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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2015, Sony Mobile Communications AB.
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 */
6
7#include <linux/interrupt.h>
8#include <linux/io.h>
9#include <linux/mailbox_client.h>
10#include <linux/mfd/syscon.h>
11#include <linux/module.h>
12#include <linux/of_irq.h>
13#include <linux/of_platform.h>
14#include <linux/platform_device.h>
15#include <linux/regmap.h>
16#include <linux/sched.h>
17#include <linux/sizes.h>
18#include <linux/slab.h>
19#include <linux/soc/qcom/smem.h>
20#include <linux/wait.h>
21#include <linux/rpmsg.h>
22#include <linux/rpmsg/qcom_smd.h>
23
24#include "rpmsg_internal.h"
25
26/*
27 * The Qualcomm Shared Memory communication solution provides point-to-point
28 * channels for clients to send and receive streaming or packet based data.
29 *
30 * Each channel consists of a control item (channel info) and a ring buffer
31 * pair. The channel info carry information related to channel state, flow
32 * control and the offsets within the ring buffer.
33 *
34 * All allocated channels are listed in an allocation table, identifying the
35 * pair of items by name, type and remote processor.
36 *
37 * Upon creating a new channel the remote processor allocates channel info and
38 * ring buffer items from the smem heap and populate the allocation table. An
39 * interrupt is sent to the other end of the channel and a scan for new
40 * channels should be done. A channel never goes away, it will only change
41 * state.
42 *
43 * The remote processor signals it intent for bring up the communication
44 * channel by setting the state of its end of the channel to "opening" and
45 * sends out an interrupt. We detect this change and register a smd device to
46 * consume the channel. Upon finding a consumer we finish the handshake and the
47 * channel is up.
48 *
49 * Upon closing a channel, the remote processor will update the state of its
50 * end of the channel and signal us, we will then unregister any attached
51 * device and close our end of the channel.
52 *
53 * Devices attached to a channel can use the qcom_smd_send function to push
54 * data to the channel, this is done by copying the data into the tx ring
55 * buffer, updating the pointers in the channel info and signaling the remote
56 * processor.
57 *
58 * The remote processor does the equivalent when it transfer data and upon
59 * receiving the interrupt we check the channel info for new data and delivers
60 * this to the attached device. If the device is not ready to receive the data
61 * we leave it in the ring buffer for now.
62 */
63
64struct smd_channel_info;
65struct smd_channel_info_pair;
66struct smd_channel_info_word;
67struct smd_channel_info_word_pair;
68
69static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops;
70
71#define SMD_ALLOC_TBL_COUNT 2
72#define SMD_ALLOC_TBL_SIZE 64
73
74/*
75 * This lists the various smem heap items relevant for the allocation table and
76 * smd channel entries.
77 */
78static const struct {
79 unsigned alloc_tbl_id;
80 unsigned info_base_id;
81 unsigned fifo_base_id;
82} smem_items[SMD_ALLOC_TBL_COUNT] = {
83 {
84 .alloc_tbl_id = 13,
85 .info_base_id = 14,
86 .fifo_base_id = 338
87 },
88 {
89 .alloc_tbl_id = 266,
90 .info_base_id = 138,
91 .fifo_base_id = 202,
92 },
93};
94
95/**
96 * struct qcom_smd_edge - representing a remote processor
97 * @dev: device associated with this edge
98 * @name: name of this edge
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 * @mbox_client: mailbox client handle
107 * @mbox_chan: apcs ipc mailbox channel handle
108 * @channels: list of all channels detected on this edge
109 * @channels_lock: guard for modifications of @channels
110 * @allocated: array of bitmaps representing already allocated channels
111 * @smem_available: last available amount of smem triggering a channel scan
112 * @new_channel_event: wait queue for new channel events
113 * @scan_work: work item for discovering new channels
114 * @state_work: work item for edge state changes
115 */
116struct qcom_smd_edge {
117 struct device dev;
118
119 const char *name;
120
121 struct device_node *of_node;
122 unsigned edge_id;
123 unsigned remote_pid;
124
125 int irq;
126
127 struct regmap *ipc_regmap;
128 int ipc_offset;
129 int ipc_bit;
130
131 struct mbox_client mbox_client;
132 struct mbox_chan *mbox_chan;
133
134 struct list_head channels;
135 spinlock_t channels_lock;
136
137 DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
138
139 unsigned smem_available;
140
141 wait_queue_head_t new_channel_event;
142
143 struct work_struct scan_work;
144 struct work_struct state_work;
145};
146
147/*
148 * SMD channel states.
149 */
150enum smd_channel_state {
151 SMD_CHANNEL_CLOSED,
152 SMD_CHANNEL_OPENING,
153 SMD_CHANNEL_OPENED,
154 SMD_CHANNEL_FLUSHING,
155 SMD_CHANNEL_CLOSING,
156 SMD_CHANNEL_RESET,
157 SMD_CHANNEL_RESET_OPENING
158};
159
160struct qcom_smd_device {
161 struct rpmsg_device rpdev;
162
163 struct qcom_smd_edge *edge;
164};
165
166struct qcom_smd_endpoint {
167 struct rpmsg_endpoint ept;
168
169 struct qcom_smd_channel *qsch;
170};
171
172#define to_smd_device(r) container_of(r, struct qcom_smd_device, rpdev)
173#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev)
174#define to_smd_endpoint(e) container_of(e, struct qcom_smd_endpoint, ept)
175
176/**
177 * struct qcom_smd_channel - smd channel struct
178 * @edge: qcom_smd_edge this channel is living on
179 * @qsept: reference to a associated smd endpoint
180 * @registered: flag to indicate if the channel is registered
181 * @name: name of the channel
182 * @state: local state of the channel
183 * @remote_state: remote state of the channel
184 * @state_change_event: state change event
185 * @info: byte aligned outgoing/incoming channel info
186 * @info_word: word aligned outgoing/incoming channel info
187 * @tx_lock: lock to make writes to the channel mutually exclusive
188 * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
189 * @tx_fifo: pointer to the outgoing ring buffer
190 * @rx_fifo: pointer to the incoming ring buffer
191 * @fifo_size: size of each ring buffer
192 * @bounce_buffer: bounce buffer for reading wrapped packets
193 * @cb: callback function registered for this channel
194 * @recv_lock: guard for rx info modifications and cb pointer
195 * @pkt_size: size of the currently handled packet
196 * @drvdata: driver private data
197 * @list: lite entry for @channels in qcom_smd_edge
198 */
199struct qcom_smd_channel {
200 struct qcom_smd_edge *edge;
201
202 struct qcom_smd_endpoint *qsept;
203 bool registered;
204
205 char *name;
206 enum smd_channel_state state;
207 enum smd_channel_state remote_state;
208 wait_queue_head_t state_change_event;
209
210 struct smd_channel_info_pair *info;
211 struct smd_channel_info_word_pair *info_word;
212
213 spinlock_t tx_lock;
214 wait_queue_head_t fblockread_event;
215
216 void *tx_fifo;
217 void *rx_fifo;
218 int fifo_size;
219
220 void *bounce_buffer;
221
222 spinlock_t recv_lock;
223
224 int pkt_size;
225
226 void *drvdata;
227
228 struct list_head list;
229};
230
231/*
232 * Format of the smd_info smem items, for byte aligned channels.
