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 * struct qcom_smd - smd struct
140 * @dev: device struct
141 * @num_edges: number of entries in @edges
142 * @edges: array of edges to be handled
148 struct qcom_smd_edge edges[0];
152 * Format of the smd_info smem items, for byte aligned channels.
154 struct smd_channel_info {
168 struct smd_channel_info_pair {
169 struct smd_channel_info tx;
170 struct smd_channel_info rx;
174 * Format of the smd_info smem items, for word aligned channels.
176 struct smd_channel_info_word {
185 __le32 fBLOCKREADINTR;
190 struct smd_channel_info_word_pair {
191 struct smd_channel_info_word tx;
192 struct smd_channel_info_word rx;
195 #define GET_RX_CHANNEL_FLAG(channel, param) \
197 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
198 channel->info_word ? \
199 le32_to_cpu(channel->info_word->rx.param) : \
200 channel->info->rx.param; \
203 #define GET_RX_CHANNEL_INFO(channel, param) \
205 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
206 le32_to_cpu(channel->info_word ? \
207 channel->info_word->rx.param : \
208 channel->info->rx.param); \
211 #define SET_RX_CHANNEL_FLAG(channel, param, value) \
213 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
214 if (channel->info_word) \
215 channel->info_word->rx.param = cpu_to_le32(value); \
217 channel->info->rx.param = value; \
220 #define SET_RX_CHANNEL_INFO(channel, param, value) \
222 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
223 if (channel->info_word) \
224 channel->info_word->rx.param = cpu_to_le32(value); \
226 channel->info->rx.param = cpu_to_le32(value); \
229 #define GET_TX_CHANNEL_FLAG(channel, param) \
231 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
232 channel->info_word ? \
233 le32_to_cpu(channel->info_word->tx.param) : \
234 channel->info->tx.param; \
237 #define GET_TX_CHANNEL_INFO(channel, param) \
239 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
240 le32_to_cpu(channel->info_word ? \
241 channel->info_word->tx.param : \
242 channel->info->tx.param); \
245 #define SET_TX_CHANNEL_FLAG(channel, param, value) \
247 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
248 if (channel->info_word) \
249 channel->info_word->tx.param = cpu_to_le32(value); \
251 channel->info->tx.param = value; \
254 #define SET_TX_CHANNEL_INFO(channel, param, value) \
256 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
257 if (channel->info_word) \
258 channel->info_word->tx.param = cpu_to_le32(value); \
260 channel->info->tx.param = cpu_to_le32(value); \
264 * struct qcom_smd_alloc_entry - channel allocation entry
265 * @name: channel name
266 * @cid: channel index
267 * @flags: channel flags and edge id
268 * @ref_count: reference count of the channel
270 struct qcom_smd_alloc_entry {
277 #define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
278 #define SMD_CHANNEL_FLAGS_STREAM BIT(8)
279 #define SMD_CHANNEL_FLAGS_PACKET BIT(9)
282 * Each smd packet contains a 20 byte header, with the first 4 being the length
285 #define SMD_PACKET_HEADER_LEN 20
288 * Signal the remote processor associated with 'channel'.
290 static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
292 struct qcom_smd_edge *edge = channel->edge;
294 regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
298 * Initialize the tx channel info
300 static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
302 SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
303 SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
304 SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
305 SET_TX_CHANNEL_FLAG(channel, fCD, 0);
306 SET_TX_CHANNEL_FLAG(channel, fRI, 0);
307 SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
308 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
309 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
310 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
311 SET_TX_CHANNEL_INFO(channel, head, 0);
312 SET_TX_CHANNEL_INFO(channel, tail, 0);
314 qcom_smd_signal_channel(channel);
316 channel->state = SMD_CHANNEL_CLOSED;
317 channel->pkt_size = 0;
321 * Set the callback for a channel, with appropriate locking
323 static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
328 spin_lock_irqsave(&channel->recv_lock, flags);
330 spin_unlock_irqrestore(&channel->recv_lock, flags);
334 * Calculate the amount of data available in the rx fifo
336 static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
341 head = GET_RX_CHANNEL_INFO(channel, head);
342 tail = GET_RX_CHANNEL_INFO(channel, tail);
344 return (head - tail) & (channel->fifo_size - 1);
348 * Set tx channel state and inform the remote processor
350 static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
353 struct qcom_smd_edge *edge = channel->edge;
354 bool is_open = state == SMD_CHANNEL_OPENED;
356 if (channel->state == state)
359 dev_dbg(edge->smd->dev, "set_state(%s, %d)\n", channel->name, state);
361 SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
362 SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
363 SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
365 SET_TX_CHANNEL_INFO(channel, state, state);
366 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
368 channel->state = state;
369 qcom_smd_signal_channel(channel);
373 * Copy count bytes of data using 32bit accesses, if that's required.
