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/smd.h>
26 #include <linux/soc/qcom/smem.h>
27 #include <linux/wait.h>
30 * The Qualcomm Shared Memory communication solution provides point-to-point
31 * channels for clients to send and receive streaming or packet based data.
33 * Each channel consists of a control item (channel info) and a ring buffer
34 * pair. The channel info carry information related to channel state, flow
35 * control and the offsets within the ring buffer.
37 * All allocated channels are listed in an allocation table, identifying the
38 * pair of items by name, type and remote processor.
40 * Upon creating a new channel the remote processor allocates channel info and
41 * ring buffer items from the smem heap and populate the allocation table. An
42 * interrupt is sent to the other end of the channel and a scan for new
43 * channels should be done. A channel never goes away, it will only change
46 * The remote processor signals it intent for bring up the communication
47 * channel by setting the state of its end of the channel to "opening" and
48 * sends out an interrupt. We detect this change and register a smd device to
49 * consume the channel. Upon finding a consumer we finish the handshake and the
52 * Upon closing a channel, the remote processor will update the state of its
53 * end of the channel and signal us, we will then unregister any attached
54 * device and close our end of the channel.
56 * Devices attached to a channel can use the qcom_smd_send function to push
57 * data to the channel, this is done by copying the data into the tx ring
58 * buffer, updating the pointers in the channel info and signaling the remote
61 * The remote processor does the equivalent when it transfer data and upon
62 * receiving the interrupt we check the channel info for new data and delivers
63 * this to the attached device. If the device is not ready to receive the data
64 * we leave it in the ring buffer for now.
67 struct smd_channel_info;
68 struct smd_channel_info_pair;
69 struct smd_channel_info_word;
70 struct smd_channel_info_word_pair;
72 #define SMD_ALLOC_TBL_COUNT 2
73 #define SMD_ALLOC_TBL_SIZE 64
76 * This lists the various smem heap items relevant for the allocation table and
77 * smd channel entries.
80 unsigned alloc_tbl_id;
81 unsigned info_base_id;
82 unsigned fifo_base_id;
83 } smem_items[SMD_ALLOC_TBL_COUNT] = {
97 * struct qcom_smd_edge - representing a remote processor
98 * @smd: handle to qcom_smd
99 * @of_node: of_node handle for information related to this edge
100 * @edge_id: identifier of this edge
101 * @remote_pid: identifier of remote processor
102 * @irq: interrupt for signals on this edge
103 * @ipc_regmap: regmap handle holding the outgoing ipc register
104 * @ipc_offset: offset within @ipc_regmap of the register for ipc
105 * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
106 * @channels: list of all channels detected on this edge
107 * @channels_lock: guard for modifications of @channels
108 * @allocated: array of bitmaps representing already allocated channels
109 * @smem_available: last available amount of smem triggering a channel scan
110 * @scan_work: work item for discovering new channels
111 * @state_work: work item for edge state changes
113 struct qcom_smd_edge {
114 struct qcom_smd *smd;
115 struct device_node *of_node;
121 struct regmap *ipc_regmap;
125 struct list_head channels;
126 rwlock_t channels_lock;
128 DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
130 unsigned smem_available;
132 wait_queue_head_t new_channel_event;
134 struct work_struct scan_work;
135 struct work_struct state_work;
139 * SMD channel states.