233 */
234struct smd_channel_info {
235 __le32 state;
236 u8 fDSR;
237 u8 fCTS;
238 u8 fCD;
239 u8 fRI;
240 u8 fHEAD;
241 u8 fTAIL;
242 u8 fSTATE;
243 u8 fBLOCKREADINTR;
244 __le32 tail;
245 __le32 head;
246};
247
248struct smd_channel_info_pair {
249 struct smd_channel_info tx;
250 struct smd_channel_info rx;
251};
252
253/*
254 * Format of the smd_info smem items, for word aligned channels.
255 */
256struct smd_channel_info_word {
257 __le32 state;
258 __le32 fDSR;
259 __le32 fCTS;
260 __le32 fCD;
261 __le32 fRI;
262 __le32 fHEAD;
263 __le32 fTAIL;
264 __le32 fSTATE;
265 __le32 fBLOCKREADINTR;
266 __le32 tail;
267 __le32 head;
268};
269
270struct smd_channel_info_word_pair {
271 struct smd_channel_info_word tx;
272 struct smd_channel_info_word rx;
273};
274
275#define GET_RX_CHANNEL_FLAG(channel, param) \
276 ({ \
277 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
278 channel->info_word ? \
279 le32_to_cpu(channel->info_word->rx.param) : \
280 channel->info->rx.param; \
281 })
282
283#define GET_RX_CHANNEL_INFO(channel, param) \
284 ({ \
285 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
286 le32_to_cpu(channel->info_word ? \
287 channel->info_word->rx.param : \
288 channel->info->rx.param); \
289 })
290
291#define SET_RX_CHANNEL_FLAG(channel, param, value) \
292 ({ \
293 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
294 if (channel->info_word) \
295 channel->info_word->rx.param = cpu_to_le32(value); \
296 else \
297 channel->info->rx.param = value; \
298 })
299
300#define SET_RX_CHANNEL_INFO(channel, param, value) \
301 ({ \
302 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
303 if (channel->info_word) \
304 channel->info_word->rx.param = cpu_to_le32(value); \
305 else \
306 channel->info->rx.param = cpu_to_le32(value); \
307 })
308
309#define GET_TX_CHANNEL_FLAG(channel, param) \
310 ({ \
311 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
312 channel->info_word ? \
313 le32_to_cpu(channel->info_word->tx.param) : \
314 channel->info->tx.param; \
315 })
316
317#define GET_TX_CHANNEL_INFO(channel, param) \
318 ({ \
319 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
320 le32_to_cpu(channel->info_word ? \
321 channel->info_word->tx.param : \
322 channel->info->tx.param); \
323 })
324
325#define SET_TX_CHANNEL_FLAG(channel, param, value) \
326 ({ \
327 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
328 if (channel->info_word) \
329 channel->info_word->tx.param = cpu_to_le32(value); \
330 else \
331 channel->info->tx.param = value; \
332 })
333
334#define SET_TX_CHANNEL_INFO(channel, param, value) \
335 ({ \
336 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
337 if (channel->info_word) \
338 channel->info_word->tx.param = cpu_to_le32(value); \
339 else \
340 channel->info->tx.param = cpu_to_le32(value); \
341 })
342
343/**
344 * struct qcom_smd_alloc_entry - channel allocation entry
345 * @name: channel name
346 * @cid: channel index
347 * @flags: channel flags and edge id
348 * @ref_count: reference count of the channel
349 */
350struct qcom_smd_alloc_entry {
351 u8 name[20];
352 __le32 cid;
353 __le32 flags;
354 __le32 ref_count;
355} __packed;
356
357#define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
358#define SMD_CHANNEL_FLAGS_STREAM BIT(8)
359#define SMD_CHANNEL_FLAGS_PACKET BIT(9)
360
361/*
362 * Each smd packet contains a 20 byte header, with the first 4 being the length
363 * of the packet.
364 */
365#define SMD_PACKET_HEADER_LEN 20
366
367/*
368 * Signal the remote processor associated with 'channel'.
369 */
370static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
371{
372 struct qcom_smd_edge *edge = channel->edge;
373
374 if (edge->mbox_chan) {
375 /*
376 * We can ignore a failing mbox_send_message() as the only
377 * possible cause is that the FIFO in the framework is full of
378 * other writes to the same bit.