375 static void smd_copy_to_fifo(void __iomem *dst,
381 __iowrite32_copy(dst, src, count / sizeof(u32));
383 memcpy_toio(dst, src, count);
388 * Copy count bytes of data using 32bit accesses, if that is required.
390 static void smd_copy_from_fifo(void *_dst, const void __iomem *_src, size_t count, bool word_aligned)
392 u32 *dst = (u32 *)_dst;
393 u32 *src = (u32 *)_src;
396 count /= sizeof(u32);
398 *dst++ = __raw_readl(src++);
400 memcpy_fromio(_dst, _src, count);
405 * Read count bytes of data from the rx fifo into buf, but don't advance the
408 static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
409 void *buf, size_t count)
415 word_aligned = channel->info_word;
416 tail = GET_RX_CHANNEL_INFO(channel, tail);
418 len = min_t(size_t, count, channel->fifo_size - tail);
420 smd_copy_from_fifo(buf,
421 channel->rx_fifo + tail,
427 smd_copy_from_fifo(buf + len,
437 * Advance the rx tail by count bytes.
439 static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
444 tail = GET_RX_CHANNEL_INFO(channel, tail);
446 tail &= (channel->fifo_size - 1);
447 SET_RX_CHANNEL_INFO(channel, tail, tail);
451 * Read out a single packet from the rx fifo and deliver it to the device
453 static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
463 tail = GET_RX_CHANNEL_INFO(channel, tail);
465 /* Use bounce buffer if the data wraps */
466 if (tail + channel->pkt_size >= channel->fifo_size) {
467 ptr = channel->bounce_buffer;
468 len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
470 ptr = channel->rx_fifo + tail;
471 len = channel->pkt_size;
474 ret = channel->cb(channel, ptr, len);
478 /* Only forward the tail if the client consumed the data */
479 qcom_smd_channel_advance(channel, len);
481 channel->pkt_size = 0;
487 * Per channel interrupt handling
489 static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
491 bool need_state_scan = false;
497 /* Handle state changes */
498 remote_state = GET_RX_CHANNEL_INFO(channel, state);
499 if (remote_state != channel->remote_state) {
500 channel->remote_state = remote_state;
501 need_state_scan = true;
503 /* Indicate that we have seen any state change */
504 SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
506 /* Signal waiting qcom_smd_send() about the interrupt */
507 if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
508 wake_up_interruptible(&channel->fblockread_event);
510 /* Don't consume any data until we've opened the channel */
511 if (channel->state != SMD_CHANNEL_OPENED)
514 /* Indicate that we've seen the new data */
515 SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
519 avail = qcom_smd_channel_get_rx_avail(channel);
521 if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
522 qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
523 qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
524 channel->pkt_size = le32_to_cpu(pktlen);
525 } else if (channel->pkt_size && avail >= channel->pkt_size) {
526 ret = qcom_smd_channel_recv_single(channel);
534 /* Indicate that we have seen and updated tail */
535 SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
537 /* Signal the remote that we've consumed the data (if requested) */
538 if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
539 /* Ensure ordering of channel info updates */
542 qcom_smd_signal_channel(channel);
546 return need_state_scan;
550 * The edge interrupts are triggered by the remote processor on state changes,
551 * channel info updates or when new channels are created.
