2 * Copyright © 2009 Keith Packard
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/module.h>
29 #include <linux/sched.h>
30 #include <linux/seq_file.h>
31 #include <linux/string_helpers.h>
33 #include <drm/display/drm_dp_helper.h>
34 #include <drm/display/drm_dp_mst_helper.h>
35 #include <drm/drm_edid.h>
36 #include <drm/drm_print.h>
37 #include <drm/drm_vblank.h>
38 #include <drm/drm_panel.h>
40 #include "drm_dp_helper_internal.h"
42 struct dp_aux_backlight {
43 struct backlight_device *base;
44 struct drm_dp_aux *aux;
45 struct drm_edp_backlight_info info;
52 * These functions contain some common logic and helpers at various abstraction
53 * levels to deal with Display Port sink devices and related things like DP aux
54 * channel transfers, EDID reading over DP aux channels, decoding certain DPCD
58 /* Helpers for DP link training */
59 static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
61 return link_status[r - DP_LANE0_1_STATUS];
64 static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE],
67 int i = DP_LANE0_1_STATUS + (lane >> 1);
68 int s = (lane & 1) * 4;
69 u8 l = dp_link_status(link_status, i);
71 return (l >> s) & 0xf;
74 bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
81 lane_align = dp_link_status(link_status,
82 DP_LANE_ALIGN_STATUS_UPDATED);
83 if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
85 for (lane = 0; lane < lane_count; lane++) {
86 lane_status = dp_get_lane_status(link_status, lane);
87 if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS)
92 EXPORT_SYMBOL(drm_dp_channel_eq_ok);
94 bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
100 for (lane = 0; lane < lane_count; lane++) {
101 lane_status = dp_get_lane_status(link_status, lane);
102 if ((lane_status & DP_LANE_CR_DONE) == 0)
107 EXPORT_SYMBOL(drm_dp_clock_recovery_ok);
109 u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
112 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
113 int s = ((lane & 1) ?
114 DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
115 DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
116 u8 l = dp_link_status(link_status, i);
118 return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
120 EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage);
122 u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
125 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
126 int s = ((lane & 1) ?
127 DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
128 DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
129 u8 l = dp_link_status(link_status, i);
131 return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
133 EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
135 /* DP 2.0 128b/132b */
136 u8 drm_dp_get_adjust_tx_ffe_preset(const u8 link_status[DP_LINK_STATUS_SIZE],
139 int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
140 int s = ((lane & 1) ?
141 DP_ADJUST_TX_FFE_PRESET_LANE1_SHIFT :
142 DP_ADJUST_TX_FFE_PRESET_LANE0_SHIFT);
143 u8 l = dp_link_status(link_status, i);
145 return (l >> s) & 0xf;
147 EXPORT_SYMBOL(drm_dp_get_adjust_tx_ffe_preset);
149 /* DP 2.0 errata for 128b/132b */
150 bool drm_dp_128b132b_lane_channel_eq_done(const u8 link_status[DP_LINK_STATUS_SIZE],
153 u8 lane_align, lane_status;
156 lane_align = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED);
157 if (!(lane_align & DP_INTERLANE_ALIGN_DONE))
160 for (lane = 0; lane < lane_count; lane++) {
161 lane_status = dp_get_lane_status(link_status, lane);
162 if (!(lane_status & DP_LANE_CHANNEL_EQ_DONE))
167 EXPORT_SYMBOL(drm_dp_128b132b_lane_channel_eq_done);
169 /* DP 2.0 errata for 128b/132b */
170 bool drm_dp_128b132b_lane_symbol_locked(const u8 link_status[DP_LINK_STATUS_SIZE],
176 for (lane = 0; lane < lane_count; lane++) {
177 lane_status = dp_get_lane_status(link_status, lane);
178 if (!(lane_status & DP_LANE_SYMBOL_LOCKED))
183 EXPORT_SYMBOL(drm_dp_128b132b_lane_symbol_locked);
185 /* DP 2.0 errata for 128b/132b */
186 bool drm_dp_128b132b_eq_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE])
188 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED);
190 return status & DP_128B132B_DPRX_EQ_INTERLANE_ALIGN_DONE;
192 EXPORT_SYMBOL(drm_dp_128b132b_eq_interlane_align_done);
194 /* DP 2.0 errata for 128b/132b */
195 bool drm_dp_128b132b_cds_interlane_align_done(const u8 link_status[DP_LINK_STATUS_SIZE])
197 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED);
199 return status & DP_128B132B_DPRX_CDS_INTERLANE_ALIGN_DONE;
201 EXPORT_SYMBOL(drm_dp_128b132b_cds_interlane_align_done);
203 /* DP 2.0 errata for 128b/132b */
204 bool drm_dp_128b132b_link_training_failed(const u8 link_status[DP_LINK_STATUS_SIZE])
206 u8 status = dp_link_status(link_status, DP_LANE_ALIGN_STATUS_UPDATED);
208 return status & DP_128B132B_LT_FAILED;
210 EXPORT_SYMBOL(drm_dp_128b132b_link_training_failed);
212 static int __8b10b_clock_recovery_delay_us(const struct drm_dp_aux *aux, u8 rd_interval)
215 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n",
216 aux->name, rd_interval);
218 if (rd_interval == 0)
221 return rd_interval * 4 * USEC_PER_MSEC;
224 static int __8b10b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval)
227 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x (max 4)\n",
228 aux->name, rd_interval);
230 if (rd_interval == 0)
233 return rd_interval * 4 * USEC_PER_MSEC;
236 static int __128b132b_channel_eq_delay_us(const struct drm_dp_aux *aux, u8 rd_interval)
238 switch (rd_interval) {
240 drm_dbg_kms(aux->drm_dev, "%s: invalid AUX interval 0x%02x\n",
241 aux->name, rd_interval);
243 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_400_US:
245 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_4_MS:
247 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_8_MS:
249 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_12_MS:
251 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_16_MS:
253 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_32_MS:
255 case DP_128B132B_TRAINING_AUX_RD_INTERVAL_64_MS:
261 * The link training delays are different for:
263 * - Clock recovery vs. channel equalization
265 * - 128b/132b vs. 8b/10b
266 * - DPCD rev 1.3 vs. later
268 * Get the correct delay in us, reading DPCD if necessary.
270 static int __read_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
271 enum drm_dp_phy dp_phy, bool uhbr, bool cr)
273 int (*parse)(const struct drm_dp_aux *aux, u8 rd_interval);
275 u8 rd_interval, mask;
277 if (dp_phy == DP_PHY_DPRX) {
282 offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL;
283 mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK;
284 parse = __128b132b_channel_eq_delay_us;
286 if (cr && dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
289 offset = DP_TRAINING_AUX_RD_INTERVAL;
290 mask = DP_TRAINING_AUX_RD_MASK;
292 parse = __8b10b_clock_recovery_delay_us;
294 parse = __8b10b_channel_eq_delay_us;
298 offset = DP_128B132B_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy);
299 mask = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK;
300 parse = __128b132b_channel_eq_delay_us;
305 offset = DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy);
306 mask = DP_TRAINING_AUX_RD_MASK;
307 parse = __8b10b_channel_eq_delay_us;
311 if (offset < DP_RECEIVER_CAP_SIZE) {
312 rd_interval = dpcd[offset];
314 if (drm_dp_dpcd_readb(aux, offset, &rd_interval) != 1) {
315 drm_dbg_kms(aux->drm_dev, "%s: failed rd interval read\n",
317 /* arbitrary default delay */
322 return parse(aux, rd_interval & mask);
325 int drm_dp_read_clock_recovery_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
326 enum drm_dp_phy dp_phy, bool uhbr)
328 return __read_delay(aux, dpcd, dp_phy, uhbr, true);
330 EXPORT_SYMBOL(drm_dp_read_clock_recovery_delay);
332 int drm_dp_read_channel_eq_delay(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
333 enum drm_dp_phy dp_phy, bool uhbr)
335 return __read_delay(aux, dpcd, dp_phy, uhbr, false);
337 EXPORT_SYMBOL(drm_dp_read_channel_eq_delay);
339 /* Per DP 2.0 Errata */
340 int drm_dp_128b132b_read_aux_rd_interval(struct drm_dp_aux *aux)
345 if (drm_dp_dpcd_readb(aux, DP_128B132B_TRAINING_AUX_RD_INTERVAL, &val) != 1) {
346 drm_err(aux->drm_dev, "%s: failed rd interval read\n",
349 val = DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK;
352 unit = (val & DP_128B132B_TRAINING_AUX_RD_INTERVAL_1MS_UNIT) ? 1 : 2;
353 val &= DP_128B132B_TRAINING_AUX_RD_INTERVAL_MASK;
355 return (val + 1) * unit * 1000;
357 EXPORT_SYMBOL(drm_dp_128b132b_read_aux_rd_interval);
359 void drm_dp_link_train_clock_recovery_delay(const struct drm_dp_aux *aux,
360 const u8 dpcd[DP_RECEIVER_CAP_SIZE])
362 u8 rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
363 DP_TRAINING_AUX_RD_MASK;
366 if (dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
369 delay_us = __8b10b_clock_recovery_delay_us(aux, rd_interval);
371 usleep_range(delay_us, delay_us * 2);
373 EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
375 static void __drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
378 int delay_us = __8b10b_channel_eq_delay_us(aux, rd_interval);
380 usleep_range(delay_us, delay_us * 2);
383 void drm_dp_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
384 const u8 dpcd[DP_RECEIVER_CAP_SIZE])
386 __drm_dp_link_train_channel_eq_delay(aux,
387 dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
388 DP_TRAINING_AUX_RD_MASK);
390 EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
392 void drm_dp_lttpr_link_train_clock_recovery_delay(void)
394 usleep_range(100, 200);
396 EXPORT_SYMBOL(drm_dp_lttpr_link_train_clock_recovery_delay);
398 static u8 dp_lttpr_phy_cap(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE], int r)
400 return phy_cap[r - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1];
403 void drm_dp_lttpr_link_train_channel_eq_delay(const struct drm_dp_aux *aux,
404 const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE])
406 u8 interval = dp_lttpr_phy_cap(phy_cap,
407 DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) &
408 DP_TRAINING_AUX_RD_MASK;
410 __drm_dp_link_train_channel_eq_delay(aux, interval);
412 EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay);
414 u8 drm_dp_link_rate_to_bw_code(int link_rate)
418 return DP_LINK_BW_10;
420 return DP_LINK_BW_13_5;
422 return DP_LINK_BW_20;
424 /* Spec says link_bw = link_rate / 0.27Gbps */
425 return link_rate / 27000;
428 EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);
430 int drm_dp_bw_code_to_link_rate(u8 link_bw)
435 case DP_LINK_BW_13_5:
440 /* Spec says link_rate = link_bw * 0.27Gbps */
441 return link_bw * 27000;
444 EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
446 #define AUX_RETRY_INTERVAL 500 /* us */
449 drm_dp_dump_access(const struct drm_dp_aux *aux,
450 u8 request, uint offset, void *buffer, int ret)
452 const char *arrow = request == DP_AUX_NATIVE_READ ? "->" : "<-";
455 drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d) %*ph\n",
456 aux->name, offset, arrow, ret, min(ret, 20), buffer);
458 drm_dbg_dp(aux->drm_dev, "%s: 0x%05x AUX %s (ret=%3d)\n",
459 aux->name, offset, arrow, ret);
465 * The DisplayPort AUX channel is an abstraction to allow generic, driver-
466 * independent access to AUX functionality. Drivers can take advantage of
467 * this by filling in the fields of the drm_dp_aux structure.
469 * Transactions are described using a hardware-independent drm_dp_aux_msg
470 * structure, which is passed into a driver's .transfer() implementation.
471 * Both native and I2C-over-AUX transactions are supported.
474 static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
475 unsigned int offset, void *buffer, size_t size)
477 struct drm_dp_aux_msg msg;
478 unsigned int retry, native_reply;
479 int err = 0, ret = 0;
481 memset(&msg, 0, sizeof(msg));
482 msg.address = offset;
483 msg.request = request;
487 mutex_lock(&aux->hw_mutex);
490 * The specification doesn't give any recommendation on how often to
491 * retry native transactions. We used to retry 7 times like for
492 * aux i2c transactions but real world devices this wasn't
493 * sufficient, bump to 32 which makes Dell 4k monitors happier.
495 for (retry = 0; retry < 32; retry++) {
496 if (ret != 0 && ret != -ETIMEDOUT) {
497 usleep_range(AUX_RETRY_INTERVAL,
498 AUX_RETRY_INTERVAL + 100);
501 ret = aux->transfer(aux, &msg);
503 native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
504 if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
514 * We want the error we return to be the error we received on
515 * the first transaction, since we may get a different error the
522 drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up. First error: %d\n",
527 mutex_unlock(&aux->hw_mutex);
532 * drm_dp_dpcd_probe() - probe a given DPCD address with a 1-byte read access
533 * @aux: DisplayPort AUX channel (SST)
534 * @offset: address of the register to probe
536 * Probe the provided DPCD address by reading 1 byte from it. The function can
537 * be used to trigger some side-effect the read access has, like waking up the
538 * sink, without the need for the read-out value.