379 */
380 mbox_send_message(edge->mbox_chan, NULL);
381 mbox_client_txdone(edge->mbox_chan, 0);
382 } else {
383 regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
384 }
385}
386
387/*
388 * Initialize the tx channel info
389 */
390static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
391{
392 SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
393 SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
394 SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
395 SET_TX_CHANNEL_FLAG(channel, fCD, 0);
396 SET_TX_CHANNEL_FLAG(channel, fRI, 0);
397 SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
398 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
399 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
400 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
401 SET_TX_CHANNEL_INFO(channel, head, 0);
402 SET_RX_CHANNEL_INFO(channel, tail, 0);
403
404 qcom_smd_signal_channel(channel);
405
406 channel->state = SMD_CHANNEL_CLOSED;
407 channel->pkt_size = 0;
408}
409
410/*
411 * Set the callback for a channel, with appropriate locking
412 */
413static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
414 rpmsg_rx_cb_t cb)
415{
416 struct rpmsg_endpoint *ept = &channel->qsept->ept;
417 unsigned long flags;
418
419 spin_lock_irqsave(&channel->recv_lock, flags);
420 ept->cb = cb;
421 spin_unlock_irqrestore(&channel->recv_lock, flags);
422};
423
424/*
425 * Calculate the amount of data available in the rx fifo
426 */
427static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
428{
429 unsigned head;
430 unsigned tail;
431
432 head = GET_RX_CHANNEL_INFO(channel, head);
433 tail = GET_RX_CHANNEL_INFO(channel, tail);
434
435 return (head - tail) & (channel->fifo_size - 1);
436}
437
438/*
439 * Set tx channel state and inform the remote processor
440 */
441static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
442 int state)
443{
444 struct qcom_smd_edge *edge = channel->edge;
445 bool is_open = state == SMD_CHANNEL_OPENED;
446
447 if (channel->state == state)
448 return;
449
450 dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state);
451
452 SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
453 SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
454 SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
455
456 SET_TX_CHANNEL_INFO(channel, state, state);
457 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
458
459 channel->state = state;
460 qcom_smd_signal_channel(channel);
461}
462
463/*
464 * Copy count bytes of data using 32bit accesses, if that's required.
465 */
466static void smd_copy_to_fifo(void __iomem *dst,
467 const void *src,
468 size_t count,
469 bool word_aligned)
470{
471 if (word_aligned) {
472 __iowrite32_copy(dst, src, count / sizeof(u32));
473 } else {
474 memcpy_toio(dst, src, count);
475 }
476}
477
478/*
479 * Copy count bytes of data using 32bit accesses, if that is required.
480 */
481static void smd_copy_from_fifo(void *dst,
482 const void __iomem *src,
483 size_t count,
484 bool word_aligned)
485{
486 if (word_aligned) {
487 __ioread32_copy(dst, src, count / sizeof(u32));
488 } else {
489 memcpy_fromio(dst, src, count);
490 }
491}
492
493/*
494 * Read count bytes of data from the rx fifo into buf, but don't advance the
495 * tail.
496 */
497static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
498 void *buf, size_t count)
499{
500 bool word_aligned;
501 unsigned tail;
502 size_t len;
503
504 word_aligned = channel->info_word;
505 tail = GET_RX_CHANNEL_INFO(channel, tail);
506
507 len = min_t(size_t, count, channel->fifo_size - tail);
508 if (len) {
509 smd_copy_from_fifo(buf,
510 channel->rx_fifo + tail,
511 len,
512 word_aligned);
513 }
514
515 if (len != count) {
516 smd_copy_from_fifo(buf + len,
517 channel->rx_fifo,
518 count - len,
519 word_aligned);
520 }
521
522 return count;
523}
524
525/*
526 * Advance the rx tail by count bytes.
527 */
528static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
529 size_t count)
530{
531 unsigned tail;
532
533 tail = GET_RX_CHANNEL_INFO(channel, tail);
534 tail += count;
535 tail &= (channel->fifo_size - 1);
536 SET_RX_CHANNEL_INFO(channel, tail, tail);
537}
538
539/*
540 * Read out a single packet from the rx fifo and deliver it to the device
541 */
542static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
543{
544 struct rpmsg_endpoint *ept = &channel->qsept->ept;
545 unsigned tail;
546 size_t len;
547 void *ptr;
548 int ret;
549
550 tail = GET_RX_CHANNEL_INFO(channel, tail);
551
552 /* Use bounce buffer if the data wraps */
553 if (tail + channel->pkt_size >= channel->fifo_size) {
554 ptr = channel->bounce_buffer;
555 len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
556 } else {
557 ptr = channel->rx_fifo + tail;
558 len = channel->pkt_size;
559 }
560
561 ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY);
562 if (ret < 0)
563 return ret;
564
565 /* Only forward the tail if the client consumed the data */
566 qcom_smd_channel_advance(channel, len);
567
568 channel->pkt_size = 0;
569
570 return 0;
571}
572
573/*
574 * Per channel interrupt handling
575 */
576static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
577{
578 bool need_state_scan = false;
579 int remote_state;
580 __le32 pktlen;
581 int avail;
582 int ret;
583
584 /* Handle state changes */
585 remote_state = GET_RX_CHANNEL_INFO(channel, state);
586 if (remote_state != channel->remote_state) {
587 channel->remote_state = remote_state;
588 need_state_scan = true;
589
590 wake_up_interruptible_all(&channel->state_change_event);
591 }
592 /* Indicate that we have seen any state change */
593 SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
594
595 /* Signal waiting qcom_smd_send() about the interrupt */
596 if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
597 wake_up_interruptible_all(&channel->fblockread_event);
598
599 /* Don't consume any data until we've opened the channel */
600 if (channel->state != SMD_CHANNEL_OPENED)
601 goto out;
602
603 /* Indicate that we've seen the new data */
604 SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
605
606 /* Consume data */
607 for (;;) {
608 avail = qcom_smd_channel_get_rx_avail(channel);
609
610 if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
611 qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
612 qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
613 channel->pkt_size = le32_to_cpu(pktlen);
614 } else if (channel->pkt_size && avail >= channel->pkt_size) {
615 ret = qcom_smd_channel_recv_single(channel);
616 if (ret)
617 break;
618 } else {
619 break;
620 }
621 }
622
623 /* Indicate that we have seen and updated tail */
624 SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
625
626 /* Signal the remote that we've consumed the data (if requested) */
627 if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
628 /* Ensure ordering of channel info updates */
629 wmb();
630
631 qcom_smd_signal_channel(channel);
632 }
633
634out:
635 return need_state_scan;
636}
637
638/*
639 * The edge interrupts are triggered by the remote processor on state changes,
640 * channel info updates or when new channels are created.