141 enum smd_channel_state {
145 SMD_CHANNEL_FLUSHING,
148 SMD_CHANNEL_RESET_OPENING
152 * struct qcom_smd_channel - smd channel struct
153 * @edge: qcom_smd_edge this channel is living on
154 * @qsdev: reference to a associated smd client device
155 * @name: name of the channel
156 * @state: local state of the channel
157 * @remote_state: remote state of the channel
158 * @info: byte aligned outgoing/incoming channel info
159 * @info_word: word aligned outgoing/incoming channel info
160 * @tx_lock: lock to make writes to the channel mutually exclusive
161 * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
162 * @tx_fifo: pointer to the outgoing ring buffer
163 * @rx_fifo: pointer to the incoming ring buffer
164 * @fifo_size: size of each ring buffer
165 * @bounce_buffer: bounce buffer for reading wrapped packets
166 * @cb: callback function registered for this channel
167 * @recv_lock: guard for rx info modifications and cb pointer
168 * @pkt_size: size of the currently handled packet
169 * @list: lite entry for @channels in qcom_smd_edge
171 struct qcom_smd_channel {
172 struct qcom_smd_edge *edge;
174 struct qcom_smd_device *qsdev;
177 enum smd_channel_state state;
178 enum smd_channel_state remote_state;
180 struct smd_channel_info_pair *info;
181 struct smd_channel_info_word_pair *info_word;
183 struct mutex tx_lock;
184 wait_queue_head_t fblockread_event;
193 spinlock_t recv_lock;
197 struct list_head list;
198 struct list_head dev_list;
202 * struct qcom_smd - smd struct
203 * @dev: device struct
204 * @num_edges: number of entries in @edges
205 * @edges: array of edges to be handled
211 struct qcom_smd_edge edges[0];
215 * Format of the smd_info smem items, for byte aligned channels.
217 struct smd_channel_info {
231 struct smd_channel_info_pair {
232 struct smd_channel_info tx;
233 struct smd_channel_info rx;
237 * Format of the smd_info smem items, for word aligned channels.
239 struct smd_channel_info_word {
248 __le32 fBLOCKREADINTR;
253 struct smd_channel_info_word_pair {
254 struct smd_channel_info_word tx;
255 struct smd_channel_info_word rx;
258 #define GET_RX_CHANNEL_FLAG(channel, param) \
260 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
261 channel->info_word ? \
262 le32_to_cpu(channel->info_word->rx.param) : \
263 channel->info->rx.param; \
266 #define GET_RX_CHANNEL_INFO(channel, param) \
268 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
269 le32_to_cpu(channel->info_word ? \
270 channel->info_word->rx.param : \
271 channel->info->rx.param); \
274 #define SET_RX_CHANNEL_FLAG(channel, param, value) \
276 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
277 if (channel->info_word) \
278 channel->info_word->rx.param = cpu_to_le32(value); \
280 channel->info->rx.param = value; \
283 #define SET_RX_CHANNEL_INFO(channel, param, value) \
285 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
286 if (channel->info_word) \
287 channel->info_word->rx.param = cpu_to_le32(value); \
289 channel->info->rx.param = cpu_to_le32(value); \
292 #define GET_TX_CHANNEL_FLAG(channel, param) \
294 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
295 channel->info_word ? \
296 le32_to_cpu(channel->info_word->tx.param) : \
297 channel->info->tx.param; \
300 #define GET_TX_CHANNEL_INFO(channel, param) \
302 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
303 le32_to_cpu(channel->info_word ? \
304 channel->info_word->tx.param : \
305 channel->info->tx.param); \
308 #define SET_TX_CHANNEL_FLAG(channel, param, value) \
310 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
311 if (channel->info_word) \
312 channel->info_word->tx.param = cpu_to_le32(value); \
314 channel->info->tx.param = value; \
317 #define SET_TX_CHANNEL_INFO(channel, param, value) \
319 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
320 if (channel->info_word) \
321 channel->info_word->tx.param = cpu_to_le32(value); \
323 channel->info->tx.param = cpu_to_le32(value); \
327 * struct qcom_smd_alloc_entry - channel allocation entry
328 * @name: channel name
329 * @cid: channel index
330 * @flags: channel flags and edge id
331 * @ref_count: reference count of the channel
333 struct qcom_smd_alloc_entry {
340 #define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
341 #define SMD_CHANNEL_FLAGS_STREAM BIT(8)
342 #define SMD_CHANNEL_FLAGS_PACKET BIT(9)
345 * Each smd packet contains a 20 byte header, with the first 4 being the length
348 #define SMD_PACKET_HEADER_LEN 20
351 * Signal the remote processor associated with 'channel'.
