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
64 struct smd_channel_info;
65 struct smd_channel_info_pair;
66 struct smd_channel_info_word;
67 struct smd_channel_info_word_pair;
68
69 static 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 */
78 static 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 */
116 struct 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 */
150 enum 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
160 struct qcom_smd_device {
161 struct rpmsg_device rpdev;
162
163 struct qcom_smd_edge *edge;
164 };
165
166 struct 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 */
199 struct 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 */
234 struct 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
248 struct 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 */
256 struct 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
270 struct 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 */
350 struct 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 */
qcom_smd_signal_channel(struct qcom_smd_channel * channel)370 static 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 */
qcom_smd_channel_reset(struct qcom_smd_channel * channel)390 static 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 */
qcom_smd_channel_set_callback(struct qcom_smd_channel * channel,rpmsg_rx_cb_t cb)413 static 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 */
qcom_smd_channel_get_rx_avail(struct qcom_smd_channel * channel)427 static 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 */
qcom_smd_channel_set_state(struct qcom_smd_channel * channel,int state)441 static 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 */
smd_copy_to_fifo(void __iomem * dst,const void * src,size_t count,bool word_aligned)466 static 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 */
smd_copy_from_fifo(void * dst,const void __iomem * src,size_t count,bool word_aligned)481 static 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 */
qcom_smd_channel_peek(struct qcom_smd_channel * channel,void * buf,size_t count)497 static 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 */
qcom_smd_channel_advance(struct qcom_smd_channel * channel,size_t count)528 static 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 */
qcom_smd_channel_recv_single(struct qcom_smd_channel * channel)542 static 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 */
qcom_smd_channel_intr(struct qcom_smd_channel * channel)576 static 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
634 out:
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 */
qcom_smd_edge_intr(int irq,void * data)642 static 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 */
qcom_smd_get_tx_avail(struct qcom_smd_channel * channel)683 static 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 */
qcom_smd_write_fifo(struct qcom_smd_channel * channel,const void * data,size_t count)698 static 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 */
__qcom_smd_send(struct qcom_smd_channel * channel,const void * data,int len,bool wait)743 static 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
806 out_unlock:
807 spin_unlock_irqrestore(&channel->tx_lock, flags);
808
809 return ret;
810 }
811
812 /*
813 * Helper for opening a channel
814 */
qcom_smd_channel_open(struct qcom_smd_channel * channel,rpmsg_rx_cb_t cb)815 static 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
856 out_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 */
qcom_smd_channel_close(struct qcom_smd_channel * channel)864 static 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
875 static struct qcom_smd_channel *
qcom_smd_find_channel(struct qcom_smd_edge * edge,const char * name)876 qcom_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
__ept_release(struct kref * kref)894 static 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
qcom_smd_create_ept(struct rpmsg_device * rpdev,rpmsg_rx_cb_t cb,void * priv,struct rpmsg_channel_info chinfo)901 static 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
947 free_ept:
948 channel->qsept = NULL;
949 kref_put(&ept->refcount, __ept_release);
950 return NULL;
951 }
952
qcom_smd_destroy_ept(struct rpmsg_endpoint * ept)953 static 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
qcom_smd_send(struct rpmsg_endpoint * ept,void * data,int len)963 static 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
qcom_smd_trysend(struct rpmsg_endpoint * ept,void * data,int len)970 static 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
qcom_smd_sendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)977 static int qcom_smd_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
978 {
979 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
980
981 return __qcom_smd_send(qsept->qsch, data, len, true);
982 }
983
qcom_smd_trysendto(struct rpmsg_endpoint * ept,void * data,int len,u32 dst)984 static int qcom_smd_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
985 {
986 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
987
988 return __qcom_smd_send(qsept->qsch, data, len, false);
989 }
990
qcom_smd_poll(struct rpmsg_endpoint * ept,struct file * filp,poll_table * wait)991 static __poll_t qcom_smd_poll(struct rpmsg_endpoint *ept,
992 struct file *filp, poll_table *wait)
993 {
994 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
995 struct qcom_smd_channel *channel = qsept->qsch;
996 __poll_t mask = 0;
997
998 poll_wait(filp, &channel->fblockread_event, wait);
999
1000 if (qcom_smd_get_tx_avail(channel) > 20)
1001 mask |= EPOLLOUT | EPOLLWRNORM;
1002
1003 return mask;
1004 }
1005
1006 /*
1007 * Finds the device_node for the smd child interested in this channel.