641 */
642static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
643{
644 struct qcom_smd_edge *edge = data;
645 struct qcom_smd_channel *channel;
646 unsigned available;
647 bool kick_scanner = false;
648 bool kick_state = false;
649
650 /*
651 * Handle state changes or data on each of the channels on this edge
652 */
653 spin_lock(&edge->channels_lock);
654 list_for_each_entry(channel, &edge->channels, list) {
655 spin_lock(&channel->recv_lock);
656 kick_state |= qcom_smd_channel_intr(channel);
657 spin_unlock(&channel->recv_lock);
658 }
659 spin_unlock(&edge->channels_lock);
660
661 /*
662 * Creating a new channel requires allocating an smem entry, so we only
663 * have to scan if the amount of available space in smem have changed
664 * since last scan.
665 */
666 available = qcom_smem_get_free_space(edge->remote_pid);
667 if (available != edge->smem_available) {
668 edge->smem_available = available;
669 kick_scanner = true;
670 }
671
672 if (kick_scanner)
673 schedule_work(&edge->scan_work);
674 if (kick_state)
675 schedule_work(&edge->state_work);
676
677 return IRQ_HANDLED;
678}
679
680/*
681 * Calculate how much space is available in the tx fifo.
682 */
683static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
684{
685 unsigned head;
686 unsigned tail;
687 unsigned mask = channel->fifo_size - 1;
688
689 head = GET_TX_CHANNEL_INFO(channel, head);
690 tail = GET_TX_CHANNEL_INFO(channel, tail);
691
692 return mask - ((head - tail) & mask);
693}
694
695/*
696 * Write count bytes of data into channel, possibly wrapping in the ring buffer
697 */
698static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
699 const void *data,
700 size_t count)
701{
702 bool word_aligned;
703 unsigned head;
704 size_t len;
705
706 word_aligned = channel->info_word;
707 head = GET_TX_CHANNEL_INFO(channel, head);
708
709 len = min_t(size_t, count, channel->fifo_size - head);
710 if (len) {
711 smd_copy_to_fifo(channel->tx_fifo + head,
712 data,
713 len,
714 word_aligned);
715 }
716
717 if (len != count) {
718 smd_copy_to_fifo(channel->tx_fifo,
719 data + len,
720 count - len,
721 word_aligned);
722 }
723
724 head += count;
725 head &= (channel->fifo_size - 1);
726 SET_TX_CHANNEL_INFO(channel, head, head);
727
728 return count;
729}
730
731/**
732 * __qcom_smd_send - write data to smd channel
733 * @channel: channel handle
734 * @data: buffer of data to write
735 * @len: number of bytes to write
736 * @wait: flag to indicate if write can wait
737 *
738 * This is a blocking write of len bytes into the channel's tx ring buffer and
739 * signal the remote end. It will sleep until there is enough space available
740 * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
741 * polling.
742 */
743static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
744 int len, bool wait)
745{
746 __le32 hdr[5] = { cpu_to_le32(len), };
747 int tlen = sizeof(hdr) + len;
748 unsigned long flags;
749 int ret = 0;
750
751 /* Word aligned channels only accept word size aligned data */
752 if (channel->info_word && len % 4)
753 return -EINVAL;
754
755 /* Reject packets that are too big */
756 if (tlen >= channel->fifo_size)
757 return -EINVAL;
758
759 /* Highlight the fact that if we enter the loop below we might sleep */
760 if (wait)
761 might_sleep();
762
763 spin_lock_irqsave(&channel->tx_lock, flags);
764
765 while (qcom_smd_get_tx_avail(channel) < tlen &&
766 channel->state == SMD_CHANNEL_OPENED) {
767 if (!wait) {
768 ret = -EAGAIN;
769 goto out_unlock;
770 }
771
772 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
773
774 /* Wait without holding the tx_lock */
775 spin_unlock_irqrestore(&channel->tx_lock, flags);
776
777 ret = wait_event_interruptible(channel->fblockread_event,
778 qcom_smd_get_tx_avail(channel) >= tlen ||
779 channel->state != SMD_CHANNEL_OPENED);
780 if (ret)
781 return ret;
782
783 spin_lock_irqsave(&channel->tx_lock, flags);
784
785 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
786 }
787
788 /* Fail if the channel was closed */
789 if (channel->state != SMD_CHANNEL_OPENED) {
790 ret = -EPIPE;
791 goto out_unlock;
792 }
793
794 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
795
796 qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
797 qcom_smd_write_fifo(channel, data, len);
798
799 SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
800
801 /* Ensure ordering of channel info updates */
802 wmb();
803
804 qcom_smd_signal_channel(channel);
805
806out_unlock:
807 spin_unlock_irqrestore(&channel->tx_lock, flags);
808
809 return ret;
810}
811
812/*
813 * Helper for opening a channel
814 */
815static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
816 rpmsg_rx_cb_t cb)
817{
818 struct qcom_smd_edge *edge = channel->edge;
819 size_t bb_size;
820 int ret;
821
822 /*
823 * Packets are maximum 4k, but reduce if the fifo is smaller
824 */
825 bb_size = min(channel->fifo_size, SZ_4K);
826 channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
827 if (!channel->bounce_buffer)
828 return -ENOMEM;
829
830 qcom_smd_channel_set_callback(channel, cb);
831 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
832
833 /* Wait for remote to enter opening or opened */
834 ret = wait_event_interruptible_timeout(channel->state_change_event,
835 channel->remote_state == SMD_CHANNEL_OPENING ||
836 channel->remote_state == SMD_CHANNEL_OPENED,
837 HZ);
838 if (!ret) {
839 dev_err(&edge->dev, "remote side did not enter opening state\n");
840 goto out_close_timeout;
841 }
842
843 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
844
845 /* Wait for remote to enter opened */
846 ret = wait_event_interruptible_timeout(channel->state_change_event,
847 channel->remote_state == SMD_CHANNEL_OPENED,
848 HZ);
849 if (!ret) {
850 dev_err(&edge->dev, "remote side did not enter open state\n");
851 goto out_close_timeout;
852 }
853