353 static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
355 struct qcom_smd_edge *edge = channel->edge;
357 regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
361 * Initialize the tx channel info
363 static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
365 SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
366 SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
367 SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
368 SET_TX_CHANNEL_FLAG(channel, fCD, 0);
369 SET_TX_CHANNEL_FLAG(channel, fRI, 0);
370 SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
371 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
372 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
373 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
374 SET_TX_CHANNEL_INFO(channel, head, 0);
375 SET_TX_CHANNEL_INFO(channel, tail, 0);
377 qcom_smd_signal_channel(channel);
379 channel->state = SMD_CHANNEL_CLOSED;
380 channel->pkt_size = 0;
384 * Set the callback for a channel, with appropriate locking
386 static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
391 spin_lock_irqsave(&channel->recv_lock, flags);
393 spin_unlock_irqrestore(&channel->recv_lock, flags);
397 * Calculate the amount of data available in the rx fifo
399 static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
404 head = GET_RX_CHANNEL_INFO(channel, head);
405 tail = GET_RX_CHANNEL_INFO(channel, tail);
407 return (head - tail) & (channel->fifo_size - 1);
411 * Set tx channel state and inform the remote processor
413 static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
416 struct qcom_smd_edge *edge = channel->edge;
417 bool is_open = state == SMD_CHANNEL_OPENED;
419 if (channel->state == state)
422 dev_dbg(edge->smd->dev, "set_state(%s, %d)\n", channel->name, state);
424 SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
425 SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
426 SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
428 SET_TX_CHANNEL_INFO(channel, state, state);
429 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
431 channel->state = state;
432 qcom_smd_signal_channel(channel);
436 * Copy count bytes of data using 32bit accesses, if that's required.
438 static void smd_copy_to_fifo(void __iomem *dst,
444 __iowrite32_copy(dst, src, count / sizeof(u32));
446 memcpy_toio(dst, src, count);
451 * Copy count bytes of data using 32bit accesses, if that is required.
453 static void smd_copy_from_fifo(void *dst,
454 const void __iomem *src,
459 __ioread32_copy(dst, src, count / sizeof(u32));
461 memcpy_fromio(dst, src, count);
466 * Read count bytes of data from the rx fifo into buf, but don't advance the
469 static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
470 void *buf, size_t count)
476 word_aligned = channel->info_word;
477 tail = GET_RX_CHANNEL_INFO(channel, tail);
479 len = min_t(size_t, count, channel->fifo_size - tail);
481 smd_copy_from_fifo(buf,
482 channel->rx_fifo + tail,
488 smd_copy_from_fifo(buf + len,
498 * Advance the rx tail by count bytes.
500 static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
505 tail = GET_RX_CHANNEL_INFO(channel, tail);
507 tail &= (channel->fifo_size - 1);
508 SET_RX_CHANNEL_INFO(channel, tail, tail);
512 * Read out a single packet from the rx fifo and deliver it to the device
514 static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
516 struct qcom_smd_device *qsdev = channel->qsdev;
525 tail = GET_RX_CHANNEL_INFO(channel, tail);
527 /* Use bounce buffer if the data wraps */
528 if (tail + channel->pkt_size >= channel->fifo_size) {
529 ptr = channel->bounce_buffer;
530 len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
532 ptr = channel->rx_fifo + tail;
533 len = channel->pkt_size;
536 ret = channel->cb(qsdev, ptr, len);
540 /* Only forward the tail if the client consumed the data */
541 qcom_smd_channel_advance(channel, len);
543 channel->pkt_size = 0;
549 * Per channel interrupt handling
551 static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
553 bool need_state_scan = false;
559 /* Handle state changes */
560 remote_state = GET_RX_CHANNEL_INFO(channel, state);
561 if (remote_state != channel->remote_state) {
562 channel->remote_state = remote_state;
563 need_state_scan = true;
565 /* Indicate that we have seen any state change */
566 SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
568 /* Signal waiting qcom_smd_send() about the interrupt */
569 if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
570 wake_up_interruptible(&channel->fblockread_event);
572 /* Don't consume any data until we've opened the channel */
573 if (channel->state != SMD_CHANNEL_OPENED)
576 /* Indicate that we've seen the new data */
577 SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
581 avail = qcom_smd_channel_get_rx_avail(channel);
583 if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
584 qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
585 qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
586 channel->pkt_size = le32_to_cpu(pktlen);
587 } else if (channel->pkt_size && avail >= channel->pkt_size) {
588 ret = qcom_smd_channel_recv_single(channel);
596 /* Indicate that we have seen and updated tail */
597 SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
599 /* Signal the remote that we've consumed the data (if requested) */
600 if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
601 /* Ensure ordering of channel info updates */
604 qcom_smd_signal_channel(channel);
608 return need_state_scan;
612 * The edge interrupts are triggered by the remote processor on state changes,
613 * channel info updates or when new channels are created.