1008 */
qcom_smd_match_channel(struct device_node * edge_node,const char * channel)1009 static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
1010 const char *channel)
1011 {
1012 struct device_node *child;
1013 const char *name;
1014 const char *key;
1015 int ret;
1016
1017 for_each_available_child_of_node(edge_node, child) {
1018 key = "qcom,smd-channels";
1019 ret = of_property_read_string(child, key, &name);
1020 if (ret)
1021 continue;
1022
1023 if (strcmp(name, channel) == 0)
1024 return child;
1025 }
1026
1027 return NULL;
1028 }
1029
qcom_smd_announce_create(struct rpmsg_device * rpdev)1030 static int qcom_smd_announce_create(struct rpmsg_device *rpdev)
1031 {
1032 struct qcom_smd_endpoint *qept = to_smd_endpoint(rpdev->ept);
1033 struct qcom_smd_channel *channel = qept->qsch;
1034 unsigned long flags;
1035 bool kick_state;
1036
1037 spin_lock_irqsave(&channel->recv_lock, flags);
1038 kick_state = qcom_smd_channel_intr(channel);
1039 spin_unlock_irqrestore(&channel->recv_lock, flags);
1040
1041 if (kick_state)
1042 schedule_work(&channel->edge->state_work);
1043
1044 return 0;
1045 }
1046
1047 static const struct rpmsg_device_ops qcom_smd_device_ops = {
1048 .create_ept = qcom_smd_create_ept,
1049 .announce_create = qcom_smd_announce_create,
1050 };
1051
1052 static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
1053 .destroy_ept = qcom_smd_destroy_ept,
1054 .send = qcom_smd_send,
1055 .sendto = qcom_smd_sendto,
1056 .trysend = qcom_smd_trysend,
1057 .trysendto = qcom_smd_trysendto,
1058 .poll = qcom_smd_poll,
1059 };
1060
qcom_smd_release_device(struct device * dev)1061 static void qcom_smd_release_device(struct device *dev)
1062 {
1063 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1064 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
1065
1066 kfree(qsdev);
1067 }
1068
1069 /*
1070 * Create a smd client device for channel that is being opened.
1071 */
qcom_smd_create_device(struct qcom_smd_channel * channel)1072 static int qcom_smd_create_device(struct qcom_smd_channel *channel)
1073 {
1074 struct qcom_smd_device *qsdev;
1075 struct rpmsg_device *rpdev;
1076 struct qcom_smd_edge *edge = channel->edge;
1077
1078 dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
1079
1080 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
1081 if (!qsdev)
1082 return -ENOMEM;
1083
1084 /* Link qsdev to our SMD edge */
1085 qsdev->edge = edge;
1086
1087 /* Assign callbacks for rpmsg_device */
1088 qsdev->rpdev.ops = &qcom_smd_device_ops;
1089
1090 /* Assign public information to the rpmsg_device */
1091 rpdev = &qsdev->rpdev;
1092 strscpy_pad(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
1093 rpdev->src = RPMSG_ADDR_ANY;
1094 rpdev->dst = RPMSG_ADDR_ANY;
1095
1096 rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
1097 rpdev->dev.parent = &edge->dev;
1098 rpdev->dev.release = qcom_smd_release_device;
1099
1100 return rpmsg_register_device(rpdev);
1101 }
1102
qcom_smd_create_chrdev(struct qcom_smd_edge * edge)1103 static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
1104 {
1105 struct qcom_smd_device *qsdev;
1106
1107 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
1108 if (!qsdev)
1109 return -ENOMEM;
1110
1111 qsdev->edge = edge;
1112 qsdev->rpdev.ops = &qcom_smd_device_ops;
1113 qsdev->rpdev.dev.parent = &edge->dev;
1114 qsdev->rpdev.dev.release = qcom_smd_release_device;
1115
1116 return rpmsg_ctrldev_register_device(&qsdev->rpdev);
1117 }
1118
1119 /*
1120 * Allocate the qcom_smd_channel object for a newly found smd channel,
1121 * retrieving and validating the smem items involved.
