2 * Copyright (c) 2015, Sony Mobile Communications AB.
3 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 and
7 * only version 2 as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/interrupt.h>
17 #include <linux/mfd/syscon.h>
18 #include <linux/module.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/soc/qcom/smem.h>
26 #include <linux/wait.h>
27 #include <linux/rpmsg.h>
28 #include <linux/rpmsg/qcom_smd.h>
30 #include "rpmsg_internal.h"
33 * The Qualcomm Shared Memory communication solution provides point-to-point
34 * channels for clients to send and receive streaming or packet based data.
36 * Each channel consists of a control item (channel info) and a ring buffer
37 * pair. The channel info carry information related to channel state, flow
38 * control and the offsets within the ring buffer.
40 * All allocated channels are listed in an allocation table, identifying the
41 * pair of items by name, type and remote processor.
43 * Upon creating a new channel the remote processor allocates channel info and
44 * ring buffer items from the smem heap and populate the allocation table. An
45 * interrupt is sent to the other end of the channel and a scan for new
46 * channels should be done. A channel never goes away, it will only change
49 * The remote processor signals it intent for bring up the communication
50 * channel by setting the state of its end of the channel to "opening" and
51 * sends out an interrupt. We detect this change and register a smd device to
52 * consume the channel. Upon finding a consumer we finish the handshake and the
55 * Upon closing a channel, the remote processor will update the state of its
56 * end of the channel and signal us, we will then unregister any attached
57 * device and close our end of the channel.
59 * Devices attached to a channel can use the qcom_smd_send function to push
60 * data to the channel, this is done by copying the data into the tx ring
61 * buffer, updating the pointers in the channel info and signaling the remote
64 * The remote processor does the equivalent when it transfer data and upon
65 * receiving the interrupt we check the channel info for new data and delivers
66 * this to the attached device. If the device is not ready to receive the data
67 * we leave it in the ring buffer for now.
70 struct smd_channel_info;
71 struct smd_channel_info_pair;
72 struct smd_channel_info_word;
73 struct smd_channel_info_word_pair;
75 static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops;
77 #define SMD_ALLOC_TBL_COUNT 2
78 #define SMD_ALLOC_TBL_SIZE 64
81 * This lists the various smem heap items relevant for the allocation table and
82 * smd channel entries.
85 unsigned alloc_tbl_id;
86 unsigned info_base_id;
87 unsigned fifo_base_id;
88 } smem_items[SMD_ALLOC_TBL_COUNT] = {
102 * struct qcom_smd_edge - representing a remote processor
103 * @of_node: of_node handle for information related to this edge
104 * @edge_id: identifier of this edge
105 * @remote_pid: identifier of remote processor
106 * @irq: interrupt for signals on this edge
107 * @ipc_regmap: regmap handle holding the outgoing ipc register
108 * @ipc_offset: offset within @ipc_regmap of the register for ipc
109 * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
110 * @channels: list of all channels detected on this edge
111 * @channels_lock: guard for modifications of @channels
112 * @allocated: array of bitmaps representing already allocated channels
113 * @smem_available: last available amount of smem triggering a channel scan
114 * @scan_work: work item for discovering new channels
115 * @state_work: work item for edge state changes
117 struct qcom_smd_edge {
122 struct device_node *of_node;
128 struct regmap *ipc_regmap;
132 struct list_head channels;
133 spinlock_t channels_lock;
135 DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
137 unsigned smem_available;
139 wait_queue_head_t new_channel_event;
141 struct work_struct scan_work;
142 struct work_struct state_work;
146 * SMD channel states.