615 static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
617 struct qcom_smd_edge *edge = data;
618 struct qcom_smd_channel *channel;
620 bool kick_worker = false;
623 * Handle state changes or data on each of the channels on this edge
625 read_lock(&edge->channels_lock);
626 list_for_each_entry(channel, &edge->channels, list) {
627 spin_lock(&channel->recv_lock);
628 kick_worker |= qcom_smd_channel_intr(channel);
629 spin_unlock(&channel->recv_lock);
631 read_unlock(&edge->channels_lock);
634 * Creating a new channel requires allocating an smem entry, so we only
635 * have to scan if the amount of available space in smem have changed
638 available = qcom_smem_get_free_space(edge->remote_pid);
639 if (available != edge->smem_available) {
640 edge->smem_available = available;
645 schedule_work(&edge->scan_work);
651 * Delivers any outstanding packets in the rx fifo, can be used after probe of
652 * the clients to deliver any packets that wasn't delivered before the client
655 static void qcom_smd_channel_resume(struct qcom_smd_channel *channel)
659 spin_lock_irqsave(&channel->recv_lock, flags);
660 qcom_smd_channel_intr(channel);
661 spin_unlock_irqrestore(&channel->recv_lock, flags);
665 * Calculate how much space is available in the tx fifo.
667 static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
671 unsigned mask = channel->fifo_size - 1;
673 head = GET_TX_CHANNEL_INFO(channel, head);
674 tail = GET_TX_CHANNEL_INFO(channel, tail);
676 return mask - ((head - tail) & mask);
680 * Write count bytes of data into channel, possibly wrapping in the ring buffer
682 static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
690 word_aligned = channel->info_word;
691 head = GET_TX_CHANNEL_INFO(channel, head);
693 len = min_t(size_t, count, channel->fifo_size - head);
695 smd_copy_to_fifo(channel->tx_fifo + head,
702 smd_copy_to_fifo(channel->tx_fifo,
709 head &= (channel->fifo_size - 1);
710 SET_TX_CHANNEL_INFO(channel, head, head);
716 * qcom_smd_send - write data to smd channel
717 * @channel: channel handle
718 * @data: buffer of data to write
719 * @len: number of bytes to write
721 * This is a blocking write of len bytes into the channel's tx ring buffer and
722 * signal the remote end. It will sleep until there is enough space available
723 * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
726 int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len)
728 __le32 hdr[5] = { cpu_to_le32(len), };
729 int tlen = sizeof(hdr) + len;
732 /* Word aligned channels only accept word size aligned data */
733 if (channel->info_word && len % 4)
736 /* Reject packets that are too big */
737 if (tlen >= channel->fifo_size)
740 ret = mutex_lock_interruptible(&channel->tx_lock);
744 while (qcom_smd_get_tx_avail(channel) < tlen) {
745 if (channel->state != SMD_CHANNEL_OPENED) {
750 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
752 ret = wait_event_interruptible(channel->fblockread_event,
753 qcom_smd_get_tx_avail(channel) >= tlen ||
754 channel->state != SMD_CHANNEL_OPENED);
758 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
761 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
763 qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
764 qcom_smd_write_fifo(channel, data, len);
766 SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
768 /* Ensure ordering of channel info updates */
771 qcom_smd_signal_channel(channel);
774 mutex_unlock(&channel->tx_lock);
778 EXPORT_SYMBOL(qcom_smd_send);
780 static struct qcom_smd_device *to_smd_device(struct device *dev)
782 return container_of(dev, struct qcom_smd_device, dev);
785 static struct qcom_smd_driver *to_smd_driver(struct device *dev)
787 struct qcom_smd_device *qsdev = to_smd_device(dev);
789 return container_of(qsdev->dev.driver, struct qcom_smd_driver, driver);
792 static int qcom_smd_dev_match(struct device *dev, struct device_driver *drv)
794 struct qcom_smd_device *qsdev = to_smd_device(dev);
795 struct qcom_smd_driver *qsdrv = container_of(drv, struct qcom_smd_driver, driver);
796 const struct qcom_smd_id *match = qsdrv->smd_match_table;
797 const char *name = qsdev->channel->name;
800 while (match->name[0]) {
801 if (!strcmp(match->name, name))
807 return of_driver_match_device(dev, drv);
811 * Helper for opening a channel
813 static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
819 * Packets are maximum 4k, but reduce if the fifo is smaller
821 bb_size = min(channel->fifo_size, SZ_4K);
822 channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
823 if (!channel->bounce_buffer)
826 qcom_smd_channel_set_callback(channel, cb);
827 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
828 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
834 * Helper for closing and resetting a channel
836 static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
838 qcom_smd_channel_set_callback(channel, NULL);
840 kfree(channel->bounce_buffer);
841 channel->bounce_buffer = NULL;
843 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
844 qcom_smd_channel_reset(channel);
848 * Probe the smd client.
