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1 | /* |
2 | * Copyright (c) 2015, Sony Mobile Communications AB. | |
3 | * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 and | |
7 | * only version 2 as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/interrupt.h> | |
16 | #include <linux/io.h> | |
17 | #include <linux/mfd/syscon.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/of_irq.h> | |
20 | #include <linux/of_platform.h> | |
21 | #include <linux/platform_device.h> | |
22 | #include <linux/regmap.h> | |
23 | #include <linux/sched.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/soc/qcom/smem.h> | |
26 | #include <linux/wait.h> | |
27 | #include <linux/rpmsg.h> | |
8fc94723 | 28 | #include <linux/rpmsg/qcom_smd.h> |
53e2822e BA |
29 | |
30 | #include "rpmsg_internal.h" | |
31 | ||
32 | /* | |
33 | * The Qualcomm Shared Memory communication solution provides point-to-point | |
34 | * channels for clients to send and receive streaming or packet based data. | |
35 | * | |
36 | * Each channel consists of a control item (channel info) and a ring buffer | |
37 | * pair. The channel info carry information related to channel state, flow | |
38 | * control and the offsets within the ring buffer. | |
39 | * | |
40 | * All allocated channels are listed in an allocation table, identifying the | |
41 | * pair of items by name, type and remote processor. | |
42 | * | |
43 | * Upon creating a new channel the remote processor allocates channel info and | |
44 | * ring buffer items from the smem heap and populate the allocation table. An | |
45 | * interrupt is sent to the other end of the channel and a scan for new | |
46 | * channels should be done. A channel never goes away, it will only change | |
47 | * state. | |
48 | * | |
49 | * The remote processor signals it intent for bring up the communication | |
50 | * channel by setting the state of its end of the channel to "opening" and | |
51 | * sends out an interrupt. We detect this change and register a smd device to | |
52 | * consume the channel. Upon finding a consumer we finish the handshake and the | |
53 | * channel is up. | |
54 | * | |
55 | * Upon closing a channel, the remote processor will update the state of its | |
56 | * end of the channel and signal us, we will then unregister any attached | |
57 | * device and close our end of the channel. | |
58 | * | |
59 | * Devices attached to a channel can use the qcom_smd_send function to push | |
60 | * data to the channel, this is done by copying the data into the tx ring | |
61 | * buffer, updating the pointers in the channel info and signaling the remote | |
62 | * processor. | |
63 | * | |
64 | * The remote processor does the equivalent when it transfer data and upon | |
65 | * receiving the interrupt we check the channel info for new data and delivers | |
66 | * this to the attached device. If the device is not ready to receive the data | |
67 | * we leave it in the ring buffer for now. | |
68 | */ | |
69 | ||
70 | struct smd_channel_info; | |
71 | struct smd_channel_info_pair; | |
72 | struct smd_channel_info_word; | |
73 | struct smd_channel_info_word_pair; | |
74 | ||
75 | static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops; | |
76 | ||
77 | #define SMD_ALLOC_TBL_COUNT 2 | |
78 | #define SMD_ALLOC_TBL_SIZE 64 | |
79 | ||
80 | /* | |
81 | * This lists the various smem heap items relevant for the allocation table and | |
82 | * smd channel entries. | |
83 | */ | |
84 | static const struct { | |
85 | unsigned alloc_tbl_id; | |
86 | unsigned info_base_id; | |
87 | unsigned fifo_base_id; | |
88 | } smem_items[SMD_ALLOC_TBL_COUNT] = { | |
89 | { | |
90 | .alloc_tbl_id = 13, | |
91 | .info_base_id = 14, | |
92 | .fifo_base_id = 338 | |
93 | }, | |
94 | { | |
95 | .alloc_tbl_id = 266, | |
96 | .info_base_id = 138, | |
97 | .fifo_base_id = 202, | |
98 | }, | |
99 | }; | |
100 | ||
101 | /** | |
102 | * struct qcom_smd_edge - representing a remote processor | |
103 | * @of_node: of_node handle for information related to this edge | |
104 | * @edge_id: identifier of this edge | |
105 | * @remote_pid: identifier of remote processor | |
106 | * @irq: interrupt for signals on this edge | |
107 | * @ipc_regmap: regmap handle holding the outgoing ipc register | |
108 | * @ipc_offset: offset within @ipc_regmap of the register for ipc | |
109 | * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap | |
110 | * @channels: list of all channels detected on this edge | |
111 | * @channels_lock: guard for modifications of @channels | |
112 | * @allocated: array of bitmaps representing already allocated channels | |
113 | * @smem_available: last available amount of smem triggering a channel scan | |
114 | * @scan_work: work item for discovering new channels | |
115 | * @state_work: work item for edge state changes | |
116 | */ | |
117 | struct qcom_smd_edge { | |
118 | struct device dev; | |
119 | ||
5e53c42c BA |
120 | const char *name; |
121 | ||
53e2822e BA |
122 | struct device_node *of_node; |
123 | unsigned edge_id; | |
124 | unsigned remote_pid; | |
125 | ||
126 | int irq; | |
127 | ||
128 | struct regmap *ipc_regmap; | |
129 | int ipc_offset; | |
130 | int ipc_bit; | |
131 | ||
132 | struct list_head channels; | |
133 | spinlock_t channels_lock; | |
134 | ||
135 | DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE); | |
136 | ||
137 | unsigned smem_available; | |
138 | ||
139 | wait_queue_head_t new_channel_event; | |
140 | ||
141 | struct work_struct scan_work; | |
142 | struct work_struct state_work; | |
143 | }; | |
144 | ||
145 | /* | |
146 | * SMD channel states. | |
147 | */ | |
148 | enum smd_channel_state { | |
149 | SMD_CHANNEL_CLOSED, | |
150 | SMD_CHANNEL_OPENING, | |
151 | SMD_CHANNEL_OPENED, | |
152 | SMD_CHANNEL_FLUSHING, | |
153 | SMD_CHANNEL_CLOSING, | |
154 | SMD_CHANNEL_RESET, | |
155 | SMD_CHANNEL_RESET_OPENING | |
156 | }; | |
157 | ||
158 | struct qcom_smd_device { | |
159 | struct rpmsg_device rpdev; | |
160 | ||
161 | struct qcom_smd_edge *edge; | |
162 | }; | |
163 | ||
164 | struct qcom_smd_endpoint { | |
165 | struct rpmsg_endpoint ept; | |
166 | ||
167 | struct qcom_smd_channel *qsch; | |
168 | }; | |
169 | ||
170 | #define to_smd_device(_rpdev) container_of(_rpdev, struct qcom_smd_device, rpdev) | |
171 | #define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev) | |