148 enum smd_channel_state {
152 SMD_CHANNEL_FLUSHING,
155 SMD_CHANNEL_RESET_OPENING
158 struct qcom_smd_device {
159 struct rpmsg_device rpdev;
161 struct qcom_smd_edge *edge;
164 struct qcom_smd_endpoint {
165 struct rpmsg_endpoint ept;
167 struct qcom_smd_channel *qsch;
170 #define to_smd_device(r) container_of(r, struct qcom_smd_device, rpdev)
171 #define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev)
172 #define to_smd_endpoint(e) container_of(e, struct qcom_smd_endpoint, ept)
175 * struct qcom_smd_channel - smd channel struct
176 * @edge: qcom_smd_edge this channel is living on
177 * @qsdev: reference to a associated smd client device
178 * @name: name of the channel
179 * @state: local state of the channel
180 * @remote_state: remote state of the channel
181 * @info: byte aligned outgoing/incoming channel info
182 * @info_word: word aligned outgoing/incoming channel info
183 * @tx_lock: lock to make writes to the channel mutually exclusive
184 * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
185 * @tx_fifo: pointer to the outgoing ring buffer
186 * @rx_fifo: pointer to the incoming ring buffer
187 * @fifo_size: size of each ring buffer
188 * @bounce_buffer: bounce buffer for reading wrapped packets
189 * @cb: callback function registered for this channel
190 * @recv_lock: guard for rx info modifications and cb pointer
191 * @pkt_size: size of the currently handled packet
192 * @list: lite entry for @channels in qcom_smd_edge
194 struct qcom_smd_channel {
195 struct qcom_smd_edge *edge;
197 struct qcom_smd_endpoint *qsept;
201 enum smd_channel_state state;
202 enum smd_channel_state remote_state;
203 wait_queue_head_t state_change_event;
205 struct smd_channel_info_pair *info;
206 struct smd_channel_info_word_pair *info_word;
209 wait_queue_head_t fblockread_event;
217 spinlock_t recv_lock;
223 struct list_head list;
227 * Format of the smd_info smem items, for byte aligned channels.
229 struct smd_channel_info {
243 struct smd_channel_info_pair {
244 struct smd_channel_info tx;
245 struct smd_channel_info rx;
249 * Format of the smd_info smem items, for word aligned channels.
251 struct smd_channel_info_word {
260 __le32 fBLOCKREADINTR;
265 struct smd_channel_info_word_pair {
266 struct smd_channel_info_word tx;
267 struct smd_channel_info_word rx;
270 #define GET_RX_CHANNEL_FLAG(channel, param) \
272 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
273 channel->info_word ? \
274 le32_to_cpu(channel->info_word->rx.param) : \
275 channel->info->rx.param; \
278 #define GET_RX_CHANNEL_INFO(channel, param) \
280 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
281 le32_to_cpu(channel->info_word ? \
282 channel->info_word->rx.param : \
283 channel->info->rx.param); \
286 #define SET_RX_CHANNEL_FLAG(channel, param, value) \
288 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
289 if (channel->info_word) \
290 channel->info_word->rx.param = cpu_to_le32(value); \
292 channel->info->rx.param = value; \
295 #define SET_RX_CHANNEL_INFO(channel, param, value) \
297 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
298 if (channel->info_word) \
299 channel->info_word->rx.param = cpu_to_le32(value); \
301 channel->info->rx.param = cpu_to_le32(value); \
304 #define GET_TX_CHANNEL_FLAG(channel, param) \
306 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
307 channel->info_word ? \
308 le32_to_cpu(channel->info_word->tx.param) : \
309 channel->info->tx.param; \
312 #define GET_TX_CHANNEL_INFO(channel, param) \
314 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
315 le32_to_cpu(channel->info_word ? \
316 channel->info_word->tx.param : \
317 channel->info->tx.param); \
320 #define SET_TX_CHANNEL_FLAG(channel, param, value) \
322 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
323 if (channel->info_word) \
324 channel->info_word->tx.param = cpu_to_le32(value); \
326 channel->info->tx.param = value; \
329 #define SET_TX_CHANNEL_INFO(channel, param, value) \
331 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
332 if (channel->info_word) \
333 channel->info_word->tx.param = cpu_to_le32(value); \
335 channel->info->tx.param = cpu_to_le32(value); \
339 * struct qcom_smd_alloc_entry - channel allocation entry
340 * @name: channel name
341 * @cid: channel index
342 * @flags: channel flags and edge id
343 * @ref_count: reference count of the channel
345 struct qcom_smd_alloc_entry {
352 #define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
353 #define SMD_CHANNEL_FLAGS_STREAM BIT(8)
354 #define SMD_CHANNEL_FLAGS_PACKET BIT(9)
357 * Each smd packet contains a 20 byte header, with the first 4 being the length
360 #define SMD_PACKET_HEADER_LEN 20
363 * Signal the remote processor associated with 'channel'.
