req.u.allocate_payload.port_number = port_num;
1100 req.u.allocate_payload.vcpi = vcpi;
1101 req.u.allocate_payload.pbn = pbn;
1102 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1103 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1104 number_sdp_streams);
1105 drm_dp_encode_sideband_req(&req, msg);
1106 msg->path_msg = true;
1109 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1110 int port_num, bool power_up)
1112 struct drm_dp_sideband_msg_req_body req;
1115 req.req_type = DP_POWER_UP_PHY;
1117 req.req_type = DP_POWER_DOWN_PHY;
1119 req.u.port_num.port_number = port_num;
1120 drm_dp_encode_sideband_req(&req, msg);
1121 msg->path_msg = true;
1124 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1125 struct drm_dp_vcpi *vcpi)
1129 mutex_lock(&mgr->payload_lock);
1130 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1131 if (ret > mgr->max_payloads) {
1133 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
1137 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1138 if (vcpi_ret > mgr->max_payloads) {
1140 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
1144 set_bit(ret, &mgr->payload_mask);
1145 set_bit(vcpi_ret, &mgr->vcpi_mask);
1146 vcpi->vcpi = vcpi_ret + 1;
1147 mgr->proposed_vcpis[ret - 1] = vcpi;
1149 mutex_unlock(&mgr->payload_lock);
1153 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1161 mutex_lock(&mgr->payload_lock);
1162 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
1163 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1165 for (i = 0; i < mgr->max_payloads; i++) {
1166 if (mgr->proposed_vcpis[i] &&
1167 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1168 mgr->proposed_vcpis[i] = NULL;
1169 clear_bit(i + 1, &mgr->payload_mask);
1172 mutex_unlock(&mgr->payload_lock);
1175 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1176 struct drm_dp_sideband_msg_tx *txmsg)
1181 * All updates to txmsg->state are protected by mgr->qlock, and the two
1182 * cases we check here are terminal states. For those the barriers
1183 * provided by the wake_up/wait_event pair are enough.
1185 state = READ_ONCE(txmsg->state);
1186 return (state == DRM_DP_SIDEBAND_TX_RX ||
1187 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1190 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1191 struct drm_dp_sideband_msg_tx *txmsg)
1193 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1194 unsigned long wait_timeout = msecs_to_jiffies(4000);
1195 unsigned long wait_expires = jiffies + wait_timeout;
1200 * If the driver provides a way for this, change to
1201 * poll-waiting for the MST reply interrupt if we didn't receive
1202 * it for 50 msec. This would cater for cases where the HPD
1203 * pulse signal got lost somewhere, even though the sink raised
1204 * the corresponding MST interrupt correctly. One example is the
1205 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1206 * filters out short pulses with a duration less than ~540 usec.
1208 * The poll period is 50 msec to avoid missing an interrupt
1209 * after the sink has cleared it (after a 110msec timeout
1210 * since it raised the interrupt).
1212 ret = wait_event_timeout(mgr->tx_waitq,
1213 check_txmsg_state(mgr, txmsg),
1214 mgr->cbs->poll_hpd_irq ?
1215 msecs_to_jiffies(50) :
1218 if (ret || !mgr->cbs->poll_hpd_irq ||
1219 time_after(jiffies, wait_expires))
1222 mgr->cbs->poll_hpd_irq(mgr);
1225 mutex_lock(&mgr->qlock);
1227 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1232 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
1234 /* dump some state */
1238 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1239 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1240 txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1241 list_del(&txmsg->next);
1244 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1245 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1247 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1249 mutex_unlock(&mgr->qlock);
1251 drm_dp_mst_kick_tx(mgr);
1255 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1257 struct drm_dp_mst_branch *mstb;
1259 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1265 memcpy(mstb->rad, rad, lct / 2);
1266 INIT_LIST_HEAD(&mstb->ports);
1267 kref_init(&mstb->topology_kref);
1268 kref_init(&mstb->malloc_kref);
1272 static void drm_dp_free_mst_branch_device(struct kref *kref)
1274 struct drm_dp_mst_branch *mstb =
1275 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1277 if (mstb->port_parent)
1278 drm_dp_mst_put_port_malloc(mstb->port_parent);
1284 * DOC: Branch device and port refcounting
1286 * Topology refcount overview
1287 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1289 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1290 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1291 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1293 * Topology refcounts are not exposed to drivers, and are handled internally
1294 * by the DP MST helpers. The helpers use them in order to prevent the
1295 * in-memory topology state from being changed in the middle of critical
1296 * operations like changing the internal state of payload allocations. This
1297 * means each branch and port will be considered to be connected to the rest
1298 * of the topology until its topology refcount reaches zero. Additionally,
1299 * for ports this means that their associated &struct drm_connector will stay
1300 * registered with userspace until the port's refcount reaches 0.
1302 * Malloc refcount overview
1303 * ~~~~~~~~~~~~~~~~~~~~~~~~
1305 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1306 * drm_dp_mst_branch allocated even after all of its topology references have
1307 * been dropped, so that the driver or MST helpers can safely access each
1308 * branch's last known state before it was disconnected from the topology.
1309 * When the malloc refcount of a port or branch reaches 0, the memory
1310 * allocation containing the &struct drm_dp_mst_branch or &struct
1311 * drm_dp_mst_port respectively will be freed.
1313 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1314 * to drivers. As of writing this documentation, there are no drivers that
1315 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1316 * helpers. Exposing this API to drivers in a race-free manner would take more
1317 * tweaking of the refcounting scheme, however patches are welcome provided
1318 * there is a legitimate driver usecase for this.
1320 * Refcount relationships in a topology
1321 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1323 * Let's take a look at why the relationship between topology and malloc
1324 * refcounts is designed the way it is.
1326 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1328 * An example of topology and malloc refs in a DP MST topology with two
1329 * active payloads. Topology refcount increments are indicated by solid
1330 * lines, and malloc refcount increments are indicated by dashed lines.
1331 * Each starts from the branch which incremented the refcount, and ends at
1332 * the branch to which the refcount belongs to, i.e. the arrow points the
1333 * same way as the C pointers used to reference a structure.
1335 * As you can see in the above figure, every branch increments the topology
1336 * refcount of its children, and increments the malloc refcount of its
1337 * parent. Additionally, every payload increments the malloc refcount of its
1338 * assigned port by 1.
1340 * So, what would happen if MSTB #3 from the above figure was unplugged from
1341 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1342 * topology would start to look like the figure below.
1344 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1346 * Ports and branch devices which have been released from memory are
1347 * colored grey, and references which have been removed are colored red.
1349 * Whenever a port or branch device's topology refcount reaches zero, it will
1350 * decrement the topology refcounts of all its children, the malloc refcount
1351 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1352 * #4, this means they both have been disconnected from the topology and freed
1353 * from memory. But, because payload #2 is still holding a reference to port
1354 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1355 * is still accessible from memory. This also means port #3 has not yet
1356 * decremented the malloc refcount of MSTB #3, so its &struct
1357 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1358 * malloc refcount reaches 0.
1360 * This relationship is necessary because in order to release payload #2, we
1361 * need to be able to figure out the last relative of port #3 that's still
1362 * connected to the topology. In this case, we would travel up the topology as
1365 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1367 * And finally, remove payload #2 by communicating with port #2 through
1368 * sideband transactions.
1372 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1374 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1376 * Increments &drm_dp_mst_branch.malloc_kref. When
1377 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1378 * will be released and @mstb may no longer be used.
1380 * See also: drm_dp_mst_put_mstb_malloc()
1383 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1385 kref_get(&mstb->malloc_kref);
1386 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1390 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1392 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1394 * Decrements &drm_dp_mst_branch.malloc_kref. When
1395 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1396 * will be released and @mstb may no longer be used.
1398 * See also: drm_dp_mst_get_mstb_malloc()
1401 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1403 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1404 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1407 static void drm_dp_free_mst_port(struct kref *kref)
1409 struct drm_dp_mst_port *port =
1410 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1412 drm_dp_mst_put_mstb_malloc(port->parent);
1417 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1418 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1420 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1421 * reaches 0, the memory allocation for @port will be released and @port may
1422 * no longer be used.
1424 * Because @port could potentially be freed at any time by the DP MST helpers
1425 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1426 * function, drivers that which to make use of &struct drm_dp_mst_port should
1427 * ensure that they grab at least one main malloc reference to their MST ports
1428 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1429 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1431 * See also: drm_dp_mst_put_port_malloc()
1434 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1436 kref_get(&port->malloc_kref);
1437 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1439 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1442 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1443 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1445 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1446 * reaches 0, the memory allocation for @port will be released and @port may
1447 * no longer be used.
1449 * See also: drm_dp_mst_get_port_malloc()
1452 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1454 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1455 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1457 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1459 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1461 #define STACK_DEPTH 8
1463 static noinline void
1464 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1465 struct drm_dp_mst_topology_ref_history *history,
1466 enum drm_dp_mst_topology_ref_type type)
1468 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1469 depot_stack_handle_t backtrace;
1470 ulong stack_entries[STACK_DEPTH];
1474 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1475 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1479 /* Try to find an existing entry for this backtrace */
1480 for (i = 0; i < history->len; i++) {
1481 if (history->entries[i].backtrace == backtrace) {
1482 entry = &history->entries[i];
1487 /* Otherwise add one */
1489 struct drm_dp_mst_topology_ref_entry *new;
1490 int new_len = history->len + 1;
1492 new = krealloc(history->entries, sizeof(*new) * new_len,
1497 entry = &new[history->len];
1498 history->len = new_len;
1499 history->entries = new;
1501 entry->backtrace = backtrace;
1506 entry->ts_nsec = ktime_get_ns();
1510 topology_ref_history_cmp(const void *a, const void *b)
1512 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1514 if (entry_a->ts_nsec > entry_b->ts_nsec)
1516 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1522 static inline const char *
1523 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1525 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1532 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1533 void *ptr, const char *type_str)
1535 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1536 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1545 /* First, sort the list so that it goes from oldest to newest
1548 sort(history->entries, history->len, sizeof(*history->entries),
1549 topology_ref_history_cmp, NULL);
1551 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1554 for (i = 0; i < history->len; i++) {
1555 const struct drm_dp_mst_topology_ref_entry *entry =
1556 &history->entries[i];
1559 u64 ts_nsec = entry->ts_nsec;
1560 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1562 nr_entries = stack_depot_fetch(entry->backtrace, &entries);
1563 stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
1565 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1567 topology_ref_type_to_str(entry->type),
1568 ts_nsec, rem_nsec / 1000, buf);
1571 /* Now free the history, since this is the only time we expose it */
1572 kfree(history->entries);
1577 static __always_inline void
1578 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1580 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1584 static __always_inline void
1585 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1587 __dump_topology_ref_history(&port->topology_ref_history, port,
1591 static __always_inline void
1592 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1593 enum drm_dp_mst_topology_ref_type type)
1595 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1598 static __always_inline void
1599 save_port_topology_ref(struct drm_dp_mst_port *port,
1600 enum drm_dp_mst_topology_ref_type type)
1602 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1606 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1608 mutex_lock(&mgr->topology_ref_history_lock);
1612 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1614 mutex_unlock(&mgr->topology_ref_history_lock);
1618 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1620 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1622 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1624 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1625 #define save_mstb_topology_ref(mstb, type)
1626 #define save_port_topology_ref(port, type)
1629 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1631 struct drm_dp_mst_branch *mstb =
1632 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1633 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1635 drm_dp_mst_dump_mstb_topology_history(mstb);
1637 INIT_LIST_HEAD(&mstb->destroy_next);
1640 * This can get called under mgr->mutex, so we need to perform the
1641 * actual destruction of the mstb in another worker
1643 mutex_lock(&mgr->delayed_destroy_lock);
1644 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1645 mutex_unlock(&mgr->delayed_destroy_lock);
1646 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1650 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1651 * branch device unless it's zero
1652 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1654 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1655 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1656 * reached 0). Holding a topology reference implies that a malloc reference
1657 * will be held to @mstb as long as the user holds the topology reference.