854 return 0;
855
856out_close_timeout:
857 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
858 return -ETIMEDOUT;
859}
860
861/*
862 * Helper for closing and resetting a channel
863 */
864static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
865{
866 qcom_smd_channel_set_callback(channel, NULL);
867
868 kfree(channel->bounce_buffer);
869 channel->bounce_buffer = NULL;
870
871 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
872 qcom_smd_channel_reset(channel);
873}
874
875static struct qcom_smd_channel *
876qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
877{
878 struct qcom_smd_channel *channel;
879 struct qcom_smd_channel *ret = NULL;
880 unsigned long flags;
881
882 spin_lock_irqsave(&edge->channels_lock, flags);
883 list_for_each_entry(channel, &edge->channels, list) {
884 if (!strcmp(channel->name, name)) {
885 ret = channel;
886 break;
887 }
888 }
889 spin_unlock_irqrestore(&edge->channels_lock, flags);
890
891 return ret;
892}
893
894static void __ept_release(struct kref *kref)
895{
896 struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
897 refcount);
898 kfree(to_smd_endpoint(ept));
899}
900
901static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev,
902 rpmsg_rx_cb_t cb, void *priv,
903 struct rpmsg_channel_info chinfo)
904{
905 struct qcom_smd_endpoint *qsept;
906 struct qcom_smd_channel *channel;
907 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
908 struct qcom_smd_edge *edge = qsdev->edge;
909 struct rpmsg_endpoint *ept;
910 const char *name = chinfo.name;
911 int ret;
912
913 /* Wait up to HZ for the channel to appear */
914 ret = wait_event_interruptible_timeout(edge->new_channel_event,
915 (channel = qcom_smd_find_channel(edge, name)) != NULL,
916 HZ);
917 if (!ret)
918 return NULL;
919
920 if (channel->state != SMD_CHANNEL_CLOSED) {
921 dev_err(&rpdev->dev, "channel %s is busy\n", channel->name);
922 return NULL;
923 }
924
925 qsept = kzalloc_obj(*qsept);
926 if (!qsept)
927 return NULL;
928
929 ept = &qsept->ept;
930
931 kref_init(&ept->refcount);
932
933 ept->rpdev = rpdev;
934 ept->cb = cb;
935 ept->priv = priv;
936 ept->ops = &qcom_smd_endpoint_ops;
937
938 channel->qsept = qsept;
939 qsept->qsch = channel;
940
941 ret = qcom_smd_channel_open(channel, cb);
942 if (ret)
943 goto free_ept;
944
945 return ept;
946
947free_ept:
948 channel->qsept = NULL;
949 kref_put(&ept->refcount, __ept_release);
950 return NULL;
951}
952
953static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept)
954{
955 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
956 struct qcom_smd_channel *ch = qsept->qsch;
957
958 qcom_smd_channel_close(ch);
959 ch->qsept = NULL;
960 kref_put(&ept->refcount, __ept_release);
961}
962
963static int qcom_smd_send(struct rpmsg_endpoint *ept, const void *data, int len)
964{
965 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
966
967 return __qcom_smd_send(qsept->qsch, data, len, true);
968}
969
970static int qcom_smd_trysend(struct rpmsg_endpoint *ept, const void *data, int len)
971{
972 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
973
974 return __qcom_smd_send(qsept->qsch, data, len, false);
975}
976
977static int qcom_smd_sendto(struct rpmsg_endpoint *ept, const void *data, int len,
978 u32 dst)
979{
980 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
981
982 return __qcom_smd_send(qsept->qsch, data, len, true);
983}
984
985static int qcom_smd_trysendto(struct rpmsg_endpoint *ept, const void *data,
986 int len, u32 dst)
987{
988 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
989
990 return __qcom_smd_send(qsept->qsch, data, len, false);
991}
992
993static __poll_t qcom_smd_poll(struct rpmsg_endpoint *ept,
994 struct file *filp, poll_table *wait)
995{
996 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
997 struct qcom_smd_channel *channel = qsept->qsch;
998 __poll_t mask = 0;
999
1000 poll_wait(filp, &channel->fblockread_event, wait);
1001
1002 if (qcom_smd_get_tx_avail(channel) > 20)
1003 mask |= EPOLLOUT | EPOLLWRNORM;
1004
1005 return mask;
1006}
1007
1008/*
1009 * Finds the device_node for the smd child interested in this channel.
1010 */
1011static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
1012 const char *channel)
1013{
1014 struct device_node *child;
1015 const char *name;
1016 const char *key;
1017 int ret;
1018
1019 for_each_available_child_of_node(edge_node, child) {
1020 key = "qcom,smd-channels";
1021 ret = of_property_read_string(child, key, &name);
1022 if (ret)
1023 continue;
1024
1025 if (strcmp(name, channel) == 0)
1026 return child;
1027 }
1028
1029 return NULL;
1030}
1031
1032static int qcom_smd_announce_create(struct rpmsg_device *rpdev)
1033{
1034 struct qcom_smd_endpoint *qept = to_smd_endpoint(rpdev->ept);
1035 struct qcom_smd_channel *channel = qept->qsch;
1036 unsigned long flags;
1037 bool kick_state;
1038
1039 spin_lock_irqsave(&channel->recv_lock, flags);
1040 kick_state = qcom_smd_channel_intr(channel);
1041 spin_unlock_irqrestore(&channel->recv_lock, flags);
1042
1043 if (kick_state)
1044 schedule_work(&channel->edge->state_work);
1045
1046 return 0;
1047}
1048
1049static const struct rpmsg_device_ops qcom_smd_device_ops = {
1050 .create_ept = qcom_smd_create_ept,
1051 .announce_create = qcom_smd_announce_create,
1052};
1053
1054static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
1055 .destroy_ept = qcom_smd_destroy_ept,
1056 .send = qcom_smd_send,
1057 .sendto = qcom_smd_sendto,
1058 .trysend = qcom_smd_trysend,
1059 .trysendto = qcom_smd_trysendto,
1060 .poll = qcom_smd_poll,
1061};
1062
1063static void qcom_smd_release_device(struct device *dev)
1064{
1065 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1066 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
1067
1068 kfree(qsdev);
1069}
1070
1071/*
1072 * Create a smd client device for channel that is being opened.
