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 has ca 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;
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(sizeof(*qsept), GFP_KERNEL);
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, 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, 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 __poll_t qcom_smd_poll(struct rpmsg_endpoint *ept,
978 struct file *filp, poll_table *wait)
979{
980 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
981 struct qcom_smd_channel *channel = qsept->qsch;
982 __poll_t mask = 0;
983
984 poll_wait(filp, &channel->fblockread_event, wait);
985
986 if (qcom_smd_get_tx_avail(channel) > 20)
987 mask |= EPOLLOUT | EPOLLWRNORM;
988
989 return mask;
990}
991
992/*
993 * Finds the device_node for the smd child interested in this channel.
994 */
995static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
996 const char *channel)
997{
998 struct device_node *child;
999 const char *name;
1000 const char *key;
1001 int ret;
1002
1003 for_each_available_child_of_node(edge_node, child) {
1004 key = "qcom,smd-channels";
1005 ret = of_property_read_string(child, key, &name);
1006 if (ret)
1007 continue;
1008
1009 if (strcmp(name, channel) == 0)
1010 return child;
1011 }
1012
1013 return NULL;
1014}
1015
1016static int qcom_smd_announce_create(struct rpmsg_device *rpdev)
1017{
1018 struct qcom_smd_endpoint *qept = to_smd_endpoint(rpdev->ept);
1019 struct qcom_smd_channel *channel = qept->qsch;
1020 unsigned long flags;
1021 bool kick_state;
1022
1023 spin_lock_irqsave(&channel->recv_lock, flags);
1024 kick_state = qcom_smd_channel_intr(channel);
1025 spin_unlock_irqrestore(&channel->recv_lock, flags);
1026
1027 if (kick_state)
1028 schedule_work(&channel->edge->state_work);
1029
1030 return 0;
1031}
1032
1033static const struct rpmsg_device_ops qcom_smd_device_ops = {
1034 .create_ept = qcom_smd_create_ept,
1035 .announce_create = qcom_smd_announce_create,
1036};
1037
1038static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
1039 .destroy_ept = qcom_smd_destroy_ept,
1040 .send = qcom_smd_send,
1041 .trysend = qcom_smd_trysend,
1042 .poll = qcom_smd_poll,
1043};
1044
1045static void qcom_smd_release_device(struct device *dev)
1046{
1047 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1048 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
1049
1050 kfree(qsdev);
1051}
1052
1053/*
1054 * Create a smd client device for channel that is being opened.
1055 */
1056static int qcom_smd_create_device(struct qcom_smd_channel *channel)
1057{
1058 struct qcom_smd_device *qsdev;
1059 struct rpmsg_device *rpdev;
1060 struct qcom_smd_edge *edge = channel->edge;
1061
1062 dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
1063
1064 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
1065 if (!qsdev)
1066 return -ENOMEM;
1067
1068 /* Link qsdev to our SMD edge */
1069 qsdev->edge = edge;
1070
1071 /* Assign callbacks for rpmsg_device */
1072 qsdev->rpdev.ops = &qcom_smd_device_ops;
1073
1074 /* Assign public information to the rpmsg_device */
1075 rpdev = &qsdev->rpdev;
1076 strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
1077 rpdev->src = RPMSG_ADDR_ANY;
1078 rpdev->dst = RPMSG_ADDR_ANY;
1079
1080 rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
1081 rpdev->dev.parent = &edge->dev;
1082 rpdev->dev.release = qcom_smd_release_device;
1083
1084 return rpmsg_register_device(rpdev);
1085}
1086
1087static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
1088{
1089 struct qcom_smd_device *qsdev;
1090
1091 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
1092 if (!qsdev)
1093 return -ENOMEM;
1094
1095 qsdev->edge = edge;
1096 qsdev->rpdev.ops = &qcom_smd_device_ops;
1097 qsdev->rpdev.dev.parent = &edge->dev;
1098 qsdev->rpdev.dev.release = qcom_smd_release_device;
1099
1100 return rpmsg_chrdev_register_device(&qsdev->rpdev);
1101}
1102
1103/*
1104 * Allocate the qcom_smd_channel object for a newly found smd channel,
1105 * retrieving and validating the smem items involved.