365 static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
367 struct qcom_smd_edge *edge = channel->edge;
369 regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
373 * Initialize the tx channel info
375 static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
377 SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
378 SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
379 SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
380 SET_TX_CHANNEL_FLAG(channel, fCD, 0);
381 SET_TX_CHANNEL_FLAG(channel, fRI, 0);
382 SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
383 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
384 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
385 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
386 SET_TX_CHANNEL_INFO(channel, head, 0);
387 SET_RX_CHANNEL_INFO(channel, tail, 0);
389 qcom_smd_signal_channel(channel);
391 channel->state = SMD_CHANNEL_CLOSED;
392 channel->pkt_size = 0;
396 * Set the callback for a channel, with appropriate locking
398 static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
401 struct rpmsg_endpoint *ept = &channel->qsept->ept;
404 spin_lock_irqsave(&channel->recv_lock, flags);
406 spin_unlock_irqrestore(&channel->recv_lock, flags);
410 * Calculate the amount of data available in the rx fifo
412 static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
417 head = GET_RX_CHANNEL_INFO(channel, head);
418 tail = GET_RX_CHANNEL_INFO(channel, tail);
420 return (head - tail) & (channel->fifo_size - 1);
424 * Set tx channel state and inform the remote processor
426 static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
429 struct qcom_smd_edge *edge = channel->edge;
430 bool is_open = state == SMD_CHANNEL_OPENED;
432 if (channel->state == state)
435 dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state);
437 SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
438 SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
439 SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
441 SET_TX_CHANNEL_INFO(channel, state, state);
442 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
444 channel->state = state;
445 qcom_smd_signal_channel(channel);
449 * Copy count bytes of data using 32bit accesses, if that's required.
451 static void smd_copy_to_fifo(void __iomem *dst,
457 __iowrite32_copy(dst, src, count / sizeof(u32));
459 memcpy_toio(dst, src, count);
464 * Copy count bytes of data using 32bit accesses, if that is required.
466 static void smd_copy_from_fifo(void *dst,
467 const void __iomem *src,
472 __ioread32_copy(dst, src, count / sizeof(u32));
474 memcpy_fromio(dst, src, count);
479 * Read count bytes of data from the rx fifo into buf, but don't advance the
482 static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
483 void *buf, size_t count)
489 word_aligned = channel->info_word;
490 tail = GET_RX_CHANNEL_INFO(channel, tail);
492 len = min_t(size_t, count, channel->fifo_size - tail);
494 smd_copy_from_fifo(buf,
495 channel->rx_fifo + tail,
501 smd_copy_from_fifo(buf + len,
511 * Advance the rx tail by count bytes.
513 static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
518 tail = GET_RX_CHANNEL_INFO(channel, tail);
520 tail &= (channel->fifo_size - 1);
521 SET_RX_CHANNEL_INFO(channel, tail, tail);
525 * Read out a single packet from the rx fifo and deliver it to the device
527 static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
529 struct rpmsg_endpoint *ept = &channel->qsept->ept;
535 tail = GET_RX_CHANNEL_INFO(channel, tail);
537 /* Use bounce buffer if the data wraps */
538 if (tail + channel->pkt_size >= channel->fifo_size) {
539 ptr = channel->bounce_buffer;
540 len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
542 ptr = channel->rx_fifo + tail;
543 len = channel->pkt_size;
546 ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY);
550 /* Only forward the tail if the client consumed the data */
551 qcom_smd_channel_advance(channel, len);
553 channel->pkt_size = 0;
559 * Per channel interrupt handling
561 static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
563 bool need_state_scan = false;
569 /* Handle state changes */
570 remote_state = GET_RX_CHANNEL_INFO(channel, state);
571 if (remote_state != channel->remote_state) {
572 channel->remote_state = remote_state;
573 need_state_scan = true;
575 wake_up_interruptible_all(&channel->state_change_event);
577 /* Indicate that we have seen any state change */
578 SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
580 /* Signal waiting qcom_smd_send() about the interrupt */
581 if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
582 wake_up_interruptible_all(&channel->fblockread_event);
584 /* Don't consume any data until we've opened the channel */
585 if (channel->state != SMD_CHANNEL_OPENED)
588 /* Indicate that we've seen the new data */
589 SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
593 avail = qcom_smd_channel_get_rx_avail(channel);
595 if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
596 qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
597 qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
598 channel->pkt_size = le32_to_cpu(pktlen);
599 } else if (channel->pkt_size && avail >= channel->pkt_size) {
600 ret = qcom_smd_channel_recv_single(channel);
608 /* Indicate that we have seen and updated tail */
609 SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
611 /* Signal the remote that we've consumed the data (if requested) */
612 if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
613 /* Ensure ordering of channel info updates */
616 qcom_smd_signal_channel(channel);
620 return need_state_scan;
624 * The edge interrupts are triggered by the remote processor on state changes,
625 * channel info updates or when new channels are created.