172 | #define to_smd_endpoint(ept) container_of(ept, struct qcom_smd_endpoint, ept) | |
173 | ||
174 | /** | |
175 | * struct qcom_smd_channel - smd channel struct | |
176 | * @edge: qcom_smd_edge this channel is living on | |
177 | * @qsdev: reference to a associated smd client device | |
178 | * @name: name of the channel | |
179 | * @state: local state of the channel | |
180 | * @remote_state: remote state of the channel | |
181 | * @info: byte aligned outgoing/incoming channel info | |
182 | * @info_word: word aligned outgoing/incoming channel info | |
183 | * @tx_lock: lock to make writes to the channel mutually exclusive | |
184 | * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR | |
185 | * @tx_fifo: pointer to the outgoing ring buffer | |
186 | * @rx_fifo: pointer to the incoming ring buffer | |
187 | * @fifo_size: size of each ring buffer | |
188 | * @bounce_buffer: bounce buffer for reading wrapped packets | |
189 | * @cb: callback function registered for this channel | |
190 | * @recv_lock: guard for rx info modifications and cb pointer | |
191 | * @pkt_size: size of the currently handled packet | |
192 | * @list: lite entry for @channels in qcom_smd_edge | |
193 | */ | |
194 | struct qcom_smd_channel { | |
195 | struct qcom_smd_edge *edge; | |
196 | ||
197 | struct qcom_smd_endpoint *qsept; | |
198 | bool registered; | |
199 | ||
200 | char *name; | |
201 | enum smd_channel_state state; | |
202 | enum smd_channel_state remote_state; | |
203 | ||
204 | struct smd_channel_info_pair *info; | |
205 | struct smd_channel_info_word_pair *info_word; | |
206 | ||
207 | struct mutex tx_lock; | |
208 | wait_queue_head_t fblockread_event; | |
209 | ||
210 | void *tx_fifo; | |
211 | void *rx_fifo; | |
212 | int fifo_size; | |
213 | ||
214 | void *bounce_buffer; | |
215 | ||
216 | spinlock_t recv_lock; | |
217 | ||
218 | int pkt_size; | |
219 | ||
220 | void *drvdata; | |
221 | ||
222 | struct list_head list; | |
223 | }; | |
224 | ||
225 | /* | |
226 | * Format of the smd_info smem items, for byte aligned channels. | |
227 | */ | |
228 | struct smd_channel_info { | |
229 | __le32 state; | |
230 | u8 fDSR; | |
231 | u8 fCTS; | |
232 | u8 fCD; | |
233 | u8 fRI; | |
234 | u8 fHEAD; | |
235 | u8 fTAIL; | |
236 | u8 fSTATE; | |
237 | u8 fBLOCKREADINTR; | |
238 | __le32 tail; | |
239 | __le32 head; | |
240 | }; | |
241 | ||
242 | struct smd_channel_info_pair { | |
243 | struct smd_channel_info tx; | |
244 | struct smd_channel_info rx; | |
245 | }; | |
246 | ||
247 | /* | |
248 | * Format of the smd_info smem items, for word aligned channels. | |
249 | */ | |
250 | struct smd_channel_info_word { | |
251 | __le32 state; | |
252 | __le32 fDSR; | |
253 | __le32 fCTS; | |
254 | __le32 fCD; | |
255 | __le32 fRI; | |
256 | __le32 fHEAD; | |
257 | __le32 fTAIL; | |
258 | __le32 fSTATE; | |
259 | __le32 fBLOCKREADINTR; | |
260 | __le32 tail; | |
261 | __le32 head; | |
262 | }; | |
263 | ||
264 | struct smd_channel_info_word_pair { | |
265 | struct smd_channel_info_word tx; | |
266 | struct smd_channel_info_word rx; | |
267 | }; | |
268 | ||
269 | #define GET_RX_CHANNEL_FLAG(channel, param) \ | |
270 | ({ \ | |
271 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \ | |
272 | channel->info_word ? \ | |
273 | le32_to_cpu(channel->info_word->rx.param) : \ | |
274 | channel->info->rx.param; \ | |
275 | }) | |
276 | ||
277 | #define GET_RX_CHANNEL_INFO(channel, param) \ | |
278 | ({ \ | |
279 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \ | |
280 | le32_to_cpu(channel->info_word ? \ | |
281 | channel->info_word->rx.param : \ | |
282 | channel->info->rx.param); \ | |
283 | }) | |
284 | ||
285 | #define SET_RX_CHANNEL_FLAG(channel, param, value) \ | |
286 | ({ \ | |
287 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \ | |
288 | if (channel->info_word) \ | |
289 | channel->info_word->rx.param = cpu_to_le32(value); \ | |
290 | else \ | |
291 | channel->info->rx.param = value; \ | |
292 | }) | |
293 | ||
294 | #define SET_RX_CHANNEL_INFO(channel, param, value) \ | |
295 | ({ \ | |
296 | BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \ | |
297 | if (channel->info_word) \ | |
298 | channel->info_word->rx.param = cpu_to_le32(value); \ | |
299 | else \ | |
300 | channel->info->rx.param = cpu_to_le32(value); \ | |
301 | }) | |
302 | ||
303 | #define GET_TX_CHANNEL_FLAG(channel, param) \ | |
304 | ({ \ | |
305 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \ | |
306 | channel->info_word ? \ | |
307 | le32_to_cpu(channel->info_word->tx.param) : \ | |
308 | channel->info->tx.param; \ | |
309 | }) | |
310 | ||
311 | #define GET_TX_CHANNEL_INFO(channel, param) \ | |
312 | ({ \ | |
313 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \ | |
314 | le32_to_cpu(channel->info_word ? \ | |
315 | channel->info_word->tx.param : \ | |
316 | channel->info->tx.param); \ | |
317 | }) | |
318 | ||
319 | #define SET_TX_CHANNEL_FLAG(channel, param, value) \ | |
320 | ({ \ | |
321 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \ | |
322 | if (channel->info_word) \ | |
323 | channel->info_word->tx.param = cpu_to_le32(value); \ | |
324 | else \ | |
325 | channel->info->tx.param = value; \ | |
326 | }) | |
327 | ||
328 | #define SET_TX_CHANNEL_INFO(channel, param, value) \ | |
329 | ({ \ | |
330 | BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \ | |
331 | if (channel->info_word) \ | |
332 | channel->info_word->tx.param = cpu_to_le32(value); \ | |
333 | else \ | |
334 | channel->info->tx.param = cpu_to_le32(value); \ | |
335 | }) | |
336 | ||
337 | /** | |
338 | * struct qcom_smd_alloc_entry - channel allocation entry | |
339 | * @name: channel name | |
340 | * @cid: channel index | |
341 | * @flags: channel flags and edge id | |
342 | * @ref_count: reference count of the channel | |
343 | */ | |
344 | struct qcom_smd_alloc_entry { | |
345 | u8 name[20]; | |
346 | __le32 cid; | |
347 | __le32 flags; | |
348 | __le32 ref_count; | |
349 | } __packed; | |
350 | ||
351 | #define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff | |
352 | #define SMD_CHANNEL_FLAGS_STREAM BIT(8) | |
353 | #define SMD_CHANNEL_FLAGS_PACKET BIT(9) | |
354 | ||
355 | /* | |
356 | * Each smd packet contains a 20 byte header, with the first 4 being the length | |
357 | * of the packet. | |
358 | */ | |