1106 */
1107static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
1108 unsigned smem_info_item,
1109 unsigned smem_fifo_item,
1110 char *name)
1111{
1112 struct qcom_smd_channel *channel;
1113 size_t fifo_size;
1114 size_t info_size;
1115 void *fifo_base;
1116 void *info;
1117 int ret;
1118
1119 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
1120 if (!channel)
1121 return ERR_PTR(-ENOMEM);
1122
1123 channel->edge = edge;
1124 channel->name = kstrdup(name, GFP_KERNEL);
1125 if (!channel->name) {
1126 ret = -ENOMEM;
1127 goto free_channel;
1128 }
1129
1130 spin_lock_init(&channel->tx_lock);
1131 spin_lock_init(&channel->recv_lock);
1132 init_waitqueue_head(&channel->fblockread_event);
1133 init_waitqueue_head(&channel->state_change_event);
1134
1135 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1136 if (IS_ERR(info)) {
1137 ret = PTR_ERR(info);
1138 goto free_name_and_channel;
1139 }
1140
1141 /*
1142 * Use the size of the item to figure out which channel info struct to
1143 * use.
1144 */
1145 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1146 channel->info_word = info;
1147 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1148 channel->info = info;
1149 } else {
1150 dev_err(&edge->dev,
1151 "channel info of size %zu not supported\n", info_size);
1152 ret = -EINVAL;
1153 goto free_name_and_channel;
1154 }
1155
1156 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1157 if (IS_ERR(fifo_base)) {
1158 ret = PTR_ERR(fifo_base);
1159 goto free_name_and_channel;
1160 }
1161
1162 /* The channel consist of a rx and tx fifo of equal size */
1163 fifo_size /= 2;
1164
1165 dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1166 name, info_size, fifo_size);
1167
1168 channel->tx_fifo = fifo_base;
1169 channel->rx_fifo = fifo_base + fifo_size;
1170 channel->fifo_size = fifo_size;
1171
1172 qcom_smd_channel_reset(channel);
1173
1174 return channel;
1175
1176free_name_and_channel:
1177 kfree(channel->name);
1178free_channel:
1179 kfree(channel);
1180
1181 return ERR_PTR(ret);
1182}
1183
1184/*
1185 * Scans the allocation table for any newly allocated channels, calls
1186 * qcom_smd_create_channel() to create representations of these and add
1187 * them to the edge's list of channels.
1188 */
1189static void qcom_channel_scan_worker(struct work_struct *work)
1190{
1191 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1192 struct qcom_smd_alloc_entry *alloc_tbl;
1193 struct qcom_smd_alloc_entry *entry;
1194 struct qcom_smd_channel *channel;
1195 unsigned long flags;
1196 unsigned fifo_id;
1197 unsigned info_id;
1198 int tbl;
1199 int i;
1200 u32 eflags, cid;
1201
1202 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1203 alloc_tbl = qcom_smem_get(edge->remote_pid,
1204 smem_items[tbl].alloc_tbl_id, NULL);
1205 if (IS_ERR(alloc_tbl))
1206 continue;
1207
1208 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1209 entry = &alloc_tbl[i];
1210 eflags = le32_to_cpu(entry->flags);
1211 if (test_bit(i, edge->allocated[tbl]))
1212 continue;
1213
1214 if (entry->ref_count == 0)
1215 continue;
1216
1217 if (!entry->name[0])
1218 continue;
1219
1220 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1221 continue;
1222
1223 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1224 continue;
1225
1226 cid = le32_to_cpu(entry->cid);
1227 info_id = smem_items[tbl].info_base_id + cid;
1228 fifo_id = smem_items[tbl].fifo_base_id + cid;
1229
1230 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1231 if (IS_ERR(channel))
1232 continue;
1233
1234 spin_lock_irqsave(&edge->channels_lock, flags);
1235 list_add(&channel->list, &edge->channels);
1236 spin_unlock_irqrestore(&edge->channels_lock, flags);
1237
1238 dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
1239 set_bit(i, edge->allocated[tbl]);
1240
1241 wake_up_interruptible_all(&edge->new_channel_event);
1242 }
1243 }
1244
1245 schedule_work(&edge->state_work);
1246}
1247
1248/*
1249 * This per edge worker scans smem for any new channels and register these. It
1250 * then scans all registered channels for state changes that should be handled
1251 * by creating or destroying smd client devices for the registered channels.