553 static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
555 struct qcom_smd_edge *edge = data;
556 struct qcom_smd_channel *channel;
558 bool kick_worker = false;
561 * Handle state changes or data on each of the channels on this edge
563 read_lock(&edge->channels_lock);
564 list_for_each_entry(channel, &edge->channels, list) {
565 spin_lock(&channel->recv_lock);
566 kick_worker |= qcom_smd_channel_intr(channel);
567 spin_unlock(&channel->recv_lock);
569 read_unlock(&edge->channels_lock);
572 * Creating a new channel requires allocating an smem entry, so we only
573 * have to scan if the amount of available space in smem have changed
576 available = qcom_smem_get_free_space(edge->remote_pid);
577 if (available != edge->smem_available) {
578 edge->smem_available = available;
583 schedule_work(&edge->scan_work);
589 * Delivers any outstanding packets in the rx fifo, can be used after probe of
590 * the clients to deliver any packets that wasn't delivered before the client
593 static void qcom_smd_channel_resume(struct qcom_smd_channel *channel)
597 spin_lock_irqsave(&channel->recv_lock, flags);
598 qcom_smd_channel_intr(channel);
599 spin_unlock_irqrestore(&channel->recv_lock, flags);
603 * Calculate how much space is available in the tx fifo.
605 static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
609 unsigned mask = channel->fifo_size - 1;
611 head = GET_TX_CHANNEL_INFO(channel, head);
612 tail = GET_TX_CHANNEL_INFO(channel, tail);
614 return mask - ((head - tail) & mask);
618 * Write count bytes of data into channel, possibly wrapping in the ring buffer
620 static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
628 word_aligned = channel->info_word;
629 head = GET_TX_CHANNEL_INFO(channel, head);
631 len = min_t(size_t, count, channel->fifo_size - head);
633 smd_copy_to_fifo(channel->tx_fifo + head,
640 smd_copy_to_fifo(channel->tx_fifo,
647 head &= (channel->fifo_size - 1);
648 SET_TX_CHANNEL_INFO(channel, head, head);
654 * qcom_smd_send - write data to smd channel
655 * @channel: channel handle
656 * @data: buffer of data to write
657 * @len: number of bytes to write
659 * This is a blocking write of len bytes into the channel's tx ring buffer and
660 * signal the remote end. It will sleep until there is enough space available
661 * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
664 int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len)
666 __le32 hdr[5] = { cpu_to_le32(len), };
667 int tlen = sizeof(hdr) + len;
670 /* Word aligned channels only accept word size aligned data */
671 if (channel->info_word && len % 4)
674 /* Reject packets that are too big */
675 if (tlen >= channel->fifo_size)
678 length = qcom_smd_get_tx_avail(channel);
680 ret = mutex_lock_interruptible(&channel->tx_lock);
684 length = qcom_smd_get_tx_avail(channel);
685 while (qcom_smd_get_tx_avail(channel) < tlen) {
686 if (channel->state != SMD_CHANNEL_OPENED) {
691 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
693 ret = wait_event_interruptible(channel->fblockread_event,
694 qcom_smd_get_tx_avail(channel) >= tlen ||
695 channel->state != SMD_CHANNEL_OPENED);
699 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
702 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
704 length = qcom_smd_get_tx_avail(channel);
705 qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
706 qcom_smd_write_fifo(channel, data, len);
708 SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
710 /* Ensure ordering of channel info updates */
713 qcom_smd_signal_channel(channel);
716 mutex_unlock(&channel->tx_lock);
720 EXPORT_SYMBOL(qcom_smd_send);
722 static struct qcom_smd_device *to_smd_device(struct device *dev)
724 return container_of(dev, struct qcom_smd_device, dev);
727 static struct qcom_smd_driver *to_smd_driver(struct device *dev)
729 struct qcom_smd_device *qsdev = to_smd_device(dev);
731 return container_of(qsdev->dev.driver, struct qcom_smd_driver, driver);
734 static int qcom_smd_dev_match(struct device *dev, struct device_driver *drv)
736 struct qcom_smd_device *qsdev = to_smd_device(dev);
737 struct qcom_smd_driver *qsdrv = container_of(drv, struct qcom_smd_driver, driver);
738 const struct qcom_smd_id *match = qsdrv->smd_match_table;
739 const char *name = qsdev->channel->name;
742 while (match->name[0]) {
743 if (!strcmp(match->name, name))
749 return of_driver_match_device(dev, drv);
753 * Helper for opening a channel
755 static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
761 * Packets are maximum 4k, but reduce if the fifo is smaller
763 bb_size = min(channel->fifo_size, SZ_4K);
764 channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
765 if (!channel->bounce_buffer)
768 qcom_smd_channel_set_callback(channel, cb);
769 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
770 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
776 * Helper for closing and resetting a channel
778 static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
780 qcom_smd_channel_set_callback(channel, NULL);
782 kfree(channel->bounce_buffer);
783 channel->bounce_buffer = NULL;
785 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
786 qcom_smd_channel_reset(channel);
790 * Probe the smd client.