1659 * Care should be taken to ensure that the user has at least one malloc
1660 * reference to @mstb. If you already have a topology reference to @mstb, you
1661 * should use drm_dp_mst_topology_get_mstb() instead.
1664 * drm_dp_mst_topology_get_mstb()
1665 * drm_dp_mst_topology_put_mstb()
1668 * * 1: A topology reference was grabbed successfully
1669 * * 0: @port is no longer in the topology, no reference was grabbed
1671 static int __must_check
1672 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1676 topology_ref_history_lock(mstb->mgr);
1677 ret = kref_get_unless_zero(&mstb->topology_kref);
1679 DRM_DEBUG("mstb %p (%d)\n",
1680 mstb, kref_read(&mstb->topology_kref));
1681 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1684 topology_ref_history_unlock(mstb->mgr);
1690 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1692 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1694 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1695 * not it's already reached 0. This is only valid to use in scenarios where
1696 * you are already guaranteed to have at least one active topology reference
1697 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1700 * drm_dp_mst_topology_try_get_mstb()
1701 * drm_dp_mst_topology_put_mstb()
1703 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1705 topology_ref_history_lock(mstb->mgr);
1707 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1708 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1709 kref_get(&mstb->topology_kref);
1710 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1712 topology_ref_history_unlock(mstb->mgr);
1716 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1718 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1720 * Releases a topology reference from @mstb by decrementing
1721 * &drm_dp_mst_branch.topology_kref.
1724 * drm_dp_mst_topology_try_get_mstb()
1725 * drm_dp_mst_topology_get_mstb()
1728 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1730 topology_ref_history_lock(mstb->mgr);
1732 DRM_DEBUG("mstb %p (%d)\n",
1733 mstb, kref_read(&mstb->topology_kref) - 1);
1734 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1736 topology_ref_history_unlock(mstb->mgr);
1737 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1740 static void drm_dp_destroy_port(struct kref *kref)
1742 struct drm_dp_mst_port *port =
1743 container_of(kref, struct drm_dp_mst_port, topology_kref);
1744 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1746 drm_dp_mst_dump_port_topology_history(port);
1748 /* There's nothing that needs locking to destroy an input port yet */
1750 drm_dp_mst_put_port_malloc(port);
1754 kfree(port->cached_edid);
1757 * we can't destroy the connector here, as we might be holding the
1758 * mode_config.mutex from an EDID retrieval
1760 mutex_lock(&mgr->delayed_destroy_lock);
1761 list_add(&port->next, &mgr->destroy_port_list);
1762 mutex_unlock(&mgr->delayed_destroy_lock);
1763 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1767 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1768 * port unless it's zero
1769 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1771 * Attempts to grab a topology reference to @port, if it hasn't yet been
1772 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1773 * 0). Holding a topology reference implies that a malloc reference will be
1774 * held to @port as long as the user holds the topology reference.
1776 * Care should be taken to ensure that the user has at least one malloc
1777 * reference to @port. If you already have a topology reference to @port, you
1778 * should use drm_dp_mst_topology_get_port() instead.
1781 * drm_dp_mst_topology_get_port()
1782 * drm_dp_mst_topology_put_port()
1785 * * 1: A topology reference was grabbed successfully
1786 * * 0: @port is no longer in the topology, no reference was grabbed
1788 static int __must_check
1789 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1793 topology_ref_history_lock(port->mgr);
1794 ret = kref_get_unless_zero(&port->topology_kref);
1796 DRM_DEBUG("port %p (%d)\n",
1797 port, kref_read(&port->topology_kref));
1798 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1801 topology_ref_history_unlock(port->mgr);
1806 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1807 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1809 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1810 * not it's already reached 0. This is only valid to use in scenarios where
1811 * you are already guaranteed to have at least one active topology reference
1812 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1815 * drm_dp_mst_topology_try_get_port()
1816 * drm_dp_mst_topology_put_port()
1818 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1820 topology_ref_history_lock(port->mgr);
1822 WARN_ON(kref_read(&port->topology_kref) == 0);
1823 kref_get(&port->topology_kref);
1824 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1825 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1827 topology_ref_history_unlock(port->mgr);
1831 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1832 * @port: The &struct drm_dp_mst_port to release the topology reference from
1834 * Releases a topology reference from @port by decrementing
1835 * &drm_dp_mst_port.topology_kref.
1838 * drm_dp_mst_topology_try_get_port()
1839 * drm_dp_mst_topology_get_port()
1841 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1843 topology_ref_history_lock(port->mgr);
1845 DRM_DEBUG("port %p (%d)\n",
1846 port, kref_read(&port->topology_kref) - 1);
1847 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1849 topology_ref_history_unlock(port->mgr);
1850 kref_put(&port->topology_kref, drm_dp_destroy_port);
1853 static struct drm_dp_mst_branch *
1854 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1855 struct drm_dp_mst_branch *to_find)
1857 struct drm_dp_mst_port *port;
1858 struct drm_dp_mst_branch *rmstb;
1860 if (to_find == mstb)
1863 list_for_each_entry(port, &mstb->ports, next) {
1865 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1866 port->mstb, to_find);
1874 static struct drm_dp_mst_branch *
1875 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1876 struct drm_dp_mst_branch *mstb)
1878 struct drm_dp_mst_branch *rmstb = NULL;
1880 mutex_lock(&mgr->lock);
1881 if (mgr->mst_primary) {
1882 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1883 mgr->mst_primary, mstb);
1885 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1888 mutex_unlock(&mgr->lock);
1892 static struct drm_dp_mst_port *
1893 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1894 struct drm_dp_mst_port *to_find)
1896 struct drm_dp_mst_port *port, *mport;
1898 list_for_each_entry(port, &mstb->ports, next) {
1899 if (port == to_find)
1903 mport = drm_dp_mst_topology_get_port_validated_locked(
1904 port->mstb, to_find);
1912 static struct drm_dp_mst_port *
1913 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1914 struct drm_dp_mst_port *port)
1916 struct drm_dp_mst_port *rport = NULL;
1918 mutex_lock(&mgr->lock);
1919 if (mgr->mst_primary) {
1920 rport = drm_dp_mst_topology_get_port_validated_locked(
1921 mgr->mst_primary, port);
1923 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1926 mutex_unlock(&mgr->lock);
1930 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1932 struct drm_dp_mst_port *port;
1935 list_for_each_entry(port, &mstb->ports, next) {
1936 if (port->port_num == port_num) {
1937 ret = drm_dp_mst_topology_try_get_port(port);
1938 return ret ? port : NULL;
1946 * calculate a new RAD for this MST branch device
1947 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1948 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1950 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1953 int parent_lct = port->parent->lct;
1955 int idx = (parent_lct - 1) / 2;
1957 if (parent_lct > 1) {
1958 memcpy(rad, port->parent->rad, idx + 1);
1959 shift = (parent_lct % 2) ? 4 : 0;
1963 rad[idx] |= port->port_num << shift;
1964 return parent_lct + 1;
1967 static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
1970 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1971 case DP_PEER_DEVICE_SST_SINK:
1973 case DP_PEER_DEVICE_MST_BRANCHING:
1974 /* For sst branch device */
1984 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
1987 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1988 struct drm_dp_mst_branch *mstb;
1992 if (port->pdt == new_pdt && port->mcs == new_mcs)
1995 /* Teardown the old pdt, if there is one */
1996 if (port->pdt != DP_PEER_DEVICE_NONE) {
1997 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
1999 * If the new PDT would also have an i2c bus,
2000 * don't bother with reregistering it
2002 if (new_pdt != DP_PEER_DEVICE_NONE &&
2003 drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2004 port->pdt = new_pdt;
2005 port->mcs = new_mcs;
2009 /* remove i2c over sideband */
2010 drm_dp_mst_unregister_i2c_bus(port);
2012 mutex_lock(&mgr->lock);
2013 drm_dp_mst_topology_put_mstb(port->mstb);
2015 mutex_unlock(&mgr->lock);
2019 port->pdt = new_pdt;
2020 port->mcs = new_mcs;
2022 if (port->pdt != DP_PEER_DEVICE_NONE) {
2023 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2024 /* add i2c over sideband */
2025 ret = drm_dp_mst_register_i2c_bus(port);
2027 lct = drm_dp_calculate_rad(port, rad);
2028 mstb = drm_dp_add_mst_branch_device(lct, rad);
2031 DRM_ERROR("Failed to create MSTB for port %p",
2036 mutex_lock(&mgr->lock);
2038 mstb->mgr = port->mgr;
2039 mstb->port_parent = port;
2042 * Make sure this port's memory allocation stays
2043 * around until its child MSTB releases it
2045 drm_dp_mst_get_port_malloc(port);
2046 mutex_unlock(&mgr->lock);
2048 /* And make sure we send a link address for this */
2055 port->pdt = DP_PEER_DEVICE_NONE;
2060 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2061 * @aux: Fake sideband AUX CH
2062 * @offset: address of the (first) register to read
2063 * @buffer: buffer to store the register values
2064 * @size: number of bytes in @buffer
2066 * Performs the same functionality for remote devices via
2067 * sideband messaging as drm_dp_dpcd_read() does for local
2068 * devices via actual AUX CH.
2070 * Return: Number of bytes read, or negative error code on failure.
2072 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2073 unsigned int offset, void *buffer, size_t size)
2075 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2078 return drm_dp_send_dpcd_read(port->mgr, port,
2079 offset, size, buffer);
2083 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2084 * @aux: Fake sideband AUX CH
2085 * @offset: address of the (first) register to write
2086 * @buffer: buffer containing the values to write
2087 * @size: number of bytes in @buffer
2089 * Performs the same functionality for remote devices via
2090 * sideband messaging as drm_dp_dpcd_write() does for local
2091 * devices via actual AUX CH.
2093 * Return: number of bytes written on success, negative error code on failure.
2095 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2096 unsigned int offset, void *buffer, size_t size)
2098 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2101 return drm_dp_send_dpcd_write(port->mgr, port,
2102 offset, size, buffer);
2105 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2109 memcpy(mstb->guid, guid, 16);
2111 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2112 if (mstb->port_parent) {
2113 ret = drm_dp_send_dpcd_write(mstb->mgr,
2115 DP_GUID, 16, mstb->guid);
2117 ret = drm_dp_dpcd_write(mstb->mgr->aux,
2118 DP_GUID, mstb->guid, 16);
2122 if (ret < 16 && ret > 0)
2125 return ret == 16 ? 0 : ret;
2128 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2131 size_t proppath_size)
2136 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2137 for (i = 0; i < (mstb->lct - 1); i++) {
2138 int shift = (i % 2) ? 0 : 4;
2139 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2141 snprintf(temp, sizeof(temp), "-%d", port_num);
2142 strlcat(proppath, temp, proppath_size);
2144 snprintf(temp, sizeof(temp), "-%d", pnum);
2145 strlcat(proppath, temp, proppath_size);
2149 * drm_dp_mst_connector_late_register() - Late MST connector registration
2150 * @connector: The MST connector
2151 * @port: The MST port for this connector
2153 * Helper to register the remote aux device for this MST port. Drivers should
2154 * call this from their mst connector's late_register hook to enable MST aux
2157 * Return: 0 on success, negative error code on failure.