1252 *
1253 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1254 * worker is killed before any channels are deallocated
1255 */
1256static void qcom_channel_state_worker(struct work_struct *work)
1257{
1258 struct qcom_smd_channel *channel;
1259 struct qcom_smd_edge *edge = container_of(work,
1260 struct qcom_smd_edge,
1261 state_work);
1262 struct rpmsg_channel_info chinfo;
1263 unsigned remote_state;
1264 unsigned long flags;
1265
1266 /*
1267 * Register a device for any closed channel where the remote processor
1268 * is showing interest in opening the channel.
1269 */
1270 spin_lock_irqsave(&edge->channels_lock, flags);
1271 list_for_each_entry(channel, &edge->channels, list) {
1272 if (channel->state != SMD_CHANNEL_CLOSED)
1273 continue;
1274
1275 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1276 if (remote_state != SMD_CHANNEL_OPENING &&
1277 remote_state != SMD_CHANNEL_OPENED)
1278 continue;
1279
1280 if (channel->registered)
1281 continue;
1282
1283 spin_unlock_irqrestore(&edge->channels_lock, flags);
1284 qcom_smd_create_device(channel);
1285 channel->registered = true;
1286 spin_lock_irqsave(&edge->channels_lock, flags);
1287
1288 channel->registered = true;
1289 }
1290
1291 /*
1292 * Unregister the device for any channel that is opened where the
1293 * remote processor is closing the channel.
1294 */
1295 list_for_each_entry(channel, &edge->channels, list) {
1296 if (channel->state != SMD_CHANNEL_OPENING &&
1297 channel->state != SMD_CHANNEL_OPENED)
1298 continue;
1299
1300 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1301 if (remote_state == SMD_CHANNEL_OPENING ||
1302 remote_state == SMD_CHANNEL_OPENED)
1303 continue;
1304
1305 spin_unlock_irqrestore(&edge->channels_lock, flags);
1306
1307 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1308 chinfo.src = RPMSG_ADDR_ANY;
1309 chinfo.dst = RPMSG_ADDR_ANY;
1310 rpmsg_unregister_device(&edge->dev, &chinfo);
1311 channel->registered = false;
1312 spin_lock_irqsave(&edge->channels_lock, flags);
1313 }
1314 spin_unlock_irqrestore(&edge->channels_lock, flags);
1315}
1316
1317/*
1318 * Parses an of_node describing an edge.