359 | #define SMD_PACKET_HEADER_LEN 20 | |
360 | ||
361 | /* | |
362 | * Signal the remote processor associated with 'channel'. | |
363 | */ | |
364 | static void qcom_smd_signal_channel(struct qcom_smd_channel *channel) | |
365 | { | |
366 | struct qcom_smd_edge *edge = channel->edge; | |
367 | ||
368 | regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit)); | |
369 | } | |
370 | ||
371 | /* | |
372 | * Initialize the tx channel info | |
373 | */ | |
374 | static void qcom_smd_channel_reset(struct qcom_smd_channel *channel) | |
375 | { | |
376 | SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED); | |
377 | SET_TX_CHANNEL_FLAG(channel, fDSR, 0); | |
378 | SET_TX_CHANNEL_FLAG(channel, fCTS, 0); | |
379 | SET_TX_CHANNEL_FLAG(channel, fCD, 0); | |
380 | SET_TX_CHANNEL_FLAG(channel, fRI, 0); | |
381 | SET_TX_CHANNEL_FLAG(channel, fHEAD, 0); | |
382 | SET_TX_CHANNEL_FLAG(channel, fTAIL, 0); | |
383 | SET_TX_CHANNEL_FLAG(channel, fSTATE, 1); | |
384 | SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); | |
385 | SET_TX_CHANNEL_INFO(channel, head, 0); | |
386 | SET_RX_CHANNEL_INFO(channel, tail, 0); | |
387 | ||
388 | qcom_smd_signal_channel(channel); | |
389 | ||
390 | channel->state = SMD_CHANNEL_CLOSED; | |
391 | channel->pkt_size = 0; | |
392 | } | |
393 | ||
394 | /* | |
395 | * Set the callback for a channel, with appropriate locking | |
396 | */ | |
397 | static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel, | |
398 | rpmsg_rx_cb_t cb) | |
399 | { | |
400 | struct rpmsg_endpoint *ept = &channel->qsept->ept; | |
401 | unsigned long flags; | |
402 | ||
403 | spin_lock_irqsave(&channel->recv_lock, flags); | |
404 | ept->cb = cb; | |
405 | spin_unlock_irqrestore(&channel->recv_lock, flags); | |
406 | }; | |
407 | ||
408 | /* | |
409 | * Calculate the amount of data available in the rx fifo | |
410 | */ | |
411 | static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel) | |
412 | { | |
413 | unsigned head; | |
414 | unsigned tail; | |
415 | ||
416 | head = GET_RX_CHANNEL_INFO(channel, head); | |
417 | tail = GET_RX_CHANNEL_INFO(channel, tail); | |
418 | ||
419 | return (head - tail) & (channel->fifo_size - 1); | |
420 | } | |
421 | ||
422 | /* | |
423 | * Set tx channel state and inform the remote processor | |
424 | */ | |
425 | static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel, | |
426 | int state) | |
427 | { | |
428 | struct qcom_smd_edge *edge = channel->edge; | |
429 | bool is_open = state == SMD_CHANNEL_OPENED; | |
430 | ||
431 | if (channel->state == state) | |
432 | return; | |
433 | ||
434 | dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state); | |
435 | ||
436 | SET_TX_CHANNEL_FLAG(channel, fDSR, is_open); | |
437 | SET_TX_CHANNEL_FLAG(channel, fCTS, is_open); | |
438 | SET_TX_CHANNEL_FLAG(channel, fCD, is_open); | |
439 | ||
440 | SET_TX_CHANNEL_INFO(channel, state, state); | |
441 | SET_TX_CHANNEL_FLAG(channel, fSTATE, 1); | |
442 | ||
443 | channel->state = state; | |
444 | qcom_smd_signal_channel(channel); | |
445 | } | |
446 | ||
447 | /* | |
448 | * Copy count bytes of data using 32bit accesses, if that's required. | |
449 | */ | |
450 | static void smd_copy_to_fifo(void __iomem *dst, | |
451 | const void *src, | |
452 | size_t count, | |
453 | bool word_aligned) | |
454 | { | |
455 | if (word_aligned) { | |
456 | __iowrite32_copy(dst, src, count / sizeof(u32)); | |
457 | } else { | |
458 | memcpy_toio(dst, src, count); | |
459 | } | |
460 | } | |
461 | ||
462 | /* | |
463 | * Copy count bytes of data using 32bit accesses, if that is required. | |
464 | */ | |
465 | static void smd_copy_from_fifo(void *dst, | |
466 | const void __iomem *src, | |
467 | size_t count, | |
468 | bool word_aligned) | |
469 | { | |
470 | if (word_aligned) { | |
471 | __ioread32_copy(dst, src, count / sizeof(u32)); | |
472 | } else { | |
473 | memcpy_fromio(dst, src, count); | |
474 | } | |
475 | } | |
476 | ||
477 | /* | |
478 | * Read count bytes of data from the rx fifo into buf, but don't advance the | |
479 | * tail. | |
480 | */ | |
481 | static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel, | |
482 | void *buf, size_t count) | |
483 | { | |
484 | bool word_aligned; | |
485 | unsigned tail; | |
486 | size_t len; | |
487 | ||
488 | word_aligned = channel->info_word; | |
489 | tail = GET_RX_CHANNEL_INFO(channel, tail); | |
490 | ||
491 | len = min_t(size_t, count, channel->fifo_size - tail); | |
492 | if (len) { | |
493 | smd_copy_from_fifo(buf, | |
494 | channel->rx_fifo + tail, | |
495 | len, | |
496 | word_aligned); | |
497 | } | |
498 | ||
499 | if (len != count) { | |
500 | smd_copy_from_fifo(buf + len, | |
501 | channel->rx_fifo, | |
502 | count - len, | |
503 | word_aligned); | |
504 | } | |
505 | ||
506 | return count; | |
507 | } | |
508 | ||
509 | /* | |
510 | * Advance the rx tail by count bytes. | |
511 | */ | |
512 | static void qcom_smd_channel_advance(struct qcom_smd_channel *channel, | |
513 | size_t count) | |
514 | { | |
515 | unsigned tail; | |
516 | ||
517 | tail = GET_RX_CHANNEL_INFO(channel, tail); | |
518 | tail += count; | |
519 | tail &= (channel->fifo_size - 1); | |
520 | SET_RX_CHANNEL_INFO(channel, tail, tail); | |
521 | } | |
522 | ||
523 | /* | |
524 | * Read out a single packet from the rx fifo and deliver it to the device | |
525 | */ | |
526 | static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel) | |
527 | { | |
528 | struct rpmsg_endpoint *ept = &channel->qsept->ept; | |
529 | unsigned tail; | |
530 | size_t len; | |
531 | void *ptr; | |
532 | int ret; | |
533 | ||
534 | tail = GET_RX_CHANNEL_INFO(channel, tail); | |
535 | ||
536 | /* Use bounce buffer if the data wraps */ | |
537 | if (tail + channel->pkt_size >= channel->fifo_size) { | |
538 | ptr = channel->bounce_buffer; | |
539 | len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size); | |
540 | } else { | |
541 | ptr = channel->rx_fifo + tail; | |
542 | len = channel->pkt_size; | |
543 | } | |
544 | ||
545 | ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY); | |
546 | if (ret < 0) | |
547 | return ret; | |
548 | ||
549 | /* Only forward the tail if the client consumed the data */ | |
550 | qcom_smd_channel_advance(channel, len); | |
551 | ||
552 | channel->pkt_size = 0; | |
553 | ||
554 | return 0; | |
555 | } | |
556 | ||
557 | /* | |