2159 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2160 struct drm_dp_mst_port *port)
2162 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
2163 port->aux.name, connector->kdev->kobj.name);
2165 port->aux.dev = connector->kdev;
2166 return drm_dp_aux_register_devnode(&port->aux);
2168 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2171 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2172 * @connector: The MST connector
2173 * @port: The MST port for this connector
2175 * Helper to unregister the remote aux device for this MST port, registered by
2176 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2177 * connector's early_unregister hook.
2179 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2180 struct drm_dp_mst_port *port)
2182 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
2183 port->aux.name, connector->kdev->kobj.name);
2184 drm_dp_aux_unregister_devnode(&port->aux);
2186 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2189 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2190 struct drm_dp_mst_port *port)
2192 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2196 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2197 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2198 if (!port->connector) {
2203 if (port->pdt != DP_PEER_DEVICE_NONE &&
2204 drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2205 port->cached_edid = drm_get_edid(port->connector,
2207 drm_connector_set_tile_property(port->connector);
2210 drm_connector_register(port->connector);
2214 DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
2218 * Drop a topology reference, and unlink the port from the in-memory topology
2222 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2223 struct drm_dp_mst_port *port)
2225 mutex_lock(&mgr->lock);
2226 port->parent->num_ports--;
2227 list_del(&port->next);
2228 mutex_unlock(&mgr->lock);
2229 drm_dp_mst_topology_put_port(port);
2232 static struct drm_dp_mst_port *
2233 drm_dp_mst_add_port(struct drm_device *dev,
2234 struct drm_dp_mst_topology_mgr *mgr,
2235 struct drm_dp_mst_branch *mstb, u8 port_number)
2237 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2242 kref_init(&port->topology_kref);
2243 kref_init(&port->malloc_kref);
2244 port->parent = mstb;
2245 port->port_num = port_number;
2247 port->aux.name = "DPMST";
2248 port->aux.dev = dev->dev;
2249 port->aux.is_remote = true;
2251 /* initialize the MST downstream port's AUX crc work queue */
2252 drm_dp_remote_aux_init(&port->aux);
2255 * Make sure the memory allocation for our parent branch stays
2256 * around until our own memory allocation is released
2258 drm_dp_mst_get_mstb_malloc(mstb);
2264 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2265 struct drm_device *dev,
2266 struct drm_dp_link_addr_reply_port *port_msg)
2268 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2269 struct drm_dp_mst_port *port;
2270 int old_ddps = 0, ret;
2271 u8 new_pdt = DP_PEER_DEVICE_NONE;
2273 bool created = false, send_link_addr = false, changed = false;
2275 port = drm_dp_get_port(mstb, port_msg->port_number);
2277 port = drm_dp_mst_add_port(dev, mgr, mstb,
2278 port_msg->port_number);
2283 } else if (!port->input && port_msg->input_port && port->connector) {
2284 /* Since port->connector can't be changed here, we create a
2285 * new port if input_port changes from 0 to 1
2287 drm_dp_mst_topology_unlink_port(mgr, port);
2288 drm_dp_mst_topology_put_port(port);
2289 port = drm_dp_mst_add_port(dev, mgr, mstb,
2290 port_msg->port_number);
2295 } else if (port->input && !port_msg->input_port) {
2297 } else if (port->connector) {
2298 /* We're updating a port that's exposed to userspace, so do it
2301 drm_modeset_lock(&mgr->base.lock, NULL);
2303 old_ddps = port->ddps;
2304 changed = port->ddps != port_msg->ddps ||
2306 (port->ldps != port_msg->legacy_device_plug_status ||
2307 port->dpcd_rev != port_msg->dpcd_revision ||
2308 port->mcs != port_msg->mcs ||
2309 port->pdt != port_msg->peer_device_type ||
2310 port->num_sdp_stream_sinks !=
2311 port_msg->num_sdp_stream_sinks));
2314 port->input = port_msg->input_port;
2316 new_pdt = port_msg->peer_device_type;
2317 new_mcs = port_msg->mcs;
2318 port->ddps = port_msg->ddps;
2319 port->ldps = port_msg->legacy_device_plug_status;
2320 port->dpcd_rev = port_msg->dpcd_revision;
2321 port->num_sdp_streams = port_msg->num_sdp_streams;
2322 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2324 /* manage mstb port lists with mgr lock - take a reference
2327 mutex_lock(&mgr->lock);
2328 drm_dp_mst_topology_get_port(port);
2329 list_add(&port->next, &mstb->ports);
2331 mutex_unlock(&mgr->lock);
2335 * Reprobe PBN caps on both hotplug, and when re-probing the link
2336 * for our parent mstb
2338 if (old_ddps != port->ddps || !created) {
2339 if (port->ddps && !port->input) {
2340 ret = drm_dp_send_enum_path_resources(mgr, mstb,
2349 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2351 send_link_addr = true;
2352 } else if (ret < 0) {
2353 DRM_ERROR("Failed to change PDT on port %p: %d\n",
2359 * If this port wasn't just created, then we're reprobing because
2360 * we're coming out of suspend. In this case, always resend the link
2361 * address if there's an MSTB on this port
2363 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2365 send_link_addr = true;
2367 if (port->connector)
2368 drm_modeset_unlock(&mgr->base.lock);
2369 else if (!port->input)
2370 drm_dp_mst_port_add_connector(mstb, port);
2372 if (send_link_addr && port->mstb) {
2373 ret = drm_dp_send_link_address(mgr, port->mstb);
2374 if (ret == 1) /* MSTB below us changed */
2380 /* put reference to this port */
2381 drm_dp_mst_topology_put_port(port);
2385 drm_dp_mst_topology_unlink_port(mgr, port);
2386 if (port->connector)
2387 drm_modeset_unlock(&mgr->base.lock);
2389 drm_dp_mst_topology_put_port(port);
2394 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2395 struct drm_dp_connection_status_notify *conn_stat)
2397 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2398 struct drm_dp_mst_port *port;
2399 int old_ddps, old_input, ret, i;
2402 bool dowork = false, create_connector = false;
2404 port = drm_dp_get_port(mstb, conn_stat->port_number);
2408 if (port->connector) {
2409 if (!port->input && conn_stat->input_port) {
2411 * We can't remove a connector from an already exposed
2412 * port, so just throw the port out and make sure we
2413 * reprobe the link address of it's parent MSTB
2415 drm_dp_mst_topology_unlink_port(mgr, port);
2416 mstb->link_address_sent = false;
2421 /* Locking is only needed if the port's exposed to userspace */
2422 drm_modeset_lock(&mgr->base.lock, NULL);
2423 } else if (port->input && !conn_stat->input_port) {
2424 create_connector = true;
2425 /* Reprobe link address so we get num_sdp_streams */
2426 mstb->link_address_sent = false;
2430 old_ddps = port->ddps;
2431 old_input = port->input;
2432 port->input = conn_stat->input_port;
2433 port->ldps = conn_stat->legacy_device_plug_status;
2434 port->ddps = conn_stat->displayport_device_plug_status;
2436 if (old_ddps != port->ddps) {
2437 if (port->ddps && !port->input)
2438 drm_dp_send_enum_path_resources(mgr, mstb, port);
2443 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2444 new_mcs = conn_stat->message_capability_status;
2445 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2448 } else if (ret < 0) {
2449 DRM_ERROR("Failed to change PDT for port %p: %d\n",
2454 if (!old_input && old_ddps != port->ddps && !port->ddps) {
2455 for (i = 0; i < mgr->max_payloads; i++) {
2456 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2457 struct drm_dp_mst_port *port_validated;
2463 container_of(vcpi, struct drm_dp_mst_port, vcpi);
2465 drm_dp_mst_topology_get_port_validated(mgr, port_validated);
2466 if (!port_validated) {
2467 mutex_lock(&mgr->payload_lock);
2468 vcpi->num_slots = 0;
2469 mutex_unlock(&mgr->payload_lock);
2471 drm_dp_mst_topology_put_port(port_validated);
2476 if (port->connector)
2477 drm_modeset_unlock(&mgr->base.lock);
2478 else if (create_connector)
2479 drm_dp_mst_port_add_connector(mstb, port);
2482 drm_dp_mst_topology_put_port(port);
2484 queue_work(system_long_wq, &mstb->mgr->work);
2487 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2490 struct drm_dp_mst_branch *mstb;
2491 struct drm_dp_mst_port *port;
2493 /* find the port by iterating down */
2495 mutex_lock(&mgr->lock);
2496 mstb = mgr->mst_primary;
2501 for (i = 0; i < lct - 1; i++) {
2502 int shift = (i % 2) ? 0 : 4;
2503 int port_num = (rad[i / 2] >> shift) & 0xf;
2505 list_for_each_entry(port, &mstb->ports, next) {
2506 if (port->port_num == port_num) {
2509 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
2517 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2521 mutex_unlock(&mgr->lock);
2525 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2526 struct drm_dp_mst_branch *mstb,
2527 const uint8_t *guid)
2529 struct drm_dp_mst_branch *found_mstb;
2530 struct drm_dp_mst_port *port;
2532 if (memcmp(mstb->guid, guid, 16) == 0)
2536 list_for_each_entry(port, &mstb->ports, next) {
2540 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2549 static struct drm_dp_mst_branch *
2550 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2551 const uint8_t *guid)
2553 struct drm_dp_mst_branch *mstb;
2556 /* find the port by iterating down */
2557 mutex_lock(&mgr->lock);
2559 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2561 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2566 mutex_unlock(&mgr->lock);
2570 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2571 struct drm_dp_mst_branch *mstb)
2573 struct drm_dp_mst_port *port;
2575 bool changed = false;
2577 if (!mstb->link_address_sent) {
2578 ret = drm_dp_send_link_address(mgr, mstb);
2585 list_for_each_entry(port, &mstb->ports, next) {
2586 struct drm_dp_mst_branch *mstb_child = NULL;
2588 if (port->input || !port->ddps)
2592 mstb_child = drm_dp_mst_topology_get_mstb_validated(
2596 ret = drm_dp_check_and_send_link_address(mgr,
2598 drm_dp_mst_topology_put_mstb(mstb_child);
2609 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2611 struct drm_dp_mst_topology_mgr *mgr =
2612 container_of(work, struct drm_dp_mst_topology_mgr, work);
2613 struct drm_device *dev = mgr->dev;
2614 struct drm_dp_mst_branch *mstb;
2616 bool clear_payload_id_table;
2618 mutex_lock(&mgr->probe_lock);
2620 mutex_lock(&mgr->lock);
2621 clear_payload_id_table = !mgr->payload_id_table_cleared;
2622 mgr->payload_id_table_cleared = true;
2624 mstb = mgr->mst_primary;
2626 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2630 mutex_unlock(&mgr->lock);
2632 mutex_unlock(&mgr->probe_lock);
2637 * Certain branch devices seem to incorrectly report an available_pbn
2638 * of 0 on downstream sinks, even after clearing the
2639 * DP_PAYLOAD_ALLOCATE_* registers in
2640 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2641 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2642 * things work again.