1319 */
1320static int qcom_smd_parse_edge(struct device *dev,
1321 struct device_node *node,
1322 struct qcom_smd_edge *edge)
1323{
1324 struct device_node *syscon_np;
1325 const char *key;
1326 int irq;
1327 int ret;
1328
1329 INIT_LIST_HEAD(&edge->channels);
1330 spin_lock_init(&edge->channels_lock);
1331
1332 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1333 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1334
1335 edge->of_node = of_node_get(node);
1336
1337 key = "qcom,smd-edge";
1338 ret = of_property_read_u32(node, key, &edge->edge_id);
1339 if (ret) {
1340 dev_err(dev, "edge missing %s property\n", key);
1341 return -EINVAL;
1342 }
1343
1344 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1345 key = "qcom,remote-pid";
1346 of_property_read_u32(node, key, &edge->remote_pid);
1347
1348 edge->mbox_client.dev = dev;
1349 edge->mbox_client.knows_txdone = true;
1350 edge->mbox_chan = mbox_request_channel(&edge->mbox_client, 0);
1351 if (IS_ERR(edge->mbox_chan)) {
1352 if (PTR_ERR(edge->mbox_chan) != -ENODEV)
1353 return PTR_ERR(edge->mbox_chan);
1354
1355 edge->mbox_chan = NULL;
1356
1357 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1358 if (!syscon_np) {
1359 dev_err(dev, "no qcom,ipc node\n");
1360 return -ENODEV;
1361 }
1362
1363 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1364 if (IS_ERR(edge->ipc_regmap))
1365 return PTR_ERR(edge->ipc_regmap);
1366
1367 key = "qcom,ipc";
1368 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1369 if (ret < 0) {
1370 dev_err(dev, "no offset in %s\n", key);
1371 return -EINVAL;
1372 }
1373
1374 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1375 if (ret < 0) {
1376 dev_err(dev, "no bit in %s\n", key);
1377 return -EINVAL;
1378 }
1379 }
1380
1381 ret = of_property_read_string(node, "label", &edge->name);
1382 if (ret < 0)
1383 edge->name = node->name;
1384
1385 irq = irq_of_parse_and_map(node, 0);
1386 if (irq < 0) {
1387 dev_err(dev, "required smd interrupt missing\n");
1388 return -EINVAL;
1389 }
1390
1391 ret = devm_request_irq(dev, irq,
1392 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1393 node->name, edge);
1394 if (ret) {
1395 dev_err(dev, "failed to request smd irq\n");
1396 return ret;
1397 }
1398
1399 edge->irq = irq;
1400
1401 return 0;
1402}
1403
1404/*
1405 * Release function for an edge.
1406 * Reset the state of each associated channel and free the edge context.
1407 */
1408static void qcom_smd_edge_release(struct device *dev)
1409{
1410 struct qcom_smd_channel *channel, *tmp;
1411 struct qcom_smd_edge *edge = to_smd_edge(dev);
1412
1413 list_for_each_entry_safe(channel, tmp, &edge->channels, list) {
1414 list_del(&channel->list);
1415 kfree(channel->name);
1416 kfree(channel);
1417 }
1418
1419 kfree(edge);
1420}
1421
1422static ssize_t rpmsg_name_show(struct device *dev,
1423 struct device_attribute *attr, char *buf)
1424{
1425 struct qcom_smd_edge *edge = to_smd_edge(dev);
1426
1427 return sprintf(buf, "%s\n", edge->name);
1428}
1429static DEVICE_ATTR_RO(rpmsg_name);
1430
1431static struct attribute *qcom_smd_edge_attrs[] = {
1432 &dev_attr_rpmsg_name.attr,
1433 NULL
1434};
1435ATTRIBUTE_GROUPS(qcom_smd_edge);
1436
1437/**
1438 * qcom_smd_register_edge() - register an edge based on an device_node
1439 * @parent: parent device for the edge
1440 * @node: device_node describing the edge
1441 *
1442 * Returns an edge reference, or negative ERR_PTR() on failure.