627 static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
629 struct qcom_smd_edge *edge = data;
630 struct qcom_smd_channel *channel;
632 bool kick_scanner = false;
633 bool kick_state = false;
636 * Handle state changes or data on each of the channels on this edge
638 spin_lock(&edge->channels_lock);
639 list_for_each_entry(channel, &edge->channels, list) {
640 spin_lock(&channel->recv_lock);
641 kick_state |= qcom_smd_channel_intr(channel);
642 spin_unlock(&channel->recv_lock);
644 spin_unlock(&edge->channels_lock);
647 * Creating a new channel requires allocating an smem entry, so we only
648 * have to scan if the amount of available space in smem have changed
651 available = qcom_smem_get_free_space(edge->remote_pid);
652 if (available != edge->smem_available) {
653 edge->smem_available = available;
658 schedule_work(&edge->scan_work);
660 schedule_work(&edge->state_work);
666 * Calculate how much space is available in the tx fifo.
668 static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
672 unsigned mask = channel->fifo_size - 1;
674 head = GET_TX_CHANNEL_INFO(channel, head);
675 tail = GET_TX_CHANNEL_INFO(channel, tail);
677 return mask - ((head - tail) & mask);
681 * Write count bytes of data into channel, possibly wrapping in the ring buffer
683 static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
691 word_aligned = channel->info_word;
692 head = GET_TX_CHANNEL_INFO(channel, head);
694 len = min_t(size_t, count, channel->fifo_size - head);
696 smd_copy_to_fifo(channel->tx_fifo + head,
703 smd_copy_to_fifo(channel->tx_fifo,
710 head &= (channel->fifo_size - 1);
711 SET_TX_CHANNEL_INFO(channel, head, head);
717 * qcom_smd_send - write data to smd channel
718 * @channel: channel handle
719 * @data: buffer of data to write
720 * @len: number of bytes to write
722 * This is a blocking write of len bytes into the channel's tx ring buffer and
723 * signal the remote end. It will sleep until there is enough space available
724 * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
727 static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
730 __le32 hdr[5] = { cpu_to_le32(len), };
731 int tlen = sizeof(hdr) + len;
735 /* Word aligned channels only accept word size aligned data */
736 if (channel->info_word && len % 4)
739 /* Reject packets that are too big */
740 if (tlen >= channel->fifo_size)
743 /* Highlight the fact that if we enter the loop below we might sleep */
747 spin_lock_irqsave(&channel->tx_lock, flags);
749 while (qcom_smd_get_tx_avail(channel) < tlen &&
750 channel->state == SMD_CHANNEL_OPENED) {
756 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
758 /* Wait without holding the tx_lock */
759 spin_unlock_irqrestore(&channel->tx_lock, flags);
761 ret = wait_event_interruptible(channel->fblockread_event,
762 qcom_smd_get_tx_avail(channel) >= tlen ||
763 channel->state != SMD_CHANNEL_OPENED);
767 spin_lock_irqsave(&channel->tx_lock, flags);
769 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
772 /* Fail if the channel was closed */
773 if (channel->state != SMD_CHANNEL_OPENED) {
778 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
780 qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
781 qcom_smd_write_fifo(channel, data, len);
783 SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
785 /* Ensure ordering of channel info updates */
788 qcom_smd_signal_channel(channel);
791 spin_unlock_irqrestore(&channel->tx_lock, flags);
797 * Helper for opening a channel
799 static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
802 struct qcom_smd_edge *edge = channel->edge;
807 * Packets are maximum 4k, but reduce if the fifo is smaller
809 bb_size = min(channel->fifo_size, SZ_4K);
810 channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
811 if (!channel->bounce_buffer)
814 qcom_smd_channel_set_callback(channel, cb);
815 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
817 /* Wait for remote to enter opening or opened */
818 ret = wait_event_interruptible_timeout(channel->state_change_event,
819 channel->remote_state == SMD_CHANNEL_OPENING ||
820 channel->remote_state == SMD_CHANNEL_OPENED,
823 dev_err(&edge->dev, "remote side did not enter opening state\n");
824 goto out_close_timeout;
827 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
829 /* Wait for remote to enter opened */
830 ret = wait_event_interruptible_timeout(channel->state_change_event,