850 * The remote side have indicated that it want the channel to be opened, so
851 * complete the state handshake and probe our client driver.
853 static int qcom_smd_dev_probe(struct device *dev)
855 struct qcom_smd_device *qsdev = to_smd_device(dev);
856 struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
857 struct qcom_smd_channel *channel = qsdev->channel;
860 ret = qcom_smd_channel_open(channel, qsdrv->callback);
864 ret = qsdrv->probe(qsdev);
868 qcom_smd_channel_resume(channel);
873 dev_err(&qsdev->dev, "probe failed\n");
875 qcom_smd_channel_close(channel);
880 * Remove the smd client.
882 * The channel is going away, for some reason, so remove the smd client and
883 * reset the channel state.
885 static int qcom_smd_dev_remove(struct device *dev)
887 struct qcom_smd_device *qsdev = to_smd_device(dev);
888 struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
889 struct qcom_smd_channel *channel = qsdev->channel;
890 struct qcom_smd_channel *tmp;
891 struct qcom_smd_channel *ch;
893 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING);
896 * Make sure we don't race with the code receiving data.
898 qcom_smd_channel_set_callback(channel, NULL);
900 /* Wake up any sleepers in qcom_smd_send() */
901 wake_up_interruptible(&channel->fblockread_event);
904 * We expect that the client might block in remove() waiting for any
905 * outstanding calls to qcom_smd_send() to wake up and finish.
908 qsdrv->remove(qsdev);
911 * The client is now gone, close and release all channels associated
914 list_for_each_entry_safe(ch, tmp, &channel->dev_list, dev_list) {
915 qcom_smd_channel_close(ch);
916 list_del(&ch->dev_list);
923 static struct bus_type qcom_smd_bus = {
925 .match = qcom_smd_dev_match,
926 .probe = qcom_smd_dev_probe,
927 .remove = qcom_smd_dev_remove,
931 * Release function for the qcom_smd_device object.
933 static void qcom_smd_release_device(struct device *dev)
935 struct qcom_smd_device *qsdev = to_smd_device(dev);
941 * Finds the device_node for the smd child interested in this channel.
943 static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
946 struct device_node *child;
951 for_each_available_child_of_node(edge_node, child) {
952 key = "qcom,smd-channels";
953 ret = of_property_read_string(child, key, &name);
957 if (strcmp(name, channel) == 0)
965 * Create a smd client device for channel that is being opened.
967 static int qcom_smd_create_device(struct qcom_smd_channel *channel)
969 struct qcom_smd_device *qsdev;
970 struct qcom_smd_edge *edge = channel->edge;
971 struct device_node *node;
972 struct qcom_smd *smd = edge->smd;
978 dev_dbg(smd->dev, "registering '%s'\n", channel->name);
980 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
984 node = qcom_smd_match_channel(edge->of_node, channel->name);
985 dev_set_name(&qsdev->dev, "%s.%s",
987 node ? node->name : channel->name);
989 qsdev->dev.parent = smd->dev;
990 qsdev->dev.bus = &qcom_smd_bus;
991 qsdev->dev.release = qcom_smd_release_device;
992 qsdev->dev.of_node = node;
994 qsdev->channel = channel;
996 channel->qsdev = qsdev;
998 ret = device_register(&qsdev->dev);
1000 dev_err(smd->dev, "device_register failed: %d\n", ret);
1001 put_device(&qsdev->dev);
1008 * Destroy a smd client device for a channel that's going away.
