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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
2b6d83e2 JB |
2 | /* |
3 | * Mailbox: Common code for Mailbox controllers and users | |
4 | * | |
5 | * Copyright (C) 2013-2014 Linaro Ltd. | |
6 | * Author: Jassi Brar <jassisinghbrar@gmail.com> | |
2b6d83e2 JB |
7 | */ |
8 | ||
9 | #include <linux/interrupt.h> | |
10 | #include <linux/spinlock.h> | |
11 | #include <linux/mutex.h> | |
12 | #include <linux/delay.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/err.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/device.h> | |
17 | #include <linux/bitops.h> | |
18 | #include <linux/mailbox_client.h> | |
19 | #include <linux/mailbox_controller.h> | |
20 | ||
86c22f8c | 21 | #include "mailbox.h" |
2b6d83e2 JB |
22 | |
23 | static LIST_HEAD(mbox_cons); | |
24 | static DEFINE_MUTEX(con_mutex); | |
25 | ||
26 | static int add_to_rbuf(struct mbox_chan *chan, void *mssg) | |
27 | { | |
28 | int idx; | |
29 | unsigned long flags; | |
30 | ||
31 | spin_lock_irqsave(&chan->lock, flags); | |
32 | ||
33 | /* See if there is any space left */ | |
34 | if (chan->msg_count == MBOX_TX_QUEUE_LEN) { | |
35 | spin_unlock_irqrestore(&chan->lock, flags); | |
36 | return -ENOBUFS; | |
37 | } | |
38 | ||
39 | idx = chan->msg_free; | |
40 | chan->msg_data[idx] = mssg; | |
41 | chan->msg_count++; | |
42 | ||
43 | if (idx == MBOX_TX_QUEUE_LEN - 1) | |
44 | chan->msg_free = 0; | |
45 | else | |
46 | chan->msg_free++; | |
47 | ||
48 | spin_unlock_irqrestore(&chan->lock, flags); | |
49 | ||
50 | return idx; | |
51 | } | |
52 | ||
53 | static void msg_submit(struct mbox_chan *chan) | |
54 | { | |
55 | unsigned count, idx; | |
56 | unsigned long flags; | |
57 | void *data; | |
52a49306 | 58 | int err = -EBUSY; |
2b6d83e2 JB |
59 | |
60 | spin_lock_irqsave(&chan->lock, flags); | |
61 | ||
62 | if (!chan->msg_count || chan->active_req) | |
63 | goto exit; | |
64 | ||
65 | count = chan->msg_count; | |
66 | idx = chan->msg_free; | |
67 | if (idx >= count) | |
68 | idx -= count; | |
69 | else | |
70 | idx += MBOX_TX_QUEUE_LEN - count; | |
71 | ||
72 | data = chan->msg_data[idx]; | |
73 | ||
97b0c7bd SH |
74 | if (chan->cl->tx_prepare) |
75 | chan->cl->tx_prepare(chan->cl, data); | |
2b6d83e2 JB |
76 | /* Try to submit a message to the MBOX controller */ |
77 | err = chan->mbox->ops->send_data(chan, data); | |
78 | if (!err) { | |
79 | chan->active_req = data; | |
80 | chan->msg_count--; | |
81 | } | |
82 | exit: | |
83 | spin_unlock_irqrestore(&chan->lock, flags); | |
52a49306 | 84 | |
c7dacf5b JB |
85 | /* kick start the timer immediately to avoid delays */ |
86 | if (!err && (chan->txdone_method & TXDONE_BY_POLL)) { | |
87 | /* but only if not already active */ | |
88 | if (!hrtimer_active(&chan->mbox->poll_hrt)) | |
89 | hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL); | |
90 | } | |
2b6d83e2 JB |
91 | } |
92 | ||
93 | static void tx_tick(struct mbox_chan *chan, int r) | |
94 | { | |
95 | unsigned long flags; | |
96 | void *mssg; | |
97 | ||
98 | spin_lock_irqsave(&chan->lock, flags); | |
99 | mssg = chan->active_req; | |
100 | chan->active_req = NULL; | |
101 | spin_unlock_irqrestore(&chan->lock, flags); | |
102 | ||
103 | /* Submit next message */ | |
104 | msg_submit(chan); | |
105 | ||
cb710ab1 SH |