792 * The remote side have indicated that it want the channel to be opened, so
793 * complete the state handshake and probe our client driver.
795 static int qcom_smd_dev_probe(struct device *dev)
797 struct qcom_smd_device *qsdev = to_smd_device(dev);
798 struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
799 struct qcom_smd_channel *channel = qsdev->channel;
802 ret = qcom_smd_channel_open(channel, qsdrv->callback);
806 ret = qsdrv->probe(qsdev);
810 qcom_smd_channel_resume(channel);
815 dev_err(&qsdev->dev, "probe failed\n");
817 qcom_smd_channel_close(channel);
822 * Remove the smd client.
824 * The channel is going away, for some reason, so remove the smd client and
825 * reset the channel state.
827 static int qcom_smd_dev_remove(struct device *dev)
829 struct qcom_smd_device *qsdev = to_smd_device(dev);
830 struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
831 struct qcom_smd_channel *channel = qsdev->channel;
832 struct qcom_smd_channel *tmp;
833 struct qcom_smd_channel *ch;
835 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING);
838 * Make sure we don't race with the code receiving data.
840 qcom_smd_channel_set_callback(channel, NULL);
842 /* Wake up any sleepers in qcom_smd_send() */
843 wake_up_interruptible(&channel->fblockread_event);
846 * We expect that the client might block in remove() waiting for any
847 * outstanding calls to qcom_smd_send() to wake up and finish.
850 qsdrv->remove(qsdev);
853 * The client is now gone, close and release all channels associated
856 list_for_each_entry_safe(ch, tmp, &channel->dev_list, dev_list) {
857 qcom_smd_channel_close(ch);
858 list_del(&ch->dev_list);
865 static struct bus_type qcom_smd_bus = {
867 .match = qcom_smd_dev_match,
868 .probe = qcom_smd_dev_probe,
869 .remove = qcom_smd_dev_remove,
873 * Release function for the qcom_smd_device object.
875 static void qcom_smd_release_device(struct device *dev)
877 struct qcom_smd_device *qsdev = to_smd_device(dev);
883 * Finds the device_node for the smd child interested in this channel.
885 static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
888 struct device_node *child;
893 for_each_available_child_of_node(edge_node, child) {
894 key = "qcom,smd-channels";
895 ret = of_property_read_string(child, key, &name);
899 if (strcmp(name, channel) == 0)
907 * Create a smd client device for channel that is being opened.
909 static int qcom_smd_create_device(struct qcom_smd_channel *channel)
911 struct qcom_smd_device *qsdev;
912 struct qcom_smd_edge *edge = channel->edge;
913 struct device_node *node;
914 struct qcom_smd *smd = edge->smd;
920 dev_dbg(smd->dev, "registering '%s'\n", channel->name);
922 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
926 node = qcom_smd_match_channel(edge->of_node, channel->name);
927 dev_set_name(&qsdev->dev, "%s.%s",
929 node ? node->name : channel->name);
931 qsdev->dev.parent = smd->dev;
932 qsdev->dev.bus = &qcom_smd_bus;
933 qsdev->dev.release = qcom_smd_release_device;
934 qsdev->dev.of_node = node;
936 qsdev->channel = channel;
938 channel->qsdev = qsdev;
940 ret = device_register(&qsdev->dev);
942 dev_err(smd->dev, "device_register failed: %d\n", ret);
943 put_device(&qsdev->dev);
950 * Destroy a smd client device for a channel that's going away.