1122 */
qcom_smd_create_channel(struct qcom_smd_edge * edge,unsigned smem_info_item,unsigned smem_fifo_item,char * name)1123 static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
1124 unsigned smem_info_item,
1125 unsigned smem_fifo_item,
1126 char *name)
1127 {
1128 struct qcom_smd_channel *channel;
1129 size_t fifo_size;
1130 size_t info_size;
1131 void *fifo_base;
1132 void *info;
1133 int ret;
1134
1135 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
1136 if (!channel)
1137 return ERR_PTR(-ENOMEM);
1138
1139 channel->edge = edge;
1140 channel->name = kstrdup(name, GFP_KERNEL);
1141 if (!channel->name) {
1142 ret = -ENOMEM;
1143 goto free_channel;
1144 }
1145
1146 spin_lock_init(&channel->tx_lock);
1147 spin_lock_init(&channel->recv_lock);
1148 init_waitqueue_head(&channel->fblockread_event);
1149 init_waitqueue_head(&channel->state_change_event);
1150
1151 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1152 if (IS_ERR(info)) {
1153 ret = PTR_ERR(info);
1154 goto free_name_and_channel;
1155 }
1156
1157 /*
1158 * Use the size of the item to figure out which channel info struct to
1159 * use.
1160 */
1161 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1162 channel->info_word = info;
1163 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1164 channel->info = info;
1165 } else {
1166 dev_err(&edge->dev,
1167 "channel info of size %zu not supported\n", info_size);
1168 ret = -EINVAL;
1169 goto free_name_and_channel;
1170 }
1171
1172 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1173 if (IS_ERR(fifo_base)) {
1174 ret = PTR_ERR(fifo_base);
1175 goto free_name_and_channel;
1176 }
1177
1178 /* The channel consist of a rx and tx fifo of equal size */
1179 fifo_size /= 2;
1180
1181 dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1182 name, info_size, fifo_size);
1183
1184 channel->tx_fifo = fifo_base;
1185 channel->rx_fifo = fifo_base + fifo_size;
1186 channel->fifo_size = fifo_size;
1187
1188 qcom_smd_channel_reset(channel);
1189
1190 return channel;
1191
1192 free_name_and_channel:
1193 kfree(channel->name);
1194 free_channel:
1195 kfree(channel);
1196
1197 return ERR_PTR(ret);
1198 }
1199
1200 /*
1201 * Scans the allocation table for any newly allocated channels, calls
1202 * qcom_smd_create_channel() to create representations of these and add
1203 * them to the edge's list of channels.
1204 */
qcom_channel_scan_worker(struct work_struct * work)1205 static void qcom_channel_scan_worker(struct work_struct *work)
1206 {
1207 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1208 struct qcom_smd_alloc_entry *alloc_tbl;
1209 struct qcom_smd_alloc_entry *entry;
1210 struct qcom_smd_channel *channel;
1211 unsigned long flags;
1212 unsigned fifo_id;
1213 unsigned info_id;
1214 int tbl;
1215 int i;
1216 u32 eflags, cid;
1217
1218 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1219 alloc_tbl = qcom_smem_get(edge->remote_pid,
1220 smem_items[tbl].alloc_tbl_id, NULL);
1221 if (IS_ERR(alloc_tbl))
1222 continue;
1223
1224 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1225 entry = &alloc_tbl[i];
1226 eflags = le32_to_cpu(entry->flags);
1227 if (test_bit(i, edge->allocated[tbl]))
1228 continue;
1229
1230 if (entry->ref_count == 0)
1231 continue;
1232
1233 if (!entry->name[0])
1234 continue;
1235
1236 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1237 continue;
1238
1239 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1240 continue;
1241
1242 cid = le32_to_cpu(entry->cid);
1243 info_id = smem_items[tbl].info_base_id + cid;
1244 fifo_id = smem_items[tbl].fifo_base_id + cid;
1245
1246 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1247 if (IS_ERR(channel))
1248 continue;
1249
1250 spin_lock_irqsave(&edge->channels_lock, flags);
1251 list_add(&channel->list, &edge->channels);
1252 spin_unlock_irqrestore(&edge->channels_lock, flags);
1253
1254 dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
1255 set_bit(i, edge->allocated[tbl]);
1256
1257 wake_up_interruptible_all(&edge->new_channel_event);
1258 }
1259 }
1260
1261 schedule_work(&edge->state_work);
1262 }
1263
1264 /*
1265 * This per edge worker scans smem for any new channels and register these. It
1266 * then scans all registered channels for state changes that should be handled
1267 * by creating or destroying smd client devices for the registered channels.