1010 static void qcom_smd_destroy_device(struct qcom_smd_channel *channel)
1014 BUG_ON(!channel->qsdev);
1016 dev = &channel->qsdev->dev;
1018 device_unregister(dev);
1019 of_node_put(dev->of_node);
1024 * qcom_smd_driver_register - register a smd driver
1025 * @qsdrv: qcom_smd_driver struct
1027 int qcom_smd_driver_register(struct qcom_smd_driver *qsdrv)
1029 qsdrv->driver.bus = &qcom_smd_bus;
1030 return driver_register(&qsdrv->driver);
1032 EXPORT_SYMBOL(qcom_smd_driver_register);
1035 * qcom_smd_driver_unregister - unregister a smd driver
1036 * @qsdrv: qcom_smd_driver struct
1038 void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv)
1040 driver_unregister(&qsdrv->driver);
1042 EXPORT_SYMBOL(qcom_smd_driver_unregister);
1044 static struct qcom_smd_channel *
1045 qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
1047 struct qcom_smd_channel *channel;
1048 struct qcom_smd_channel *ret = NULL;
1051 read_lock(&edge->channels_lock);
1052 list_for_each_entry(channel, &edge->channels, list) {
1053 if (strcmp(channel->name, name))
1056 state = GET_RX_CHANNEL_INFO(channel, state);
1057 if (state != SMD_CHANNEL_OPENING &&
1058 state != SMD_CHANNEL_OPENED)
1064 read_unlock(&edge->channels_lock);
1070 * qcom_smd_open_channel() - claim additional channels on the same edge
1071 * @sdev: smd_device handle
1072 * @name: channel name
1073 * @cb: callback method to use for incoming data
1075 * Returns a channel handle on success, or -EPROBE_DEFER if the channel isn't
1078 struct qcom_smd_channel *qcom_smd_open_channel(struct qcom_smd_device *sdev,
1082 struct qcom_smd_channel *channel;
1083 struct qcom_smd_edge *edge = sdev->channel->edge;
1086 /* Wait up to HZ for the channel to appear */
1087 ret = wait_event_interruptible_timeout(edge->new_channel_event,
1088 (channel = qcom_smd_find_channel(edge, name)) != NULL,
1091 return ERR_PTR(-ETIMEDOUT);
1093 if (channel->state != SMD_CHANNEL_CLOSED) {
1094 dev_err(&sdev->dev, "channel %s is busy\n", channel->name);
1095 return ERR_PTR(-EBUSY);
1098 channel->qsdev = sdev;
1099 ret = qcom_smd_channel_open(channel, cb);
1101 channel->qsdev = NULL;
1102 return ERR_PTR(ret);
1106 * Append the list of channel to the channels associated with the sdev
1108 list_add_tail(&channel->dev_list, &sdev->channel->dev_list);
1112 EXPORT_SYMBOL(qcom_smd_open_channel);
1115 * Allocate the qcom_smd_channel object for a newly found smd channel,
1116 * retrieving and validating the smem items involved.