831 channel->remote_state == SMD_CHANNEL_OPENED,
834 dev_err(&edge->dev, "remote side did not enter open state\n");
835 goto out_close_timeout;
841 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
846 * Helper for closing and resetting a channel
848 static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
850 qcom_smd_channel_set_callback(channel, NULL);
852 kfree(channel->bounce_buffer);
853 channel->bounce_buffer = NULL;
855 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
856 qcom_smd_channel_reset(channel);
859 static struct qcom_smd_channel *
860 qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
862 struct qcom_smd_channel *channel;
863 struct qcom_smd_channel *ret = NULL;
866 spin_lock_irqsave(&edge->channels_lock, flags);
867 list_for_each_entry(channel, &edge->channels, list) {
868 if (!strcmp(channel->name, name)) {
873 spin_unlock_irqrestore(&edge->channels_lock, flags);
878 static void __ept_release(struct kref *kref)
880 struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
882 kfree(to_smd_endpoint(ept));
885 static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev,
886 rpmsg_rx_cb_t cb, void *priv,
887 struct rpmsg_channel_info chinfo)
889 struct qcom_smd_endpoint *qsept;
890 struct qcom_smd_channel *channel;
891 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
892 struct qcom_smd_edge *edge = qsdev->edge;
893 struct rpmsg_endpoint *ept;
894 const char *name = chinfo.name;
897 /* Wait up to HZ for the channel to appear */
898 ret = wait_event_interruptible_timeout(edge->new_channel_event,
899 (channel = qcom_smd_find_channel(edge, name)) != NULL,
904 if (channel->state != SMD_CHANNEL_CLOSED) {
905 dev_err(&rpdev->dev, "channel %s is busy\n", channel->name);
909 qsept = kzalloc(sizeof(*qsept), GFP_KERNEL);
915 kref_init(&ept->refcount);
920 ept->ops = &qcom_smd_endpoint_ops;
922 channel->qsept = qsept;
923 qsept->qsch = channel;
925 ret = qcom_smd_channel_open(channel, cb);
932 channel->qsept = NULL;
933 kref_put(&ept->refcount, __ept_release);
937 static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept)
939 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
940 struct qcom_smd_channel *ch = qsept->qsch;
942 qcom_smd_channel_close(ch);
944 kref_put(&ept->refcount, __ept_release);
947 static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len)
949 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
951 return __qcom_smd_send(qsept->qsch, data, len, true);
954 static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
956 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
958 return __qcom_smd_send(qsept->qsch, data, len, false);
961 static __poll_t qcom_smd_poll(struct rpmsg_endpoint *ept,
962 struct file *filp, poll_table *wait)
964 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
965 struct qcom_smd_channel *channel = qsept->qsch;
968 poll_wait(filp, &channel->fblockread_event, wait);
970 if (qcom_smd_get_tx_avail(channel) > 20)
971 mask |= EPOLLOUT | EPOLLWRNORM;
977 * Finds the device_node for the smd child interested in this channel.
979 static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
982 struct device_node *child;
987 for_each_available_child_of_node(edge_node, child) {
988 key = "qcom,smd-channels";
989 ret = of_property_read_string(child, key, &name);
993 if (strcmp(name, channel) == 0)
1000 static int qcom_smd_announce_create(struct rpmsg_device *rpdev)
1002 struct qcom_smd_endpoint *qept = to_smd_endpoint(rpdev->ept);
1003 struct qcom_smd_channel *channel = qept->qsch;
1004 unsigned long flags;
1007 spin_lock_irqsave(&channel->recv_lock, flags);
1008 kick_state = qcom_smd_channel_intr(channel);
1009 spin_unlock_irqrestore(&channel->recv_lock, flags);
1012 schedule_work(&channel->edge->state_work);
1017 static const struct rpmsg_device_ops qcom_smd_device_ops = {
1018 .create_ept = qcom_smd_create_ept,
1019 .announce_create = qcom_smd_announce_create,
1022 static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
1023 .destroy_ept = qcom_smd_destroy_ept,
1024 .send = qcom_smd_send,
1025 .trysend = qcom_smd_trysend,
1026 .poll = qcom_smd_poll,
1029 static void qcom_smd_release_device(struct device *dev)
1031 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1032 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
1038 * Create a smd client device for channel that is being opened.