1268 *
1269 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1270 * worker is killed before any channels are deallocated
1271 */
qcom_channel_state_worker(struct work_struct * work)1272 static void qcom_channel_state_worker(struct work_struct *work)
1273 {
1274 struct qcom_smd_channel *channel;
1275 struct qcom_smd_edge *edge = container_of(work,
1276 struct qcom_smd_edge,
1277 state_work);
1278 struct rpmsg_channel_info chinfo;
1279 unsigned remote_state;
1280 unsigned long flags;
1281
1282 /*
1283 * Register a device for any closed channel where the remote processor
1284 * is showing interest in opening the channel.
1285 */
1286 spin_lock_irqsave(&edge->channels_lock, flags);
1287 list_for_each_entry(channel, &edge->channels, list) {
1288 if (channel->state != SMD_CHANNEL_CLOSED)
1289 continue;
1290
1291 /*
1292 * Always open rpm_requests, even when already opened which is
1293 * required on some SoCs like msm8953.
1294 */
1295 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1296 if (remote_state != SMD_CHANNEL_OPENING &&
1297 remote_state != SMD_CHANNEL_OPENED &&
1298 strcmp(channel->name, "rpm_requests"))
1299 continue;
1300
1301 if (channel->registered)
1302 continue;
1303
1304 spin_unlock_irqrestore(&edge->channels_lock, flags);
1305 qcom_smd_create_device(channel);
1306 spin_lock_irqsave(&edge->channels_lock, flags);
1307 channel->registered = true;
1308 }
1309
1310 /*
1311 * Unregister the device for any channel that is opened where the
1312 * remote processor is closing the channel.
1313 */
1314 list_for_each_entry(channel, &edge->channels, list) {
1315 if (channel->state != SMD_CHANNEL_OPENING &&
1316 channel->state != SMD_CHANNEL_OPENED)
1317 continue;
1318
1319 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1320 if (remote_state == SMD_CHANNEL_OPENING ||
1321 remote_state == SMD_CHANNEL_OPENED)
1322 continue;
1323
1324 spin_unlock_irqrestore(&edge->channels_lock, flags);
1325
1326 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1327 chinfo.src = RPMSG_ADDR_ANY;
1328 chinfo.dst = RPMSG_ADDR_ANY;
1329 rpmsg_unregister_device(&edge->dev, &chinfo);
1330 channel->registered = false;
1331 spin_lock_irqsave(&edge->channels_lock, flags);
1332 }
1333 spin_unlock_irqrestore(&edge->channels_lock, flags);
1334 }
1335
1336 /*
1337 * Parses an of_node describing an edge.