540 * Returns 0 if the read access suceeded, or a negative error code on failure.
542 int drm_dp_dpcd_probe(struct drm_dp_aux *aux, unsigned int offset)
547 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, 1);
550 drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, &buffer, ret);
552 return ret < 0 ? ret : 0;
554 EXPORT_SYMBOL(drm_dp_dpcd_probe);
557 * drm_dp_dpcd_read() - read a series of bytes from the DPCD
558 * @aux: DisplayPort AUX channel (SST or MST)
559 * @offset: address of the (first) register to read
560 * @buffer: buffer to store the register values
561 * @size: number of bytes in @buffer
563 * Returns the number of bytes transferred on success, or a negative error
564 * code on failure. -EIO is returned if the request was NAKed by the sink or
565 * if the retry count was exceeded. If not all bytes were transferred, this
566 * function returns -EPROTO. Errors from the underlying AUX channel transfer
567 * function, with the exception of -EBUSY (which causes the transaction to
568 * be retried), are propagated to the caller.
570 ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
571 void *buffer, size_t size)
576 * HP ZR24w corrupts the first DPCD access after entering power save
577 * mode. Eg. on a read, the entire buffer will be filled with the same
578 * byte. Do a throw away read to avoid corrupting anything we care
579 * about. Afterwards things will work correctly until the monitor
580 * gets woken up and subsequently re-enters power save mode.
582 * The user pressing any button on the monitor is enough to wake it
583 * up, so there is no particularly good place to do the workaround.
584 * We just have to do it before any DPCD access and hope that the
585 * monitor doesn't power down exactly after the throw away read.
587 if (!aux->is_remote) {
588 ret = drm_dp_dpcd_probe(aux, DP_DPCD_REV);
594 ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size);
596 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset,
599 drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret);
602 EXPORT_SYMBOL(drm_dp_dpcd_read);
605 * drm_dp_dpcd_write() - write a series of bytes to the DPCD
606 * @aux: DisplayPort AUX channel (SST or MST)
607 * @offset: address of the (first) register to write
608 * @buffer: buffer containing the values to write
609 * @size: number of bytes in @buffer
611 * Returns the number of bytes transferred on success, or a negative error
612 * code on failure. -EIO is returned if the request was NAKed by the sink or
613 * if the retry count was exceeded. If not all bytes were transferred, this
614 * function returns -EPROTO. Errors from the underlying AUX channel transfer
615 * function, with the exception of -EBUSY (which causes the transaction to
616 * be retried), are propagated to the caller.
618 ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
619 void *buffer, size_t size)
624 ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size);
626 ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset,
629 drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret);
632 EXPORT_SYMBOL(drm_dp_dpcd_write);
635 * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207)
636 * @aux: DisplayPort AUX channel
637 * @status: buffer to store the link status in (must be at least 6 bytes)
639 * Returns the number of bytes transferred on success or a negative error
642 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
643 u8 status[DP_LINK_STATUS_SIZE])
645 return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status,
646 DP_LINK_STATUS_SIZE);
648 EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
651 * drm_dp_dpcd_read_phy_link_status - get the link status information for a DP PHY
652 * @aux: DisplayPort AUX channel
653 * @dp_phy: the DP PHY to get the link status for
654 * @link_status: buffer to return the status in
656 * Fetch the AUX DPCD registers for the DPRX or an LTTPR PHY link status. The
657 * layout of the returned @link_status matches the DPCD register layout of the
658 * DPRX PHY link status.
660 * Returns 0 if the information was read successfully or a negative error code
663 int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
664 enum drm_dp_phy dp_phy,
665 u8 link_status[DP_LINK_STATUS_SIZE])
669 if (dp_phy == DP_PHY_DPRX) {
670 ret = drm_dp_dpcd_read(aux,
673 DP_LINK_STATUS_SIZE);
678 WARN_ON(ret != DP_LINK_STATUS_SIZE);
683 ret = drm_dp_dpcd_read(aux,
684 DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy),
686 DP_LINK_STATUS_SIZE - 1);
691 WARN_ON(ret != DP_LINK_STATUS_SIZE - 1);
693 /* Convert the LTTPR to the sink PHY link status layout */
694 memmove(&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS + 1],
695 &link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS],
696 DP_LINK_STATUS_SIZE - (DP_SINK_STATUS - DP_LANE0_1_STATUS) - 1);
697 link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS] = 0;
701 EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status);
703 static bool is_edid_digital_input_dp(const struct edid *edid)
705 return edid && edid->revision >= 4 &&
706 edid->input & DRM_EDID_INPUT_DIGITAL &&
707 (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP;
711 * drm_dp_downstream_is_type() - is the downstream facing port of certain type?
712 * @dpcd: DisplayPort configuration data
713 * @port_cap: port capabilities
714 * @type: port type to be checked. Can be:
715 * %DP_DS_PORT_TYPE_DP, %DP_DS_PORT_TYPE_VGA, %DP_DS_PORT_TYPE_DVI,
716 * %DP_DS_PORT_TYPE_HDMI, %DP_DS_PORT_TYPE_NON_EDID,
717 * %DP_DS_PORT_TYPE_DP_DUALMODE or %DP_DS_PORT_TYPE_WIRELESS.
719 * Caveat: Only works with DPCD 1.1+ port caps.
721 * Returns: whether the downstream facing port matches the type.
723 bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
724 const u8 port_cap[4], u8 type)
726 return drm_dp_is_branch(dpcd) &&
727 dpcd[DP_DPCD_REV] >= 0x11 &&
728 (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type;
730 EXPORT_SYMBOL(drm_dp_downstream_is_type);
733 * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS?
734 * @dpcd: DisplayPort configuration data
735 * @port_cap: port capabilities
738 * Returns: whether the downstream facing port is TMDS (HDMI/DVI).
740 bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
741 const u8 port_cap[4],
742 const struct edid *edid)
744 if (dpcd[DP_DPCD_REV] < 0x11) {
745 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
746 case DP_DWN_STRM_PORT_TYPE_TMDS:
753 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
754 case DP_DS_PORT_TYPE_DP_DUALMODE:
755 if (is_edid_digital_input_dp(edid))
758 case DP_DS_PORT_TYPE_DVI:
759 case DP_DS_PORT_TYPE_HDMI:
765 EXPORT_SYMBOL(drm_dp_downstream_is_tmds);
768 * drm_dp_send_real_edid_checksum() - send back real edid checksum value
769 * @aux: DisplayPort AUX channel
770 * @real_edid_checksum: real edid checksum for the last block
775 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
776 u8 real_edid_checksum)
778 u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0;
780 if (drm_dp_dpcd_read(aux, DP_DEVICE_SERVICE_IRQ_VECTOR,
781 &auto_test_req, 1) < 1) {
782 drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n",
783 aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR);
786 auto_test_req &= DP_AUTOMATED_TEST_REQUEST;
788 if (drm_dp_dpcd_read(aux, DP_TEST_REQUEST, &link_edid_read, 1) < 1) {
789 drm_err(aux->drm_dev, "%s: DPCD failed read at register 0x%x\n",
790 aux->name, DP_TEST_REQUEST);
793 link_edid_read &= DP_TEST_LINK_EDID_READ;
795 if (!auto_test_req || !link_edid_read) {
796 drm_dbg_kms(aux->drm_dev, "%s: Source DUT does not support TEST_EDID_READ\n",
801 if (drm_dp_dpcd_write(aux, DP_DEVICE_SERVICE_IRQ_VECTOR,
802 &auto_test_req, 1) < 1) {
803 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n",
804 aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR);
808 /* send back checksum for the last edid extension block data */
809 if (drm_dp_dpcd_write(aux, DP_TEST_EDID_CHECKSUM,
810 &real_edid_checksum, 1) < 1) {
811 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n",
812 aux->name, DP_TEST_EDID_CHECKSUM);
816 test_resp |= DP_TEST_EDID_CHECKSUM_WRITE;
817 if (drm_dp_dpcd_write(aux, DP_TEST_RESPONSE, &test_resp, 1) < 1) {
818 drm_err(aux->drm_dev, "%s: DPCD failed write at register 0x%x\n",
819 aux->name, DP_TEST_RESPONSE);
825 EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
827 static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
829 u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK;
831 if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4)
837 static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
838 u8 dpcd[DP_RECEIVER_CAP_SIZE])
840 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
844 * Prior to DP1.3 the bit represented by
845 * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
846 * If it is set DP_DPCD_REV at 0000h could be at a value less than
847 * the true capability of the panel. The only way to check is to
848 * then compare 0000h and 2200h.
850 if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
851 DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
854 ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext,
858 if (ret != sizeof(dpcd_ext))
861 if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
862 drm_dbg_kms(aux->drm_dev,
863 "%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n",
864 aux->name, dpcd[DP_DPCD_REV], dpcd_ext[DP_DPCD_REV]);
868 if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
871 drm_dbg_kms(aux->drm_dev, "%s: Base DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
873 memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
879 * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
881 * @aux: DisplayPort AUX channel
882 * @dpcd: Buffer to store the resulting DPCD in
884 * Attempts to read the base DPCD caps for @aux. Additionally, this function
885 * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
888 * Returns: %0 if the DPCD was read successfully, negative error code
891 int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
892 u8 dpcd[DP_RECEIVER_CAP_SIZE])
896 ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
899 if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
902 ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
906 drm_dbg_kms(aux->drm_dev, "%s: DPCD: %*ph\n", aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
910 EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
913 * drm_dp_read_downstream_info() - read DPCD downstream port info if available
914 * @aux: DisplayPort AUX channel
915 * @dpcd: A cached copy of the port's DPCD
916 * @downstream_ports: buffer to store the downstream port info in
919 * drm_dp_downstream_max_clock()
920 * drm_dp_downstream_max_bpc()
922 * Returns: 0 if either the downstream port info was read successfully or
923 * there was no downstream info to read, or a negative error code otherwise.
925 int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
926 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
927 u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS])
932 memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS);
934 /* No downstream info to read */
935 if (!drm_dp_is_branch(dpcd) || dpcd[DP_DPCD_REV] == DP_DPCD_REV_10)
938 /* Some branches advertise having 0 downstream ports, despite also advertising they have a
939 * downstream port present. The DP spec isn't clear on if this is allowed or not, but since
940 * some branches do it we need to handle it regardless.
942 len = drm_dp_downstream_port_count(dpcd);
946 if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE)
949 ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len);
955 drm_dbg_kms(aux->drm_dev, "%s: DPCD DFP: %*ph\n", aux->name, len, downstream_ports);
959 EXPORT_SYMBOL(drm_dp_read_downstream_info);
962 * drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock
963 * @dpcd: DisplayPort configuration data
964 * @port_cap: port capabilities
966 * Returns: Downstream facing port max dot clock in kHz on success,
967 * or 0 if max clock not defined
969 int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
970 const u8 port_cap[4])
972 if (!drm_dp_is_branch(dpcd))
975 if (dpcd[DP_DPCD_REV] < 0x11)
978 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
979 case DP_DS_PORT_TYPE_VGA:
980 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
982 return port_cap[1] * 8000;
987 EXPORT_SYMBOL(drm_dp_downstream_max_dotclock);
990 * drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock
991 * @dpcd: DisplayPort configuration data
992 * @port_cap: port capabilities
995 * Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success,
996 * or 0 if max TMDS clock not defined
998 int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
999 const u8 port_cap[4],
1000 const struct edid *edid)
1002 if (!drm_dp_is_branch(dpcd))
1005 if (dpcd[DP_DPCD_REV] < 0x11) {
1006 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
1007 case DP_DWN_STRM_PORT_TYPE_TMDS:
1014 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1015 case DP_DS_PORT_TYPE_DP_DUALMODE:
1016 if (is_edid_digital_input_dp(edid))
1019 * It's left up to the driver to check the
1020 * DP dual mode adapter's max TMDS clock.
1022 * Unfortunately it looks like branch devices
1023 * may not fordward that the DP dual mode i2c
1024 * access so we just usually get i2c nak :(
1027 case DP_DS_PORT_TYPE_HDMI:
1029 * We should perhaps assume 165 MHz when detailed cap
1030 * info is not available. But looks like many typical
1031 * branch devices fall into that category and so we'd
1032 * probably end up with users complaining that they can't
1033 * get high resolution modes with their favorite dongle.
1035 * So let's limit to 300 MHz instead since DPCD 1.4
1036 * HDMI 2.0 DFPs are required to have the detailed cap
1037 * info. So it's more likely we're dealing with a HDMI 1.4
1038 * compatible* device here.
1040 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
1042 return port_cap[1] * 2500;
1043 case DP_DS_PORT_TYPE_DVI:
1044 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
1046 /* FIXME what to do about DVI dual link? */
1047 return port_cap[1] * 2500;
1052 EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock);
1055 * drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock
1056 * @dpcd: DisplayPort configuration data
1057 * @port_cap: port capabilities
1060 * Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success,
1061 * or 0 if max TMDS clock not defined
1063 int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1064 const u8 port_cap[4],
1065 const struct edid *edid)
1067 if (!drm_dp_is_branch(dpcd))
1070 if (dpcd[DP_DPCD_REV] < 0x11) {
1071 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
1072 case DP_DWN_STRM_PORT_TYPE_TMDS:
1079 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1080 case DP_DS_PORT_TYPE_DP_DUALMODE:
1081 if (is_edid_digital_input_dp(edid))
1084 case DP_DS_PORT_TYPE_DVI:
1085 case DP_DS_PORT_TYPE_HDMI:
1087 * Unclear whether the protocol converter could
1088 * utilize pixel replication. Assume it won't.