1073 */
1074static int qcom_smd_create_device(struct qcom_smd_channel *channel)
1075{
1076 struct qcom_smd_device *qsdev;
1077 struct rpmsg_device *rpdev;
1078 struct qcom_smd_edge *edge = channel->edge;
1079
1080 dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
1081
1082 qsdev = kzalloc_obj(*qsdev);
1083 if (!qsdev)
1084 return -ENOMEM;
1085
1086 /* Link qsdev to our SMD edge */
1087 qsdev->edge = edge;
1088
1089 /* Assign callbacks for rpmsg_device */
1090 qsdev->rpdev.ops = &qcom_smd_device_ops;
1091
1092 /* Assign public information to the rpmsg_device */
1093 rpdev = &qsdev->rpdev;
1094 strscpy(rpdev->id.name, channel->name);
1095 rpdev->src = RPMSG_ADDR_ANY;
1096 rpdev->dst = RPMSG_ADDR_ANY;
1097
1098 rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
1099 rpdev->dev.parent = &edge->dev;
1100 rpdev->dev.release = qcom_smd_release_device;
1101
1102 return rpmsg_register_device(rpdev);
1103}
1104
1105static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
1106{
1107 struct qcom_smd_device *qsdev;
1108
1109 qsdev = kzalloc_obj(*qsdev);
1110 if (!qsdev)
1111 return -ENOMEM;
1112
1113 qsdev->edge = edge;
1114 qsdev->rpdev.ops = &qcom_smd_device_ops;
1115 qsdev->rpdev.dev.parent = &edge->dev;
1116 qsdev->rpdev.dev.release = qcom_smd_release_device;
1117
1118 return rpmsg_ctrldev_register_device(&qsdev->rpdev);
1119}
1120
1121/*
1122 * Allocate the qcom_smd_channel object for a newly found smd channel,
1123 * retrieving and validating the smem items involved.
1124 */
1125static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
1126 unsigned smem_info_item,
1127 unsigned smem_fifo_item,
1128 char *name)
1129{
1130 struct qcom_smd_channel *channel;
1131 size_t fifo_size;
1132 size_t info_size;
1133 void *fifo_base;
1134 void *info;
1135 int ret;
1136
1137 channel = kzalloc_obj(*channel);
1138 if (!channel)
1139 return ERR_PTR(-ENOMEM);
1140
1141 channel->edge = edge;
1142 channel->name = kstrdup(name, GFP_KERNEL);
1143 if (!channel->name) {
1144 ret = -ENOMEM;
1145 goto free_channel;
1146 }
1147
1148 spin_lock_init(&channel->tx_lock);
1149 spin_lock_init(&channel->recv_lock);
1150 init_waitqueue_head(&channel->fblockread_event);
1151 init_waitqueue_head(&channel->state_change_event);
1152
1153 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1154 if (IS_ERR(info)) {
1155 ret = PTR_ERR(info);
1156 goto free_name_and_channel;
1157 }
1158
1159 /*
1160 * Use the size of the item to figure out which channel info struct to
1161 * use.
1162 */
1163 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1164 channel->info_word = info;
1165 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1166 channel->info = info;
1167 } else {
1168 dev_err(&edge->dev,
1169 "channel info of size %zu not supported\n", info_size);
1170 ret = -EINVAL;
1171 goto free_name_and_channel;
1172 }
1173
1174 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1175 if (IS_ERR(fifo_base)) {
1176 ret = PTR_ERR(fifo_base);
1177 goto free_name_and_channel;
1178 }
1179
1180 /* The channel consist of a rx and tx fifo of equal size */
1181 fifo_size /= 2;
1182
1183 dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1184 name, info_size, fifo_size);
1185
1186 channel->tx_fifo = fifo_base;
1187 channel->rx_fifo = fifo_base + fifo_size;
1188 channel->fifo_size = fifo_size;
1189
1190 qcom_smd_channel_reset(channel);
1191
1192 return channel;
1193
1194free_name_and_channel:
1195 kfree(channel->name);
1196free_channel:
1197 kfree(channel);
1198
1199 return ERR_PTR(ret);
1200}
1201
1202/*
1203 * Scans the allocation table for any newly allocated channels, calls
1204 * qcom_smd_create_channel() to create representations of these and add
1205 * them to the edge's list of channels.
1206 */
1207static void qcom_channel_scan_worker(struct work_struct *work)
1208{
1209 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1210 struct qcom_smd_alloc_entry *alloc_tbl;
1211 struct qcom_smd_alloc_entry *entry;
1212 struct qcom_smd_channel *channel;
1213 unsigned long flags;
1214 unsigned fifo_id;
1215 unsigned info_id;
1216 int tbl;
1217 int i;
1218 u32 eflags, cid;
1219
1220 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1221 alloc_tbl = qcom_smem_get(edge->remote_pid,
1222 smem_items[tbl].alloc_tbl_id, NULL);
1223 if (IS_ERR(alloc_tbl))
1224 continue;
1225
1226 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1227 entry = &alloc_tbl[i];
1228 eflags = le32_to_cpu(entry->flags);
1229 if (test_bit(i, edge->allocated[tbl]))
1230 continue;
1231
1232 if (entry->ref_count == 0)
1233 continue;
1234
1235 if (!entry->name[0])
1236 continue;
1237
1238 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1239 continue;
1240
1241 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1242 continue;
1243
1244 cid = le32_to_cpu(entry->cid);
1245 info_id = smem_items[tbl].info_base_id + cid;
1246 fifo_id = smem_items[tbl].fifo_base_id + cid;
1247
1248 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1249 if (IS_ERR(channel))
1250 continue;
1251
1252 spin_lock_irqsave(&edge->channels_lock, flags);
1253 list_add(&channel->list, &edge->channels);
1254 spin_unlock_irqrestore(&edge->channels_lock, flags);
1255
1256 dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
1257 set_bit(i, edge->allocated[tbl]);
1258
1259 wake_up_interruptible_all(&edge->new_channel_event);
1260 }
1261 }
1262
1263 schedule_work(&edge->state_work);
1264}
1265
1266/*
1267 * This per edge worker scans smem for any new channels and register these. It
1268 * then scans all registered channels for state changes that should be handled
1269 * by creating or destroying smd client devices for the registered channels.