2644 if (clear_payload_id_table) {
2645 DRM_DEBUG_KMS("Clearing payload ID table\n");
2646 drm_dp_send_clear_payload_id_table(mgr, mstb);
2649 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2650 drm_dp_mst_topology_put_mstb(mstb);
2652 mutex_unlock(&mgr->probe_lock);
2654 drm_kms_helper_hotplug_event(dev);
2657 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2662 if (memchr_inv(guid, 0, 16))
2665 salt = get_jiffies_64();
2667 memcpy(&guid[0], &salt, sizeof(u64));
2668 memcpy(&guid[8], &salt, sizeof(u64));
2673 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2674 u8 port_num, u32 offset, u8 num_bytes)
2676 struct drm_dp_sideband_msg_req_body req;
2678 req.req_type = DP_REMOTE_DPCD_READ;
2679 req.u.dpcd_read.port_number = port_num;
2680 req.u.dpcd_read.dpcd_address = offset;
2681 req.u.dpcd_read.num_bytes = num_bytes;
2682 drm_dp_encode_sideband_req(&req, msg);
2685 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2686 bool up, u8 *msg, int len)
2689 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2690 int tosend, total, offset;
2697 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2699 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2702 if (ret != tosend) {
2703 if (ret == -EIO && retries < 5) {
2707 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
2713 } while (total > 0);
2717 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2718 struct drm_dp_sideband_msg_tx *txmsg)
2720 struct drm_dp_mst_branch *mstb = txmsg->dst;
2723 req_type = txmsg->msg[0] & 0x7f;
2724 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2725 req_type == DP_RESOURCE_STATUS_NOTIFY)
2729 hdr->path_msg = txmsg->path_msg;
2730 hdr->lct = mstb->lct;
2731 hdr->lcr = mstb->lct - 1;
2733 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
2738 * process a single block of the next message in the sideband queue
2740 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2741 struct drm_dp_sideband_msg_tx *txmsg,
2745 struct drm_dp_sideband_msg_hdr hdr;
2746 int len, space, idx, tosend;
2749 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2752 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2754 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2755 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2757 /* make hdr from dst mst */
2758 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2762 /* amount left to send in this message */
2763 len = txmsg->cur_len - txmsg->cur_offset;
2765 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2766 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2768 tosend = min(len, space);
2769 if (len == txmsg->cur_len)
2775 hdr.msg_len = tosend + 1;
2776 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2777 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2778 /* add crc at end */
2779 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2782 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2783 if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
2784 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2786 drm_printf(&p, "sideband msg failed to send\n");
2787 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2791 txmsg->cur_offset += tosend;
2792 if (txmsg->cur_offset == txmsg->cur_len) {
2793 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2799 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2801 struct drm_dp_sideband_msg_tx *txmsg;
2804 WARN_ON(!mutex_is_locked(&mgr->qlock));
2806 /* construct a chunk from the first msg in the tx_msg queue */
2807 if (list_empty(&mgr->tx_msg_downq))
2810 txmsg = list_first_entry(&mgr->tx_msg_downq,
2811 struct drm_dp_sideband_msg_tx, next);
2812 ret = process_single_tx_qlock(mgr, txmsg, false);
2814 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2815 list_del(&txmsg->next);
2816 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2817 wake_up_all(&mgr->tx_waitq);
2821 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2822 struct drm_dp_sideband_msg_tx *txmsg)
2824 mutex_lock(&mgr->qlock);
2825 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2827 if (drm_debug_enabled(DRM_UT_DP)) {
2828 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2830 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2833 if (list_is_singular(&mgr->tx_msg_downq))
2834 process_single_down_tx_qlock(mgr);
2835 mutex_unlock(&mgr->qlock);
2839 drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
2841 struct drm_dp_link_addr_reply_port *port_reply;
2844 for (i = 0; i < reply->nports; i++) {
2845 port_reply = &reply->ports[i];
2846 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2848 port_reply->input_port,
2849 port_reply->peer_device_type,
2850 port_reply->port_number,
2851 port_reply->dpcd_revision,
2854 port_reply->legacy_device_plug_status,
2855 port_reply->num_sdp_streams,
2856 port_reply->num_sdp_stream_sinks);
2860 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2861 struct drm_dp_mst_branch *mstb)
2863 struct drm_dp_sideband_msg_tx *txmsg;
2864 struct drm_dp_link_address_ack_reply *reply;
2865 struct drm_dp_mst_port *port, *tmp;
2866 int i, ret, port_mask = 0;
2867 bool changed = false;
2869 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2874 build_link_address(txmsg);
2876 mstb->link_address_sent = true;
2877 drm_dp_queue_down_tx(mgr, txmsg);
2879 /* FIXME: Actually do some real error handling here */
2880 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2882 DRM_ERROR("Sending link address failed with %d\n", ret);
2885 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2886 DRM_ERROR("link address NAK received\n");
2891 reply = &txmsg->reply.u.link_addr;
2892 DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
2893 drm_dp_dump_link_address(reply);
2895 ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2899 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2900 DRM_ERROR("GUID check on %s failed: %d\n",
2905 for (i = 0; i < reply->nports; i++) {
2906 port_mask |= BIT(reply->ports[i].port_number);
2907 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2915 /* Prune any ports that are currently a part of mstb in our in-memory
2916 * topology, but were not seen in this link address. Usually this
2917 * means that they were removed while the topology was out of sync,
2918 * e.g. during suspend/resume
2920 mutex_lock(&mgr->lock);
2921 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2922 if (port_mask & BIT(port->port_num))
2925 DRM_DEBUG_KMS("port %d was not in link address, removing\n",
2927 list_del(&port->next);
2928 drm_dp_mst_topology_put_port(port);
2931 mutex_unlock(&mgr->lock);
2935 mstb->link_address_sent = false;
2937 return ret < 0 ? ret : changed;
2941 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2942 struct drm_dp_mst_branch *mstb)
2944 struct drm_dp_sideband_msg_tx *txmsg;
2947 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2952 build_clear_payload_id_table(txmsg);
2954 drm_dp_queue_down_tx(mgr, txmsg);
2956 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2957 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2958 DRM_DEBUG_KMS("clear payload table id nak received\n");
2964 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2965 struct drm_dp_mst_branch *mstb,
2966 struct drm_dp_mst_port *port)
2968 struct drm_dp_enum_path_resources_ack_reply *path_res;
2969 struct drm_dp_sideband_msg_tx *txmsg;
2972 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2977 build_enum_path_resources(txmsg, port->port_num);
2979 drm_dp_queue_down_tx(mgr, txmsg);
2981 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2984 path_res = &txmsg->reply.u.path_resources;
2986 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2987 DRM_DEBUG_KMS("enum path resources nak received\n");
2989 if (port->port_num != path_res->port_number)
2990 DRM_ERROR("got incorrect port in response\n");
2992 DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
2993 path_res->port_number,
2994 path_res->full_payload_bw_number,
2995 path_res->avail_payload_bw_number);
2998 * If something changed, make sure we send a
3001 if (port->full_pbn != path_res->full_payload_bw_number ||
3002 port->fec_capable != path_res->fec_capable)
3005 port->full_pbn = path_res->full_payload_bw_number;
3006 port->fec_capable = path_res->fec_capable;
3014 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3016 if (!mstb->port_parent)
3019 if (mstb->port_parent->mstb != mstb)
3020 return mstb->port_parent;
3022 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3026 * Searches upwards in the topology starting from mstb to try to find the
3027 * closest available parent of mstb that's still connected to the rest of the
3028 * topology. This can be used in order to perform operations like releasing
3029 * payloads, where the branch device which owned the payload may no longer be
3030 * around and thus would require that the payload on the last living relative
3033 static struct drm_dp_mst_branch *
3034 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3035 struct drm_dp_mst_branch *mstb,
3038 struct drm_dp_mst_branch *rmstb = NULL;
3039 struct drm_dp_mst_port *found_port;
3041 mutex_lock(&mgr->lock);
3042 if (!mgr->mst_primary)
3046 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3050 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3051 rmstb = found_port->parent;
3052 *port_num = found_port->port_num;
3054 /* Search again, starting from this parent */
3055 mstb = found_port->parent;
3059 mutex_unlock(&mgr->lock);
3063 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3064 struct drm_dp_mst_port *port,
3068 struct drm_dp_sideband_msg_tx *txmsg;
3069 struct drm_dp_mst_branch *mstb;
3071 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3074 port_num = port->port_num;
3075 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3077 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3085 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3091 for (i = 0; i < port->num_sdp_streams; i++)
3095 build_allocate_payload(txmsg, port_num,
3097 pbn, port->num_sdp_streams, sinks);
3099 drm_dp_queue_down_tx(mgr, txmsg);
3102 * FIXME: there is a small chance that between getting the last
3103 * connected mstb and sending the payload message, the last connected
3104 * mstb could also be removed from the topology. In the future, this
3105 * needs to be fixed by restarting the
3106 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3107 * timeout if the topology is still connected to the system.
3109 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3111 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3118 drm_dp_mst_topology_put_mstb(mstb);
3122 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3123 struct drm_dp_mst_port *port, bool power_up)
3125 struct drm_dp_sideband_msg_tx *txmsg;
3128 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3132 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3134 drm_dp_mst_topology_put_port(port);
3138 txmsg->dst = port->parent;
3139 build_power_updown_phy(txmsg, port->port_num, power_up);
3140 drm_dp_queue_down_tx(mgr, txmsg);
3142 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3144 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3150 drm_dp_mst_topology_put_port(port);
3154 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3156 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3158 struct drm_dp_payload *payload)
3162 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3164 payload->payload_state = 0;
3167 payload->payload_state = DP_PAYLOAD_LOCAL;
3171 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3172 struct drm_dp_mst_port *port,
3174 struct drm_dp_payload *payload)
3178 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3181 payload->payload_state = DP_PAYLOAD_REMOTE;
3185 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3186 struct drm_dp_mst_port *port,
3188 struct drm_dp_payload *payload)
3190 DRM_DEBUG_KMS("\n");
3191 /* it's okay for these to fail */
3193 drm_dp_payload_send_msg(mgr, port, id, 0);
3196 drm_dp_dpcd_write_payload(mgr, id, payload);
3197 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3201 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3203 struct drm_dp_payload *payload)
3205 payload->payload_state = 0;
3210 * drm_dp_update_payload_part1() - Execute payload update part 1
3211 * @mgr: manager to use.
3213 * This iterates over all proposed virtual channels, and tries to
3214 * allocate space in the link for them. For 0->slots transitions,
3215 * this step just writes the VCPI to the MST device. For slots->0
3216 * transitions, this writes the updated VCPIs and removes the
3217 * remote VC payloads.