952 static void qcom_smd_destroy_device(struct qcom_smd_channel *channel)
956 BUG_ON(!channel->qsdev);
958 dev = &channel->qsdev->dev;
960 device_unregister(dev);
961 of_node_put(dev->of_node);
966 * qcom_smd_driver_register - register a smd driver
967 * @qsdrv: qcom_smd_driver struct
969 int qcom_smd_driver_register(struct qcom_smd_driver *qsdrv)
971 qsdrv->driver.bus = &qcom_smd_bus;
972 return driver_register(&qsdrv->driver);
974 EXPORT_SYMBOL(qcom_smd_driver_register);
976 void *qcom_smd_get_drvdata(struct qcom_smd_channel *channel)
978 return channel->drvdata;
980 EXPORT_SYMBOL(qcom_smd_get_drvdata);
982 void qcom_smd_set_drvdata(struct qcom_smd_channel *channel, void *data)
984 channel->drvdata = data;
986 EXPORT_SYMBOL(qcom_smd_set_drvdata);
989 * qcom_smd_driver_unregister - unregister a smd driver
990 * @qsdrv: qcom_smd_driver struct
992 void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv)
994 driver_unregister(&qsdrv->driver);
996 EXPORT_SYMBOL(qcom_smd_driver_unregister);
998 static struct qcom_smd_channel *
999 qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
1001 struct qcom_smd_channel *channel;
1002 struct qcom_smd_channel *ret = NULL;
1005 read_lock(&edge->channels_lock);
1006 list_for_each_entry(channel, &edge->channels, list) {
1007 if (strcmp(channel->name, name))
1010 state = GET_RX_CHANNEL_INFO(channel, state);
1011 if (state != SMD_CHANNEL_OPENING &&
1012 state != SMD_CHANNEL_OPENED)
1018 read_unlock(&edge->channels_lock);
1024 * qcom_smd_open_channel() - claim additional channels on the same edge
1025 * @sdev: smd_device handle
1026 * @name: channel name
1027 * @cb: callback method to use for incoming data
1029 * Returns a channel handle on success, or -EPROBE_DEFER if the channel isn't
1032 struct qcom_smd_channel *qcom_smd_open_channel(struct qcom_smd_channel *parent,
1036 struct qcom_smd_channel *channel;
1037 struct qcom_smd_device *sdev = parent->qsdev;
1038 struct qcom_smd_edge *edge = parent->edge;
1041 /* Wait up to HZ for the channel to appear */
1042 ret = wait_event_interruptible_timeout(edge->new_channel_event,
1043 (channel = qcom_smd_find_channel(edge, name)) != NULL,
1046 return ERR_PTR(-ETIMEDOUT);
1048 if (channel->state != SMD_CHANNEL_CLOSED) {
1049 dev_err(&sdev->dev, "channel %s is busy\n", channel->name);
1050 return ERR_PTR(-EBUSY);
1053 channel->qsdev = sdev;
1054 ret = qcom_smd_channel_open(channel, cb);
1056 channel->qsdev = NULL;
1057 return ERR_PTR(ret);
1061 * Append the list of channel to the channels associated with the sdev
1063 list_add_tail(&channel->dev_list, &sdev->channel->dev_list);
1067 EXPORT_SYMBOL(qcom_smd_open_channel);
1070 * Allocate the qcom_smd_channel object for a newly found smd channel,
1071 * retrieving and validating the smem items involved.