1095 EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock);
1098 * drm_dp_downstream_max_bpc() - extract downstream facing port max
1099 * bits per component
1100 * @dpcd: DisplayPort configuration data
1101 * @port_cap: downstream facing port capabilities
1104 * Returns: Max bpc on success or 0 if max bpc not defined
1106 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1107 const u8 port_cap[4],
1108 const struct edid *edid)
1110 if (!drm_dp_is_branch(dpcd))
1113 if (dpcd[DP_DPCD_REV] < 0x11) {
1114 switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
1115 case DP_DWN_STRM_PORT_TYPE_DP:
1122 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1123 case DP_DS_PORT_TYPE_DP:
1125 case DP_DS_PORT_TYPE_DP_DUALMODE:
1126 if (is_edid_digital_input_dp(edid))
1129 case DP_DS_PORT_TYPE_HDMI:
1130 case DP_DS_PORT_TYPE_DVI:
1131 case DP_DS_PORT_TYPE_VGA:
1132 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
1135 switch (port_cap[2] & DP_DS_MAX_BPC_MASK) {
1152 EXPORT_SYMBOL(drm_dp_downstream_max_bpc);
1155 * drm_dp_downstream_420_passthrough() - determine downstream facing port
1156 * YCbCr 4:2:0 pass-through capability
1157 * @dpcd: DisplayPort configuration data
1158 * @port_cap: downstream facing port capabilities
1160 * Returns: whether the downstream facing port can pass through YCbCr 4:2:0
1162 bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1163 const u8 port_cap[4])
1165 if (!drm_dp_is_branch(dpcd))
1168 if (dpcd[DP_DPCD_REV] < 0x13)
1171 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1172 case DP_DS_PORT_TYPE_DP:
1174 case DP_DS_PORT_TYPE_HDMI:
1175 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
1178 return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH;
1183 EXPORT_SYMBOL(drm_dp_downstream_420_passthrough);
1186 * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port
1187 * YCbCr 4:4:4->4:2:0 conversion capability
1188 * @dpcd: DisplayPort configuration data
1189 * @port_cap: downstream facing port capabilities
1191 * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0
1193 bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1194 const u8 port_cap[4])
1196 if (!drm_dp_is_branch(dpcd))
1199 if (dpcd[DP_DPCD_REV] < 0x13)
1202 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1203 case DP_DS_PORT_TYPE_HDMI:
1204 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
1207 return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV;
1212 EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion);
1215 * drm_dp_downstream_rgb_to_ycbcr_conversion() - determine downstream facing port
1216 * RGB->YCbCr conversion capability
1217 * @dpcd: DisplayPort configuration data
1218 * @port_cap: downstream facing port capabilities
1219 * @color_spc: Colorspace for which conversion cap is sought
1221 * Returns: whether the downstream facing port can convert RGB->YCbCr for a given
1224 bool drm_dp_downstream_rgb_to_ycbcr_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1225 const u8 port_cap[4],
1228 if (!drm_dp_is_branch(dpcd))
1231 if (dpcd[DP_DPCD_REV] < 0x13)
1234 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1235 case DP_DS_PORT_TYPE_HDMI:
1236 if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
1239 return port_cap[3] & color_spc;
1244 EXPORT_SYMBOL(drm_dp_downstream_rgb_to_ycbcr_conversion);
1247 * drm_dp_downstream_mode() - return a mode for downstream facing port
1249 * @dpcd: DisplayPort configuration data
1250 * @port_cap: port capabilities
1252 * Provides a suitable mode for downstream facing ports without EDID.
1254 * Returns: A new drm_display_mode on success or NULL on failure
1256 struct drm_display_mode *
1257 drm_dp_downstream_mode(struct drm_device *dev,
1258 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1259 const u8 port_cap[4])
1264 if (!drm_dp_is_branch(dpcd))
1267 if (dpcd[DP_DPCD_REV] < 0x11)
1270 switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
1271 case DP_DS_PORT_TYPE_NON_EDID:
1272 switch (port_cap[0] & DP_DS_NON_EDID_MASK) {
1273 case DP_DS_NON_EDID_720x480i_60:
1276 case DP_DS_NON_EDID_720x480i_50:
1279 case DP_DS_NON_EDID_1920x1080i_60:
1282 case DP_DS_NON_EDID_1920x1080i_50:
1285 case DP_DS_NON_EDID_1280x720_60:
1288 case DP_DS_NON_EDID_1280x720_50:
1294 return drm_display_mode_from_cea_vic(dev, vic);
1299 EXPORT_SYMBOL(drm_dp_downstream_mode);
1302 * drm_dp_downstream_id() - identify branch device
1303 * @aux: DisplayPort AUX channel
1304 * @id: DisplayPort branch device id
1306 * Returns branch device id on success or NULL on failure
1308 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6])
1310 return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6);
1312 EXPORT_SYMBOL(drm_dp_downstream_id);
1315 * drm_dp_downstream_debug() - debug DP branch devices
1316 * @m: pointer for debugfs file
1317 * @dpcd: DisplayPort configuration data
1318 * @port_cap: port capabilities
1320 * @aux: DisplayPort AUX channel
1323 void drm_dp_downstream_debug(struct seq_file *m,
1324 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1325 const u8 port_cap[4],
1326 const struct edid *edid,
1327 struct drm_dp_aux *aux)
1329 bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
1330 DP_DETAILED_CAP_INFO_AVAILABLE;
1336 int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
1337 bool branch_device = drm_dp_is_branch(dpcd);
1339 seq_printf(m, "\tDP branch device present: %s\n",
1340 str_yes_no(branch_device));
1346 case DP_DS_PORT_TYPE_DP:
1347 seq_puts(m, "\t\tType: DisplayPort\n");
1349 case DP_DS_PORT_TYPE_VGA:
1350 seq_puts(m, "\t\tType: VGA\n");
1352 case DP_DS_PORT_TYPE_DVI:
1353 seq_puts(m, "\t\tType: DVI\n");
1355 case DP_DS_PORT_TYPE_HDMI:
1356 seq_puts(m, "\t\tType: HDMI\n");
1358 case DP_DS_PORT_TYPE_NON_EDID:
1359 seq_puts(m, "\t\tType: others without EDID support\n");
1361 case DP_DS_PORT_TYPE_DP_DUALMODE:
1362 seq_puts(m, "\t\tType: DP++\n");
1364 case DP_DS_PORT_TYPE_WIRELESS:
1365 seq_puts(m, "\t\tType: Wireless\n");
1368 seq_puts(m, "\t\tType: N/A\n");
1371 memset(id, 0, sizeof(id));
1372 drm_dp_downstream_id(aux, id);
1373 seq_printf(m, "\t\tID: %s\n", id);
1375 len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1);
1377 seq_printf(m, "\t\tHW: %d.%d\n",
1378 (rev[0] & 0xf0) >> 4, rev[0] & 0xf);
1380 len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, rev, 2);
1382 seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]);
1384 if (detailed_cap_info) {
1385 clk = drm_dp_downstream_max_dotclock(dpcd, port_cap);
1387 seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk);
1389 clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, edid);
1391 seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk);
1393 clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, edid);
1395 seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk);
1397 bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid);
1400 seq_printf(m, "\t\tMax bpc: %d\n", bpc);
1403 EXPORT_SYMBOL(drm_dp_downstream_debug);
1406 * drm_dp_subconnector_type() - get DP branch device type
1407 * @dpcd: DisplayPort configuration data
1408 * @port_cap: port capabilities
1410 enum drm_mode_subconnector
1411 drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1412 const u8 port_cap[4])
1415 if (!drm_dp_is_branch(dpcd))
1416 return DRM_MODE_SUBCONNECTOR_Native;
1417 /* DP 1.0 approach */
1418 if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) {
1419 type = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
1420 DP_DWN_STRM_PORT_TYPE_MASK;
1423 case DP_DWN_STRM_PORT_TYPE_TMDS:
1424 /* Can be HDMI or DVI-D, DVI-D is a safer option */
1425 return DRM_MODE_SUBCONNECTOR_DVID;
1426 case DP_DWN_STRM_PORT_TYPE_ANALOG:
1427 /* Can be VGA or DVI-A, VGA is more popular */
1428 return DRM_MODE_SUBCONNECTOR_VGA;
1429 case DP_DWN_STRM_PORT_TYPE_DP:
1430 return DRM_MODE_SUBCONNECTOR_DisplayPort;
1431 case DP_DWN_STRM_PORT_TYPE_OTHER:
1433 return DRM_MODE_SUBCONNECTOR_Unknown;
1436 type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
1439 case DP_DS_PORT_TYPE_DP:
1440 case DP_DS_PORT_TYPE_DP_DUALMODE:
1441 return DRM_MODE_SUBCONNECTOR_DisplayPort;
1442 case DP_DS_PORT_TYPE_VGA:
1443 return DRM_MODE_SUBCONNECTOR_VGA;
1444 case DP_DS_PORT_TYPE_DVI:
1445 return DRM_MODE_SUBCONNECTOR_DVID;
1446 case DP_DS_PORT_TYPE_HDMI:
1447 return DRM_MODE_SUBCONNECTOR_HDMIA;
1448 case DP_DS_PORT_TYPE_WIRELESS:
1449 return DRM_MODE_SUBCONNECTOR_Wireless;
1450 case DP_DS_PORT_TYPE_NON_EDID:
1452 return DRM_MODE_SUBCONNECTOR_Unknown;
1455 EXPORT_SYMBOL(drm_dp_subconnector_type);
1458 * drm_dp_set_subconnector_property - set subconnector for DP connector
1459 * @connector: connector to set property on
1460 * @status: connector status
1461 * @dpcd: DisplayPort configuration data
1462 * @port_cap: port capabilities
1464 * Called by a driver on every detect event.
1466 void drm_dp_set_subconnector_property(struct drm_connector *connector,
1467 enum drm_connector_status status,
1469 const u8 port_cap[4])
1471 enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown;
1473 if (status == connector_status_connected)
1474 subconnector = drm_dp_subconnector_type(dpcd, port_cap);
1475 drm_object_property_set_value(&connector->base,
1476 connector->dev->mode_config.dp_subconnector_property,
1479 EXPORT_SYMBOL(drm_dp_set_subconnector_property);
1482 * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink
1484 * @connector: The DRM connector to check
1485 * @dpcd: A cached copy of the connector's DPCD RX capabilities
1486 * @desc: A cached copy of the connector's DP descriptor
1488 * See also: drm_dp_read_sink_count()
1490 * Returns: %True if the (e)DP connector has a valid sink count that should
1491 * be probed, %false otherwise.
1493 bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
1494 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
1495 const struct drm_dp_desc *desc)
1497 /* Some eDP panels don't set a valid value for the sink count */
1498 return connector->connector_type != DRM_MODE_CONNECTOR_eDP &&
1499 dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 &&
1500 dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT &&
1501 !drm_dp_has_quirk(desc, DP_DPCD_QUIRK_NO_SINK_COUNT);
1503 EXPORT_SYMBOL(drm_dp_read_sink_count_cap);
1506 * drm_dp_read_sink_count() - Retrieve the sink count for a given sink
1507 * @aux: The DP AUX channel to use
1509 * See also: drm_dp_read_sink_count_cap()
1511 * Returns: The current sink count reported by @aux, or a negative error code
1514 int drm_dp_read_sink_count(struct drm_dp_aux *aux)
1519 ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count);
1525 return DP_GET_SINK_COUNT(count);
1527 EXPORT_SYMBOL(drm_dp_read_sink_count);
1530 * I2C-over-AUX implementation
1533 static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter)
1535 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
1536 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
1537 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
1538 I2C_FUNC_10BIT_ADDR;
1541 static void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg)
1544 * In case of i2c defer or short i2c ack reply to a write,
1545 * we need to switch to WRITE_STATUS_UPDATE to drain the
1546 * rest of the message
1548 if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) {
1549 msg->request &= DP_AUX_I2C_MOT;
1550 msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE;
1554 #define AUX_PRECHARGE_LEN 10 /* 10 to 16 */
1555 #define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */
1556 #define AUX_STOP_LEN 4
1557 #define AUX_CMD_LEN 4
1558 #define AUX_ADDRESS_LEN 20
1559 #define AUX_REPLY_PAD_LEN 4
1560 #define AUX_LENGTH_LEN 8
1563 * Calculate the duration of the AUX request/reply in usec. Gives the
1564 * "best" case estimate, ie. successful while as short as possible.
1566 static int drm_dp_aux_req_duration(const struct drm_dp_aux_msg *msg)
1568 int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN +
1569 AUX_CMD_LEN + AUX_ADDRESS_LEN + AUX_LENGTH_LEN;
1571 if ((msg->request & DP_AUX_I2C_READ) == 0)
1572 len += msg->size * 8;
1577 static int drm_dp_aux_reply_duration(const struct drm_dp_aux_msg *msg)
1579 int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN +
1580 AUX_CMD_LEN + AUX_REPLY_PAD_LEN;
1583 * For read we expect what was asked. For writes there will
1584 * be 0 or 1 data bytes. Assume 0 for the "best" case.