558 | * Per channel interrupt handling | |
559 | */ | |
560 | static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel) | |
561 | { | |
562 | bool need_state_scan = false; | |
563 | int remote_state; | |
564 | __le32 pktlen; | |
565 | int avail; | |
566 | int ret; | |
567 | ||
568 | /* Handle state changes */ | |
569 | remote_state = GET_RX_CHANNEL_INFO(channel, state); | |
570 | if (remote_state != channel->remote_state) { | |
571 | channel->remote_state = remote_state; | |
572 | need_state_scan = true; | |
573 | } | |
574 | /* Indicate that we have seen any state change */ | |
575 | SET_RX_CHANNEL_FLAG(channel, fSTATE, 0); | |
576 | ||
577 | /* Signal waiting qcom_smd_send() about the interrupt */ | |
578 | if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) | |
579 | wake_up_interruptible(&channel->fblockread_event); | |
580 | ||
581 | /* Don't consume any data until we've opened the channel */ | |
582 | if (channel->state != SMD_CHANNEL_OPENED) | |
583 | goto out; | |
584 | ||
585 | /* Indicate that we've seen the new data */ | |
586 | SET_RX_CHANNEL_FLAG(channel, fHEAD, 0); | |
587 | ||
588 | /* Consume data */ | |
589 | for (;;) { | |
590 | avail = qcom_smd_channel_get_rx_avail(channel); | |
591 | ||
592 | if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) { | |
593 | qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen)); | |
594 | qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN); | |
595 | channel->pkt_size = le32_to_cpu(pktlen); | |
596 | } else if (channel->pkt_size && avail >= channel->pkt_size) { | |
597 | ret = qcom_smd_channel_recv_single(channel); | |
598 | if (ret) | |
599 | break; | |
600 | } else { | |
601 | break; | |
602 | } | |
603 | } | |
604 | ||
605 | /* Indicate that we have seen and updated tail */ | |
606 | SET_RX_CHANNEL_FLAG(channel, fTAIL, 1); | |
607 | ||
608 | /* Signal the remote that we've consumed the data (if requested) */ | |
609 | if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) { | |
610 | /* Ensure ordering of channel info updates */ | |
611 | wmb(); | |
612 | ||
613 | qcom_smd_signal_channel(channel); | |
614 | } | |
615 | ||
616 | out: | |
617 | return need_state_scan; | |
618 | } | |
619 | ||
620 | /* | |
621 | * The edge interrupts are triggered by the remote processor on state changes, | |
622 | * channel info updates or when new channels are created. | |
623 | */ | |
624 | static irqreturn_t qcom_smd_edge_intr(int irq, void *data) | |
625 | { | |
626 | struct qcom_smd_edge *edge = data; | |
627 | struct qcom_smd_channel *channel; | |
628 | unsigned available; | |
629 | bool kick_scanner = false; | |
630 | bool kick_state = false; | |
631 | ||
632 | /* | |
633 | * Handle state changes or data on each of the channels on this edge | |
634 | */ | |
635 | spin_lock(&edge->channels_lock); | |
636 | list_for_each_entry(channel, &edge->channels, list) { | |
637 | spin_lock(&channel->recv_lock); | |
638 | kick_state |= qcom_smd_channel_intr(channel); | |
639 | spin_unlock(&channel->recv_lock); | |
640 | } | |
641 | spin_unlock(&edge->channels_lock); | |
642 | ||
643 | /* | |
644 | * Creating a new channel requires allocating an smem entry, so we only | |
645 | * have to scan if the amount of available space in smem have changed | |
646 | * since last scan. | |
647 | */ | |
648 | available = qcom_smem_get_free_space(edge->remote_pid); | |
649 | if (available != edge->smem_available) { | |
650 | edge->smem_available = available; | |
651 | kick_scanner = true; | |
652 | } | |
653 | ||
654 | if (kick_scanner) | |
655 | schedule_work(&edge->scan_work); | |
656 | if (kick_state) | |
657 | schedule_work(&edge->state_work); | |
658 | ||
659 | return IRQ_HANDLED; | |
660 | } | |
661 | ||
662 | /* | |
663 | * Calculate how much space is available in the tx fifo. | |
664 | */ | |
665 | static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel) | |
666 | { | |
667 | unsigned head; | |
668 | unsigned tail; | |
669 | unsigned mask = channel->fifo_size - 1; | |
670 | ||
671 | head = GET_TX_CHANNEL_INFO(channel, head); | |
672 | tail = GET_TX_CHANNEL_INFO(channel, tail); | |
673 | ||
674 | return mask - ((head - tail) & mask); | |
675 | } | |
676 | ||
677 | /* | |
678 | * Write count bytes of data into channel, possibly wrapping in the ring buffer | |
679 | */ | |
680 | static int qcom_smd_write_fifo(struct qcom_smd_channel *channel, | |
681 | const void *data, | |
682 | size_t count) | |
683 | { | |
684 | bool word_aligned; | |
685 | unsigned head; | |
686 | size_t len; | |
687 | ||
688 | word_aligned = channel->info_word; | |
689 | head = GET_TX_CHANNEL_INFO(channel, head); | |
690 | ||
691 | len = min_t(size_t, count, channel->fifo_size - head); | |
692 | if (len) { | |
693 | smd_copy_to_fifo(channel->tx_fifo + head, | |
694 | data, | |
695 | len, | |
696 | word_aligned); | |
697 | } | |
698 | ||
699 | if (len != count) { | |
700 | smd_copy_to_fifo(channel->tx_fifo, | |
701 | data + len, | |
702 | count - len, | |
703 | word_aligned); | |
704 | } | |
705 | ||
706 | head += count; | |
707 | head &= (channel->fifo_size - 1); | |
708 | SET_TX_CHANNEL_INFO(channel, head, head); | |
709 | ||
710 | return count; | |
711 | } | |
712 | ||
713 | /** | |
714 | * qcom_smd_send - write data to smd channel | |
715 | * @channel: channel handle | |
716 | * @data: buffer of data to write | |
717 | * @len: number of bytes to write | |
718 | * | |
719 | * This is a blocking write of len bytes into the channel's tx ring buffer and | |
720 | * signal the remote end. It will sleep until there is enough space available | |
721 | * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid | |
722 | * polling. | |
723 | */ | |
724 | static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data, | |
725 | int len, bool wait) | |
726 | { | |
727 | __le32 hdr[5] = { cpu_to_le32(len), }; | |
728 | int tlen = sizeof(hdr) + len; | |
729 | int ret; | |
730 | ||
731 | /* Word aligned channels only accept word size aligned data */ | |
732 | if (channel->info_word && len % 4) | |
733 | return -EINVAL; | |
734 | ||
735 | /* Reject packets that are too big */ | |
736 | if (tlen >= channel->fifo_size) | |
737 | return -EINVAL; | |
738 | ||
739 | ret = mutex_lock_interruptible(&channel->tx_lock); | |
740 | if (ret) | |
741 | return ret; | |
742 | ||
743 | while (qcom_smd_get_tx_avail(channel) < tlen) { | |