1118 static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
1119 unsigned smem_info_item,
1120 unsigned smem_fifo_item,
1123 struct qcom_smd_channel *channel;
1124 struct qcom_smd *smd = edge->smd;
1131 channel = devm_kzalloc(smd->dev, sizeof(*channel), GFP_KERNEL);
1133 return ERR_PTR(-ENOMEM);
1135 INIT_LIST_HEAD(&channel->dev_list);
1136 channel->edge = edge;
1137 channel->name = devm_kstrdup(smd->dev, name, GFP_KERNEL);
1139 return ERR_PTR(-ENOMEM);
1141 mutex_init(&channel->tx_lock);
1142 spin_lock_init(&channel->recv_lock);
1143 init_waitqueue_head(&channel->fblockread_event);
1145 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1147 ret = PTR_ERR(info);
1148 goto free_name_and_channel;
1152 * Use the size of the item to figure out which channel info struct to
1155 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1156 channel->info_word = info;
1157 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1158 channel->info = info;
1161 "channel info of size %zu not supported\n", info_size);
1163 goto free_name_and_channel;
1166 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1167 if (IS_ERR(fifo_base)) {
1168 ret = PTR_ERR(fifo_base);
1169 goto free_name_and_channel;
1172 /* The channel consist of a rx and tx fifo of equal size */
1175 dev_dbg(smd->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1176 name, info_size, fifo_size);
1178 channel->tx_fifo = fifo_base;
1179 channel->rx_fifo = fifo_base + fifo_size;
1180 channel->fifo_size = fifo_size;
1182 qcom_smd_channel_reset(channel);
1186 free_name_and_channel:
1187 devm_kfree(smd->dev, channel->name);
1188 devm_kfree(smd->dev, channel);
1190 return ERR_PTR(ret);
1194 * Scans the allocation table for any newly allocated channels, calls
1195 * qcom_smd_create_channel() to create representations of these and add
1196 * them to the edge's list of channels.
1198 static void qcom_channel_scan_worker(struct work_struct *work)
1200 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1201 struct qcom_smd_alloc_entry *alloc_tbl;
1202 struct qcom_smd_alloc_entry *entry;
1203 struct qcom_smd_channel *channel;
1204 struct qcom_smd *smd = edge->smd;
1205 unsigned long flags;
1212 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1213 alloc_tbl = qcom_smem_get(edge->remote_pid,
1214 smem_items[tbl].alloc_tbl_id, NULL);
1215 if (IS_ERR(alloc_tbl))
1218 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1219 entry = &alloc_tbl[i];
1220 eflags = le32_to_cpu(entry->flags);
1221 if (test_bit(i, edge->allocated[tbl]))
1224 if (entry->ref_count == 0)
1227 if (!entry->name[0])
1230 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1233 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1236 cid = le32_to_cpu(entry->cid);
1237 info_id = smem_items[tbl].info_base_id + cid;
1238 fifo_id = smem_items[tbl].fifo_base_id + cid;
1240 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1241 if (IS_ERR(channel))
1244 write_lock_irqsave(&edge->channels_lock, flags);
1245 list_add(&channel->list, &edge->channels);
1246 write_unlock_irqrestore(&edge->channels_lock, flags);
1248 dev_dbg(smd->dev, "new channel found: '%s'\n", channel->name);
1249 set_bit(i, edge->allocated[tbl]);
1251 wake_up_interruptible(&edge->new_channel_event);
1255 schedule_work(&edge->state_work);
1259 * This per edge worker scans smem for any new channels and register these. It
1260 * then scans all registered channels for state changes that should be handled
1261 * by creating or destroying smd client devices for the registered channels.
1263 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1264 * worker is killed before any channels are deallocated
1266 static void qcom_channel_state_worker(struct work_struct *work)
1268 struct qcom_smd_channel *channel;
1269 struct qcom_smd_edge *edge = container_of(work,
1270 struct qcom_smd_edge,
1272 unsigned remote_state;
1275 * Register a device for any closed channel where the remote processor
1276 * is showing interest in opening the channel.
1278 read_lock(&edge->channels_lock);
1279 list_for_each_entry(channel, &edge->channels, list) {
1280 if (channel->state != SMD_CHANNEL_CLOSED)
1283 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1284 if (remote_state != SMD_CHANNEL_OPENING &&
1285 remote_state != SMD_CHANNEL_OPENED)
1288 read_unlock(&edge->channels_lock);
1289 qcom_smd_create_device(channel);
1290 read_lock(&edge->channels_lock);
1294 * Unregister the device for any channel that is opened where the
1295 * remote processor is closing the channel.
1297 list_for_each_entry(channel, &edge->channels, list) {
1298 if (channel->state != SMD_CHANNEL_OPENING &&
1299 channel->state != SMD_CHANNEL_OPENED)
1302 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1303 if (remote_state == SMD_CHANNEL_OPENING ||
1304 remote_state == SMD_CHANNEL_OPENED)
1307 read_unlock(&edge->channels_lock);
1308 qcom_smd_destroy_device(channel);
1309 read_lock(&edge->channels_lock);
1311 read_unlock(&edge->channels_lock);
1315 * Parses an of_node describing an edge.