1073 static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
1074 unsigned smem_info_item,
1075 unsigned smem_fifo_item,
1078 struct qcom_smd_channel *channel;
1079 struct qcom_smd *smd = edge->smd;
1086 channel = devm_kzalloc(smd->dev, sizeof(*channel), GFP_KERNEL);
1088 return ERR_PTR(-ENOMEM);
1090 INIT_LIST_HEAD(&channel->dev_list);
1091 channel->edge = edge;
1092 channel->name = devm_kstrdup(smd->dev, name, GFP_KERNEL);
1094 return ERR_PTR(-ENOMEM);
1096 mutex_init(&channel->tx_lock);
1097 spin_lock_init(&channel->recv_lock);
1098 init_waitqueue_head(&channel->fblockread_event);
1100 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1102 ret = PTR_ERR(info);
1103 goto free_name_and_channel;
1107 * Use the size of the item to figure out which channel info struct to
1110 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1111 channel->info_word = info;
1112 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1113 channel->info = info;
1116 "channel info of size %zu not supported\n", info_size);
1118 goto free_name_and_channel;
1121 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1122 if (IS_ERR(fifo_base)) {
1123 ret = PTR_ERR(fifo_base);
1124 goto free_name_and_channel;
1127 /* The channel consist of a rx and tx fifo of equal size */
1130 dev_err(smd->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1131 name, info_size, fifo_size);
1133 channel->tx_fifo = fifo_base;
1134 channel->rx_fifo = fifo_base + fifo_size;
1135 channel->fifo_size = fifo_size;
1137 qcom_smd_channel_reset(channel);
1141 free_name_and_channel:
1142 devm_kfree(smd->dev, channel->name);
1143 devm_kfree(smd->dev, channel);
1145 return ERR_PTR(ret);
1149 * Scans the allocation table for any newly allocated channels, calls
1150 * qcom_smd_create_channel() to create representations of these and add
1151 * them to the edge's list of channels.
1153 static void qcom_channel_scan_worker(struct work_struct *work)
1155 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1156 struct qcom_smd_alloc_entry *alloc_tbl;
1157 struct qcom_smd_alloc_entry *entry;
1158 struct qcom_smd_channel *channel;
1159 struct qcom_smd *smd = edge->smd;
1160 unsigned long flags;
1167 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1168 alloc_tbl = qcom_smem_get(edge->remote_pid,
1169 smem_items[tbl].alloc_tbl_id, NULL);
1170 if (IS_ERR(alloc_tbl))
1173 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1174 entry = &alloc_tbl[i];
1175 eflags = le32_to_cpu(entry->flags);
1176 if (test_bit(i, edge->allocated[tbl]))
1179 if (entry->ref_count == 0)
1182 if (!entry->name[0])
1185 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1188 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1191 cid = le32_to_cpu(entry->cid);
1192 info_id = smem_items[tbl].info_base_id + cid;
1193 fifo_id = smem_items[tbl].fifo_base_id + cid;
1195 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1196 if (IS_ERR(channel))
1199 write_lock_irqsave(&edge->channels_lock, flags);
1200 list_add(&channel->list, &edge->channels);
1201 write_unlock_irqrestore(&edge->channels_lock, flags);
1203 dev_dbg(smd->dev, "new channel found: '%s'\n", channel->name);
1204 set_bit(i, edge->allocated[tbl]);
1206 wake_up_interruptible(&edge->new_channel_event);
1210 schedule_work(&edge->state_work);
1214 * This per edge worker scans smem for any new channels and register these. It
1215 * then scans all registered channels for state changes that should be handled
1216 * by creating or destroying smd client devices for the registered channels.
1218 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1219 * worker is killed before any channels are deallocated
1221 static void qcom_channel_state_worker(struct work_struct *work)
1223 struct qcom_smd_channel *channel;
1224 struct qcom_smd_edge *edge = container_of(work,
1225 struct qcom_smd_edge,
1227 unsigned remote_state;
1230 * Register a device for any closed channel where the remote processor
1231 * is showing interest in opening the channel.
1233 read_lock(&edge->channels_lock);
1234 list_for_each_entry(channel, &edge->channels, list) {
1235 if (channel->state != SMD_CHANNEL_CLOSED)
1238 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1239 if (remote_state != SMD_CHANNEL_OPENING &&
1240 remote_state != SMD_CHANNEL_OPENED)
1243 read_unlock(&edge->channels_lock);
1244 qcom_smd_create_device(channel);
1245 read_lock(&edge->channels_lock);
1249 * Unregister the device for any channel that is opened where the
1250 * remote processor is closing the channel.
1252 list_for_each_entry(channel, &edge->channels, list) {
1253 if (channel->state != SMD_CHANNEL_OPENING &&
1254 channel->state != SMD_CHANNEL_OPENED)
1257 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1258 if (remote_state == SMD_CHANNEL_OPENING ||
1259 remote_state == SMD_CHANNEL_OPENED)
1262 read_unlock(&edge->channels_lock);
1263 qcom_smd_destroy_device(channel);
1264 read_lock(&edge->channels_lock);
1266 read_unlock(&edge->channels_lock);
1270 * Parses an of_node describing an edge.