744 | if (!wait) { | |
1d74e7ed | 745 | ret = -EAGAIN; |
53e2822e BA |
746 | goto out; |
747 | } | |
748 | ||
749 | if (channel->state != SMD_CHANNEL_OPENED) { | |
750 | ret = -EPIPE; | |
751 | goto out; | |
752 | } | |
753 | ||
754 | SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0); | |
755 | ||
756 | ret = wait_event_interruptible(channel->fblockread_event, | |
757 | qcom_smd_get_tx_avail(channel) >= tlen || | |
758 | channel->state != SMD_CHANNEL_OPENED); | |
759 | if (ret) | |
760 | goto out; | |
761 | ||
762 | SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); | |
763 | } | |
764 | ||
765 | SET_TX_CHANNEL_FLAG(channel, fTAIL, 0); | |
766 | ||
767 | qcom_smd_write_fifo(channel, hdr, sizeof(hdr)); | |
768 | qcom_smd_write_fifo(channel, data, len); | |
769 | ||
770 | SET_TX_CHANNEL_FLAG(channel, fHEAD, 1); | |
771 | ||
772 | /* Ensure ordering of channel info updates */ | |
773 | wmb(); | |
774 | ||
775 | qcom_smd_signal_channel(channel); | |
776 | ||
777 | out: | |
778 | mutex_unlock(&channel->tx_lock); | |
779 | ||
780 | return ret; | |
781 | } | |
782 | ||
783 | /* | |
784 | * Helper for opening a channel | |
785 | */ | |
786 | static int qcom_smd_channel_open(struct qcom_smd_channel *channel, | |
787 | rpmsg_rx_cb_t cb) | |
788 | { | |
789 | size_t bb_size; | |
790 | ||
791 | /* | |
792 | * Packets are maximum 4k, but reduce if the fifo is smaller | |
793 | */ | |
794 | bb_size = min(channel->fifo_size, SZ_4K); | |
795 | channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL); | |
796 | if (!channel->bounce_buffer) | |
797 | return -ENOMEM; | |
798 | ||
799 | qcom_smd_channel_set_callback(channel, cb); | |
800 | qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING); | |
801 | qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED); | |
802 | ||
803 | return 0; | |
804 | } | |
805 | ||
806 | /* | |
807 | * Helper for closing and resetting a channel | |
808 | */ | |
809 | static void qcom_smd_channel_close(struct qcom_smd_channel *channel) | |
810 | { | |
811 | qcom_smd_channel_set_callback(channel, NULL); | |
812 | ||
813 | kfree(channel->bounce_buffer); | |
814 | channel->bounce_buffer = NULL; | |
815 | ||
816 | qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED); | |
817 | qcom_smd_channel_reset(channel); | |
818 | } | |
819 | ||
820 | static struct qcom_smd_channel * | |
821 | qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name) | |
822 | { | |
823 | struct qcom_smd_channel *channel; | |
824 | struct qcom_smd_channel *ret = NULL; | |
825 | unsigned long flags; | |
53e2822e BA |
826 | |
827 | spin_lock_irqsave(&edge->channels_lock, flags); | |
828 | list_for_each_entry(channel, &edge->channels, list) { | |
66dca399 BA |
829 | if (!strcmp(channel->name, name)) { |
830 | ret = channel; | |
831 | break; | |
832 | } | |
53e2822e BA |
833 | } |
834 | spin_unlock_irqrestore(&edge->channels_lock, flags); | |
835 | ||
836 | return ret; | |
837 | } | |
838 | ||
839 | static void __ept_release(struct kref *kref) | |
840 | { | |
841 | struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, | |
842 | refcount); | |
843 | kfree(to_smd_endpoint(ept)); | |
844 | } | |
845 | ||
846 | static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev, | |
847 | rpmsg_rx_cb_t cb, void *priv, | |
848 | struct rpmsg_channel_info chinfo) | |
849 | { | |
850 | struct qcom_smd_endpoint *qsept; | |
851 | struct qcom_smd_channel *channel; | |
852 | struct qcom_smd_device *qsdev = to_smd_device(rpdev); | |
853 | struct qcom_smd_edge *edge = qsdev->edge; | |
854 | struct rpmsg_endpoint *ept; | |
855 | const char *name = chinfo.name; | |
856 | int ret; | |
857 | ||
858 | /* Wait up to HZ for the channel to appear */ | |
859 | ret = wait_event_interruptible_timeout(edge->new_channel_event, | |
860 | (channel = qcom_smd_find_channel(edge, name)) != NULL, | |
861 | HZ); | |
862 | if (!ret) | |
863 | return NULL; | |
864 | ||
865 | if (channel->state != SMD_CHANNEL_CLOSED) { | |
866 | dev_err(&rpdev->dev, "channel %s is busy\n", channel->name); | |
867 | return NULL; | |
868 | } | |
869 | ||
870 | qsept = kzalloc(sizeof(*qsept), GFP_KERNEL); | |
871 | if (!qsept) | |
872 | return NULL; | |
873 | ||
874 | ept = &qsept->ept; | |
875 | ||
876 | kref_init(&ept->refcount); | |
877 | ||
878 | ept->rpdev = rpdev; | |
879 | ept->cb = cb; | |
880 | ept->priv = priv; | |
881 | ept->ops = &qcom_smd_endpoint_ops; | |
882 | ||
883 | channel->qsept = qsept; | |
884 | qsept->qsch = channel; | |
885 | ||
886 | ret = qcom_smd_channel_open(channel, cb); | |
887 | if (ret) | |
888 | goto free_ept; | |
889 | ||
890 | return ept; | |
891 | ||
892 | free_ept: | |
893 | channel->qsept = NULL; | |
894 | kref_put(&ept->refcount, __ept_release); | |
895 | return NULL; | |
896 | } | |
897 | ||
898 | static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept) | |
899 | { | |
900 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); | |
901 | struct qcom_smd_channel *ch = qsept->qsch; | |
902 | ||
903 | qcom_smd_channel_close(ch); | |
904 | ch->qsept = NULL; | |
905 | kref_put(&ept->refcount, __ept_release); | |
906 | } | |
907 | ||
908 | static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len) | |
909 | { | |
910 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); | |
911 | ||
912 | return __qcom_smd_send(qsept->qsch, data, len, true); | |
913 | } | |
914 | ||
915 | static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len) | |
916 | { | |
917 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); | |
918 | ||
919 | return __qcom_smd_send(qsept->qsch, data, len, false); | |
920 | } | |
921 | ||
adaa11b0 BA |
922 | static unsigned int qcom_smd_poll(struct rpmsg_endpoint *ept, |
923 | struct file *filp, poll_table *wait) | |
924 | { | |
925 | struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept); | |
926 | struct qcom_smd_channel *channel = qsept->qsch; | |
927 | unsigned int mask = 0; | |
928 | ||
929 | poll_wait(filp, &channel->fblockread_event, wait); | |
930 | ||
931 | if (qcom_smd_get_tx_avail(channel) > 20) | |
932 | mask |= POLLOUT | POLLWRNORM; | |
933 | ||
934 | return mask; | |
935 | } | |
936 | ||
53e2822e BA |
937 | /* |
938 | * Finds the device_node for the smd child interested in this channel. | |
939 | */ | |
940 | static struct device_node *qcom_smd_match_channel(struct device_node *edge_node, | |