1270 *
1271 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1272 * worker is killed before any channels are deallocated
1273 */
1274static void qcom_channel_state_worker(struct work_struct *work)
1275{
1276 struct qcom_smd_channel *channel;
1277 struct qcom_smd_edge *edge = container_of(work,
1278 struct qcom_smd_edge,
1279 state_work);
1280 struct rpmsg_channel_info chinfo;
1281 unsigned remote_state;
1282 unsigned long flags;
1283
1284 /*
1285 * Register a device for any closed channel where the remote processor
1286 * is showing interest in opening the channel.
1287 */
1288 spin_lock_irqsave(&edge->channels_lock, flags);
1289 list_for_each_entry(channel, &edge->channels, list) {
1290 if (channel->state != SMD_CHANNEL_CLOSED)
1291 continue;
1292
1293 /*
1294 * Always open rpm_requests, even when already opened which is
1295 * required on some SoCs like msm8953.
1296 */
1297 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1298 if (remote_state != SMD_CHANNEL_OPENING &&
1299 remote_state != SMD_CHANNEL_OPENED &&
1300 strcmp(channel->name, "rpm_requests"))
1301 continue;
1302
1303 if (channel->registered)
1304 continue;
1305
1306 spin_unlock_irqrestore(&edge->channels_lock, flags);
1307 qcom_smd_create_device(channel);
1308 spin_lock_irqsave(&edge->channels_lock, flags);
1309 channel->registered = true;
1310 }
1311
1312 /*
1313 * Unregister the device for any channel that is opened where the
1314 * remote processor is closing the channel.
1315 */
1316 list_for_each_entry(channel, &edge->channels, list) {
1317 if (channel->state != SMD_CHANNEL_OPENING &&
1318 channel->state != SMD_CHANNEL_OPENED)
1319 continue;
1320
1321 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1322 if (remote_state == SMD_CHANNEL_OPENING ||
1323 remote_state == SMD_CHANNEL_OPENED)
1324 continue;
1325
1326 spin_unlock_irqrestore(&edge->channels_lock, flags);
1327
1328 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1329 chinfo.src = RPMSG_ADDR_ANY;
1330 chinfo.dst = RPMSG_ADDR_ANY;
1331 rpmsg_unregister_device(&edge->dev, &chinfo);
1332 channel->registered = false;
1333 spin_lock_irqsave(&edge->channels_lock, flags);
1334 }
1335 spin_unlock_irqrestore(&edge->channels_lock, flags);
1336}
1337
1338/*
1339 * Parses an of_node describing an edge.
1340 */
1341static int qcom_smd_parse_edge(struct device *dev,
1342 struct device_node *node,
1343 struct qcom_smd_edge *edge)
1344{
1345 struct device_node *syscon_np;
1346 const char *key;
1347 int irq;
1348 int ret;
1349
1350 INIT_LIST_HEAD(&edge->channels);
1351 spin_lock_init(&edge->channels_lock);
1352
1353 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1354 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1355
1356 edge->of_node = of_node_get(node);
1357
1358 key = "qcom,smd-edge";
1359 ret = of_property_read_u32(node, key, &edge->edge_id);
1360 if (ret) {
1361 dev_err(dev, "edge missing %s property\n", key);
1362 goto put_node;
1363 }
1364
1365 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1366 key = "qcom,remote-pid";
1367 of_property_read_u32(node, key, &edge->remote_pid);
1368
1369 edge->mbox_client.dev = dev;
1370 edge->mbox_client.knows_txdone = true;
1371 edge->mbox_chan = mbox_request_channel(&edge->mbox_client, 0);
1372 if (IS_ERR(edge->mbox_chan)) {
1373 if (PTR_ERR(edge->mbox_chan) != -ENOENT) {
1374 ret = dev_err_probe(dev, PTR_ERR(edge->mbox_chan),
1375 "failed to acquire IPC mailbox\n");
1376 goto put_node;
1377 }
1378
1379 edge->mbox_chan = NULL;
1380
1381 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1382 if (!syscon_np) {
1383 dev_err(dev, "no qcom,ipc node\n");
1384 ret = -ENODEV;
1385 goto put_node;
1386 }
1387
1388 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1389 of_node_put(syscon_np);
1390 if (IS_ERR(edge->ipc_regmap)) {
1391 ret = PTR_ERR(edge->ipc_regmap);
1392 dev_err(dev, "failed to get regmap from syscon: %d\n", ret);
1393 goto put_node;
1394 }
1395
1396 key = "qcom,ipc";
1397 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1398 if (ret < 0) {
1399 dev_err(dev, "no offset in %s\n", key);
1400 goto put_node;
1401 }
1402
1403 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1404 if (ret < 0) {
1405 dev_err(dev, "no bit in %s\n", key);
1406 goto put_node;
1407 }
1408 }
1409
1410 ret = of_property_read_string(node, "label", &edge->name);
1411 if (ret < 0)
1412 edge->name = node->name;
1413
1414 irq = irq_of_parse_and_map(node, 0);
1415 if (!irq) {
1416 dev_err(dev, "required smd interrupt missing\n");
1417 ret = -EINVAL;
1418 goto put_node;
1419 }
1420
1421 ret = devm_request_irq(dev, irq,
1422 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1423 node->name, edge);
1424 if (ret) {
1425 dev_err(dev, "failed to request smd irq\n");
1426 goto put_node;
1427 }
1428
1429 edge->irq = irq;
1430
1431 return 0;
1432
1433put_node:
1434 of_node_put(node);
1435 edge->of_node = NULL;
1436
1437 return ret;
1438}
1439
1440/*
1441 * Release function for an edge.