1443 */
1444struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
1445 struct device_node *node)
1446{
1447 struct qcom_smd_edge *edge;
1448 int ret;
1449
1450 edge = kzalloc(sizeof(*edge), GFP_KERNEL);
1451 if (!edge)
1452 return ERR_PTR(-ENOMEM);
1453
1454 init_waitqueue_head(&edge->new_channel_event);
1455
1456 edge->dev.parent = parent;
1457 edge->dev.release = qcom_smd_edge_release;
1458 edge->dev.of_node = node;
1459 edge->dev.groups = qcom_smd_edge_groups;
1460 dev_set_name(&edge->dev, "%s:%pOFn", dev_name(parent), node);
1461 ret = device_register(&edge->dev);
1462 if (ret) {
1463 pr_err("failed to register smd edge\n");
1464 put_device(&edge->dev);
1465 return ERR_PTR(ret);
1466 }
1467
1468 ret = qcom_smd_parse_edge(&edge->dev, node, edge);
1469 if (ret) {
1470 dev_err(&edge->dev, "failed to parse smd edge\n");
1471 goto unregister_dev;
1472 }
1473
1474 ret = qcom_smd_create_chrdev(edge);
1475 if (ret) {
1476 dev_err(&edge->dev, "failed to register chrdev for edge\n");
1477 goto unregister_dev;
1478 }
1479
1480 schedule_work(&edge->scan_work);
1481
1482 return edge;
1483
1484unregister_dev:
1485 if (!IS_ERR_OR_NULL(edge->mbox_chan))
1486 mbox_free_channel(edge->mbox_chan);
1487
1488 device_unregister(&edge->dev);
1489 return ERR_PTR(ret);
1490}
1491EXPORT_SYMBOL(qcom_smd_register_edge);
1492
1493static int qcom_smd_remove_device(struct device *dev, void *data)
1494{
1495 device_unregister(dev);
1496
1497 return 0;
1498}
1499
1500/**
1501 * qcom_smd_unregister_edge() - release an edge and its children
1502 * @edge: edge reference acquired from qcom_smd_register_edge
1503 */
1504int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
1505{
1506 int ret;
1507
1508 disable_irq(edge->irq);
1509 cancel_work_sync(&edge->scan_work);
1510 cancel_work_sync(&edge->state_work);
1511
1512 ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
1513 if (ret)
1514 dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
1515
1516 mbox_free_channel(edge->mbox_chan);
1517 device_unregister(&edge->dev);
1518
1519 return 0;
1520}
1521EXPORT_SYMBOL(qcom_smd_unregister_edge);
1522
1523static int qcom_smd_probe(struct platform_device *pdev)
1524{
1525 struct device_node *node;
1526 void *p;
1527
1528 /* Wait for smem */
1529 p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
1530 if (PTR_ERR(p) == -EPROBE_DEFER)
1531 return PTR_ERR(p);
1532
1533 for_each_available_child_of_node(pdev->dev.of_node, node)
1534 qcom_smd_register_edge(&pdev->dev, node);
1535
1536 return 0;
1537}
1538
1539static int qcom_smd_remove_edge(struct device *dev, void *data)
1540{
1541 struct qcom_smd_edge *edge = to_smd_edge(dev);
1542
1543 return qcom_smd_unregister_edge(edge);
1544}
1545
1546/*
1547 * Shut down all smd clients by making sure that each edge stops processing
1548 * events and scanning for new channels, then call destroy on the devices.
1549 */
1550static int qcom_smd_remove(struct platform_device *pdev)
1551{
1552 int ret;
1553
1554 ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
1555 if (ret)
1556 dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret);
1557
1558 return ret;
1559}
1560
1561static const struct of_device_id qcom_smd_of_match[] = {
1562 { .compatible = "qcom,smd" },
1563 {}
1564};
1565MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1566
1567static struct platform_driver qcom_smd_driver = {
1568 .probe = qcom_smd_probe,
1569 .remove = qcom_smd_remove,
1570 .driver = {
1571 .name = "qcom-smd",
1572 .of_match_table = qcom_smd_of_match,
1573 },
1574};
1575
1576static int __init qcom_smd_init(void)
1577{
1578 return platform_driver_register(&qcom_smd_driver);
1579}
1580subsys_initcall(qcom_smd_init);
1581
1582static void __exit qcom_smd_exit(void)
1583{
1584 platform_driver_unregister(&qcom_smd_driver);
1585}
1586module_exit(qcom_smd_exit);
1587
1588MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
1589MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1590MODULE_LICENSE("GPL v2");
1591