106 | if (!mssg) |
107 | return; | |
108 | ||
2b6d83e2 | 109 | /* Notify the client */ |
cb710ab1 | 110 | if (chan->cl->tx_done) |
2b6d83e2 JB |
111 | chan->cl->tx_done(chan->cl, mssg, r); |
112 | ||
cc6eeaa3 | 113 | if (r != -ETIME && chan->cl->tx_block) |
2b6d83e2 JB |
114 | complete(&chan->tx_complete); |
115 | } | |
116 | ||
0cc67945 | 117 | static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer) |
2b6d83e2 | 118 | { |
0cc67945 SH |
119 | struct mbox_controller *mbox = |
120 | container_of(hrtimer, struct mbox_controller, poll_hrt); | |
2b6d83e2 JB |
121 | bool txdone, resched = false; |
122 | int i; | |
123 | ||
124 | for (i = 0; i < mbox->num_chans; i++) { | |
125 | struct mbox_chan *chan = &mbox->chans[i]; | |
126 | ||
127 | if (chan->active_req && chan->cl) { | |
c7dacf5b | 128 | resched = true; |
2b6d83e2 JB |
129 | txdone = chan->mbox->ops->last_tx_done(chan); |
130 | if (txdone) | |
131 | tx_tick(chan, 0); | |
132 | } | |
133 | } | |
134 | ||
0cc67945 SH |
135 | if (resched) { |
136 | hrtimer_forward_now(hrtimer, ms_to_ktime(mbox->txpoll_period)); | |
137 | return HRTIMER_RESTART; | |
138 | } | |
139 | return HRTIMER_NORESTART; | |
2b6d83e2 JB |
140 | } |
141 | ||
142 | /** | |
143 | * mbox_chan_received_data - A way for controller driver to push data | |
144 | * received from remote to the upper layer. | |
145 | * @chan: Pointer to the mailbox channel on which RX happened. | |
146 | * @mssg: Client specific message typecasted as void * | |
147 | * | |
148 | * After startup and before shutdown any data received on the chan | |
149 | * is passed on to the API via atomic mbox_chan_received_data(). | |
150 | * The controller should ACK the RX only after this call returns. | |
151 | */ | |
152 | void mbox_chan_received_data(struct mbox_chan *chan, void *mssg) | |
153 | { | |
154 | /* No buffering the received data */ | |
155 | if (chan->cl->rx_callback) | |
156 | chan->cl->rx_callback(chan->cl, mssg); | |
157 | } | |
158 | EXPORT_SYMBOL_GPL(mbox_chan_received_data); | |
159 | ||
160 | /** | |
161 | * mbox_chan_txdone - A way for controller driver to notify the | |
162 | * framework that the last TX has completed. | |
163 | * @chan: Pointer to the mailbox chan on which TX happened. | |
164 | * @r: Status of last TX - OK or ERROR | |
165 | * | |
166 | * The controller that has IRQ for TX ACK calls this atomic API | |
167 | * to tick the TX state machine. It works only if txdone_irq | |
168 | * is set by the controller. | |
169 | */ | |
170 | void mbox_chan_txdone(struct mbox_chan *chan, int r) | |
171 | { | |
172 | if (unlikely(!(chan->txdone_method & TXDONE_BY_IRQ))) { | |
173 | dev_err(chan->mbox->dev, | |
174 | "Controller can't run the TX ticker\n"); | |
175 | return; | |
176 | } | |
177 | ||
178 | tx_tick(chan, r); | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(mbox_chan_txdone); | |
181 | ||
182 | /** | |
183 | * mbox_client_txdone - The way for a client to run the TX state machine. | |
184 | * @chan: Mailbox channel assigned to this client. | |
185 | * @r: Success status of last transmission. | |
186 | * | |
187 | * The client/protocol had received some 'ACK' packet and it notifies | |
188 | * the API that the last packet was sent successfully. This only works | |
189 | * if the controller can't sense TX-Done. | |