1586 if (msg->request & DP_AUX_I2C_READ)
1587 len += msg->size * 8;
1592 #define I2C_START_LEN 1
1593 #define I2C_STOP_LEN 1
1594 #define I2C_ADDR_LEN 9 /* ADDRESS + R/W + ACK/NACK */
1595 #define I2C_DATA_LEN 9 /* DATA + ACK/NACK */
1598 * Calculate the length of the i2c transfer in usec, assuming
1599 * the i2c bus speed is as specified. Gives the the "worst"
1600 * case estimate, ie. successful while as long as possible.
1601 * Doesn't account the "MOT" bit, and instead assumes each
1602 * message includes a START, ADDRESS and STOP. Neither does it
1603 * account for additional random variables such as clock stretching.
1605 static int drm_dp_i2c_msg_duration(const struct drm_dp_aux_msg *msg,
1608 /* AUX bitrate is 1MHz, i2c bitrate as specified */
1609 return DIV_ROUND_UP((I2C_START_LEN + I2C_ADDR_LEN +
1610 msg->size * I2C_DATA_LEN +
1611 I2C_STOP_LEN) * 1000, i2c_speed_khz);
1615 * Determine how many retries should be attempted to successfully transfer
1616 * the specified message, based on the estimated durations of the
1617 * i2c and AUX transfers.
1619 static int drm_dp_i2c_retry_count(const struct drm_dp_aux_msg *msg,
1622 int aux_time_us = drm_dp_aux_req_duration(msg) +
1623 drm_dp_aux_reply_duration(msg);
1624 int i2c_time_us = drm_dp_i2c_msg_duration(msg, i2c_speed_khz);
1626 return DIV_ROUND_UP(i2c_time_us, aux_time_us + AUX_RETRY_INTERVAL);
1630 * FIXME currently assumes 10 kHz as some real world devices seem
1631 * to require it. We should query/set the speed via DPCD if supported.
1633 static int dp_aux_i2c_speed_khz __read_mostly = 10;
1634 module_param_unsafe(dp_aux_i2c_speed_khz, int, 0644);
1635 MODULE_PARM_DESC(dp_aux_i2c_speed_khz,
1636 "Assumed speed of the i2c bus in kHz, (1-400, default 10)");
1639 * Transfer a single I2C-over-AUX message and handle various error conditions,
1640 * retrying the transaction as appropriate. It is assumed that the
1641 * &drm_dp_aux.transfer function does not modify anything in the msg other than the
1644 * Returns bytes transferred on success, or a negative error code on failure.
1646 static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
1648 unsigned int retry, defer_i2c;
1651 * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device
1652 * is required to retry at least seven times upon receiving AUX_DEFER
1653 * before giving up the AUX transaction.
1655 * We also try to account for the i2c bus speed.
1657 int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
1659 for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
1660 ret = aux->transfer(aux, msg);
1666 * While timeouts can be errors, they're usually normal
1667 * behavior (for instance, when a driver tries to
1668 * communicate with a non-existent DisplayPort device).
1669 * Avoid spamming the kernel log with timeout errors.
1671 if (ret == -ETIMEDOUT)
1672 drm_dbg_kms_ratelimited(aux->drm_dev, "%s: transaction timed out\n",
1675 drm_dbg_kms(aux->drm_dev, "%s: transaction failed: %d\n",
1681 switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) {
1682 case DP_AUX_NATIVE_REPLY_ACK:
1684 * For I2C-over-AUX transactions this isn't enough, we
1685 * need to check for the I2C ACK reply.
1689 case DP_AUX_NATIVE_REPLY_NACK:
1690 drm_dbg_kms(aux->drm_dev, "%s: native nack (result=%d, size=%zu)\n",
1691 aux->name, ret, msg->size);
1694 case DP_AUX_NATIVE_REPLY_DEFER:
1695 drm_dbg_kms(aux->drm_dev, "%s: native defer\n", aux->name);
1697 * We could check for I2C bit rate capabilities and if
1698 * available adjust this interval. We could also be
1699 * more careful with DP-to-legacy adapters where a
1700 * long legacy cable may force very low I2C bit rates.
1702 * For now just defer for long enough to hopefully be
1703 * safe for all use-cases.
1705 usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
1709 drm_err(aux->drm_dev, "%s: invalid native reply %#04x\n",
1710 aux->name, msg->reply);
1714 switch (msg->reply & DP_AUX_I2C_REPLY_MASK) {
1715 case DP_AUX_I2C_REPLY_ACK:
1717 * Both native ACK and I2C ACK replies received. We
1718 * can assume the transfer was successful.
1720 if (ret != msg->size)
1721 drm_dp_i2c_msg_write_status_update(msg);
1724 case DP_AUX_I2C_REPLY_NACK:
1725 drm_dbg_kms(aux->drm_dev, "%s: I2C nack (result=%d, size=%zu)\n",
1726 aux->name, ret, msg->size);
1727 aux->i2c_nack_count++;
1730 case DP_AUX_I2C_REPLY_DEFER:
1731 drm_dbg_kms(aux->drm_dev, "%s: I2C defer\n", aux->name);
1732 /* DP Compliance Test 4.2.2.5 Requirement:
1733 * Must have at least 7 retries for I2C defers on the
1734 * transaction to pass this test
1736 aux->i2c_defer_count++;
1739 usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
1740 drm_dp_i2c_msg_write_status_update(msg);
1745 drm_err(aux->drm_dev, "%s: invalid I2C reply %#04x\n",
1746 aux->name, msg->reply);
1751 drm_dbg_kms(aux->drm_dev, "%s: Too many retries, giving up\n", aux->name);
1755 static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg,
1756 const struct i2c_msg *i2c_msg)
1758 msg->request = (i2c_msg->flags & I2C_M_RD) ?
1759 DP_AUX_I2C_READ : DP_AUX_I2C_WRITE;
1760 if (!(i2c_msg->flags & I2C_M_STOP))
1761 msg->request |= DP_AUX_I2C_MOT;
1765 * Keep retrying drm_dp_i2c_do_msg until all data has been transferred.
1767 * Returns an error code on failure, or a recommended transfer size on success.
1769 static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg)
1771 int err, ret = orig_msg->size;
1772 struct drm_dp_aux_msg msg = *orig_msg;
1774 while (msg.size > 0) {
1775 err = drm_dp_i2c_do_msg(aux, &msg);
1777 return err == 0 ? -EPROTO : err;
1779 if (err < msg.size && err < ret) {
1780 drm_dbg_kms(aux->drm_dev,
1781 "%s: Partial I2C reply: requested %zu bytes got %d bytes\n",
1782 aux->name, msg.size, err);
1794 * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX
1795 * packets to be as large as possible. If not, the I2C transactions never
1796 * succeed. Hence the default is maximum.
1798 static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES;
1799 module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644);
1800 MODULE_PARM_DESC(dp_aux_i2c_transfer_size,
1801 "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)");
1803 static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
1806 struct drm_dp_aux *aux = adapter->algo_data;
1808 unsigned transfer_size;
1809 struct drm_dp_aux_msg msg;
1812 dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES);
1814 memset(&msg, 0, sizeof(msg));
1816 for (i = 0; i < num; i++) {
1817 msg.address = msgs[i].addr;
1818 drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
1819 /* Send a bare address packet to start the transaction.
1820 * Zero sized messages specify an address only (bare
1821 * address) transaction.
1825 err = drm_dp_i2c_do_msg(aux, &msg);
1828 * Reset msg.request in case in case it got
1829 * changed into a WRITE_STATUS_UPDATE.
1831 drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
1835 /* We want each transaction to be as large as possible, but
1836 * we'll go to smaller sizes if the hardware gives us a
1839 transfer_size = dp_aux_i2c_transfer_size;
1840 for (j = 0; j < msgs[i].len; j += msg.size) {
1841 msg.buffer = msgs[i].buf + j;
1842 msg.size = min(transfer_size, msgs[i].len - j);
1844 err = drm_dp_i2c_drain_msg(aux, &msg);
1847 * Reset msg.request in case in case it got
1848 * changed into a WRITE_STATUS_UPDATE.
1850 drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
1854 transfer_size = err;
1861 /* Send a bare address packet to close out the transaction.
1862 * Zero sized messages specify an address only (bare
1863 * address) transaction.
1865 msg.request &= ~DP_AUX_I2C_MOT;
1868 (void)drm_dp_i2c_do_msg(aux, &msg);
1873 static const struct i2c_algorithm drm_dp_i2c_algo = {
1874 .functionality = drm_dp_i2c_functionality,
1875 .master_xfer = drm_dp_i2c_xfer,
1878 static struct drm_dp_aux *i2c_to_aux(struct i2c_adapter *i2c)
1880 return container_of(i2c, struct drm_dp_aux, ddc);
1883 static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
1885 mutex_lock(&i2c_to_aux(i2c)->hw_mutex);
1888 static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
1890 return mutex_trylock(&i2c_to_aux(i2c)->hw_mutex);
1893 static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
1895 mutex_unlock(&i2c_to_aux(i2c)->hw_mutex);
1898 static const struct i2c_lock_operations drm_dp_i2c_lock_ops = {
1899 .lock_bus = lock_bus,
1900 .trylock_bus = trylock_bus,
1901 .unlock_bus = unlock_bus,
1904 static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc)
1909 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
1913 WARN_ON(!(buf & DP_TEST_SINK_START));
1915 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK_MISC, &buf);
1919 count = buf & DP_TEST_COUNT_MASK;
1920 if (count == aux->crc_count)
1921 return -EAGAIN; /* No CRC yet */
1923 aux->crc_count = count;
1926 * At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes
1927 * per component (RGB or CrYCb).
1929 ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6);
1936 static void drm_dp_aux_crc_work(struct work_struct *work)
1938 struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux,
1940 struct drm_crtc *crtc;
1945 if (WARN_ON(!aux->crtc))
1949 while (crtc->crc.opened) {
1950 drm_crtc_wait_one_vblank(crtc);
1951 if (!crtc->crc.opened)
1954 ret = drm_dp_aux_get_crc(aux, crc_bytes);
1955 if (ret == -EAGAIN) {
1956 usleep_range(1000, 2000);
1957 ret = drm_dp_aux_get_crc(aux, crc_bytes);
1960 if (ret == -EAGAIN) {
1961 drm_dbg_kms(aux->drm_dev, "%s: Get CRC failed after retrying: %d\n",
1965 drm_dbg_kms(aux->drm_dev, "%s: Failed to get a CRC: %d\n", aux->name, ret);
1969 crcs[0] = crc_bytes[0] | crc_bytes[1] << 8;
1970 crcs[1] = crc_bytes[2] | crc_bytes[3] << 8;
1971 crcs[2] = crc_bytes[4] | crc_bytes[5] << 8;
1972 drm_crtc_add_crc_entry(crtc, false, 0, crcs);
1977 * drm_dp_remote_aux_init() - minimally initialise a remote aux channel
1978 * @aux: DisplayPort AUX channel
1980 * Used for remote aux channel in general. Merely initialize the crc work
1983 void drm_dp_remote_aux_init(struct drm_dp_aux *aux)
1985 INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);
1987 EXPORT_SYMBOL(drm_dp_remote_aux_init);
1990 * drm_dp_aux_init() - minimally initialise an aux channel
1991 * @aux: DisplayPort AUX channel
1993 * If you need to use the drm_dp_aux's i2c adapter prior to registering it with
1994 * the outside world, call drm_dp_aux_init() first. For drivers which are
1995 * grandparents to their AUX adapters (e.g. the AUX adapter is parented by a
1996 * &drm_connector), you must still call drm_dp_aux_register() once the connector
1997 * has been registered to allow userspace access to the auxiliary DP channel.
1998 * Likewise, for such drivers you should also assign &drm_dp_aux.drm_dev as
1999 * early as possible so that the &drm_device that corresponds to the AUX adapter
2000 * may be mentioned in debugging output from the DRM DP helpers.
2002 * For devices which use a separate platform device for their AUX adapters, this
2003 * may be called as early as required by the driver.
2006 void drm_dp_aux_init(struct drm_dp_aux *aux)
2008 mutex_init(&aux->hw_mutex);
2009 mutex_init(&aux->cec.lock);
2010 INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);
2012 aux->ddc.algo = &drm_dp_i2c_algo;
2013 aux->ddc.algo_data = aux;
2014 aux->ddc.retries = 3;
2016 aux->ddc.lock_ops = &drm_dp_i2c_lock_ops;
2018 EXPORT_SYMBOL(drm_dp_aux_init);
2021 * drm_dp_aux_register() - initialise and register aux channel
2022 * @aux: DisplayPort AUX channel
2024 * Automatically calls drm_dp_aux_init() if this hasn't been done yet. This
2025 * should only be called once the parent of @aux, &drm_dp_aux.dev, is
2026 * initialized. For devices which are grandparents of their AUX channels,
2027 * &drm_dp_aux.dev will typically be the &drm_connector &device which
2028 * corresponds to @aux. For these devices, it's advised to call
2029 * drm_dp_aux_register() in &drm_connector_funcs.late_register, and likewise to
2030 * call drm_dp_aux_unregister() in &drm_connector_funcs.early_unregister.