1040 static int qcom_smd_create_device(struct qcom_smd_channel *channel)
1042 struct qcom_smd_device *qsdev;
1043 struct rpmsg_device *rpdev;
1044 struct qcom_smd_edge *edge = channel->edge;
1046 dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
1048 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
1052 /* Link qsdev to our SMD edge */
1055 /* Assign callbacks for rpmsg_device */
1056 qsdev->rpdev.ops = &qcom_smd_device_ops;
1058 /* Assign public information to the rpmsg_device */
1059 rpdev = &qsdev->rpdev;
1060 strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
1061 rpdev->src = RPMSG_ADDR_ANY;
1062 rpdev->dst = RPMSG_ADDR_ANY;
1064 rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
1065 rpdev->dev.parent = &edge->dev;
1066 rpdev->dev.release = qcom_smd_release_device;
1068 return rpmsg_register_device(rpdev);
1071 static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
1073 struct qcom_smd_device *qsdev;
1075 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
1080 qsdev->rpdev.ops = &qcom_smd_device_ops;
1081 qsdev->rpdev.dev.parent = &edge->dev;
1082 qsdev->rpdev.dev.release = qcom_smd_release_device;
1084 return rpmsg_chrdev_register_device(&qsdev->rpdev);
1088 * Allocate the qcom_smd_channel object for a newly found smd channel,
1089 * retrieving and validating the smem items involved.
1091 static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
1092 unsigned smem_info_item,
1093 unsigned smem_fifo_item,
1096 struct qcom_smd_channel *channel;
1103 channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL);
1105 return ERR_PTR(-ENOMEM);
1107 channel->edge = edge;
1108 channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL);
1110 return ERR_PTR(-ENOMEM);
1112 spin_lock_init(&channel->tx_lock);
1113 spin_lock_init(&channel->recv_lock);
1114 init_waitqueue_head(&channel->fblockread_event);
1115 init_waitqueue_head(&channel->state_change_event);
1117 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1119 ret = PTR_ERR(info);
1120 goto free_name_and_channel;
1124 * Use the size of the item to figure out which channel info struct to
1127 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1128 channel->info_word = info;
1129 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1130 channel->info = info;
1133 "channel info of size %zu not supported\n", info_size);
1135 goto free_name_and_channel;
1138 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1139 if (IS_ERR(fifo_base)) {
1140 ret = PTR_ERR(fifo_base);
1141 goto free_name_and_channel;
1144 /* The channel consist of a rx and tx fifo of equal size */
1147 dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1148 name, info_size, fifo_size);
1150 channel->tx_fifo = fifo_base;
1151 channel->rx_fifo = fifo_base + fifo_size;
1152 channel->fifo_size = fifo_size;
1154 qcom_smd_channel_reset(channel);
1158 free_name_and_channel:
1159 devm_kfree(&edge->dev, channel->name);
1160 devm_kfree(&edge->dev, channel);
1162 return ERR_PTR(ret);
1166 * Scans the allocation table for any newly allocated channels, calls
1167 * qcom_smd_create_channel() to create representations of these and add
1168 * them to the edge's list of channels.
1170 static void qcom_channel_scan_worker(struct work_struct *work)
1172 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1173 struct qcom_smd_alloc_entry *alloc_tbl;
1174 struct qcom_smd_alloc_entry *entry;
1175 struct qcom_smd_channel *channel;
1176 unsigned long flags;
1183 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1184 alloc_tbl = qcom_smem_get(edge->remote_pid,
1185 smem_items[tbl].alloc_tbl_id, NULL);
1186 if (IS_ERR(alloc_tbl))
1189 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1190 entry = &alloc_tbl[i];
1191 eflags = le32_to_cpu(entry->flags);
1192 if (test_bit(i, edge->allocated[tbl]))
1195 if (entry->ref_count == 0)
1198 if (!entry->name[0])
1201 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1204 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1207 cid = le32_to_cpu(entry->cid);
1208 info_id = smem_items[tbl].info_base_id + cid;
1209 fifo_id = smem_items[tbl].fifo_base_id + cid;
1211 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1212 if (IS_ERR(channel))
1215 spin_lock_irqsave(&edge->channels_lock, flags);
1216 list_add(&channel->list, &edge->channels);
1217 spin_unlock_irqrestore(&edge->channels_lock, flags);
1219 dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
1220 set_bit(i, edge->allocated[tbl]);
1222 wake_up_interruptible_all(&edge->new_channel_event);
1226 schedule_work(&edge->state_work);
1230 * This per edge worker scans smem for any new channels and register these. It
1231 * then scans all registered channels for state changes that should be handled
1232 * by creating or destroying smd client devices for the registered channels.