3219 * after calling this the driver should generate ACT and payload
3222 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
3224 struct drm_dp_payload req_payload;
3225 struct drm_dp_mst_port *port;
3229 mutex_lock(&mgr->payload_lock);
3230 for (i = 0; i < mgr->max_payloads; i++) {
3231 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3232 struct drm_dp_payload *payload = &mgr->payloads[i];
3233 bool put_port = false;
3235 /* solve the current payloads - compare to the hw ones
3236 - update the hw view */
3237 req_payload.start_slot = cur_slots;
3239 port = container_of(vcpi, struct drm_dp_mst_port,
3242 /* Validated ports don't matter if we're releasing
3245 if (vcpi->num_slots) {
3246 port = drm_dp_mst_topology_get_port_validated(
3249 mutex_unlock(&mgr->payload_lock);
3255 req_payload.num_slots = vcpi->num_slots;
3256 req_payload.vcpi = vcpi->vcpi;
3259 req_payload.num_slots = 0;
3262 payload->start_slot = req_payload.start_slot;
3263 /* work out what is required to happen with this payload */
3264 if (payload->num_slots != req_payload.num_slots) {
3266 /* need to push an update for this payload */
3267 if (req_payload.num_slots) {
3268 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3270 payload->num_slots = req_payload.num_slots;
3271 payload->vcpi = req_payload.vcpi;
3273 } else if (payload->num_slots) {
3274 payload->num_slots = 0;
3275 drm_dp_destroy_payload_step1(mgr, port,
3278 req_payload.payload_state =
3279 payload->payload_state;
3280 payload->start_slot = 0;
3282 payload->payload_state = req_payload.payload_state;
3284 cur_slots += req_payload.num_slots;
3287 drm_dp_mst_topology_put_port(port);
3290 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3291 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3296 DRM_DEBUG_KMS("removing payload %d\n", i);
3297 for (j = i; j < mgr->max_payloads - 1; j++) {
3298 mgr->payloads[j] = mgr->payloads[j + 1];
3299 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3301 if (mgr->proposed_vcpis[j] &&
3302 mgr->proposed_vcpis[j]->num_slots) {
3303 set_bit(j + 1, &mgr->payload_mask);
3305 clear_bit(j + 1, &mgr->payload_mask);
3309 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3310 sizeof(struct drm_dp_payload));
3311 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3312 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3314 mutex_unlock(&mgr->payload_lock);
3318 EXPORT_SYMBOL(drm_dp_update_payload_part1);
3321 * drm_dp_update_payload_part2() - Execute payload update part 2
3322 * @mgr: manager to use.
3324 * This iterates over all proposed virtual channels, and tries to
3325 * allocate space in the link for them. For 0->slots transitions,
3326 * this step writes the remote VC payload commands. For slots->0
3327 * this just resets some internal state.
3329 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3331 struct drm_dp_mst_port *port;
3335 mutex_lock(&mgr->payload_lock);
3336 for (i = 0; i < mgr->max_payloads; i++) {
3338 if (!mgr->proposed_vcpis[i])
3341 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3343 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
3344 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3345 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3346 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3347 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3350 mutex_unlock(&mgr->payload_lock);
3354 mutex_unlock(&mgr->payload_lock);
3357 EXPORT_SYMBOL(drm_dp_update_payload_part2);
3359 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3360 struct drm_dp_mst_port *port,
3361 int offset, int size, u8 *bytes)
3364 struct drm_dp_sideband_msg_tx *txmsg;
3365 struct drm_dp_mst_branch *mstb;
3367 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3371 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3377 build_dpcd_read(txmsg, port->port_num, offset, size);
3378 txmsg->dst = port->parent;
3380 drm_dp_queue_down_tx(mgr, txmsg);
3382 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3386 /* DPCD read should never be NACKed */
3387 if (txmsg->reply.reply_type == 1) {
3388 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3389 mstb, port->port_num, offset, size);
3394 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3399 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3401 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3406 drm_dp_mst_topology_put_mstb(mstb);
3411 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3412 struct drm_dp_mst_port *port,
3413 int offset, int size, u8 *bytes)
3416 struct drm_dp_sideband_msg_tx *txmsg;
3417 struct drm_dp_mst_branch *mstb;
3419 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3423 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3429 build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3432 drm_dp_queue_down_tx(mgr, txmsg);
3434 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3436 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3444 drm_dp_mst_topology_put_mstb(mstb);
3448 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3450 struct drm_dp_sideband_msg_reply_body reply;
3452 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3453 reply.req_type = req_type;
3454 drm_dp_encode_sideband_reply(&reply, msg);
3458 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3459 struct drm_dp_mst_branch *mstb,
3460 int req_type, bool broadcast)
3462 struct drm_dp_sideband_msg_tx *txmsg;
3464 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3469 drm_dp_encode_up_ack_reply(txmsg, req_type);
3471 mutex_lock(&mgr->qlock);
3472 /* construct a chunk from the first msg in the tx_msg queue */
3473 process_single_tx_qlock(mgr, txmsg, true);
3474 mutex_unlock(&mgr->qlock);
3480 static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
3482 if (dp_link_bw == 0 || dp_link_count == 0)
3483 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
3484 dp_link_bw, dp_link_count);
3486 return dp_link_bw * dp_link_count / 2;
3490 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3491 * @mgr: manager to set state for
3492 * @mst_state: true to enable MST on this connector - false to disable.
3494 * This is called by the driver when it detects an MST capable device plugged
3495 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3497 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3500 struct drm_dp_mst_branch *mstb = NULL;
3502 mutex_lock(&mgr->payload_lock);
3503 mutex_lock(&mgr->lock);
3504 if (mst_state == mgr->mst_state)
3507 mgr->mst_state = mst_state;
3508 /* set the device into MST mode */
3510 struct drm_dp_payload reset_pay;
3512 WARN_ON(mgr->mst_primary);
3515 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
3516 if (ret != DP_RECEIVER_CAP_SIZE) {
3517 DRM_DEBUG_KMS("failed to read DPCD\n");
3521 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
3522 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
3523 if (mgr->pbn_div == 0) {
3528 /* add initial branch device at LCT 1 */
3529 mstb = drm_dp_add_mst_branch_device(1, NULL);
3536 /* give this the main reference */
3537 mgr->mst_primary = mstb;
3538 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3540 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3543 DP_UPSTREAM_IS_SRC);
3547 reset_pay.start_slot = 0;
3548 reset_pay.num_slots = 0x3f;
3549 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3551 queue_work(system_long_wq, &mgr->work);
3555 /* disable MST on the device */
3556 mstb = mgr->mst_primary;
3557 mgr->mst_primary = NULL;
3558 /* this can fail if the device is gone */
3559 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3561 memset(mgr->payloads, 0,
3562 mgr->max_payloads * sizeof(mgr->payloads[0]));
3563 memset(mgr->proposed_vcpis, 0,
3564 mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
3565 mgr->payload_mask = 0;
3566 set_bit(0, &mgr->payload_mask);
3568 mgr->payload_id_table_cleared = false;
3572 mutex_unlock(&mgr->lock);
3573 mutex_unlock(&mgr->payload_lock);
3575 drm_dp_mst_topology_put_mstb(mstb);
3579 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3582 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3584 struct drm_dp_mst_port *port;
3586 /* The link address will need to be re-sent on resume */
3587 mstb->link_address_sent = false;
3589 list_for_each_entry(port, &mstb->ports, next)
3591 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3595 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3596 * @mgr: manager to suspend
3598 * This function tells the MST device that we can't handle UP messages
3599 * anymore. This should stop it from sending any since we are suspended.
3601 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3603 mutex_lock(&mgr->lock);
3604 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3605 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3606 mutex_unlock(&mgr->lock);
3607 flush_work(&mgr->up_req_work);
3608 flush_work(&mgr->work);
3609 flush_work(&mgr->delayed_destroy_work);
3611 mutex_lock(&mgr->lock);
3612 if (mgr->mst_state && mgr->mst_primary)
3613 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3614 mutex_unlock(&mgr->lock);
3616 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3619 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3620 * @mgr: manager to resume
3621 * @sync: whether or not to perform topology reprobing synchronously
3623 * This will fetch DPCD and see if the device is still there,
3624 * if it is, it will rewrite the MSTM control bits, and return.
3626 * If the device fails this returns -1, and the driver should do
3627 * a full MST reprobe, in case we were undocked.
3629 * During system resume (where it is assumed that the driver will be calling
3630 * drm_atomic_helper_resume()) this function should be called beforehand with
3631 * @sync set to true. In contexts like runtime resume where the driver is not
3632 * expected to be calling drm_atomic_helper_resume(), this function should be
3633 * called with @sync set to false in order to avoid deadlocking.
3635 * Returns: -1 if the MST topology was removed while we were suspended, 0
3638 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3644 mutex_lock(&mgr->lock);
3645 if (!mgr->mst_primary)
3648 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3649 DP_RECEIVER_CAP_SIZE);
3650 if (ret != DP_RECEIVER_CAP_SIZE) {
3651 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3655 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3658 DP_UPSTREAM_IS_SRC);
3660 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
3664 /* Some hubs forget their guids after they resume */
3665 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3667 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3671 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3673 DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n");
3678 * For the final step of resuming the topology, we need to bring the
3679 * state of our in-memory topology back into sync with reality. So,
3680 * restart the probing process as if we're probing a new hub
3682 queue_work(system_long_wq, &mgr->work);
3683 mutex_unlock(&mgr->lock);
3686 DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
3687 flush_work(&mgr->work);
3693 mutex_unlock(&mgr->lock);
3696 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3699 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3700 struct drm_dp_mst_branch **mstb)
3704 int replylen, curreply;
3707 struct drm_dp_sideband_msg_hdr hdr;
3708 struct drm_dp_sideband_msg_rx *msg =
3709 up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3710 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3711 DP_SIDEBAND_MSG_DOWN_REP_BASE;
3716 len = min(mgr->max_dpcd_transaction_bytes, 16);
3717 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3719 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
3723 ret = drm_dp_decode_sideband_msg_hdr(&hdr, replyblock, len, &hdrlen);
3725 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3726 1, replyblock, len, false);
3727 DRM_DEBUG_KMS("ERROR: failed header\n");
3732 /* Caller is responsible for giving back this reference */
3733 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3735 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3741 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3742 DRM_DEBUG_KMS("sideband msg set header failed %d\n",
3747 replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3748 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3750 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
3754 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3756 while (replylen > 0) {
3757 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3758 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3761 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
3766 ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3768 DRM_DEBUG_KMS("failed to build sideband msg\n");
3778 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3780 struct drm_dp_sideband_msg_tx *txmsg;
3781 struct drm_dp_mst_branch *mstb = NULL;
3782 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3784 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3787 /* Multi-packet message transmission, don't clear the reply */
3788 if (!msg->have_eomt)
3791 /* find the message */
3792 mutex_lock(&mgr->qlock);
3793 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
3794 struct drm_dp_sideband_msg_tx, next);
3795 mutex_unlock(&mgr->qlock);
3797 /* Were we actually expecting a response, and from this mstb? */
3798 if (!txmsg || txmsg->dst != mstb) {
3799 struct drm_dp_sideband_msg_hdr *hdr;
3801 hdr = &msg->initial_hdr;
3802 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
3803 mstb, hdr->seqno, hdr->lct, hdr->rad[0],
3805 goto out_clear_reply;
3808 drm_dp_sideband_parse_reply(msg, &txmsg->reply);
3810 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3811 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3812 txmsg->reply.req_type,
3813 drm_dp_mst_req_type_str(txmsg->reply.req_type),
3814 txmsg->reply.u.nak.reason,
3815 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3816 txmsg->reply.u.nak.nak_data);
3819 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3820 drm_dp_mst_topology_put_mstb(mstb);
3822 mutex_lock(&mgr->qlock);
3823 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3824 list_del(&txmsg->next);
3825 mutex_unlock(&mgr->qlock);
3827 wake_up_all(&mgr->tx_waitq);
3832 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3835 drm_dp_mst_topology_put_mstb(mstb);
3841 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3842 struct drm_dp_pending_up_req *up_req)
3844 struct drm_dp_mst_branch *mstb = NULL;
3845 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3846 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3847 bool hotplug = false;
3849 if (hdr->broadcast) {
3850 const u8 *guid = NULL;
3852 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3853 guid = msg->u.conn_stat.guid;
3854 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3855 guid = msg->u.resource_stat.guid;
3858 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3860 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3864 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3869 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3870 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3871 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3875 drm_dp_mst_topology_put_mstb(mstb);
3879 static void drm_dp_mst_up_req_work(struct work_struct *work)
3881 struct drm_dp_mst_topology_mgr *mgr =
3882 container_of(work, struct drm_dp_mst_topology_mgr,
3884 struct drm_dp_pending_up_req *up_req;
3885 bool send_hotplug = false;
3887 mutex_lock(&mgr->probe_lock);
3889 mutex_lock(&mgr->up_req_lock);
3890 up_req = list_first_entry_or_null(&mgr->up_req_list,
3891 struct drm_dp_pending_up_req,
3894 list_del(&up_req->next);
3895 mutex_unlock(&mgr->up_req_lock);
3900 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
3903 mutex_unlock(&mgr->probe_lock);
3906 drm_kms_helper_hotplug_event(mgr->dev);
3909 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
3911 struct drm_dp_pending_up_req *up_req;
3913 if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
3916 if (!mgr->up_req_recv.have_eomt)
3919 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
3921 DRM_ERROR("Not enough memory to process MST up req\n");
3924 INIT_LIST_HEAD(&up_req->next);
3926 drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg);
3928 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
3929 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
3930 DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
3931 up_req->msg.req_type);
3936 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
3939 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
3940 const struct drm_dp_connection_status_notify *conn_stat =
3941 &up_req->msg.u.conn_stat;
3943 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
3944 conn_stat->port_number,
3945 conn_stat->legacy_device_plug_status,
3946 conn_stat->displayport_device_plug_status,
3947 conn_stat->message_capability_status,
3948 conn_stat->input_port,
3949 conn_stat->peer_device_type);
3950 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
3951 const struct drm_dp_resource_status_notify *res_stat =
3952 &up_req->msg.u.resource_stat;
3954 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
3955 res_stat->port_number,
3956 res_stat->available_pbn);
3959 up_req->hdr = mgr->up_req_recv.initial_hdr;
3960 mutex_lock(&mgr->up_req_lock);
3961 list_add_tail(&up_req->next, &mgr->up_req_list);
3962 mutex_unlock(&mgr->up_req_lock);
3963 queue_work(system_long_wq, &mgr->up_req_work);
3966 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3971 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3972 * @mgr: manager to notify irq for.