2031 * Functions which don't follow this will likely Oops when
2032 * %CONFIG_DRM_DP_AUX_CHARDEV is enabled.
2034 * For devices where the AUX channel is a device that exists independently of
2035 * the &drm_device that uses it, such as SoCs and bridge devices, it is
2036 * recommended to call drm_dp_aux_register() after a &drm_device has been
2037 * assigned to &drm_dp_aux.drm_dev, and likewise to call
2038 * drm_dp_aux_unregister() once the &drm_device should no longer be associated
2039 * with the AUX channel (e.g. on bridge detach).
2041 * Drivers which need to use the aux channel before either of the two points
2042 * mentioned above need to call drm_dp_aux_init() in order to use the AUX
2043 * channel before registration.
2045 * Returns 0 on success or a negative error code on failure.
2047 int drm_dp_aux_register(struct drm_dp_aux *aux)
2051 WARN_ON_ONCE(!aux->drm_dev);
2054 drm_dp_aux_init(aux);
2056 aux->ddc.class = I2C_CLASS_DDC;
2057 aux->ddc.owner = THIS_MODULE;
2058 aux->ddc.dev.parent = aux->dev;
2060 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2061 sizeof(aux->ddc.name));
2063 ret = drm_dp_aux_register_devnode(aux);
2067 ret = i2c_add_adapter(&aux->ddc);
2069 drm_dp_aux_unregister_devnode(aux);
2075 EXPORT_SYMBOL(drm_dp_aux_register);
2078 * drm_dp_aux_unregister() - unregister an AUX adapter
2079 * @aux: DisplayPort AUX channel
2081 void drm_dp_aux_unregister(struct drm_dp_aux *aux)
2083 drm_dp_aux_unregister_devnode(aux);
2084 i2c_del_adapter(&aux->ddc);
2086 EXPORT_SYMBOL(drm_dp_aux_unregister);
2088 #define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x)
2091 * drm_dp_psr_setup_time() - PSR setup in time usec
2092 * @psr_cap: PSR capabilities from DPCD
2095 * PSR setup time for the panel in microseconds, negative
2096 * error code on failure.
2098 int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE])
2100 static const u16 psr_setup_time_us[] = {
2101 PSR_SETUP_TIME(330),
2102 PSR_SETUP_TIME(275),
2103 PSR_SETUP_TIME(220),
2104 PSR_SETUP_TIME(165),
2105 PSR_SETUP_TIME(110),
2111 i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT;
2112 if (i >= ARRAY_SIZE(psr_setup_time_us))
2115 return psr_setup_time_us[i];
2117 EXPORT_SYMBOL(drm_dp_psr_setup_time);
2119 #undef PSR_SETUP_TIME
2122 * drm_dp_start_crc() - start capture of frame CRCs
2123 * @aux: DisplayPort AUX channel
2124 * @crtc: CRTC displaying the frames whose CRCs are to be captured
2126 * Returns 0 on success or a negative error code on failure.
2128 int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc)
2133 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
2137 ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START);
2143 schedule_work(&aux->crc_work);
2147 EXPORT_SYMBOL(drm_dp_start_crc);
2150 * drm_dp_stop_crc() - stop capture of frame CRCs
2151 * @aux: DisplayPort AUX channel
2153 * Returns 0 on success or a negative error code on failure.
2155 int drm_dp_stop_crc(struct drm_dp_aux *aux)
2160 ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
2164 ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START);
2168 flush_work(&aux->crc_work);
2173 EXPORT_SYMBOL(drm_dp_stop_crc);
2182 #define OUI(first, second, third) { (first), (second), (third) }
2183 #define DEVICE_ID(first, second, third, fourth, fifth, sixth) \
2184 { (first), (second), (third), (fourth), (fifth), (sixth) }
2186 #define DEVICE_ID_ANY DEVICE_ID(0, 0, 0, 0, 0, 0)
2188 static const struct dpcd_quirk dpcd_quirk_list[] = {
2189 /* Analogix 7737 needs reduced M and N at HBR2 link rates */
2190 { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
2191 /* LG LP140WF6-SPM1 eDP panel */
2192 { OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
2193 /* Apple panels need some additional handling to support PSR */
2194 { OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) },
2195 /* CH7511 seems to leave SINK_COUNT zeroed */
2196 { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) },
2197 /* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */
2198 { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) },
2199 /* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */
2200 { OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) },
2206 * Get a bit mask of DPCD quirks for the sink/branch device identified by
2207 * ident. The quirk data is shared but it's up to the drivers to act on the
2210 * For now, only the OUI (first three bytes) is used, but this may be extended
2211 * to device identification string and hardware/firmware revisions later.
2214 drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
2216 const struct dpcd_quirk *quirk;
2219 u8 any_device[] = DEVICE_ID_ANY;
2221 for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) {
2222 quirk = &dpcd_quirk_list[i];
2224 if (quirk->is_branch != is_branch)
2227 if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0)
2230 if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 &&
2231 memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0)
2234 quirks |= quirk->quirks;
2240 #undef DEVICE_ID_ANY
2244 * drm_dp_read_desc - read sink/branch descriptor from DPCD
2245 * @aux: DisplayPort AUX channel
2246 * @desc: Device descriptor to fill from DPCD
2247 * @is_branch: true for branch devices, false for sink devices
2249 * Read DPCD 0x400 (sink) or 0x500 (branch) into @desc. Also debug log the
2252 * Returns 0 on success or a negative error code on failure.
2254 int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
2257 struct drm_dp_dpcd_ident *ident = &desc->ident;
2258 unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI;
2259 int ret, dev_id_len;
2261 ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident));
2265 desc->quirks = drm_dp_get_quirks(ident, is_branch);
2267 dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id));
2269 drm_dbg_kms(aux->drm_dev,
2270 "%s: DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n",
2271 aux->name, is_branch ? "branch" : "sink",
2272 (int)sizeof(ident->oui), ident->oui, dev_id_len,
2273 ident->device_id, ident->hw_rev >> 4, ident->hw_rev & 0xf,
2274 ident->sw_major_rev, ident->sw_minor_rev, desc->quirks);
2278 EXPORT_SYMBOL(drm_dp_read_desc);
2281 * drm_dp_dsc_sink_max_slice_count() - Get the max slice count
2282 * supported by the DSC sink.
2283 * @dsc_dpcd: DSC capabilities from DPCD
2284 * @is_edp: true if its eDP, false for DP
2286 * Read the slice capabilities DPCD register from DSC sink to get
2287 * the maximum slice count supported. This is used to populate
2288 * the DSC parameters in the &struct drm_dsc_config by the driver.
2289 * Driver creates an infoframe using these parameters to populate
2290 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC
2291 * infoframe using the helper function drm_dsc_pps_infoframe_pack()
2294 * Maximum slice count supported by DSC sink or 0 its invalid
2296 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
2299 u8 slice_cap1 = dsc_dpcd[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
2302 /* For eDP, register DSC_SLICE_CAPABILITIES_1 gives slice count */
2303 if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK)
2305 if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK)
2307 if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK)
2310 /* For DP, use values from DSC_SLICE_CAP_1 and DSC_SLICE_CAP2 */
2311 u8 slice_cap2 = dsc_dpcd[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
2313 if (slice_cap2 & DP_DSC_24_PER_DP_DSC_SINK)
2315 if (slice_cap2 & DP_DSC_20_PER_DP_DSC_SINK)
2317 if (slice_cap2 & DP_DSC_16_PER_DP_DSC_SINK)
2319 if (slice_cap1 & DP_DSC_12_PER_DP_DSC_SINK)
2321 if (slice_cap1 & DP_DSC_10_PER_DP_DSC_SINK)
2323 if (slice_cap1 & DP_DSC_8_PER_DP_DSC_SINK)
2325 if (slice_cap1 & DP_DSC_6_PER_DP_DSC_SINK)
2327 if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK)
2329 if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK)
2331 if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK)
2337 EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count);
2340 * drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits
2341 * @dsc_dpcd: DSC capabilities from DPCD
2343 * Read the DSC DPCD register to parse the line buffer depth in bits which is
2344 * number of bits of precision within the decoder line buffer supported by
2345 * the DSC sink. This is used to populate the DSC parameters in the
2346 * &struct drm_dsc_config by the driver.
2347 * Driver creates an infoframe using these parameters to populate
2348 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC
2349 * infoframe using the helper function drm_dsc_pps_infoframe_pack()
2352 * Line buffer depth supported by DSC panel or 0 its invalid
2354 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
2356 u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT];
2358 switch (line_buf_depth & DP_DSC_LINE_BUF_BIT_DEPTH_MASK) {
2359 case DP_DSC_LINE_BUF_BIT_DEPTH_9:
2361 case DP_DSC_LINE_BUF_BIT_DEPTH_10:
2363 case DP_DSC_LINE_BUF_BIT_DEPTH_11:
2365 case DP_DSC_LINE_BUF_BIT_DEPTH_12:
2367 case DP_DSC_LINE_BUF_BIT_DEPTH_13:
2369 case DP_DSC_LINE_BUF_BIT_DEPTH_14:
2371 case DP_DSC_LINE_BUF_BIT_DEPTH_15:
2373 case DP_DSC_LINE_BUF_BIT_DEPTH_16:
2375 case DP_DSC_LINE_BUF_BIT_DEPTH_8:
2381 EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth);
2384 * drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component
2385 * values supported by the DSC sink.
2386 * @dsc_dpcd: DSC capabilities from DPCD
2387 * @dsc_bpc: An array to be filled by this helper with supported
2390 * Read the DSC DPCD from the sink device to parse the supported bits per
2391 * component values. This is used to populate the DSC parameters
2392 * in the &struct drm_dsc_config by the driver.
2393 * Driver creates an infoframe using these parameters to populate
2394 * &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC
2395 * infoframe using the helper function drm_dsc_pps_infoframe_pack()
2398 * Number of input BPC values parsed from the DPCD
2400 int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
2404 u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
2406 if (color_depth & DP_DSC_12_BPC)
2407 dsc_bpc[num_bpc++] = 12;
2408 if (color_depth & DP_DSC_10_BPC)
2409 dsc_bpc[num_bpc++] = 10;
2410 if (color_depth & DP_DSC_8_BPC)
2411 dsc_bpc[num_bpc++] = 8;
2415 EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs);
2417 static int drm_dp_read_lttpr_regs(struct drm_dp_aux *aux,
2418 const u8 dpcd[DP_RECEIVER_CAP_SIZE], int address,
2419 u8 *buf, int buf_size)
2422 * At least the DELL P2715Q monitor with a DPCD_REV < 0x14 returns
2423 * corrupted values when reading from the 0xF0000- range with a block
2424 * size bigger than 1.
2426 int block_size = dpcd[DP_DPCD_REV] < 0x14 ? 1 : buf_size;
2430 for (offset = 0; offset < buf_size; offset += block_size) {
2431 ret = drm_dp_dpcd_read(aux,
2433 &buf[offset], block_size);
2437 WARN_ON(ret != block_size);
2444 * drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities
2445 * @aux: DisplayPort AUX channel
2446 * @dpcd: DisplayPort configuration data
2447 * @caps: buffer to return the capability info in
2449 * Read capabilities common to all LTTPRs.
2451 * Returns 0 on success or a negative error code on failure.
2453 int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
2454 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
2455 u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
2457 return drm_dp_read_lttpr_regs(aux, dpcd,
2458 DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV,
2459 caps, DP_LTTPR_COMMON_CAP_SIZE);
2461 EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps);
2464 * drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY
2465 * @aux: DisplayPort AUX channel
2466 * @dpcd: DisplayPort configuration data
2467 * @dp_phy: LTTPR PHY to read the capabilities for
2468 * @caps: buffer to return the capability info in
2470 * Read the capabilities for the given LTTPR PHY.
2472 * Returns 0 on success or a negative error code on failure.
2474 int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
2475 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
2476 enum drm_dp_phy dp_phy,
2477 u8 caps[DP_LTTPR_PHY_CAP_SIZE])
2479 return drm_dp_read_lttpr_regs(aux, dpcd,
2480 DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy),
2481 caps, DP_LTTPR_PHY_CAP_SIZE);
2483 EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps);
2485 static u8 dp_lttpr_common_cap(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE], int r)
2487 return caps[r - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV];
2491 * drm_dp_lttpr_count - get the number of detected LTTPRs
2492 * @caps: LTTPR common capabilities
2494 * Get the number of detected LTTPRs from the LTTPR common capabilities info.
2497 * -ERANGE if more than supported number (8) of LTTPRs are detected
2498 * -EINVAL if the DP_PHY_REPEATER_CNT register contains an invalid value
2499 * otherwise the number of detected LTTPRs
2501 int drm_dp_lttpr_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
2503 u8 count = dp_lttpr_common_cap(caps, DP_PHY_REPEATER_CNT);
2505 switch (hweight8(count)) {
2509 return 8 - ilog2(count);
2516 EXPORT_SYMBOL(drm_dp_lttpr_count);
2519 * drm_dp_lttpr_max_link_rate - get the maximum link rate supported by all LTTPRs
2520 * @caps: LTTPR common capabilities
2522 * Returns the maximum link rate supported by all detected LTTPRs.