941 | const char *channel) | |
942 | { | |
943 | struct device_node *child; | |
944 | const char *name; | |
945 | const char *key; | |
946 | int ret; | |
947 | ||
948 | for_each_available_child_of_node(edge_node, child) { | |
949 | key = "qcom,smd-channels"; | |
950 | ret = of_property_read_string(child, key, &name); | |
951 | if (ret) | |
952 | continue; | |
953 | ||
954 | if (strcmp(name, channel) == 0) | |
955 | return child; | |
956 | } | |
957 | ||
958 | return NULL; | |
959 | } | |
960 | ||
961 | static const struct rpmsg_device_ops qcom_smd_device_ops = { | |
962 | .create_ept = qcom_smd_create_ept, | |
963 | }; | |
964 | ||
965 | static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = { | |
966 | .destroy_ept = qcom_smd_destroy_ept, | |
967 | .send = qcom_smd_send, | |
968 | .trysend = qcom_smd_trysend, | |
adaa11b0 | 969 | .poll = qcom_smd_poll, |
53e2822e BA |
970 | }; |
971 | ||
972 | /* | |
973 | * Create a smd client device for channel that is being opened. | |
974 | */ | |
975 | static int qcom_smd_create_device(struct qcom_smd_channel *channel) | |
976 | { | |
977 | struct qcom_smd_device *qsdev; | |
978 | struct rpmsg_device *rpdev; | |
979 | struct qcom_smd_edge *edge = channel->edge; | |
980 | ||
981 | dev_dbg(&edge->dev, "registering '%s'\n", channel->name); | |
982 | ||
983 | qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL); | |
984 | if (!qsdev) | |
985 | return -ENOMEM; | |
986 | ||
987 | /* Link qsdev to our SMD edge */ | |
988 | qsdev->edge = edge; | |
989 | ||
990 | /* Assign callbacks for rpmsg_device */ | |
991 | qsdev->rpdev.ops = &qcom_smd_device_ops; | |
992 | ||
993 | /* Assign public information to the rpmsg_device */ | |
994 | rpdev = &qsdev->rpdev; | |
995 | strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE); | |
996 | rpdev->src = RPMSG_ADDR_ANY; | |
997 | rpdev->dst = RPMSG_ADDR_ANY; | |
998 | ||
999 | rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name); | |
1000 | rpdev->dev.parent = &edge->dev; | |
1001 | ||
1002 | return rpmsg_register_device(rpdev); | |
1003 | } | |
1004 | ||
0be363bf BA |
1005 | static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge) |
1006 | { | |
1007 | struct qcom_smd_device *qsdev; | |
1008 | ||
1009 | qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL); | |
1010 | if (!qsdev) | |
1011 | return -ENOMEM; | |
1012 | ||
1013 | qsdev->edge = edge; | |
1014 | qsdev->rpdev.ops = &qcom_smd_device_ops; | |
1015 | qsdev->rpdev.dev.parent = &edge->dev; | |
1016 | return rpmsg_chrdev_register_device(&qsdev->rpdev); | |
1017 | } | |
1018 | ||
53e2822e BA |
1019 | /* |
1020 | * Allocate the qcom_smd_channel object for a newly found smd channel, | |
1021 | * retrieving and validating the smem items involved. | |
1022 | */ | |
1023 | static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge, | |
1024 | unsigned smem_info_item, | |
1025 | unsigned smem_fifo_item, | |
1026 | char *name) | |
1027 | { | |
1028 | struct qcom_smd_channel *channel; | |
1029 | size_t fifo_size; | |
1030 | size_t info_size; | |
1031 | void *fifo_base; | |
1032 | void *info; | |
1033 | int ret; | |
1034 | ||
1035 | channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL); | |
1036 | if (!channel) | |
1037 | return ERR_PTR(-ENOMEM); | |
1038 | ||
1039 | channel->edge = edge; | |
1040 | channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL); | |
1041 | if (!channel->name) | |
1042 | return ERR_PTR(-ENOMEM); | |
1043 | ||
1044 | mutex_init(&channel->tx_lock); | |
1045 | spin_lock_init(&channel->recv_lock); | |
1046 | init_waitqueue_head(&channel->fblockread_event); | |
1047 | ||
1048 | info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size); | |
1049 | if (IS_ERR(info)) { | |
1050 | ret = PTR_ERR(info); | |
1051 | goto free_name_and_channel; | |
1052 | } | |
1053 | ||
1054 | /* | |
1055 | * Use the size of the item to figure out which channel info struct to | |
1056 | * use. | |
1057 | */ | |
1058 | if (info_size == 2 * sizeof(struct smd_channel_info_word)) { | |
1059 | channel->info_word = info; | |
1060 | } else if (info_size == 2 * sizeof(struct smd_channel_info)) { | |
1061 | channel->info = info; | |
1062 | } else { | |
1063 | dev_err(&edge->dev, | |
1064 | "channel info of size %zu not supported\n", info_size); | |
1065 | ret = -EINVAL; | |
1066 | goto free_name_and_channel; | |
1067 | } | |
1068 | ||
1069 | fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size); | |
1070 | if (IS_ERR(fifo_base)) { | |
1071 | ret = PTR_ERR(fifo_base); | |
1072 | goto free_name_and_channel; | |
1073 | } | |
1074 | ||
1075 | /* The channel consist of a rx and tx fifo of equal size */ | |
1076 | fifo_size /= 2; | |
1077 | ||
1078 | dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n", | |
1079 | name, info_size, fifo_size); | |
1080 | ||
1081 | channel->tx_fifo = fifo_base; | |
1082 | channel->rx_fifo = fifo_base + fifo_size; | |
1083 | channel->fifo_size = fifo_size; | |
1084 | ||
1085 | qcom_smd_channel_reset(channel); | |
1086 | ||
1087 | return channel; | |
1088 | ||
1089 | free_name_and_channel: | |
1090 | devm_kfree(&edge->dev, channel->name); | |
1091 | devm_kfree(&edge->dev, channel); | |
1092 | ||
1093 | return ERR_PTR(ret); | |
1094 | } | |
1095 | ||
1096 | /* | |
1097 | * Scans the allocation table for any newly allocated channels, calls | |
1098 | * qcom_smd_create_channel() to create representations of these and add | |
1099 | * them to the edge's list of channels. | |
1100 | */ | |
1101 | static void qcom_channel_scan_worker(struct work_struct *work) | |
1102 | { | |
1103 | struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work); | |
1104 | struct qcom_smd_alloc_entry *alloc_tbl; | |
1105 | struct qcom_smd_alloc_entry *entry; | |
1106 | struct qcom_smd_channel *channel; | |
1107 | unsigned long flags; | |
1108 | unsigned fifo_id; | |
1109 | unsigned info_id; | |
1110 | int tbl; | |
1111 | int i; | |
1112 | u32 eflags, cid; | |
1113 | ||
1114 | for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) { | |
1115 | alloc_tbl = qcom_smem_get(edge->remote_pid, | |
1116 | smem_items[tbl].alloc_tbl_id, NULL); | |
1117 | if (IS_ERR(alloc_tbl)) | |
1118 | continue; | |
1119 | ||
1120 | for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) { | |
1121 | entry = &alloc_tbl[i]; | |