3973 * @esi: 4 bytes from SINK_COUNT_ESI
3974 * @handled: whether the hpd interrupt was consumed or not
3976 * This should be called from the driver when it detects a short IRQ,
3977 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3978 * topology manager will process the sideband messages received as a result
3981 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
3988 if (sc != mgr->sink_count) {
3989 mgr->sink_count = sc;
3993 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
3994 ret = drm_dp_mst_handle_down_rep(mgr);
3998 if (esi[1] & DP_UP_REQ_MSG_RDY) {
3999 ret |= drm_dp_mst_handle_up_req(mgr);
4003 drm_dp_mst_kick_tx(mgr);
4006 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
4009 * drm_dp_mst_detect_port() - get connection status for an MST port
4010 * @connector: DRM connector for this port
4011 * @ctx: The acquisition context to use for grabbing locks
4012 * @mgr: manager for this port
4013 * @port: pointer to a port
4015 * This returns the current connection state for a port.
4018 drm_dp_mst_detect_port(struct drm_connector *connector,
4019 struct drm_modeset_acquire_ctx *ctx,
4020 struct drm_dp_mst_topology_mgr *mgr,
4021 struct drm_dp_mst_port *port)
4025 /* we need to search for the port in the mgr in case it's gone */
4026 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4028 return connector_status_disconnected;
4030 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4034 ret = connector_status_disconnected;
4039 switch (port->pdt) {
4040 case DP_PEER_DEVICE_NONE:
4041 case DP_PEER_DEVICE_MST_BRANCHING:
4043 ret = connector_status_connected;
4046 case DP_PEER_DEVICE_SST_SINK:
4047 ret = connector_status_connected;
4048 /* for logical ports - cache the EDID */
4049 if (port->port_num >= 8 && !port->cached_edid) {
4050 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4053 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4055 ret = connector_status_connected;
4059 drm_dp_mst_topology_put_port(port);
4062 EXPORT_SYMBOL(drm_dp_mst_detect_port);
4065 * drm_dp_mst_get_edid() - get EDID for an MST port
4066 * @connector: toplevel connector to get EDID for
4067 * @mgr: manager for this port
4068 * @port: unverified pointer to a port.
4070 * This returns an EDID for the port connected to a connector,
4071 * It validates the pointer still exists so the caller doesn't require a
4074 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4076 struct edid *edid = NULL;
4078 /* we need to search for the port in the mgr in case it's gone */
4079 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4083 if (port->cached_edid)
4084 edid = drm_edid_duplicate(port->cached_edid);
4086 edid = drm_get_edid(connector, &port->aux.ddc);
4088 port->has_audio = drm_detect_monitor_audio(edid);
4089 drm_dp_mst_topology_put_port(port);
4092 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4095 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4096 * @mgr: manager to use
4097 * @pbn: payload bandwidth to convert into slots.
4099 * Calculate the number of VCPI slots that will be required for the given PBN
4100 * value. This function is deprecated, and should not be used in atomic
4104 * The total slots required for this port, or error.
4106 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4111 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4113 /* max. time slots - one slot for MTP header */
4118 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4120 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4121 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4125 /* max. time slots - one slot for MTP header */
4130 vcpi->aligned_pbn = slots * mgr->pbn_div;
4131 vcpi->num_slots = slots;
4133 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4140 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4141 * @state: global atomic state
4142 * @mgr: MST topology manager for the port
4143 * @port: port to find vcpi slots for
4144 * @pbn: bandwidth required for the mode in PBN
4145 * @pbn_div: divider for DSC mode that takes FEC into account
4147 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4148 * may have had. Any atomic drivers which support MST must call this function
4149 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4150 * current VCPI allocation for the new state, but only when
4151 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4152 * to ensure compatibility with userspace applications that still use the
4153 * legacy modesetting UAPI.
4155 * Allocations set by this function are not checked against the bandwidth
4156 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4158 * Additionally, it is OK to call this function multiple times on the same
4159 * @port as needed. It is not OK however, to call this function and
4160 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4163 * drm_dp_atomic_release_vcpi_slots()
4164 * drm_dp_mst_atomic_check()
4167 * Total slots in the atomic state assigned for this port, or a negative error
4168 * code if the port no longer exists
4170 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4171 struct drm_dp_mst_topology_mgr *mgr,
4172 struct drm_dp_mst_port *port, int pbn,
4175 struct drm_dp_mst_topology_state *topology_state;
4176 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4177 int prev_slots, prev_bw, req_slots;
4179 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4180 if (IS_ERR(topology_state))
4181 return PTR_ERR(topology_state);
4183 /* Find the current allocation for this port, if any */
4184 list_for_each_entry(pos, &topology_state->vcpis, next) {
4185 if (pos->port == port) {
4187 prev_slots = vcpi->vcpi;
4188 prev_bw = vcpi->pbn;
4191 * This should never happen, unless the driver tries
4192 * releasing and allocating the same VCPI allocation,
4195 if (WARN_ON(!prev_slots)) {
4196 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4210 pbn_div = mgr->pbn_div;
4212 req_slots = DIV_ROUND_UP(pbn, pbn_div);
4214 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4215 port->connector->base.id, port->connector->name,
4216 port, prev_slots, req_slots);
4217 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4218 port->connector->base.id, port->connector->name,
4219 port, prev_bw, pbn);
4221 /* Add the new allocation to the state */
4223 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4227 drm_dp_mst_get_port_malloc(port);
4229 list_add(&vcpi->next, &topology_state->vcpis);
4231 vcpi->vcpi = req_slots;
4236 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4239 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4240 * @state: global atomic state
4241 * @mgr: MST topology manager for the port
4242 * @port: The port to release the VCPI slots from
4244 * Releases any VCPI slots that have been allocated to a port in the atomic
4245 * state. Any atomic drivers which support MST must call this function in
4246 * their &drm_connector_helper_funcs.atomic_check() callback when the
4247 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4248 * removed) when it had VCPI allocated in the previous atomic state.
4250 * It is OK to call this even if @port has been removed from the system.
4251 * Additionally, it is OK to call this function multiple times on the same
4252 * @port as needed. It is not OK however, to call this function and
4253 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4257 * drm_dp_atomic_find_vcpi_slots()
4258 * drm_dp_mst_atomic_check()
4261 * 0 if all slots for this port were added back to
4262 * &drm_dp_mst_topology_state.avail_slots or negative error code
4264 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4265 struct drm_dp_mst_topology_mgr *mgr,
4266 struct drm_dp_mst_port *port)
4268 struct drm_dp_mst_topology_state *topology_state;
4269 struct drm_dp_vcpi_allocation *pos;
4272 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4273 if (IS_ERR(topology_state))
4274 return PTR_ERR(topology_state);
4276 list_for_each_entry(pos, &topology_state->vcpis, next) {
4277 if (pos->port == port) {
4282 if (WARN_ON(!found)) {
4283 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
4284 port, &topology_state->base);
4288 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4290 drm_dp_mst_put_port_malloc(port);
4297 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4300 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4301 * @mgr: manager for this port
4302 * @port: port to allocate a virtual channel for.
4303 * @pbn: payload bandwidth number to request
4304 * @slots: returned number of slots for this PBN.
4306 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4307 struct drm_dp_mst_port *port, int pbn, int slots)
4311 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4318 if (port->vcpi.vcpi > 0) {
4319 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4320 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4321 if (pbn == port->vcpi.pbn) {
4322 drm_dp_mst_topology_put_port(port);
4327 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4329 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
4330 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4333 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
4334 pbn, port->vcpi.num_slots);
4336 /* Keep port allocated until its payload has been removed */
4337 drm_dp_mst_get_port_malloc(port);
4338 drm_dp_mst_topology_put_port(port);
4343 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4345 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4349 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4353 slots = port->vcpi.num_slots;
4354 drm_dp_mst_topology_put_port(port);
4357 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4360 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4361 * @mgr: manager for this port
4362 * @port: unverified pointer to a port.
4364 * This just resets the number of slots for the ports VCPI for later programming.
4366 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4369 * A port with VCPI will remain allocated until its VCPI is
4370 * released, no verified ref needed
4373 port->vcpi.num_slots = 0;
4375 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4378 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4379 * @mgr: manager for this port
4380 * @port: port to deallocate vcpi for
4382 * This can be called unconditionally, regardless of whether
4383 * drm_dp_mst_allocate_vcpi() succeeded or not.
4385 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4386 struct drm_dp_mst_port *port)
4388 if (!port->vcpi.vcpi)
4391 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4392 port->vcpi.num_slots = 0;
4394 port->vcpi.aligned_pbn = 0;
4395 port->vcpi.vcpi = 0;
4396 drm_dp_mst_put_port_malloc(port);
4398 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4400 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4401 int id, struct drm_dp_payload *payload)
4403 u8 payload_alloc[3], status;
4407 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4408 DP_PAYLOAD_TABLE_UPDATED);
4410 payload_alloc[0] = id;
4411 payload_alloc[1] = payload->start_slot;
4412 payload_alloc[2] = payload->num_slots;
4414 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4416 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
4421 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4423 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4427 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4430 usleep_range(10000, 20000);
4433 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
4442 static int do_get_act_status(struct drm_dp_aux *aux)
4447 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4455 * drm_dp_check_act_status() - Polls for ACT handled status.
4456 * @mgr: manager to use
4458 * Tries waiting for the MST hub to finish updating it's payload table by
4459 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4463 * 0 if the ACT was handled in time, negative error code on failure.