1442 * Reset the state of each associated channel and free the edge context.
1443 */
1444static void qcom_smd_edge_release(struct device *dev)
1445{
1446 struct qcom_smd_channel *channel, *tmp;
1447 struct qcom_smd_edge *edge = to_smd_edge(dev);
1448
1449 list_for_each_entry_safe(channel, tmp, &edge->channels, list) {
1450 list_del(&channel->list);
1451 kfree(channel->name);
1452 kfree(channel);
1453 }
1454
1455 kfree(edge);
1456}
1457
1458static ssize_t rpmsg_name_show(struct device *dev,
1459 struct device_attribute *attr, char *buf)
1460{
1461 struct qcom_smd_edge *edge = to_smd_edge(dev);
1462
1463 return sysfs_emit(buf, "%s\n", edge->name);
1464}
1465static DEVICE_ATTR_RO(rpmsg_name);
1466
1467static struct attribute *qcom_smd_edge_attrs[] = {
1468 &dev_attr_rpmsg_name.attr,
1469 NULL
1470};
1471ATTRIBUTE_GROUPS(qcom_smd_edge);
1472
1473/**
1474 * qcom_smd_register_edge() - register an edge based on an device_node
1475 * @parent: parent device for the edge
1476 * @node: device_node describing the edge
1477 *
1478 * Return: an edge reference, or negative ERR_PTR() on failure.
1479 */
1480struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
1481 struct device_node *node)
1482{
1483 struct qcom_smd_edge *edge;
1484 int ret;
1485
1486 if (!qcom_smem_is_available())
1487 return ERR_PTR(-EPROBE_DEFER);
1488
1489 edge = kzalloc_obj(*edge);
1490 if (!edge)
1491 return ERR_PTR(-ENOMEM);
1492
1493 init_waitqueue_head(&edge->new_channel_event);
1494
1495 edge->dev.parent = parent;
1496 edge->dev.release = qcom_smd_edge_release;
1497 edge->dev.of_node = node;
1498 edge->dev.groups = qcom_smd_edge_groups;
1499 dev_set_name(&edge->dev, "%s:%pOFn", dev_name(parent), node);
1500 ret = device_register(&edge->dev);
1501 if (ret) {
1502 pr_err("failed to register smd edge\n");
1503 put_device(&edge->dev);
1504 return ERR_PTR(ret);
1505 }
1506
1507 ret = qcom_smd_parse_edge(&edge->dev, node, edge);
1508 if (ret)
1509 goto unregister_dev;
1510
1511 ret = qcom_smd_create_chrdev(edge);
1512 if (ret) {
1513 dev_err(&edge->dev, "failed to register chrdev for edge\n");
1514 goto unregister_dev;
1515 }
1516
1517 schedule_work(&edge->scan_work);
1518
1519 return edge;
1520
1521unregister_dev:
1522 if (!IS_ERR_OR_NULL(edge->mbox_chan))
1523 mbox_free_channel(edge->mbox_chan);
1524
1525 device_unregister(&edge->dev);
1526 return ERR_PTR(ret);
1527}
1528EXPORT_SYMBOL(qcom_smd_register_edge);
1529
1530static int qcom_smd_remove_device(struct device *dev, void *data)
1531{
1532 device_unregister(dev);
1533
1534 return 0;
1535}
1536
1537/**
1538 * qcom_smd_unregister_edge() - release an edge and its children
1539 * @edge: edge reference acquired from qcom_smd_register_edge
1540 */
1541void qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
1542{
1543 int ret;
1544
1545 disable_irq(edge->irq);
1546 cancel_work_sync(&edge->scan_work);
1547 cancel_work_sync(&edge->state_work);
1548
1549 ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
1550 if (ret)
1551 dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
1552
1553 mbox_free_channel(edge->mbox_chan);
1554 device_unregister(&edge->dev);
1555}
1556EXPORT_SYMBOL(qcom_smd_unregister_edge);
1557
1558static int qcom_smd_probe(struct platform_device *pdev)
1559{
1560 struct device_node *node;
1561
1562 if (!qcom_smem_is_available())
1563 return -EPROBE_DEFER;
1564
1565 for_each_available_child_of_node(pdev->dev.of_node, node)
1566 qcom_smd_register_edge(&pdev->dev, node);
1567
1568 return 0;
1569}
1570
1571static int qcom_smd_remove_edge(struct device *dev, void *data)
1572{
1573 struct qcom_smd_edge *edge = to_smd_edge(dev);
1574
1575 qcom_smd_unregister_edge(edge);
1576
1577 return 0;
1578}
1579
1580/*
1581 * Shut down all smd clients by making sure that each edge stops processing
1582 * events and scanning for new channels, then call destroy on the devices.
1583 */
1584static void qcom_smd_remove(struct platform_device *pdev)
1585{
1586 /*
1587 * qcom_smd_remove_edge always returns zero, so there is no need to
1588 * check the return value of device_for_each_child.
1589 */
1590 device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
1591}
1592
1593static const struct of_device_id qcom_smd_of_match[] = {
1594 { .compatible = "qcom,smd" },
1595 {}
1596};
1597MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1598
1599static struct platform_driver qcom_smd_driver = {
1600 .probe = qcom_smd_probe,
1601 .remove = qcom_smd_remove,
1602 .driver = {
1603 .name = "qcom-smd",
1604 .of_match_table = qcom_smd_of_match,
1605 },
1606};
1607
1608static int __init qcom_smd_init(void)
1609{
1610 return platform_driver_register(&qcom_smd_driver);
1611}
1612arch_initcall(qcom_smd_init);
1613
1614static void __exit qcom_smd_exit(void)
1615{
1616 platform_driver_unregister(&qcom_smd_driver);
1617}
1618module_exit(qcom_smd_exit);
1619
1620MODULE_AUTHOR("Bjorn Andersson <[email protected]>");
1621MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1622MODULE_LICENSE("GPL v2");