1122 | eflags = le32_to_cpu(entry->flags); | |
1123 | if (test_bit(i, edge->allocated[tbl])) | |
1124 | continue; | |
1125 | ||
1126 | if (entry->ref_count == 0) | |
1127 | continue; | |
1128 | ||
1129 | if (!entry->name[0]) | |
1130 | continue; | |
1131 | ||
1132 | if (!(eflags & SMD_CHANNEL_FLAGS_PACKET)) | |
1133 | continue; | |
1134 | ||
1135 | if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id) | |
1136 | continue; | |
1137 | ||
1138 | cid = le32_to_cpu(entry->cid); | |
1139 | info_id = smem_items[tbl].info_base_id + cid; | |
1140 | fifo_id = smem_items[tbl].fifo_base_id + cid; | |
1141 | ||
1142 | channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name); | |
1143 | if (IS_ERR(channel)) | |
1144 | continue; | |
1145 | ||
1146 | spin_lock_irqsave(&edge->channels_lock, flags); | |
1147 | list_add(&channel->list, &edge->channels); | |
1148 | spin_unlock_irqrestore(&edge->channels_lock, flags); | |
1149 | ||
1150 | dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name); | |
1151 | set_bit(i, edge->allocated[tbl]); | |
1152 | ||
1153 | wake_up_interruptible(&edge->new_channel_event); | |
1154 | } | |
1155 | } | |
1156 | ||
1157 | schedule_work(&edge->state_work); | |
1158 | } | |
1159 | ||
1160 | /* | |
1161 | * This per edge worker scans smem for any new channels and register these. It | |
1162 | * then scans all registered channels for state changes that should be handled | |
1163 | * by creating or destroying smd client devices for the registered channels. | |
1164 | * | |
1165 | * LOCKING: edge->channels_lock only needs to cover the list operations, as the | |
1166 | * worker is killed before any channels are deallocated | |
1167 | */ | |
1168 | static void qcom_channel_state_worker(struct work_struct *work) | |
1169 | { | |
1170 | struct qcom_smd_channel *channel; | |
1171 | struct qcom_smd_edge *edge = container_of(work, | |
1172 | struct qcom_smd_edge, | |
1173 | state_work); | |
1174 | struct rpmsg_channel_info chinfo; | |
1175 | unsigned remote_state; | |
1176 | unsigned long flags; | |
1177 | ||
1178 | /* | |
1179 | * Register a device for any closed channel where the remote processor | |
1180 | * is showing interest in opening the channel. | |
1181 | */ | |
1182 | spin_lock_irqsave(&edge->channels_lock, flags); | |
1183 | list_for_each_entry(channel, &edge->channels, list) { | |
1184 | if (channel->state != SMD_CHANNEL_CLOSED) | |
1185 | continue; | |
1186 | ||
1187 | remote_state = GET_RX_CHANNEL_INFO(channel, state); | |
1188 | if (remote_state != SMD_CHANNEL_OPENING && | |
1189 | remote_state != SMD_CHANNEL_OPENED) | |
1190 | continue; | |
1191 | ||
1192 | if (channel->registered) | |
1193 | continue; | |
1194 | ||
1195 | spin_unlock_irqrestore(&edge->channels_lock, flags); | |
1196 | qcom_smd_create_device(channel); | |
1197 | channel->registered = true; | |
1198 | spin_lock_irqsave(&edge->channels_lock, flags); | |
1199 | ||
1200 | channel->registered = true; | |
1201 | } | |
1202 | ||
1203 | /* | |
1204 | * Unregister the device for any channel that is opened where the | |
1205 | * remote processor is closing the channel. | |
1206 | */ | |
1207 | list_for_each_entry(channel, &edge->channels, list) { | |
1208 | if (channel->state != SMD_CHANNEL_OPENING && | |
1209 | channel->state != SMD_CHANNEL_OPENED) | |
1210 | continue; | |
1211 | ||
1212 | remote_state = GET_RX_CHANNEL_INFO(channel, state); | |
1213 | if (remote_state == SMD_CHANNEL_OPENING || | |
1214 | remote_state == SMD_CHANNEL_OPENED) | |
1215 | continue; | |
1216 | ||
1217 | spin_unlock_irqrestore(&edge->channels_lock, flags); | |
1218 | ||
1219 | strncpy(chinfo.name, channel->name, sizeof(chinfo.name)); | |
1220 | chinfo.src = RPMSG_ADDR_ANY; | |
1221 | chinfo.dst = RPMSG_ADDR_ANY; | |
1222 | rpmsg_unregister_device(&edge->dev, &chinfo); | |
1223 | channel->registered = false; | |
1224 | spin_lock_irqsave(&edge->channels_lock, flags); | |
1225 | } | |
1226 | spin_unlock_irqrestore(&edge->channels_lock, flags); | |
1227 | } | |
1228 | ||
1229 | /* | |
1230 | * Parses an of_node describing an edge. | |
1231 | */ | |
1232 | static int qcom_smd_parse_edge(struct device *dev, | |
1233 | struct device_node *node, | |
1234 | struct qcom_smd_edge *edge) | |
1235 | { | |
1236 | struct device_node *syscon_np; | |
1237 | const char *key; | |
1238 | int irq; | |
1239 | int ret; | |
1240 | ||
1241 | INIT_LIST_HEAD(&edge->channels); | |
1242 | spin_lock_init(&edge->channels_lock); | |
1243 | ||
1244 | INIT_WORK(&edge->scan_work, qcom_channel_scan_worker); | |
1245 | INIT_WORK(&edge->state_work, qcom_channel_state_worker); | |
1246 | ||
1247 | edge->of_node = of_node_get(node); | |
1248 | ||
1249 | key = "qcom,smd-edge"; | |
1250 | ret = of_property_read_u32(node, key, &edge->edge_id); | |
1251 | if (ret) { | |
1252 | dev_err(dev, "edge missing %s property\n", key); | |
1253 | return -EINVAL; | |
1254 | } | |
1255 | ||
1256 | edge->remote_pid = QCOM_SMEM_HOST_ANY; | |
1257 | key = "qcom,remote-pid"; | |
1258 | of_property_read_u32(node, key, &edge->remote_pid); | |
1259 | ||
1260 | syscon_np = of_parse_phandle(node, "qcom,ipc", 0); | |
1261 | if (!syscon_np) { | |
1262 | dev_err(dev, "no qcom,ipc node\n"); | |
1263 | return -ENODEV; | |
1264 | } | |
1265 | ||
1266 | edge->ipc_regmap = syscon_node_to_regmap(syscon_np); | |
1267 | if (IS_ERR(edge->ipc_regmap)) | |
1268 | return PTR_ERR(edge->ipc_regmap); | |
1269 | ||
1270 | key = "qcom,ipc"; | |
1271 | ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset); | |
1272 | if (ret < 0) { | |
1273 | dev_err(dev, "no offset in %s\n", key); | |
1274 | return -EINVAL; | |
1275 | } | |
1276 | ||
1277 | ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit); | |
1278 | if (ret < 0) { | |
1279 | dev_err(dev, "no bit in %s\n", key); | |
1280 | return -EINVAL; | |
1281 | } | |
1282 | ||
5e53c42c BA |
1283 | ret = of_property_read_string(node, "label", &edge->name); |
1284 | if (ret < 0) | |
1285 | edge->name = node->name; | |
1286 | ||
53e2822e BA |
1287 | irq = irq_of_parse_and_map(node, 0); |
1288 | if (irq < 0) { | |
1289 | dev_err(dev, "required smd interrupt missing\n"); | |
1290 | return -EINVAL; | |
1291 | } | |
1292 | ||
1293 | ret = devm_request_irq(dev, irq, | |
1294 | qcom_smd_edge_intr, IRQF_TRIGGER_RISING, | |
1295 | node->name, edge); | |
1296 | if (ret) { | |