190 | */ | |
191 | void mbox_client_txdone(struct mbox_chan *chan, int r) | |
192 | { | |
193 | if (unlikely(!(chan->txdone_method & TXDONE_BY_ACK))) { | |
194 | dev_err(chan->mbox->dev, "Client can't run the TX ticker\n"); | |
195 | return; | |
196 | } | |
197 | ||
198 | tx_tick(chan, r); | |
199 | } | |
200 | EXPORT_SYMBOL_GPL(mbox_client_txdone); | |
201 | ||
202 | /** | |
203 | * mbox_client_peek_data - A way for client driver to pull data | |
204 | * received from remote by the controller. | |
205 | * @chan: Mailbox channel assigned to this client. | |
206 | * | |
207 | * A poke to controller driver for any received data. | |
208 | * The data is actually passed onto client via the | |
209 | * mbox_chan_received_data() | |
210 | * The call can be made from atomic context, so the controller's | |
211 | * implementation of peek_data() must not sleep. | |
212 | * | |
213 | * Return: True, if controller has, and is going to push after this, | |
214 | * some data. | |
215 | * False, if controller doesn't have any data to be read. | |
216 | */ | |
217 | bool mbox_client_peek_data(struct mbox_chan *chan) | |
218 | { | |
219 | if (chan->mbox->ops->peek_data) | |
220 | return chan->mbox->ops->peek_data(chan); | |
221 | ||
222 | return false; | |
223 | } | |
224 | EXPORT_SYMBOL_GPL(mbox_client_peek_data); | |
225 | ||
226 | /** | |
227 | * mbox_send_message - For client to submit a message to be | |
228 | * sent to the remote. | |
229 | * @chan: Mailbox channel assigned to this client. | |
230 | * @mssg: Client specific message typecasted. | |
231 | * | |
232 | * For client to submit data to the controller destined for a remote | |
233 | * processor. If the client had set 'tx_block', the call will return | |
234 | * either when the remote receives the data or when 'tx_tout' millisecs | |
235 | * run out. | |
236 | * In non-blocking mode, the requests are buffered by the API and a | |
237 | * non-negative token is returned for each queued request. If the request | |
238 | * is not queued, a negative token is returned. Upon failure or successful | |
239 | * TX, the API calls 'tx_done' from atomic context, from which the client | |
240 | * could submit yet another request. | |
241 | * The pointer to message should be preserved until it is sent | |
242 | * over the chan, i.e, tx_done() is made. | |
243 | * This function could be called from atomic context as it simply | |
244 | * queues the data and returns a token against the request. | |
245 | * | |
246 | * Return: Non-negative integer for successful submission (non-blocking mode) | |
247 | * or transmission over chan (blocking mode). | |
248 | * Negative value denotes failure. | |
249 | */ | |
250 | int mbox_send_message(struct mbox_chan *chan, void *mssg) | |
251 | { | |
252 | int t; | |
253 | ||
254 | if (!chan || !chan->cl) | |
255 | return -EINVAL; | |
256 | ||
257 | t = add_to_rbuf(chan, mssg); | |
258 | if (t < 0) { | |
259 | dev_err(chan->mbox->dev, "Try increasing MBOX_TX_QUEUE_LEN\n"); | |
260 | return t; | |
261 | } | |
262 | ||
263 | msg_submit(chan); | |
264 | ||
c61b781e | 265 | if (chan->cl->tx_block) { |
2b6d83e2 JB |
266 | unsigned long wait; |
267 | int ret; | |
268 | ||
269 | if (!chan->cl->tx_tout) /* wait forever */ | |
270 | wait = msecs_to_jiffies(3600000); | |
271 | else | |