1338 */
qcom_smd_parse_edge(struct device * dev,struct device_node * node,struct qcom_smd_edge * edge)1339 static int qcom_smd_parse_edge(struct device *dev,
1340 struct device_node *node,
1341 struct qcom_smd_edge *edge)
1342 {
1343 struct device_node *syscon_np;
1344 const char *key;
1345 int irq;
1346 int ret;
1347
1348 INIT_LIST_HEAD(&edge->channels);
1349 spin_lock_init(&edge->channels_lock);
1350
1351 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1352 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1353
1354 edge->of_node = of_node_get(node);
1355
1356 key = "qcom,smd-edge";
1357 ret = of_property_read_u32(node, key, &edge->edge_id);
1358 if (ret) {
1359 dev_err(dev, "edge missing %s property\n", key);
1360 goto put_node;
1361 }
1362
1363 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1364 key = "qcom,remote-pid";
1365 of_property_read_u32(node, key, &edge->remote_pid);
1366
1367 edge->mbox_client.dev = dev;
1368 edge->mbox_client.knows_txdone = true;
1369 edge->mbox_chan = mbox_request_channel(&edge->mbox_client, 0);
1370 if (IS_ERR(edge->mbox_chan)) {
1371 if (PTR_ERR(edge->mbox_chan) != -ENODEV) {
1372 ret = PTR_ERR(edge->mbox_chan);
1373 goto put_node;
1374 }
1375
1376 edge->mbox_chan = NULL;
1377
1378 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1379 if (!syscon_np) {
1380 dev_err(dev, "no qcom,ipc node\n");
1381 ret = -ENODEV;
1382 goto put_node;
1383 }
1384
1385 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1386 of_node_put(syscon_np);
1387 if (IS_ERR(edge->ipc_regmap)) {
1388 ret = PTR_ERR(edge->ipc_regmap);
1389 goto put_node;
1390 }
1391
1392 key = "qcom,ipc";
1393 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1394 if (ret < 0) {
1395 dev_err(dev, "no offset in %s\n", key);
1396 goto put_node;
1397 }
1398
1399 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1400 if (ret < 0) {
1401 dev_err(dev, "no bit in %s\n", key);
1402 goto put_node;
1403 }
1404 }
1405
1406 ret = of_property_read_string(node, "label", &edge->name);
1407 if (ret < 0)
1408 edge->name = node->name;
1409
1410 irq = irq_of_parse_and_map(node, 0);
1411 if (!irq) {
1412 dev_err(dev, "required smd interrupt missing\n");
1413 ret = -EINVAL;
1414 goto put_node;
1415 }
1416
1417 ret = devm_request_irq(dev, irq,
1418 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1419 node->name, edge);
1420 if (ret) {
1421 dev_err(dev, "failed to request smd irq\n");
1422 goto put_node;
1423 }
1424
1425 edge->irq = irq;
1426
1427 return 0;
1428
1429 put_node:
1430 of_node_put(node);
1431 edge->of_node = NULL;
1432
1433 return ret;
1434 }
1435
1436 /*
1437 * Release function for an edge.
1438 * Reset the state of each associated channel and free the edge context.
1439 */
qcom_smd_edge_release(struct device * dev)1440 static void qcom_smd_edge_release(struct device *dev)
1441 {
1442 struct qcom_smd_channel *channel, *tmp;
1443 struct qcom_smd_edge *edge = to_smd_edge(dev);
1444
1445 list_for_each_entry_safe(channel, tmp, &edge->channels, list) {
1446 list_del(&channel->list);
1447 kfree(channel->name);
1448 kfree(channel);
1449 }
1450
1451 kfree(edge);
1452 }
1453
rpmsg_name_show(struct device * dev,struct device_attribute * attr,char * buf)1454 static ssize_t rpmsg_name_show(struct device *dev,
1455 struct device_attribute *attr, char *buf)
1456 {
1457 struct qcom_smd_edge *edge = to_smd_edge(dev);
1458
1459 return sprintf(buf, "%s\n", edge->name);
1460 }
1461 static DEVICE_ATTR_RO(rpmsg_name);
1462
1463 static struct attribute *qcom_smd_edge_attrs[] = {
1464 &dev_attr_rpmsg_name.attr,
1465 NULL
1466 };
1467 ATTRIBUTE_GROUPS(qcom_smd_edge);
1468
1469 /**
1470 * qcom_smd_register_edge() - register an edge based on an device_node
1471 * @parent: parent device for the edge
1472 * @node: device_node describing the edge
1473 *
1474 * Return: an edge reference, or negative ERR_PTR() on failure.