1297 | dev_err(dev, "failed to request smd irq\n"); | |
1298 | return ret; | |
1299 | } | |
1300 | ||
1301 | edge->irq = irq; | |
1302 | ||
1303 | return 0; | |
1304 | } | |
1305 | ||
1306 | /* | |
1307 | * Release function for an edge. | |
1308 | * Reset the state of each associated channel and free the edge context. | |
1309 | */ | |
1310 | static void qcom_smd_edge_release(struct device *dev) | |
1311 | { | |
1312 | struct qcom_smd_channel *channel; | |
1313 | struct qcom_smd_edge *edge = to_smd_edge(dev); | |
1314 | ||
1315 | list_for_each_entry(channel, &edge->channels, list) { | |
1316 | SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED); | |
1317 | SET_RX_CHANNEL_INFO(channel, head, 0); | |
1318 | SET_RX_CHANNEL_INFO(channel, tail, 0); | |
1319 | } | |
1320 | ||
1321 | kfree(edge); | |
1322 | } | |
1323 | ||
5e53c42c BA |
1324 | static ssize_t rpmsg_name_show(struct device *dev, |
1325 | struct device_attribute *attr, char *buf) | |
1326 | { | |
1327 | struct qcom_smd_edge *edge = to_smd_edge(dev); | |
1328 | ||
1329 | return sprintf(buf, "%s\n", edge->name); | |
1330 | } | |
1331 | static DEVICE_ATTR_RO(rpmsg_name); | |
1332 | ||
1333 | static struct attribute *qcom_smd_edge_attrs[] = { | |
1334 | &dev_attr_rpmsg_name.attr, | |
1335 | NULL | |
1336 | }; | |
1337 | ATTRIBUTE_GROUPS(qcom_smd_edge); | |
1338 | ||
53e2822e BA |
1339 | /** |
1340 | * qcom_smd_register_edge() - register an edge based on an device_node | |
1341 | * @parent: parent device for the edge | |
1342 | * @node: device_node describing the edge | |
1343 | * | |
1344 | * Returns an edge reference, or negative ERR_PTR() on failure. | |
1345 | */ | |
1346 | struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent, | |
1347 | struct device_node *node) | |
1348 | { | |
1349 | struct qcom_smd_edge *edge; | |
1350 | int ret; | |
1351 | ||
1352 | edge = kzalloc(sizeof(*edge), GFP_KERNEL); | |
1353 | if (!edge) | |
1354 | return ERR_PTR(-ENOMEM); | |
1355 | ||
1356 | init_waitqueue_head(&edge->new_channel_event); | |
1357 | ||
1358 | edge->dev.parent = parent; | |
1359 | edge->dev.release = qcom_smd_edge_release; | |
5e53c42c | 1360 | edge->dev.groups = qcom_smd_edge_groups; |
53e2822e BA |
1361 | dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name); |
1362 | ret = device_register(&edge->dev); | |
1363 | if (ret) { | |
1364 | pr_err("failed to register smd edge\n"); | |
1365 | return ERR_PTR(ret); | |
1366 | } | |
1367 | ||
1368 | ret = qcom_smd_parse_edge(&edge->dev, node, edge); | |
1369 | if (ret) { | |
1370 | dev_err(&edge->dev, "failed to parse smd edge\n"); | |
1371 | goto unregister_dev; | |
1372 | } | |
1373 | ||
0be363bf BA |
1374 | ret = qcom_smd_create_chrdev(edge); |
1375 | if (ret) { | |
1376 | dev_err(&edge->dev, "failed to register chrdev for edge\n"); | |
1377 | goto unregister_dev; | |
1378 | } | |
1379 | ||
53e2822e BA |
1380 | schedule_work(&edge->scan_work); |
1381 | ||
1382 | return edge; | |
1383 | ||
1384 | unregister_dev: | |
1385 | put_device(&edge->dev); | |
1386 | return ERR_PTR(ret); | |
1387 | } | |
1388 | EXPORT_SYMBOL(qcom_smd_register_edge); | |
1389 | ||
1390 | static int qcom_smd_remove_device(struct device *dev, void *data) | |
1391 | { | |
1392 | device_unregister(dev); | |
1393 | ||
1394 | return 0; | |
1395 | } | |
1396 | ||
1397 | /** | |
1398 | * qcom_smd_unregister_edge() - release an edge and its children | |
1399 | * @edge: edge reference acquired from qcom_smd_register_edge | |
1400 | */ | |
1401 | int qcom_smd_unregister_edge(struct qcom_smd_edge *edge) | |
1402 | { | |
1403 | int ret; | |
1404 | ||
1405 | disable_irq(edge->irq); | |
1406 | cancel_work_sync(&edge->scan_work); | |
1407 | cancel_work_sync(&edge->state_work); | |
1408 | ||
1409 | ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device); | |
1410 | if (ret) | |
1411 | dev_warn(&edge->dev, "can't remove smd device: %d\n", ret); | |
1412 | ||
1413 | device_unregister(&edge->dev); | |
1414 | ||
1415 | return 0; | |
1416 | } | |
1417 | EXPORT_SYMBOL(qcom_smd_unregister_edge); | |
1418 | ||
1419 | static int qcom_smd_probe(struct platform_device *pdev) | |
1420 | { | |
1421 | struct device_node *node; | |
1422 | void *p; | |
1423 | ||
1424 | /* Wait for smem */ | |
1425 | p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL); | |
1426 | if (PTR_ERR(p) == -EPROBE_DEFER) | |
1427 | return PTR_ERR(p); | |
1428 | ||
1429 | for_each_available_child_of_node(pdev->dev.of_node, node) | |
1430 | qcom_smd_register_edge(&pdev->dev, node); | |
1431 | ||
1432 | return 0; | |
1433 | } | |
1434 | ||
1435 | static int qcom_smd_remove_edge(struct device *dev, void *data) | |
1436 | { | |
1437 | struct qcom_smd_edge *edge = to_smd_edge(dev); | |
1438 | ||
1439 | return qcom_smd_unregister_edge(edge); | |
1440 | } | |
1441 | ||
1442 | /* | |
1443 | * Shut down all smd clients by making sure that each edge stops processing | |
1444 | * events and scanning for new channels, then call destroy on the devices. | |
1445 | */ | |
1446 | static int qcom_smd_remove(struct platform_device *pdev) | |
1447 | { | |
1448 | int ret; | |
1449 | ||
1450 | ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge); | |
1451 | if (ret) | |
1452 | dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret); | |
1453 | ||
1454 | return ret; | |
1455 | } | |
1456 | ||
1457 | static const struct of_device_id qcom_smd_of_match[] = { | |
1458 | { .compatible = "qcom,smd" }, | |
1459 | {} | |
1460 | }; | |
1461 | MODULE_DEVICE_TABLE(of, qcom_smd_of_match); | |
1462 | ||
1463 | static struct platform_driver qcom_smd_driver = { | |
1464 | .probe = qcom_smd_probe, | |
1465 | .remove = qcom_smd_remove, | |
1466 | .driver = { | |
1467 | .name = "qcom-smd", | |
1468 | .of_match_table = qcom_smd_of_match, | |
1469 | }, | |
1470 | }; | |
1471 | ||
1472 | static int __init qcom_smd_init(void) | |
1473 | { | |
1474 | return platform_driver_register(&qcom_smd_driver); | |
1475 | } | |
1476 | subsys_initcall(qcom_smd_init); | |
1477 | ||
1478 | static void __exit qcom_smd_exit(void) | |
1479 | { | |
1480 | platform_driver_unregister(&qcom_smd_driver); | |
1481 | } | |
1482 | module_exit(qcom_smd_exit); | |
1483 | ||
1484 | MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>"); | |
1485 | MODULE_DESCRIPTION("Qualcomm Shared Memory Driver"); | |
1486 | MODULE_LICENSE("GPL v2"); |