4465 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4468 * There doesn't seem to be any recommended retry count or timeout in
4469 * the MST specification. Since some hubs have been observed to take
4470 * over 1 second to update their payload allocations under certain
4471 * conditions, we use a rather large timeout value.
4473 const int timeout_ms = 3000;
4476 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4477 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4478 200, timeout_ms * USEC_PER_MSEC);
4479 if (ret < 0 && status >= 0) {
4480 DRM_ERROR("Failed to get ACT after %dms, last status: %02x\n",
4481 timeout_ms, status);
4483 } else if (status < 0) {
4485 * Failure here isn't unexpected - the hub may have
4486 * just been unplugged
4488 DRM_DEBUG_KMS("Failed to read payload table status: %d\n",
4495 EXPORT_SYMBOL(drm_dp_check_act_status);
4498 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4499 * @clock: dot clock for the mode
4500 * @bpp: bpp for the mode.
4501 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4503 * This uses the formula in the spec to calculate the PBN value for a mode.
4505 int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4508 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4509 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4510 * common multiplier to render an integer PBN for all link rate/lane
4511 * counts combinations
4513 * peak_kbps *= (1006/1000)
4514 * peak_kbps *= (64/54)
4515 * peak_kbps *= 8 convert to bytes
4517 * If the bpp is in units of 1/16, further divide by 16. Put this
4518 * factor in the numerator rather than the denominator to avoid
4523 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4524 8 * 54 * 1000 * 1000);
4526 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4527 8 * 54 * 1000 * 1000);
4529 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4531 /* we want to kick the TX after we've ack the up/down IRQs. */
4532 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4534 queue_work(system_long_wq, &mgr->tx_work);
4537 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4538 struct drm_dp_mst_branch *mstb)
4540 struct drm_dp_mst_port *port;
4541 int tabs = mstb->lct;
4545 for (i = 0; i < tabs; i++)
4549 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
4550 list_for_each_entry(port, &mstb->ports, next) {
4551 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
4553 drm_dp_mst_dump_mstb(m, port->mstb);
4557 #define DP_PAYLOAD_TABLE_SIZE 64
4559 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4564 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4565 if (drm_dp_dpcd_read(mgr->aux,
4566 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4573 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4574 struct drm_dp_mst_port *port, char *name,
4577 struct edid *mst_edid;
4579 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4580 drm_edid_get_monitor_name(mst_edid, name, namelen);
4584 * drm_dp_mst_dump_topology(): dump topology to seq file.
4585 * @m: seq_file to dump output to
4586 * @mgr: manager to dump current topology for.
4588 * helper to dump MST topology to a seq file for debugfs.
4590 void drm_dp_mst_dump_topology(struct seq_file *m,
4591 struct drm_dp_mst_topology_mgr *mgr)
4594 struct drm_dp_mst_port *port;
4596 mutex_lock(&mgr->lock);
4597 if (mgr->mst_primary)
4598 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4601 mutex_unlock(&mgr->lock);
4603 mutex_lock(&mgr->payload_lock);
4604 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
4607 for (i = 0; i < mgr->max_payloads; i++) {
4608 if (mgr->proposed_vcpis[i]) {
4611 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4612 fetch_monitor_name(mgr, port, name, sizeof(name));
4613 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
4614 port->port_num, port->vcpi.vcpi,
4615 port->vcpi.num_slots,
4616 (*name != 0) ? name : "Unknown");
4618 seq_printf(m, "vcpi %d:unused\n", i);
4620 for (i = 0; i < mgr->max_payloads; i++) {
4621 seq_printf(m, "payload %d: %d, %d, %d\n",
4623 mgr->payloads[i].payload_state,
4624 mgr->payloads[i].start_slot,
4625 mgr->payloads[i].num_slots);
4629 mutex_unlock(&mgr->payload_lock);
4631 mutex_lock(&mgr->lock);
4632 if (mgr->mst_primary) {
4633 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4636 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4638 seq_printf(m, "dpcd read failed\n");
4641 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4643 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4645 seq_printf(m, "faux/mst read failed\n");
4648 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4650 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4652 seq_printf(m, "mst ctrl read failed\n");
4655 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4657 /* dump the standard OUI branch header */
4658 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4660 seq_printf(m, "branch oui read failed\n");
4663 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4665 for (i = 0x3; i < 0x8 && buf[i]; i++)
4666 seq_printf(m, "%c", buf[i]);
4667 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4668 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4669 if (dump_dp_payload_table(mgr, buf))
4670 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4674 mutex_unlock(&mgr->lock);
4677 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4679 static void drm_dp_tx_work(struct work_struct *work)
4681 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4683 mutex_lock(&mgr->qlock);
4684 if (!list_empty(&mgr->tx_msg_downq))
4685 process_single_down_tx_qlock(mgr);
4686 mutex_unlock(&mgr->qlock);
4690 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4692 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4694 if (port->connector) {
4695 drm_connector_unregister(port->connector);
4696 drm_connector_put(port->connector);
4699 drm_dp_mst_put_port_malloc(port);
4703 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4705 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4706 struct drm_dp_mst_port *port, *port_tmp;
4707 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4708 bool wake_tx = false;
4710 mutex_lock(&mgr->lock);
4711 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4712 list_del(&port->next);
4713 drm_dp_mst_topology_put_port(port);
4715 mutex_unlock(&mgr->lock);
4717 /* drop any tx slot msg */
4718 mutex_lock(&mstb->mgr->qlock);
4719 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
4720 if (txmsg->dst != mstb)
4723 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4724 list_del(&txmsg->next);
4727 mutex_unlock(&mstb->mgr->qlock);
4730 wake_up_all(&mstb->mgr->tx_waitq);
4732 drm_dp_mst_put_mstb_malloc(mstb);
4735 static void drm_dp_delayed_destroy_work(struct work_struct *work)
4737 struct drm_dp_mst_topology_mgr *mgr =
4738 container_of(work, struct drm_dp_mst_topology_mgr,
4739 delayed_destroy_work);
4740 bool send_hotplug = false, go_again;
4743 * Not a regular list traverse as we have to drop the destroy
4744 * connector lock before destroying the mstb/port, to avoid AB->BA
4745 * ordering between this lock and the config mutex.
4751 struct drm_dp_mst_branch *mstb;
4753 mutex_lock(&mgr->delayed_destroy_lock);
4754 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4755 struct drm_dp_mst_branch,
4758 list_del(&mstb->destroy_next);
4759 mutex_unlock(&mgr->delayed_destroy_lock);
4764 drm_dp_delayed_destroy_mstb(mstb);
4769 struct drm_dp_mst_port *port;
4771 mutex_lock(&mgr->delayed_destroy_lock);
4772 port = list_first_entry_or_null(&mgr->destroy_port_list,
4773 struct drm_dp_mst_port,
4776 list_del(&port->next);
4777 mutex_unlock(&mgr->delayed_destroy_lock);
4782 drm_dp_delayed_destroy_port(port);
4783 send_hotplug = true;
4789 drm_kms_helper_hotplug_event(mgr->dev);
4792 static struct drm_private_state *
4793 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
4795 struct drm_dp_mst_topology_state *state, *old_state =
4796 to_dp_mst_topology_state(obj->state);
4797 struct drm_dp_vcpi_allocation *pos, *vcpi;
4799 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
4803 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
4805 INIT_LIST_HEAD(&state->vcpis);
4807 list_for_each_entry(pos, &old_state->vcpis, next) {
4808 /* Prune leftover freed VCPI allocations */
4812 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
4816 drm_dp_mst_get_port_malloc(vcpi->port);
4817 list_add(&vcpi->next, &state->vcpis);
4820 return &state->base;
4823 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
4824 drm_dp_mst_put_port_malloc(pos->port);
4832 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
4833 struct drm_private_state *state)
4835 struct drm_dp_mst_topology_state *mst_state =
4836 to_dp_mst_topology_state(state);
4837 struct drm_dp_vcpi_allocation *pos, *tmp;
4839 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
4840 /* We only keep references to ports with non-zero VCPIs */
4842 drm_dp_mst_put_port_malloc(pos->port);
4849 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
4850 struct drm_dp_mst_branch *branch)
4852 while (port->parent) {
4853 if (port->parent == branch)
4856 if (port->parent->port_parent)
4857 port = port->parent->port_parent;
4865 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
4866 struct drm_dp_mst_topology_state *state);
4869 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
4870 struct drm_dp_mst_topology_state *state)
4872 struct drm_dp_vcpi_allocation *vcpi;
4873 struct drm_dp_mst_port *port;
4874 int pbn_used = 0, ret;
4877 /* Check that we have at least one port in our state that's downstream
4878 * of this branch, otherwise we can skip this branch
4880 list_for_each_entry(vcpi, &state->vcpis, next) {
4882 !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
4891 if (mstb->port_parent)
4892 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
4893 mstb->port_parent->parent, mstb->port_parent,
4896 DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
4899 list_for_each_entry(port, &mstb->ports, next) {
4900 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
4911 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
4912 struct drm_dp_mst_topology_state *state)
4914 struct drm_dp_vcpi_allocation *vcpi;
4917 if (port->pdt == DP_PEER_DEVICE_NONE)
4920 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
4923 list_for_each_entry(vcpi, &state->vcpis, next) {
4924 if (vcpi->port != port)
4935 /* This should never happen, as it means we tried to
4936 * set a mode before querying the full_pbn
4938 if (WARN_ON(!port->full_pbn))
4941 pbn_used = vcpi->pbn;
4943 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
4949 if (pbn_used > port->full_pbn) {
4950 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
4951 port->parent, port, pbn_used,
4956 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
4957 port->parent, port, pbn_used, port->full_pbn);
4963 drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
4964 struct drm_dp_mst_topology_state *mst_state)
4966 struct drm_dp_vcpi_allocation *vcpi;
4967 int avail_slots = 63, payload_count = 0;
4969 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
4970 /* Releasing VCPI is always OK-even if the port is gone */
4972 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
4977 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
4978 vcpi->port, vcpi->vcpi);
4980 avail_slots -= vcpi->vcpi;
4981 if (avail_slots < 0) {
4982 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
4983 vcpi->port, mst_state,
4984 avail_slots + vcpi->vcpi);
4988 if (++payload_count > mgr->max_payloads) {
4989 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
4990 mgr, mst_state, mgr->max_payloads);
4994 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
4995 mgr, mst_state, avail_slots,
5002 * drm_dp_mst_add_affected_dsc_crtcs
5003 * @state: Pointer to the new struct drm_dp_mst_topology_state
5004 * @mgr: MST topology manager
5006 * Whenever there is a change in mst topology
5007 * DSC configuration would have to be recalculated
5008 * therefore we need to trigger modeset on all affected
5009 * CRTCs in that topology
5012 * drm_dp_mst_atomic_enable_dsc()
5014 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5016 struct drm_dp_mst_topology_state *mst_state;
5017 struct drm_dp_vcpi_allocation *pos;
5018 struct drm_connector *connector;
5019 struct drm_connector_state *conn_state;
5020 struct drm_crtc *crtc;
5021 struct drm_crtc_state *crtc_state;
5023 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5025 if (IS_ERR(mst_state))
5028 list_for_each_entry(pos, &mst_state->vcpis, next) {
5030 connector = pos->port->connector;
5035 conn_state = drm_atomic_get_connector_state(state, connector);
5037 if (IS_ERR(conn_state))
5038 return PTR_ERR(conn_state);
5040 crtc = conn_state->crtc;
5045 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5048 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5050 if (IS_ERR(crtc_state))
5051 return PTR_ERR(crtc_state);
5053 DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5056 crtc_state->mode_changed = true;
5060 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5063 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5064 * @state: Pointer to the new drm_atomic_state
5065 * @port: Pointer to the affected MST Port
5066 * @pbn: Newly recalculated bw required for link with DSC enabled
5067 * @pbn_div: Divider to calculate correct number of pbn per slot
5068 * @enable: Boolean flag to enable or disable DSC on the port
5070 * This function enables DSC on the given Port
5071 * by recalculating its vcpi from pbn provided
5072 * and sets dsc_enable flag to keep track of which
5073 * ports have DSC enabled
5076 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5077 struct drm_dp_mst_port *port,
5078 int pbn, int pbn_div,
5081 struct drm_dp_mst_topology_state *mst_state;
5082 struct drm_dp_vcpi_allocation *pos;
5086 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5088 if (IS_ERR(mst_state))
5089 return PTR_ERR(mst_state);
5091 list_for_each_entry(pos, &mst_state->vcpis, next) {
5092 if (pos->port == port) {
5099 DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5104 if (pos->dsc_enabled == enable) {
5105 DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5106 port, enable, pos->vcpi);
5111 vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5112 DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5118 pos->dsc_enabled = enable;
5122 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5124 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5125 * atomic update is valid
5126 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5128 * Checks the given topology state for an atomic update to ensure that it's
5129 * valid. This includes checking whether there's enough bandwidth to support
5130 * the new VCPI allocations in the atomic update.