1234 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1235 * worker is killed before any channels are deallocated
1237 static void qcom_channel_state_worker(struct work_struct *work)
1239 struct qcom_smd_channel *channel;
1240 struct qcom_smd_edge *edge = container_of(work,
1241 struct qcom_smd_edge,
1243 struct rpmsg_channel_info chinfo;
1244 unsigned remote_state;
1245 unsigned long flags;
1248 * Register a device for any closed channel where the remote processor
1249 * is showing interest in opening the channel.
1251 spin_lock_irqsave(&edge->channels_lock, flags);
1252 list_for_each_entry(channel, &edge->channels, list) {
1253 if (channel->state != SMD_CHANNEL_CLOSED)
1256 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1257 if (remote_state != SMD_CHANNEL_OPENING &&
1258 remote_state != SMD_CHANNEL_OPENED)
1261 if (channel->registered)
1264 spin_unlock_irqrestore(&edge->channels_lock, flags);
1265 qcom_smd_create_device(channel);
1266 channel->registered = true;
1267 spin_lock_irqsave(&edge->channels_lock, flags);
1269 channel->registered = true;
1273 * Unregister the device for any channel that is opened where the
1274 * remote processor is closing the channel.
1276 list_for_each_entry(channel, &edge->channels, list) {
1277 if (channel->state != SMD_CHANNEL_OPENING &&
1278 channel->state != SMD_CHANNEL_OPENED)
1281 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1282 if (remote_state == SMD_CHANNEL_OPENING ||
1283 remote_state == SMD_CHANNEL_OPENED)
1286 spin_unlock_irqrestore(&edge->channels_lock, flags);
1288 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1289 chinfo.src = RPMSG_ADDR_ANY;
1290 chinfo.dst = RPMSG_ADDR_ANY;
1291 rpmsg_unregister_device(&edge->dev, &chinfo);
1292 channel->registered = false;
1293 spin_lock_irqsave(&edge->channels_lock, flags);
1295 spin_unlock_irqrestore(&edge->channels_lock, flags);
1299 * Parses an of_node describing an edge.
1301 static int qcom_smd_parse_edge(struct device *dev,
1302 struct device_node *node,
1303 struct qcom_smd_edge *edge)
1305 struct device_node *syscon_np;
1310 INIT_LIST_HEAD(&edge->channels);
1311 spin_lock_init(&edge->channels_lock);
1313 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1314 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1316 edge->of_node = of_node_get(node);
1318 key = "qcom,smd-edge";
1319 ret = of_property_read_u32(node, key, &edge->edge_id);
1321 dev_err(dev, "edge missing %s property\n", key);
1325 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1326 key = "qcom,remote-pid";
1327 of_property_read_u32(node, key, &edge->remote_pid);
1329 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1331 dev_err(dev, "no qcom,ipc node\n");
1335 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1336 if (IS_ERR(edge->ipc_regmap))
1337 return PTR_ERR(edge->ipc_regmap);
1340 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1342 dev_err(dev, "no offset in %s\n", key);
1346 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1348 dev_err(dev, "no bit in %s\n", key);
1352 ret = of_property_read_string(node, "label", &edge->name);
1354 edge->name = node->name;
1356 irq = irq_of_parse_and_map(node, 0);
1358 dev_err(dev, "required smd interrupt missing\n");
1362 ret = devm_request_irq(dev, irq,
1363 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1366 dev_err(dev, "failed to request smd irq\n");
1376 * Release function for an edge.
1377 * Reset the state of each associated channel and free the edge context.