272 | wait = msecs_to_jiffies(chan->cl->tx_tout); | |
273 | ||
274 | ret = wait_for_completion_timeout(&chan->tx_complete, wait); | |
275 | if (ret == 0) { | |
cc6eeaa3 SH |
276 | t = -ETIME; |
277 | tx_tick(chan, t); | |
2b6d83e2 JB |
278 | } |
279 | } | |
280 | ||
281 | return t; | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(mbox_send_message); | |
284 | ||
a8803d74 TR |
285 | /** |
286 | * mbox_flush - flush a mailbox channel | |
287 | * @chan: mailbox channel to flush | |
288 | * @timeout: time, in milliseconds, to allow the flush operation to succeed | |
289 | * | |
290 | * Mailbox controllers that need to work in atomic context can implement the | |
291 | * ->flush() callback to busy loop until a transmission has been completed. | |
292 | * The implementation must call mbox_chan_txdone() upon success. Clients can | |
293 | * call the mbox_flush() function at any time after mbox_send_message() to | |
294 | * flush the transmission. After the function returns success, the mailbox | |
295 | * transmission is guaranteed to have completed. | |
296 | * | |
297 | * Returns: 0 on success or a negative error code on failure. | |
298 | */ | |
299 | int mbox_flush(struct mbox_chan *chan, unsigned long timeout) | |
300 | { | |
301 | int ret; | |
302 | ||
303 | if (!chan->mbox->ops->flush) | |
304 | return -ENOTSUPP; | |
305 | ||
306 | ret = chan->mbox->ops->flush(chan, timeout); | |
307 | if (ret < 0) | |
308 | tx_tick(chan, ret); | |
309 | ||
310 | return ret; | |
311 | } | |
4f055779 | 312 | EXPORT_SYMBOL_GPL(mbox_flush); |
a8803d74 | 313 | |
2b6d83e2 JB |
314 | /** |
315 | * mbox_request_channel - Request a mailbox channel. | |
316 | * @cl: Identity of the client requesting the channel. | |
317 | * @index: Index of mailbox specifier in 'mboxes' property. | |
318 | * | |
319 | * The Client specifies its requirements and capabilities while asking for | |
320 | * a mailbox channel. It can't be called from atomic context. | |
321 | * The channel is exclusively allocated and can't be used by another | |
322 | * client before the owner calls mbox_free_channel. | |
323 | * After assignment, any packet received on this channel will be | |
324 | * handed over to the client via the 'rx_callback'. | |
325 | * The framework holds reference to the client, so the mbox_client | |
326 | * structure shouldn't be modified until the mbox_free_channel returns. | |
327 | * | |
328 | * Return: Pointer to the channel assigned to the client if successful. | |
329 | * ERR_PTR for request failure. | |
330 | */ | |
331 | struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index) | |
332 | { | |
333 | struct device *dev = cl->dev; | |
334 | struct mbox_controller *mbox; | |
335 | struct of_phandle_args spec; | |
336 | struct mbox_chan *chan; | |
337 | unsigned long flags; | |
338 | int ret; | |
339 | ||
340 | if (!dev || !dev->of_node) { | |
341 | pr_debug("%s: No owner device node\n", __func__); | |
342 | return ERR_PTR(-ENODEV); | |
343 | } | |
344 | ||
345 | mutex_lock(&con_mutex); | |
346 | ||
347 | if (of_parse_phandle_with_args(dev->of_node, "mboxes", | |
348 | "#mbox-cells", index, &spec)) { | |
349 | dev_dbg(dev, "%s: can't parse \"mboxes\" property\n", __func__); | |
350 | mutex_unlock(&con_mutex); | |
351 | return ERR_PTR(-ENODEV); | |
352 | } | |
353 | ||