5132 * Any atomic drivers supporting DP MST must make sure to call this after
5133 * checking the rest of their state in their
5134 * &drm_mode_config_funcs.atomic_check() callback.
5137 * drm_dp_atomic_find_vcpi_slots()
5138 * drm_dp_atomic_release_vcpi_slots()
5142 * 0 if the new state is valid, negative error code otherwise.
5144 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5146 struct drm_dp_mst_topology_mgr *mgr;
5147 struct drm_dp_mst_topology_state *mst_state;
5150 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5151 if (!mgr->mst_state)
5154 ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5158 mutex_lock(&mgr->lock);
5159 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5161 mutex_unlock(&mgr->lock);
5170 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5172 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5173 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5174 .atomic_destroy_state = drm_dp_mst_destroy_state,
5176 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5179 * drm_atomic_get_mst_topology_state: get MST topology state
5181 * @state: global atomic state
5182 * @mgr: MST topology manager, also the private object in this case
5184 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5185 * state vtable so that the private object state returned is that of a MST
5186 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5187 * to care of the locking, so warn if don't hold the connection_mutex.
5191 * The MST topology state or error pointer.
5193 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5194 struct drm_dp_mst_topology_mgr *mgr)
5196 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5198 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5201 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5202 * @mgr: manager struct to initialise
5203 * @dev: device providing this structure - for i2c addition.
5204 * @aux: DP helper aux channel to talk to this device
5205 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5206 * @max_payloads: maximum number of payloads this GPU can source
5207 * @conn_base_id: the connector object ID the MST device is connected to.
5209 * Return 0 for success, or negative error code on failure
5211 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5212 struct drm_device *dev, struct drm_dp_aux *aux,
5213 int max_dpcd_transaction_bytes,
5214 int max_payloads, int conn_base_id)
5216 struct drm_dp_mst_topology_state *mst_state;
5218 mutex_init(&mgr->lock);
5219 mutex_init(&mgr->qlock);
5220 mutex_init(&mgr->payload_lock);
5221 mutex_init(&mgr->delayed_destroy_lock);
5222 mutex_init(&mgr->up_req_lock);
5223 mutex_init(&mgr->probe_lock);
5224 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5225 mutex_init(&mgr->topology_ref_history_lock);
5227 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5228 INIT_LIST_HEAD(&mgr->destroy_port_list);
5229 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5230 INIT_LIST_HEAD(&mgr->up_req_list);
5233 * delayed_destroy_work will be queued on a dedicated WQ, so that any
5234 * requeuing will be also flushed when deiniting the topology manager.
5236 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5237 if (mgr->delayed_destroy_wq == NULL)
5240 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5241 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5242 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5243 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5244 init_waitqueue_head(&mgr->tx_waitq);
5247 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5248 mgr->max_payloads = max_payloads;
5249 mgr->conn_base_id = conn_base_id;
5250 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5251 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5253 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5256 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5257 if (!mgr->proposed_vcpis)
5259 set_bit(0, &mgr->payload_mask);
5261 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5262 if (mst_state == NULL)
5265 mst_state->mgr = mgr;
5266 INIT_LIST_HEAD(&mst_state->vcpis);
5268 drm_atomic_private_obj_init(dev, &mgr->base,
5270 &drm_dp_mst_topology_state_funcs);
5274 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5277 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5278 * @mgr: manager to destroy
5280 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5282 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5283 flush_work(&mgr->work);
5284 /* The following will also drain any requeued work on the WQ. */
5285 if (mgr->delayed_destroy_wq) {
5286 destroy_workqueue(mgr->delayed_destroy_wq);
5287 mgr->delayed_destroy_wq = NULL;
5289 mutex_lock(&mgr->payload_lock);
5290 kfree(mgr->payloads);
5291 mgr->payloads = NULL;
5292 kfree(mgr->proposed_vcpis);
5293 mgr->proposed_vcpis = NULL;
5294 mutex_unlock(&mgr->payload_lock);
5297 drm_atomic_private_obj_fini(&mgr->base);
5300 mutex_destroy(&mgr->delayed_destroy_lock);
5301 mutex_destroy(&mgr->payload_lock);
5302 mutex_destroy(&mgr->qlock);
5303 mutex_destroy(&mgr->lock);
5304 mutex_destroy(&mgr->up_req_lock);
5305 mutex_destroy(&mgr->probe_lock);
5306 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5307 mutex_destroy(&mgr->topology_ref_history_lock);
5310 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5312 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5316 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5319 for (i = 0; i < num - 1; i++) {
5320 if (msgs[i].flags & I2C_M_RD ||
5325 return msgs[num - 1].flags & I2C_M_RD &&
5326 msgs[num - 1].len <= 0xff;
5330 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
5333 struct drm_dp_aux *aux = adapter->algo_data;
5334 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
5335 struct drm_dp_mst_branch *mstb;
5336 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5338 struct drm_dp_sideband_msg_req_body msg;
5339 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5342 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5346 if (!remote_i2c_read_ok(msgs, num)) {
5347 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
5352 memset(&msg, 0, sizeof(msg));
5353 msg.req_type = DP_REMOTE_I2C_READ;
5354 msg.u.i2c_read.num_transactions = num - 1;
5355 msg.u.i2c_read.port_number = port->port_num;
5356 for (i = 0; i < num - 1; i++) {
5357 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5358 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5359 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5360 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5362 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5363 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5365 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5372 drm_dp_encode_sideband_req(&msg, txmsg);
5374 drm_dp_queue_down_tx(mgr, txmsg);
5376 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5379 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5383 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5387 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5392 drm_dp_mst_topology_put_mstb(mstb);
5396 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5398 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5399 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5400 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5401 I2C_FUNC_10BIT_ADDR;
5404 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5405 .functionality = drm_dp_mst_i2c_functionality,
5406 .master_xfer = drm_dp_mst_i2c_xfer,
5410 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5411 * @port: The port to add the I2C bus on
5413 * Returns 0 on success or a negative error code on failure.
5415 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5417 struct drm_dp_aux *aux = &port->aux;
5418 struct device *parent_dev = port->mgr->dev->dev;
5420 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5421 aux->ddc.algo_data = aux;
5422 aux->ddc.retries = 3;
5424 aux->ddc.class = I2C_CLASS_DDC;
5425 aux->ddc.owner = THIS_MODULE;
5426 /* FIXME: set the kdev of the port's connector as parent */
5427 aux->ddc.dev.parent = parent_dev;
5428 aux->ddc.dev.of_node = parent_dev->of_node;
5430 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5431 sizeof(aux->ddc.name));
5433 return i2c_add_adapter(&aux->ddc);
5437 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5438 * @port: The port to remove the I2C bus from
5440 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5442 i2c_del_adapter(&port->aux.ddc);
5446 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5447 * @port: The port to check
5449 * A single physical MST hub object can be represented in the topology
5450 * by multiple branches, with virtual ports between those branches.
5452 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5453 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5454 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5456 * May acquire mgr->lock
5459 * true if the port is a virtual DP peer device, false otherwise
5461 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5463 struct drm_dp_mst_port *downstream_port;
5465 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5468 /* Virtual DP Sink (Internal Display Panel) */
5469 if (port->port_num >= 8)
5472 /* DP-to-HDMI Protocol Converter */
5473 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5479 mutex_lock(&port->mgr->lock);
5480 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5482 port->mstb->num_ports == 2) {
5483 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5484 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5485 !downstream_port->input) {
5486 mutex_unlock(&port->mgr->lock);
5491 mutex_unlock(&port->mgr->lock);
5497 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5498 * @port: The port to check. A leaf of the MST tree with an attached display.
5500 * Depending on the situation, DSC may be enabled via the endpoint aux,
5501 * the immediately upstream aux, or the connector's physical aux.
5503 * This is both the correct aux to read DSC_CAPABILITY and the
5504 * correct aux to write DSC_ENABLED.
5506 * This operation can be expensive (up to four aux reads), so
5507 * the caller should cache the return.
5510 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5512 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5514 struct drm_dp_mst_port *immediate_upstream_port;
5515 struct drm_dp_mst_port *fec_port;
5516 struct drm_dp_desc desc = {};
5523 if (port->parent->port_parent)
5524 immediate_upstream_port = port->parent->port_parent;
5526 immediate_upstream_port = NULL;
5528 fec_port = immediate_upstream_port;
5531 * Each physical link (i.e. not a virtual port) between the
5532 * output and the primary device must support FEC
5534 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5535 !fec_port->fec_capable)
5538 fec_port = fec_port->parent->port_parent;
5541 /* DP-to-DP peer device */
5542 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5545 if (drm_dp_dpcd_read(&port->aux,
5546 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5548 if (drm_dp_dpcd_read(&port->aux,
5549 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5551 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5552 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5555 /* Enpoint decompression with DP-to-DP peer device */
5556 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5557 (endpoint_fec & DP_FEC_CAPABLE) &&
5558 (upstream_dsc & 0x2) /* DSC passthrough */)
5561 /* Virtual DPCD decompression with DP-to-DP peer device */
5562 return &immediate_upstream_port->aux;
5565 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5566 if (drm_dp_mst_is_virtual_dpcd(port))
5571 * Applies to ports for which:
5572 * - Physical aux has Synaptics OUI
5573 * - DPv1.4 or higher
5574 * - Port is on primary branch device
5575 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5577 if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5580 if (drm_dp_has_quirk(&desc, 0,
5581 DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5582 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5583 port->parent == port->mgr->mst_primary) {
5586 if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
5587 &downstreamport, 1) < 0)
5590 if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
5591 ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
5592 != DP_DWN_STRM_PORT_TYPE_ANALOG))
5593 return port->mgr->aux;
5597 * The check below verifies if the MST sink
5598 * connected to the GPU is capable of DSC -
5599 * therefore the endpoint needs to be
5600 * both DSC and FEC capable.
5602 if (drm_dp_dpcd_read(&port->aux,
5603 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5605 if (drm_dp_dpcd_read(&port->aux,
5606 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5608 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5609 (endpoint_fec & DP_FEC_CAPABLE))
5614 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);