1379 static void qcom_smd_edge_release(struct device *dev)
1381 struct qcom_smd_channel *channel;
1382 struct qcom_smd_edge *edge = to_smd_edge(dev);
1384 list_for_each_entry(channel, &edge->channels, list) {
1385 SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
1386 SET_RX_CHANNEL_INFO(channel, head, 0);
1387 SET_RX_CHANNEL_INFO(channel, tail, 0);
1393 static ssize_t rpmsg_name_show(struct device *dev,
1394 struct device_attribute *attr, char *buf)
1396 struct qcom_smd_edge *edge = to_smd_edge(dev);
1398 return sprintf(buf, "%s\n", edge->name);
1400 static DEVICE_ATTR_RO(rpmsg_name);
1402 static struct attribute *qcom_smd_edge_attrs[] = {
1403 &dev_attr_rpmsg_name.attr,
1406 ATTRIBUTE_GROUPS(qcom_smd_edge);
1409 * qcom_smd_register_edge() - register an edge based on an device_node
1410 * @parent: parent device for the edge
1411 * @node: device_node describing the edge
1413 * Returns an edge reference, or negative ERR_PTR() on failure.
1415 struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
1416 struct device_node *node)
1418 struct qcom_smd_edge *edge;
1421 edge = kzalloc(sizeof(*edge), GFP_KERNEL);
1423 return ERR_PTR(-ENOMEM);
1425 init_waitqueue_head(&edge->new_channel_event);
1427 edge->dev.parent = parent;
1428 edge->dev.release = qcom_smd_edge_release;
1429 edge->dev.of_node = node;
1430 edge->dev.groups = qcom_smd_edge_groups;
1431 dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name);
1432 ret = device_register(&edge->dev);
1434 pr_err("failed to register smd edge\n");
1435 put_device(&edge->dev);
1436 return ERR_PTR(ret);
1439 ret = qcom_smd_parse_edge(&edge->dev, node, edge);
1441 dev_err(&edge->dev, "failed to parse smd edge\n");
1442 goto unregister_dev;
1445 ret = qcom_smd_create_chrdev(edge);
1447 dev_err(&edge->dev, "failed to register chrdev for edge\n");
1448 goto unregister_dev;
1451 schedule_work(&edge->scan_work);
1456 device_unregister(&edge->dev);
1457 return ERR_PTR(ret);
1459 EXPORT_SYMBOL(qcom_smd_register_edge);
1461 static int qcom_smd_remove_device(struct device *dev, void *data)
1463 device_unregister(dev);
1469 * qcom_smd_unregister_edge() - release an edge and its children
1470 * @edge: edge reference acquired from qcom_smd_register_edge
1472 int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
1476 disable_irq(edge->irq);
1477 cancel_work_sync(&edge->scan_work);
1478 cancel_work_sync(&edge->state_work);
1480 ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
1482 dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
1484 device_unregister(&edge->dev);
1488 EXPORT_SYMBOL(qcom_smd_unregister_edge);
1490 static int qcom_smd_probe(struct platform_device *pdev)
1492 struct device_node *node;
1496 p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
1497 if (PTR_ERR(p) == -EPROBE_DEFER)
1500 for_each_available_child_of_node(pdev->dev.of_node, node)
1501 qcom_smd_register_edge(&pdev->dev, node);
1506 static int qcom_smd_remove_edge(struct device *dev, void *data)
1508 struct qcom_smd_edge *edge = to_smd_edge(dev);
1510 return qcom_smd_unregister_edge(edge);
1514 * Shut down all smd clients by making sure that each edge stops processing
1515 * events and scanning for new channels, then call destroy on the devices.
1517 static int qcom_smd_remove(struct platform_device *pdev)
1521 ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
1523 dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret);
1528 static const struct of_device_id qcom_smd_of_match[] = {
1529 { .compatible = "qcom,smd" },
1532 MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1534 static struct platform_driver qcom_smd_driver = {
1535 .probe = qcom_smd_probe,
1536 .remove = qcom_smd_remove,
1539 .of_match_table = qcom_smd_of_match,
1543 static int __init qcom_smd_init(void)
1545 return platform_driver_register(&qcom_smd_driver);
1547 subsys_initcall(qcom_smd_init);
1549 static void __exit qcom_smd_exit(void)
1551 platform_driver_unregister(&qcom_smd_driver);
1553 module_exit(qcom_smd_exit);
1555 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
1556 MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1557 MODULE_LICENSE("GPL v2");