1272 static int qcom_smd_parse_edge(struct device *dev,
1273 struct device_node *node,
1274 struct qcom_smd_edge *edge)
1276 struct device_node *syscon_np;
1281 INIT_LIST_HEAD(&edge->channels);
1282 rwlock_init(&edge->channels_lock);
1284 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1285 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1287 edge->of_node = of_node_get(node);
1289 irq = irq_of_parse_and_map(node, 0);
1291 dev_err(dev, "required smd interrupt missing\n");
1295 ret = devm_request_irq(dev, irq,
1296 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1299 dev_err(dev, "failed to request smd irq\n");
1305 key = "qcom,smd-edge";
1306 ret = of_property_read_u32(node, key, &edge->edge_id);
1308 dev_err(dev, "edge missing %s property\n", key);
1312 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1313 key = "qcom,remote-pid";
1314 of_property_read_u32(node, key, &edge->remote_pid);
1316 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1318 dev_err(dev, "no qcom,ipc node\n");
1322 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1323 if (IS_ERR(edge->ipc_regmap))
1324 return PTR_ERR(edge->ipc_regmap);
1327 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1329 dev_err(dev, "no offset in %s\n", key);
1333 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1335 dev_err(dev, "no bit in %s\n", key);
1342 static int qcom_smd_probe(struct platform_device *pdev)
1344 struct qcom_smd_edge *edge;
1345 struct device_node *node;
1346 struct qcom_smd *smd;
1354 p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
1355 if (PTR_ERR(p) == -EPROBE_DEFER)
1358 num_edges = of_get_available_child_count(pdev->dev.of_node);
1359 array_size = sizeof(*smd) + num_edges * sizeof(struct qcom_smd_edge);
1360 smd = devm_kzalloc(&pdev->dev, array_size, GFP_KERNEL);
1363 smd->dev = &pdev->dev;
1365 smd->num_edges = num_edges;
1366 for_each_available_child_of_node(pdev->dev.of_node, node) {
1367 edge = &smd->edges[i++];
1369 init_waitqueue_head(&edge->new_channel_event);
1371 ret = qcom_smd_parse_edge(&pdev->dev, node, edge);
1375 schedule_work(&edge->scan_work);
1378 platform_set_drvdata(pdev, smd);
1384 * Shut down all smd clients by making sure that each edge stops processing
1385 * events and scanning for new channels, then call destroy on the devices.
1387 static int qcom_smd_remove(struct platform_device *pdev)
1389 struct qcom_smd_channel *channel;
1390 struct qcom_smd_edge *edge;
1391 struct qcom_smd *smd = platform_get_drvdata(pdev);
1394 for (i = 0; i < smd->num_edges; i++) {
1395 edge = &smd->edges[i];
1397 disable_irq(edge->irq);
1398 cancel_work_sync(&edge->scan_work);
1399 cancel_work_sync(&edge->state_work);
1401 /* No need to lock here, because the writer is gone */
1402 list_for_each_entry(channel, &edge->channels, list) {
1403 if (!channel->qsdev)
1406 qcom_smd_destroy_device(channel);
1413 static const struct of_device_id qcom_smd_of_match[] = {
1414 { .compatible = "qcom,smd" },
1417 MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1419 static struct platform_driver qcom_smd_driver = {
1420 .probe = qcom_smd_probe,
1421 .remove = qcom_smd_remove,
1424 .of_match_table = qcom_smd_of_match,
1428 static int __init qcom_smd_init(void)
1432 ret = bus_register(&qcom_smd_bus);
1434 pr_err("failed to register smd bus: %d\n", ret);
1438 return platform_driver_register(&qcom_smd_driver);
1440 postcore_initcall(qcom_smd_init);
1442 static void __exit qcom_smd_exit(void)
1444 platform_driver_unregister(&qcom_smd_driver);
1445 bus_unregister(&qcom_smd_bus);
1447 module_exit(qcom_smd_exit);
1449 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
1450 MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1451 MODULE_LICENSE("GPL v2");