1475 */
qcom_smd_register_edge(struct device * parent,struct device_node * node)1476 struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
1477 struct device_node *node)
1478 {
1479 struct qcom_smd_edge *edge;
1480 int ret;
1481
1482 if (!qcom_smem_is_available())
1483 return ERR_PTR(-EPROBE_DEFER);
1484
1485 edge = kzalloc(sizeof(*edge), GFP_KERNEL);
1486 if (!edge)
1487 return ERR_PTR(-ENOMEM);
1488
1489 init_waitqueue_head(&edge->new_channel_event);
1490
1491 edge->dev.parent = parent;
1492 edge->dev.release = qcom_smd_edge_release;
1493 edge->dev.of_node = node;
1494 edge->dev.groups = qcom_smd_edge_groups;
1495 dev_set_name(&edge->dev, "%s:%pOFn", dev_name(parent), node);
1496 ret = device_register(&edge->dev);
1497 if (ret) {
1498 pr_err("failed to register smd edge\n");
1499 put_device(&edge->dev);
1500 return ERR_PTR(ret);
1501 }
1502
1503 ret = qcom_smd_parse_edge(&edge->dev, node, edge);
1504 if (ret) {
1505 dev_err(&edge->dev, "failed to parse smd edge\n");
1506 goto unregister_dev;
1507 }
1508
1509 ret = qcom_smd_create_chrdev(edge);
1510 if (ret) {
1511 dev_err(&edge->dev, "failed to register chrdev for edge\n");
1512 goto unregister_dev;
1513 }
1514
1515 schedule_work(&edge->scan_work);
1516
1517 return edge;
1518
1519 unregister_dev:
1520 if (!IS_ERR_OR_NULL(edge->mbox_chan))
1521 mbox_free_channel(edge->mbox_chan);
1522
1523 device_unregister(&edge->dev);
1524 return ERR_PTR(ret);
1525 }
1526 EXPORT_SYMBOL(qcom_smd_register_edge);
1527
qcom_smd_remove_device(struct device * dev,void * data)1528 static int qcom_smd_remove_device(struct device *dev, void *data)
1529 {
1530 device_unregister(dev);
1531
1532 return 0;
1533 }
1534
1535 /**
1536 * qcom_smd_unregister_edge() - release an edge and its children
1537 * @edge: edge reference acquired from qcom_smd_register_edge
1538 */
qcom_smd_unregister_edge(struct qcom_smd_edge * edge)1539 void qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
1540 {
1541 int ret;
1542
1543 disable_irq(edge->irq);
1544 cancel_work_sync(&edge->scan_work);
1545 cancel_work_sync(&edge->state_work);
1546
1547 ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
1548 if (ret)
1549 dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
1550
1551 mbox_free_channel(edge->mbox_chan);
1552 device_unregister(&edge->dev);
1553 }
1554 EXPORT_SYMBOL(qcom_smd_unregister_edge);
1555
qcom_smd_probe(struct platform_device * pdev)1556 static int qcom_smd_probe(struct platform_device *pdev)
1557 {
1558 struct device_node *node;
1559
1560 if (!qcom_smem_is_available())
1561 return -EPROBE_DEFER;
1562
1563 for_each_available_child_of_node(pdev->dev.of_node, node)
1564 qcom_smd_register_edge(&pdev->dev, node);
1565
1566 return 0;
1567 }
1568
qcom_smd_remove_edge(struct device * dev,void * data)1569 static int qcom_smd_remove_edge(struct device *dev, void *data)
1570 {
1571 struct qcom_smd_edge *edge = to_smd_edge(dev);
1572
1573 qcom_smd_unregister_edge(edge);
1574
1575 return 0;
1576 }
1577
1578 /*
1579 * Shut down all smd clients by making sure that each edge stops processing
1580 * events and scanning for new channels, then call destroy on the devices.
1581 */
qcom_smd_remove(struct platform_device * pdev)1582 static void qcom_smd_remove(struct platform_device *pdev)
1583 {
1584 /*
1585 * qcom_smd_remove_edge always returns zero, so there is no need to
1586 * check the return value of device_for_each_child.
1587 */
1588 device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
1589 }
1590
1591 static const struct of_device_id qcom_smd_of_match[] = {
1592 { .compatible = "qcom,smd" },
1593 {}
1594 };
1595 MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1596
1597 static struct platform_driver qcom_smd_driver = {
1598 .probe = qcom_smd_probe,
1599 .remove_new = qcom_smd_remove,
1600 .driver = {
1601 .name = "qcom-smd",
1602 .of_match_table = qcom_smd_of_match,
1603 },
1604 };
1605
qcom_smd_init(void)1606 static int __init qcom_smd_init(void)
1607 {
1608 return platform_driver_register(&qcom_smd_driver);
1609 }
1610 arch_initcall(qcom_smd_init);
1611
qcom_smd_exit(void)1612 static void __exit qcom_smd_exit(void)
1613 {
1614 platform_driver_unregister(&qcom_smd_driver);
1615 }
1616 module_exit(qcom_smd_exit);
1617
1618 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
1619 MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1620 MODULE_LICENSE("GPL v2");
1621