1317 static int qcom_smd_parse_edge(struct device *dev,
1318 struct device_node *node,
1319 struct qcom_smd_edge *edge)
1321 struct device_node *syscon_np;
1326 INIT_LIST_HEAD(&edge->channels);
1327 rwlock_init(&edge->channels_lock);
1329 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1330 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1332 edge->of_node = of_node_get(node);
1334 irq = irq_of_parse_and_map(node, 0);
1336 dev_err(dev, "required smd interrupt missing\n");
1340 ret = devm_request_irq(dev, irq,
1341 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1344 dev_err(dev, "failed to request smd irq\n");
1350 key = "qcom,smd-edge";
1351 ret = of_property_read_u32(node, key, &edge->edge_id);
1353 dev_err(dev, "edge missing %s property\n", key);
1357 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1358 key = "qcom,remote-pid";
1359 of_property_read_u32(node, key, &edge->remote_pid);
1361 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1363 dev_err(dev, "no qcom,ipc node\n");
1367 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1368 if (IS_ERR(edge->ipc_regmap))
1369 return PTR_ERR(edge->ipc_regmap);
1372 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1374 dev_err(dev, "no offset in %s\n", key);
1378 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1380 dev_err(dev, "no bit in %s\n", key);
1387 static int qcom_smd_probe(struct platform_device *pdev)
1389 struct qcom_smd_edge *edge;
1390 struct device_node *node;
1391 struct qcom_smd *smd;
1399 p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
1400 if (PTR_ERR(p) == -EPROBE_DEFER)
1403 num_edges = of_get_available_child_count(pdev->dev.of_node);
1404 array_size = sizeof(*smd) + num_edges * sizeof(struct qcom_smd_edge);
1405 smd = devm_kzalloc(&pdev->dev, array_size, GFP_KERNEL);
1408 smd->dev = &pdev->dev;
1410 smd->num_edges = num_edges;
1411 for_each_available_child_of_node(pdev->dev.of_node, node) {
1412 edge = &smd->edges[i++];
1414 init_waitqueue_head(&edge->new_channel_event);
1416 ret = qcom_smd_parse_edge(&pdev->dev, node, edge);
1420 schedule_work(&edge->scan_work);
1423 platform_set_drvdata(pdev, smd);
1429 * Shut down all smd clients by making sure that each edge stops processing
1430 * events and scanning for new channels, then call destroy on the devices.
1432 static int qcom_smd_remove(struct platform_device *pdev)
1434 struct qcom_smd_channel *channel;
1435 struct qcom_smd_edge *edge;
1436 struct qcom_smd *smd = platform_get_drvdata(pdev);
1439 for (i = 0; i < smd->num_edges; i++) {
1440 edge = &smd->edges[i];
1442 disable_irq(edge->irq);
1443 cancel_work_sync(&edge->scan_work);
1444 cancel_work_sync(&edge->state_work);
1446 /* No need to lock here, because the writer is gone */
1447 list_for_each_entry(channel, &edge->channels, list) {
1448 if (!channel->qsdev)
1451 qcom_smd_destroy_device(channel);
1458 static const struct of_device_id qcom_smd_of_match[] = {
1459 { .compatible = "qcom,smd" },
1462 MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1464 static struct platform_driver qcom_smd_driver = {
1465 .probe = qcom_smd_probe,
1466 .remove = qcom_smd_remove,
1469 .of_match_table = qcom_smd_of_match,
1473 static int __init qcom_smd_init(void)
1477 ret = bus_register(&qcom_smd_bus);
1479 pr_err("failed to register smd bus: %d\n", ret);
1483 return platform_driver_register(&qcom_smd_driver);
1485 postcore_initcall(qcom_smd_init);
1487 static void __exit qcom_smd_exit(void)
1489 platform_driver_unregister(&qcom_smd_driver);
1490 bus_unregister(&qcom_smd_bus);
1492 module_exit(qcom_smd_exit);
1494 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
1495 MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1496 MODULE_LICENSE("GPL v2");