2524 int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
2526 u8 rate = dp_lttpr_common_cap(caps, DP_MAX_LINK_RATE_PHY_REPEATER);
2528 return drm_dp_bw_code_to_link_rate(rate);
2530 EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate);
2533 * drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs
2534 * @caps: LTTPR common capabilities
2536 * Returns the maximum lane count supported by all detected LTTPRs.
2538 int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
2540 u8 max_lanes = dp_lttpr_common_cap(caps, DP_MAX_LANE_COUNT_PHY_REPEATER);
2542 return max_lanes & DP_MAX_LANE_COUNT_MASK;
2544 EXPORT_SYMBOL(drm_dp_lttpr_max_lane_count);
2547 * drm_dp_lttpr_voltage_swing_level_3_supported - check for LTTPR vswing3 support
2548 * @caps: LTTPR PHY capabilities
2550 * Returns true if the @caps for an LTTPR TX PHY indicate support for
2551 * voltage swing level 3.
2554 drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE])
2556 u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1);
2558 return txcap & DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED;
2560 EXPORT_SYMBOL(drm_dp_lttpr_voltage_swing_level_3_supported);
2563 * drm_dp_lttpr_pre_emphasis_level_3_supported - check for LTTPR preemph3 support
2564 * @caps: LTTPR PHY capabilities
2566 * Returns true if the @caps for an LTTPR TX PHY indicate support for
2567 * pre-emphasis level 3.
2570 drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE])
2572 u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1);
2574 return txcap & DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED;
2576 EXPORT_SYMBOL(drm_dp_lttpr_pre_emphasis_level_3_supported);
2579 * drm_dp_get_phy_test_pattern() - get the requested pattern from the sink.
2580 * @aux: DisplayPort AUX channel
2581 * @data: DP phy compliance test parameters.
2583 * Returns 0 on success or a negative error code on failure.
2585 int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
2586 struct drm_dp_phy_test_params *data)
2591 err = drm_dp_dpcd_readb(aux, DP_TEST_LINK_RATE, &rate);
2594 data->link_rate = drm_dp_bw_code_to_link_rate(rate);
2596 err = drm_dp_dpcd_readb(aux, DP_TEST_LANE_COUNT, &lanes);
2599 data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK;
2601 if (lanes & DP_ENHANCED_FRAME_CAP)
2602 data->enhanced_frame_cap = true;
2604 err = drm_dp_dpcd_readb(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern);
2608 switch (data->phy_pattern) {
2609 case DP_PHY_TEST_PATTERN_80BIT_CUSTOM:
2610 err = drm_dp_dpcd_read(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0,
2611 &data->custom80, sizeof(data->custom80));
2616 case DP_PHY_TEST_PATTERN_CP2520:
2617 err = drm_dp_dpcd_read(aux, DP_TEST_HBR2_SCRAMBLER_RESET,
2619 sizeof(data->hbr2_reset));
2626 EXPORT_SYMBOL(drm_dp_get_phy_test_pattern);
2629 * drm_dp_set_phy_test_pattern() - set the pattern to the sink.
2630 * @aux: DisplayPort AUX channel
2631 * @data: DP phy compliance test parameters.
2632 * @dp_rev: DP revision to use for compliance testing
2634 * Returns 0 on success or a negative error code on failure.
2636 int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
2637 struct drm_dp_phy_test_params *data, u8 dp_rev)
2643 link_config[0] = drm_dp_link_rate_to_bw_code(data->link_rate);
2644 link_config[1] = data->num_lanes;
2645 if (data->enhanced_frame_cap)
2646 link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
2647 err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, link_config, 2);
2651 test_pattern = data->phy_pattern;
2652 if (dp_rev < 0x12) {
2653 test_pattern = (test_pattern << 2) &
2654 DP_LINK_QUAL_PATTERN_11_MASK;
2655 err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET,
2660 for (i = 0; i < data->num_lanes; i++) {
2661 err = drm_dp_dpcd_writeb(aux,
2662 DP_LINK_QUAL_LANE0_SET + i,
2671 EXPORT_SYMBOL(drm_dp_set_phy_test_pattern);
2673 static const char *dp_pixelformat_get_name(enum dp_pixelformat pixelformat)
2675 if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED)
2678 switch (pixelformat) {
2679 case DP_PIXELFORMAT_RGB:
2681 case DP_PIXELFORMAT_YUV444:
2683 case DP_PIXELFORMAT_YUV422:
2685 case DP_PIXELFORMAT_YUV420:
2687 case DP_PIXELFORMAT_Y_ONLY:
2689 case DP_PIXELFORMAT_RAW:
2696 static const char *dp_colorimetry_get_name(enum dp_pixelformat pixelformat,
2697 enum dp_colorimetry colorimetry)
2699 if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED)
2702 switch (colorimetry) {
2703 case DP_COLORIMETRY_DEFAULT:
2704 switch (pixelformat) {
2705 case DP_PIXELFORMAT_RGB:
2707 case DP_PIXELFORMAT_YUV444:
2708 case DP_PIXELFORMAT_YUV422:
2709 case DP_PIXELFORMAT_YUV420:
2711 case DP_PIXELFORMAT_Y_ONLY:
2712 return "DICOM PS3.14";
2713 case DP_PIXELFORMAT_RAW:
2714 return "Custom Color Profile";
2718 case DP_COLORIMETRY_RGB_WIDE_FIXED: /* and DP_COLORIMETRY_BT709_YCC */
2719 switch (pixelformat) {
2720 case DP_PIXELFORMAT_RGB:
2721 return "Wide Fixed";
2722 case DP_PIXELFORMAT_YUV444:
2723 case DP_PIXELFORMAT_YUV422:
2724 case DP_PIXELFORMAT_YUV420:
2729 case DP_COLORIMETRY_RGB_WIDE_FLOAT: /* and DP_COLORIMETRY_XVYCC_601 */
2730 switch (pixelformat) {
2731 case DP_PIXELFORMAT_RGB:
2732 return "Wide Float";
2733 case DP_PIXELFORMAT_YUV444:
2734 case DP_PIXELFORMAT_YUV422:
2735 case DP_PIXELFORMAT_YUV420:
2740 case DP_COLORIMETRY_OPRGB: /* and DP_COLORIMETRY_XVYCC_709 */
2741 switch (pixelformat) {
2742 case DP_PIXELFORMAT_RGB:
2744 case DP_PIXELFORMAT_YUV444:
2745 case DP_PIXELFORMAT_YUV422:
2746 case DP_PIXELFORMAT_YUV420:
2751 case DP_COLORIMETRY_DCI_P3_RGB: /* and DP_COLORIMETRY_SYCC_601 */
2752 switch (pixelformat) {
2753 case DP_PIXELFORMAT_RGB:
2755 case DP_PIXELFORMAT_YUV444:
2756 case DP_PIXELFORMAT_YUV422:
2757 case DP_PIXELFORMAT_YUV420:
2762 case DP_COLORIMETRY_RGB_CUSTOM: /* and DP_COLORIMETRY_OPYCC_601 */
2763 switch (pixelformat) {
2764 case DP_PIXELFORMAT_RGB:
2765 return "Custom Profile";
2766 case DP_PIXELFORMAT_YUV444:
2767 case DP_PIXELFORMAT_YUV422:
2768 case DP_PIXELFORMAT_YUV420:
2773 case DP_COLORIMETRY_BT2020_RGB: /* and DP_COLORIMETRY_BT2020_CYCC */
2774 switch (pixelformat) {
2775 case DP_PIXELFORMAT_RGB:
2776 return "BT.2020 RGB";
2777 case DP_PIXELFORMAT_YUV444:
2778 case DP_PIXELFORMAT_YUV422:
2779 case DP_PIXELFORMAT_YUV420:
2780 return "BT.2020 CYCC";
2784 case DP_COLORIMETRY_BT2020_YCC:
2785 switch (pixelformat) {
2786 case DP_PIXELFORMAT_YUV444:
2787 case DP_PIXELFORMAT_YUV422:
2788 case DP_PIXELFORMAT_YUV420:
2789 return "BT.2020 YCC";
2798 static const char *dp_dynamic_range_get_name(enum dp_dynamic_range dynamic_range)
2800 switch (dynamic_range) {
2801 case DP_DYNAMIC_RANGE_VESA:
2802 return "VESA range";
2803 case DP_DYNAMIC_RANGE_CTA:
2810 static const char *dp_content_type_get_name(enum dp_content_type content_type)
2812 switch (content_type) {
2813 case DP_CONTENT_TYPE_NOT_DEFINED:
2814 return "Not defined";
2815 case DP_CONTENT_TYPE_GRAPHICS:
2817 case DP_CONTENT_TYPE_PHOTO:
2819 case DP_CONTENT_TYPE_VIDEO:
2821 case DP_CONTENT_TYPE_GAME:
2828 void drm_dp_vsc_sdp_log(const char *level, struct device *dev,
2829 const struct drm_dp_vsc_sdp *vsc)
2831 #define DP_SDP_LOG(fmt, ...) dev_printk(level, dev, fmt, ##__VA_ARGS__)
2832 DP_SDP_LOG("DP SDP: %s, revision %u, length %u\n", "VSC",
2833 vsc->revision, vsc->length);
2834 DP_SDP_LOG(" pixelformat: %s\n",
2835 dp_pixelformat_get_name(vsc->pixelformat));
2836 DP_SDP_LOG(" colorimetry: %s\n",
2837 dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry));
2838 DP_SDP_LOG(" bpc: %u\n", vsc->bpc);
2839 DP_SDP_LOG(" dynamic range: %s\n",
2840 dp_dynamic_range_get_name(vsc->dynamic_range));
2841 DP_SDP_LOG(" content type: %s\n",
2842 dp_content_type_get_name(vsc->content_type));
2845 EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
2848 * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON
2849 * @dpcd: DisplayPort configuration data
2850 * @port_cap: port capabilities
2852 * Returns maximum frl bandwidth supported by PCON in GBPS,
2853 * returns 0 if not supported.
2855 int drm_dp_get_pcon_max_frl_bw(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
2856 const u8 port_cap[4])
2862 bw = buf & DP_PCON_MAX_FRL_BW;
2865 case DP_PCON_MAX_9GBPS:
2867 case DP_PCON_MAX_18GBPS:
2869 case DP_PCON_MAX_24GBPS:
2871 case DP_PCON_MAX_32GBPS:
2873 case DP_PCON_MAX_40GBPS:
2875 case DP_PCON_MAX_48GBPS:
2877 case DP_PCON_MAX_0GBPS:
2884 EXPORT_SYMBOL(drm_dp_get_pcon_max_frl_bw);
2887 * drm_dp_pcon_frl_prepare() - Prepare PCON for FRL.
2888 * @aux: DisplayPort AUX channel
2889 * @enable_frl_ready_hpd: Configure DP_PCON_ENABLE_HPD_READY.
2891 * Returns 0 if success, else returns negative error code.
2893 int drm_dp_pcon_frl_prepare(struct drm_dp_aux *aux, bool enable_frl_ready_hpd)
2896 u8 buf = DP_PCON_ENABLE_SOURCE_CTL_MODE |
2897 DP_PCON_ENABLE_LINK_FRL_MODE;
2899 if (enable_frl_ready_hpd)
2900 buf |= DP_PCON_ENABLE_HPD_READY;
2902 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf);
2906 EXPORT_SYMBOL(drm_dp_pcon_frl_prepare);
2909 * drm_dp_pcon_is_frl_ready() - Is PCON ready for FRL
2910 * @aux: DisplayPort AUX channel
2912 * Returns true if success, else returns false.
2914 bool drm_dp_pcon_is_frl_ready(struct drm_dp_aux *aux)
2919 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf);
2923 if (buf & DP_PCON_FRL_READY)
2928 EXPORT_SYMBOL(drm_dp_pcon_is_frl_ready);
2931 * drm_dp_pcon_frl_configure_1() - Set HDMI LINK Configuration-Step1
2932 * @aux: DisplayPort AUX channel
2933 * @max_frl_gbps: maximum frl bw to be configured between PCON and HDMI sink
2934 * @frl_mode: FRL Training mode, it can be either Concurrent or Sequential.
2935 * In Concurrent Mode, the FRL link bring up can be done along with
2936 * DP Link training. In Sequential mode, the FRL link bring up is done prior to
2937 * the DP Link training.
2939 * Returns 0 if success, else returns negative error code.
2942 int drm_dp_pcon_frl_configure_1(struct drm_dp_aux *aux, int max_frl_gbps,
2948 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf);
2952 if (frl_mode == DP_PCON_ENABLE_CONCURRENT_LINK)
2953 buf |= DP_PCON_ENABLE_CONCURRENT_LINK;
2955 buf &= ~DP_PCON_ENABLE_CONCURRENT_LINK;
2957 switch (max_frl_gbps) {
2959 buf |= DP_PCON_ENABLE_MAX_BW_9GBPS;
2962 buf |= DP_PCON_ENABLE_MAX_BW_18GBPS;
2965 buf |= DP_PCON_ENABLE_MAX_BW_24GBPS;
2968 buf |= DP_PCON_ENABLE_MAX_BW_32GBPS;
2971 buf |= DP_PCON_ENABLE_MAX_BW_40GBPS;
2974 buf |= DP_PCON_ENABLE_MAX_BW_48GBPS;
2977 buf |= DP_PCON_ENABLE_MAX_BW_0GBPS;
2983 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf);
2989 EXPORT_SYMBOL(drm_dp_pcon_frl_configure_1);
2992 * drm_dp_pcon_frl_configure_2() - Set HDMI Link configuration Step-2
2993 * @aux: DisplayPort AUX channel
2994 * @max_frl_mask : Max FRL BW to be tried by the PCON with HDMI Sink
2995 * @frl_type : FRL training type, can be Extended, or Normal.
2996 * In Normal FRL training, the PCON tries each frl bw from the max_frl_mask
2997 * starting from min, and stops when link training is successful. In Extended
2998 * FRL training, all frl bw selected in the mask are trained by the PCON.
3000 * Returns 0 if success, else returns negative error code.
3002 int drm_dp_pcon_frl_configure_2(struct drm_dp_aux *aux, int max_frl_mask,
3006 u8 buf = max_frl_mask;
3008 if (frl_type == DP_PCON_FRL_LINK_TRAIN_EXTENDED)
3009 buf |= DP_PCON_FRL_LINK_TRAIN_EXTENDED;
3011 buf &= ~DP_PCON_FRL_LINK_TRAIN_EXTENDED;
3013 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_2, buf);
3019 EXPORT_SYMBOL(drm_dp_pcon_frl_configure_2);
3022 * drm_dp_pcon_reset_frl_config() - Re-Set HDMI Link configuration.
3023 * @aux: DisplayPort AUX channel
3025 * Returns 0 if success, else returns negative error code.
3027 int drm_dp_pcon_reset_frl_config(struct drm_dp_aux *aux)
3031 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, 0x0);
3037 EXPORT_SYMBOL(drm_dp_pcon_reset_frl_config);
3040 * drm_dp_pcon_frl_enable() - Enable HDMI link through FRL
3041 * @aux: DisplayPort AUX channel
3043 * Returns 0 if success, else returns negative error code.
3045 int drm_dp_pcon_frl_enable(struct drm_dp_aux *aux)
3050 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_LINK_CONFIG_1, &buf);
3053 if (!(buf & DP_PCON_ENABLE_SOURCE_CTL_MODE)) {
3054 drm_dbg_kms(aux->drm_dev, "%s: PCON in Autonomous mode, can't enable FRL\n",
3058 buf |= DP_PCON_ENABLE_HDMI_LINK;
3059 ret = drm_dp_dpcd_writeb(aux, DP_PCON_HDMI_LINK_CONFIG_1, buf);
3065 EXPORT_SYMBOL(drm_dp_pcon_frl_enable);
3068 * drm_dp_pcon_hdmi_link_active() - check if the PCON HDMI LINK status is active.
3069 * @aux: DisplayPort AUX channel
3071 * Returns true if link is active else returns false.
3073 bool drm_dp_pcon_hdmi_link_active(struct drm_dp_aux *aux)
3078 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_TX_LINK_STATUS, &buf);
3082 return buf & DP_PCON_HDMI_TX_LINK_ACTIVE;
3084 EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_active);
3087 * drm_dp_pcon_hdmi_link_mode() - get the PCON HDMI LINK MODE
3088 * @aux: DisplayPort AUX channel
3089 * @frl_trained_mask: pointer to store bitmask of the trained bw configuration.
3090 * Valid only if the MODE returned is FRL. For Normal Link training mode
3091 * only 1 of the bits will be set, but in case of Extended mode, more than
3092 * one bits can be set.
3094 * Returns the link mode : TMDS or FRL on success, else returns negative error
3097 int drm_dp_pcon_hdmi_link_mode(struct drm_dp_aux *aux, u8 *frl_trained_mask)
3103 ret = drm_dp_dpcd_readb(aux, DP_PCON_HDMI_POST_FRL_STATUS, &buf);
3107 mode = buf & DP_PCON_HDMI_LINK_MODE;
3109 if (frl_trained_mask && DP_PCON_HDMI_MODE_FRL == mode)
3110 *frl_trained_mask = (buf & DP_PCON_HDMI_FRL_TRAINED_BW) >> 1;
3114 EXPORT_SYMBOL(drm_dp_pcon_hdmi_link_mode);
3117 * drm_dp_pcon_hdmi_frl_link_error_count() - print the error count per lane
3118 * during link failure between PCON and HDMI sink
3119 * @aux: DisplayPort AUX channel
3120 * @connector: DRM connector
3124 void drm_dp_pcon_hdmi_frl_link_error_count(struct drm_dp_aux *aux,
3125 struct drm_connector *connector)
3127 u8 buf, error_count;
3129 struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
3131 for (i = 0; i < hdmi->max_lanes; i++) {
3132 if (drm_dp_dpcd_readb(aux, DP_PCON_HDMI_ERROR_STATUS_LN0 + i, &buf) < 0)
3135 error_count = buf & DP_PCON_HDMI_ERROR_COUNT_MASK;
3136 switch (error_count) {
3137 case DP_PCON_HDMI_ERROR_COUNT_HUNDRED_PLUS:
3140 case DP_PCON_HDMI_ERROR_COUNT_TEN_PLUS:
3143 case DP_PCON_HDMI_ERROR_COUNT_THREE_PLUS:
3150 drm_err(aux->drm_dev, "%s: More than %d errors since the last read for lane %d",
3151 aux->name, num_error, i);
3154 EXPORT_SYMBOL(drm_dp_pcon_hdmi_frl_link_error_count);
3157 * drm_dp_pcon_enc_is_dsc_1_2 - Does PCON Encoder supports DSC 1.2
3158 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder
3160 * Returns true is PCON encoder is DSC 1.2 else returns false.
3162 bool drm_dp_pcon_enc_is_dsc_1_2(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE])
3165 u8 major_v, minor_v;
3167 buf = pcon_dsc_dpcd[DP_PCON_DSC_VERSION - DP_PCON_DSC_ENCODER];
3168 major_v = (buf & DP_PCON_DSC_MAJOR_MASK) >> DP_PCON_DSC_MAJOR_SHIFT;
3169 minor_v = (buf & DP_PCON_DSC_MINOR_MASK) >> DP_PCON_DSC_MINOR_SHIFT;
3171 if (major_v == 1 && minor_v == 2)
3176 EXPORT_SYMBOL(drm_dp_pcon_enc_is_dsc_1_2);
3179 * drm_dp_pcon_dsc_max_slices - Get max slices supported by PCON DSC Encoder
3180 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder
3182 * Returns maximum no. of slices supported by the PCON DSC Encoder.
3184 int drm_dp_pcon_dsc_max_slices(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE])
3186 u8 slice_cap1, slice_cap2;
3188 slice_cap1 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_1 - DP_PCON_DSC_ENCODER];
3189 slice_cap2 = pcon_dsc_dpcd[DP_PCON_DSC_SLICE_CAP_2 - DP_PCON_DSC_ENCODER];
3191 if (slice_cap2 & DP_PCON_DSC_24_PER_DSC_ENC)
3193 if (slice_cap2 & DP_PCON_DSC_20_PER_DSC_ENC)
3195 if (slice_cap2 & DP_PCON_DSC_16_PER_DSC_ENC)
3197 if (slice_cap1 & DP_PCON_DSC_12_PER_DSC_ENC)
3199 if (slice_cap1 & DP_PCON_DSC_10_PER_DSC_ENC)
3201 if (slice_cap1 & DP_PCON_DSC_8_PER_DSC_ENC)
3203 if (slice_cap1 & DP_PCON_DSC_6_PER_DSC_ENC)
3205 if (slice_cap1 & DP_PCON_DSC_4_PER_DSC_ENC)
3207 if (slice_cap1 & DP_PCON_DSC_2_PER_DSC_ENC)
3209 if (slice_cap1 & DP_PCON_DSC_1_PER_DSC_ENC)
3214 EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slices);
3217 * drm_dp_pcon_dsc_max_slice_width() - Get max slice width for Pcon DSC encoder
3218 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder
3220 * Returns maximum width of the slices in pixel width i.e. no. of pixels x 320.
3222 int drm_dp_pcon_dsc_max_slice_width(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE])
3226 buf = pcon_dsc_dpcd[DP_PCON_DSC_MAX_SLICE_WIDTH - DP_PCON_DSC_ENCODER];
3228 return buf * DP_DSC_SLICE_WIDTH_MULTIPLIER;
3230 EXPORT_SYMBOL(drm_dp_pcon_dsc_max_slice_width);
3233 * drm_dp_pcon_dsc_bpp_incr() - Get bits per pixel increment for PCON DSC encoder
3234 * @pcon_dsc_dpcd: DSC capabilities of the PCON DSC Encoder
3236 * Returns the bpp precision supported by the PCON encoder.
3238 int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE])
3242 buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER];
3244 switch (buf & DP_PCON_DSC_BPP_INCR_MASK) {
3245 case DP_PCON_DSC_ONE_16TH_BPP:
3247 case DP_PCON_DSC_ONE_8TH_BPP:
3249 case DP_PCON_DSC_ONE_4TH_BPP:
3251 case DP_PCON_DSC_ONE_HALF_BPP:
3253 case DP_PCON_DSC_ONE_BPP:
3259 EXPORT_SYMBOL(drm_dp_pcon_dsc_bpp_incr);
3262 int drm_dp_pcon_configure_dsc_enc(struct drm_dp_aux *aux, u8 pps_buf_config)
3267 ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf);
3271 buf |= DP_PCON_ENABLE_DSC_ENCODER;
3273 if (pps_buf_config <= DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER) {
3274 buf &= ~DP_PCON_ENCODER_PPS_OVERRIDE_MASK;
3275 buf |= pps_buf_config << 2;
3278 ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf);
3286 * drm_dp_pcon_pps_default() - Let PCON fill the default pps parameters
3287 * for DSC1.2 between PCON & HDMI2.1 sink
3288 * @aux: DisplayPort AUX channel
3290 * Returns 0 on success, else returns negative error code.
3292 int drm_dp_pcon_pps_default(struct drm_dp_aux *aux)
3296 ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_DISABLED);
3302 EXPORT_SYMBOL(drm_dp_pcon_pps_default);
3305 * drm_dp_pcon_pps_override_buf() - Configure PPS encoder override buffer for
3307 * @aux: DisplayPort AUX channel
3308 * @pps_buf: 128 bytes to be written into PPS buffer for HDMI sink by PCON.
3310 * Returns 0 on success, else returns negative error code.
3312 int drm_dp_pcon_pps_override_buf(struct drm_dp_aux *aux, u8 pps_buf[128])
3316 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVERRIDE_BASE, &pps_buf, 128);
3320 ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER);
3326 EXPORT_SYMBOL(drm_dp_pcon_pps_override_buf);
3329 * drm_dp_pcon_pps_override_param() - Write PPS parameters to DSC encoder
3330 * override registers
3331 * @aux: DisplayPort AUX channel
3332 * @pps_param: 3 Parameters (2 Bytes each) : Slice Width, Slice Height,
3335 * Returns 0 on success, else returns negative error code.
3337 int drm_dp_pcon_pps_override_param(struct drm_dp_aux *aux, u8 pps_param[6])
3341 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_HEIGHT, &pps_param[0], 2);
3344 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_SLICE_WIDTH, &pps_param[2], 2);
3347 ret = drm_dp_dpcd_write(aux, DP_PCON_HDMI_PPS_OVRD_BPP, &pps_param[4], 2);
3351 ret = drm_dp_pcon_configure_dsc_enc(aux, DP_PCON_ENC_PPS_OVERRIDE_EN_BUFFER);
3357 EXPORT_SYMBOL(drm_dp_pcon_pps_override_param);
3360 * drm_dp_pcon_convert_rgb_to_ycbcr() - Configure the PCon to convert RGB to Ycbcr
3361 * @aux: displayPort AUX channel
3362 * @color_spc: Color-space/s for which conversion is to be enabled, 0 for disable.
3364 * Returns 0 on success, else returns negative error code.
3366 int drm_dp_pcon_convert_rgb_to_ycbcr(struct drm_dp_aux *aux, u8 color_spc)
3371 ret = drm_dp_dpcd_readb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, &buf);
3375 if (color_spc & DP_CONVERSION_RGB_YCBCR_MASK)
3376 buf |= (color_spc & DP_CONVERSION_RGB_YCBCR_MASK);
3378 buf &= ~DP_CONVERSION_RGB_YCBCR_MASK;
3380 ret = drm_dp_dpcd_writeb(aux, DP_PROTOCOL_CONVERTER_CONTROL_2, buf);
3386 EXPORT_SYMBOL(drm_dp_pcon_convert_rgb_to_ycbcr);
3389 * drm_edp_backlight_set_level() - Set the backlight level of an eDP panel via AUX
3390 * @aux: The DP AUX channel to use
3391 * @bl: Backlight capability info from drm_edp_backlight_init()
3392 * @level: The brightness level to set
3394 * Sets the brightness level of an eDP panel's backlight. Note that the panel's backlight must
3395 * already have been enabled by the driver by calling drm_edp_backlight_enable().
3397 * Returns: %0 on success, negative error code on failure
3399 int drm_edp_backlight_set_level(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
3405 /* The panel uses the PWM for controlling brightness levels */
3409 if (bl->lsb_reg_used) {
3410 buf[0] = (level & 0xff00) >> 8;
3411 buf[1] = (level & 0x00ff);
3416 ret = drm_dp_dpcd_write(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, sizeof(buf));
3417 if (ret != sizeof(buf)) {
3418 drm_err(aux->drm_dev,
3419 "%s: Failed to write aux backlight level: %d\n",
3421 return ret < 0 ? ret : -EIO;
3426 EXPORT_SYMBOL(drm_edp_backlight_set_level);
3429 drm_edp_backlight_set_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
3435 /* This panel uses the EDP_BL_PWR GPIO for enablement */
3436 if (!bl->aux_enable)
3439 ret = drm_dp_dpcd_readb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &buf);
3441 drm_err(aux->drm_dev, "%s: Failed to read eDP display control register: %d\n",
3443 return ret < 0 ? ret : -EIO;
3446 buf |= DP_EDP_BACKLIGHT_ENABLE;
3448 buf &= ~DP_EDP_BACKLIGHT_ENABLE;
3450 ret = drm_dp_dpcd_writeb(aux, DP_EDP_DISPLAY_CONTROL_REGISTER, buf);
3452 drm_err(aux->drm_dev, "%s: Failed to write eDP display control register: %d\n",
3454 return ret < 0 ? ret : -EIO;
3461 * drm_edp_backlight_enable() - Enable an eDP panel's backlight using DPCD
3462 * @aux: The DP AUX channel to use
3463 * @bl: Backlight capability info from drm_edp_backlight_init()
3464 * @level: The initial backlight level to set via AUX, if there is one
3466 * This function handles enabling DPCD backlight controls on a panel over DPCD, while additionally
3467 * restoring any important backlight state such as the given backlight level, the brightness byte
3468 * count, backlight frequency, etc.
3470 * Note that certain panels do not support being enabled or disabled via DPCD, but instead require
3471 * that the driver handle enabling/disabling the panel through implementation-specific means using
3472 * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false,
3473 * this function becomes a no-op, and the driver is expected to handle powering the panel on using
3474 * the EDP_BL_PWR GPIO.
3476 * Returns: %0 on success, negative error code on failure.
3478 int drm_edp_backlight_enable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl,
3485 dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
3487 dpcd_buf = DP_EDP_BACKLIGHT_CONTROL_MODE_PWM;
3489 if (bl->pwmgen_bit_count) {
3490 ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, bl->pwmgen_bit_count);
3492 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n",
3496 if (bl->pwm_freq_pre_divider) {
3497 ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_FREQ_SET, bl->pwm_freq_pre_divider);
3499 drm_dbg_kms(aux->drm_dev,
3500 "%s: Failed to write aux backlight frequency: %d\n",
3503 dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
3506 ret = drm_dp_dpcd_writeb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf);
3508 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux backlight mode: %d\n",
3510 return ret < 0 ? ret : -EIO;
3513 ret = drm_edp_backlight_set_level(aux, bl, level);
3516 ret = drm_edp_backlight_set_enable(aux, bl, true);
3522 EXPORT_SYMBOL(drm_edp_backlight_enable);
3525 * drm_edp_backlight_disable() - Disable an eDP backlight using DPCD, if supported
3526 * @aux: The DP AUX channel to use
3527 * @bl: Backlight capability info from drm_edp_backlight_init()
3529 * This function handles disabling DPCD backlight controls on a panel over AUX.
3531 * Note that certain panels do not support being enabled or disabled via DPCD, but instead require
3532 * that the driver handle enabling/disabling the panel through implementation-specific means using
3533 * the EDP_BL_PWR GPIO. For such panels, &drm_edp_backlight_info.aux_enable will be set to %false,
3534 * this function becomes a no-op, and the driver is expected to handle powering the panel off using
3535 * the EDP_BL_PWR GPIO.
3537 * Returns: %0 on success or no-op, negative error code on failure.
3539 int drm_edp_backlight_disable(struct drm_dp_aux *aux, const struct drm_edp_backlight_info *bl)
3543 ret = drm_edp_backlight_set_enable(aux, bl, false);
3549 EXPORT_SYMBOL(drm_edp_backlight_disable);
3552 drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
3553 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE])
3555 int fxp, fxp_min, fxp_max, fxp_actual, f = 1;
3557 u8 pn, pn_min, pn_max;
3562 ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT, &pn);
3564 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap: %d\n",
3569 pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
3570 bl->max = (1 << pn) - 1;
3571 if (!driver_pwm_freq_hz)
3575 * Set PWM Frequency divider to match desired frequency provided by the driver.
3576 * The PWM Frequency is calculated as 27Mhz / (F x P).
3577 * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the
3578 * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
3579 * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the
3580 * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
3583 /* Find desired value of (F x P)
3584 * Note that, if F x P is out of supported range, the maximum value or minimum value will
3585 * applied automatically. So no need to check that.
3587 fxp = DIV_ROUND_CLOSEST(1000 * DP_EDP_BACKLIGHT_FREQ_BASE_KHZ, driver_pwm_freq_hz);
3589 /* Use highest possible value of Pn for more granularity of brightness adjustment while
3590 * satisfying the conditions below.
3591 * - Pn is in the range of Pn_min and Pn_max
3592 * - F is in the range of 1 and 255
3593 * - FxP is within 25% of desired value.
3594 * Note: 25% is arbitrary value and may need some tweak.
3596 ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min);
3598 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap min: %d\n",
3602 ret = drm_dp_dpcd_readb(aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max);
3604 drm_dbg_kms(aux->drm_dev, "%s: Failed to read pwmgen bit count cap max: %d\n",
3608 pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
3609 pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
3611 /* Ensure frequency is within 25% of desired value */
3612 fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
3613 fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
3614 if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) {
3615 drm_dbg_kms(aux->drm_dev,
3616 "%s: Driver defined backlight frequency (%d) out of range\n",
3617 aux->name, driver_pwm_freq_hz);
3621 for (pn = pn_max; pn >= pn_min; pn--) {
3622 f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
3623 fxp_actual = f << pn;
3624 if (fxp_min <= fxp_actual && fxp_actual <= fxp_max)
3628 ret = drm_dp_dpcd_writeb(aux, DP_EDP_PWMGEN_BIT_COUNT, pn);
3630 drm_dbg_kms(aux->drm_dev, "%s: Failed to write aux pwmgen bit count: %d\n",
3634 bl->pwmgen_bit_count = pn;
3635 bl->max = (1 << pn) - 1;
3637 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) {
3638 bl->pwm_freq_pre_divider = f;
3639 drm_dbg_kms(aux->drm_dev, "%s: Using backlight frequency from driver (%dHz)\n",
3640 aux->name, driver_pwm_freq_hz);
3647 drm_edp_backlight_probe_state(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
3654 ret = drm_dp_dpcd_readb(aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &mode_reg);
3656 drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight mode: %d\n",
3658 return ret < 0 ? ret : -EIO;
3661 *current_mode = (mode_reg & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK);
3665 if (*current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
3666 int size = 1 + bl->lsb_reg_used;
3668 ret = drm_dp_dpcd_read(aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, buf, size);
3670 drm_dbg_kms(aux->drm_dev, "%s: Failed to read backlight level: %d\n",
3672 return ret < 0 ? ret : -EIO;
3675 if (bl->lsb_reg_used)
3676 return (buf[0] << 8) | buf[1];
3682 * If we're not in DPCD control mode yet, the programmed brightness value is meaningless and
3683 * the driver should assume max brightness
3689 * drm_edp_backlight_init() - Probe a display panel's TCON using the standard VESA eDP backlight
3691 * @aux: The DP aux device to use for probing
3692 * @bl: The &drm_edp_backlight_info struct to fill out with information on the backlight
3693 * @driver_pwm_freq_hz: Optional PWM frequency from the driver in hz
3694 * @edp_dpcd: A cached copy of the eDP DPCD
3695 * @current_level: Where to store the probed brightness level, if any
3696 * @current_mode: Where to store the currently set backlight control mode
3698 * Initializes a &drm_edp_backlight_info struct by probing @aux for it's backlight capabilities,
3699 * along with also probing the current and maximum supported brightness levels.
3701 * If @driver_pwm_freq_hz is non-zero, this will be used as the backlight frequency. Otherwise, the
3702 * default frequency from the panel is used.
3704 * Returns: %0 on success, negative error code on failure.
3707 drm_edp_backlight_init(struct drm_dp_aux *aux, struct drm_edp_backlight_info *bl,
3708 u16 driver_pwm_freq_hz, const u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE],
3709 u16 *current_level, u8 *current_mode)
3713 if (edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)
3714 bl->aux_enable = true;
3715 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)
3717 if (edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
3718 bl->lsb_reg_used = true;
3720 /* Sanity check caps */
3721 if (!bl->aux_set && !(edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) {
3722 drm_dbg_kms(aux->drm_dev,
3723 "%s: Panel supports neither AUX or PWM brightness control? Aborting\n",
3728 ret = drm_edp_backlight_probe_max(aux, bl, driver_pwm_freq_hz, edp_dpcd);
3732 ret = drm_edp_backlight_probe_state(aux, bl, current_mode);
3735 *current_level = ret;
3737 drm_dbg_kms(aux->drm_dev,
3738 "%s: Found backlight: aux_set=%d aux_enable=%d mode=%d\n",
3739 aux->name, bl->aux_set, bl->aux_enable, *current_mode);
3741 drm_dbg_kms(aux->drm_dev,
3742 "%s: Backlight caps: level=%d/%d pwm_freq_pre_divider=%d lsb_reg_used=%d\n",
3743 aux->name, *current_level, bl->max, bl->pwm_freq_pre_divider,
3749 EXPORT_SYMBOL(drm_edp_backlight_init);
3751 #if IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
3752 (IS_MODULE(CONFIG_DRM_KMS_HELPER) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE))
3754 static int dp_aux_backlight_update_status(struct backlight_device *bd)
3756 struct dp_aux_backlight *bl = bl_get_data(bd);
3757 u16 brightness = backlight_get_brightness(bd);
3760 if (!backlight_is_blank(bd)) {
3762 drm_edp_backlight_enable(bl->aux, &bl->info, brightness);
3766 ret = drm_edp_backlight_set_level(bl->aux, &bl->info, brightness);
3769 drm_edp_backlight_disable(bl->aux, &bl->info);
3770 bl->enabled = false;
3777 static const struct backlight_ops dp_aux_bl_ops = {
3778 .update_status = dp_aux_backlight_update_status,
3782 * drm_panel_dp_aux_backlight - create and use DP AUX backlight
3784 * @aux: The DP AUX channel to use
3786 * Use this function to create and handle backlight if your panel
3787 * supports backlight control over DP AUX channel using DPCD
3788 * registers as per VESA's standard backlight control interface.
3790 * When the panel is enabled backlight will be enabled after a
3791 * successful call to &drm_panel_funcs.enable()
3793 * When the panel is disabled backlight will be disabled before the
3794 * call to &drm_panel_funcs.disable().
3796 * A typical implementation for a panel driver supporting backlight
3797 * control over DP AUX will call this function at probe time.
3798 * Backlight will then be handled transparently without requiring
3799 * any intervention from the driver.
3801 * drm_panel_dp_aux_backlight() must be called after the call to drm_panel_init().
3803 * Return: 0 on success or a negative error code on failure.
3805 int drm_panel_dp_aux_backlight(struct drm_panel *panel, struct drm_dp_aux *aux)
3807 struct dp_aux_backlight *bl;
3808 struct backlight_properties props = { 0 };
3811 u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
3814 if (!panel || !panel->dev || !aux)
3817 ret = drm_dp_dpcd_read(aux, DP_EDP_DPCD_REV, edp_dpcd,
3818 EDP_DISPLAY_CTL_CAP_SIZE);
3822 if (!drm_edp_backlight_supported(edp_dpcd)) {
3823 DRM_DEV_INFO(panel->dev, "DP AUX backlight is not supported\n");
3827 bl = devm_kzalloc(panel->dev, sizeof(*bl), GFP_KERNEL);
3833 ret = drm_edp_backlight_init(aux, &bl->info, 0, edp_dpcd,
3834 ¤t_level, ¤t_mode);
3838 props.type = BACKLIGHT_RAW;
3839 props.brightness = current_level;
3840 props.max_brightness = bl->info.max;
3842 bl->base = devm_backlight_device_register(panel->dev, "dp_aux_backlight",
3844 &dp_aux_bl_ops, &props);
3845 if (IS_ERR(bl->base))
3846 return PTR_ERR(bl->base);
3848 backlight_disable(bl->base);
3850 panel->backlight = bl->base;
3854 EXPORT_SYMBOL(drm_panel_dp_aux_backlight);