2d805fc1 | 354 | chan = ERR_PTR(-EPROBE_DEFER); |
2b6d83e2 JB |
355 | list_for_each_entry(mbox, &mbox_cons, node) |
356 | if (mbox->dev->of_node == spec.np) { | |
357 | chan = mbox->of_xlate(mbox, &spec); | |
8ed82e23 MP |
358 | if (!IS_ERR(chan)) |
359 | break; | |
2b6d83e2 JB |
360 | } |
361 | ||
362 | of_node_put(spec.np); | |
363 | ||
2d805fc1 BL |
364 | if (IS_ERR(chan)) { |
365 | mutex_unlock(&con_mutex); | |
366 | return chan; | |
367 | } | |
368 | ||
369 | if (chan->cl || !try_module_get(mbox->dev->driver->owner)) { | |
2b6d83e2 JB |
370 | dev_dbg(dev, "%s: mailbox not free\n", __func__); |
371 | mutex_unlock(&con_mutex); | |
372 | return ERR_PTR(-EBUSY); | |
373 | } | |
374 | ||
375 | spin_lock_irqsave(&chan->lock, flags); | |
376 | chan->msg_free = 0; | |
377 | chan->msg_count = 0; | |
378 | chan->active_req = NULL; | |
379 | chan->cl = cl; | |
380 | init_completion(&chan->tx_complete); | |
381 | ||
382 | if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) | |
33cd7123 | 383 | chan->txdone_method = TXDONE_BY_ACK; |
2b6d83e2 JB |
384 | |
385 | spin_unlock_irqrestore(&chan->lock, flags); | |
386 | ||
b7133d6f BA |
387 | if (chan->mbox->ops->startup) { |
388 | ret = chan->mbox->ops->startup(chan); | |
389 | ||
390 | if (ret) { | |
391 | dev_err(dev, "Unable to startup the chan (%d)\n", ret); | |
392 | mbox_free_channel(chan); | |
393 | chan = ERR_PTR(ret); | |
394 | } | |
2b6d83e2 JB |
395 | } |
396 | ||
397 | mutex_unlock(&con_mutex); | |
398 | return chan; | |
399 | } | |
400 | EXPORT_SYMBOL_GPL(mbox_request_channel); | |
401 | ||
dfabde20 LJ |
402 | struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl, |
403 | const char *name) | |
404 | { | |
405 | struct device_node *np = cl->dev->of_node; | |
406 | struct property *prop; | |
407 | const char *mbox_name; | |
408 | int index = 0; | |
409 | ||
410 | if (!np) { | |
411 | dev_err(cl->dev, "%s() currently only supports DT\n", __func__); | |
0c44d789 | 412 | return ERR_PTR(-EINVAL); |
dfabde20 LJ |
413 | } |
414 | ||
415 | if (!of_get_property(np, "mbox-names", NULL)) { | |
416 | dev_err(cl->dev, | |
417 | "%s() requires an \"mbox-names\" property\n", __func__); | |
0c44d789 | 418 | return ERR_PTR(-EINVAL); |
dfabde20 LJ |
419 | } |
420 | ||
421 | of_property_for_each_string(np, "mbox-names", prop, mbox_name) { | |
422 | if (!strncmp(name, mbox_name, strlen(name))) | |
25777e57 | 423 | return mbox_request_channel(cl, index); |
dfabde20 LJ |
424 | index++; |
425 | } | |
426 | ||
25777e57 | 427 | dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n", |
428 | __func__, name); | |
429 | return ERR_PTR(-EINVAL); | |
dfabde20 LJ |
430 | } |
431 | EXPORT_SYMBOL_GPL(mbox_request_channel_byname); | |
432 | ||
2b6d83e2 JB |
433 | /** |
434 | * mbox_free_channel - The client relinquishes control of a mailbox | |
435 | * channel by this call. | |
436 | * @chan: The mailbox channel to be freed. | |
437 | */ | |
438 | void mbox_free_channel(struct mbox_chan *chan) | |
439 | { | |
440 | unsigned long flags; | |
441 | ||
442 | if (!chan || !chan->cl) | |
443 | return; | |
444 | ||
b7133d6f BA |
445 | if (chan->mbox->ops->shutdown) |
446 | chan->mbox->ops->shutdown(chan); | |
2b6d83e2 JB |
447 | |
448 | /* The queued TX requests are simply aborted, no callbacks are made */ | |
449 | spin_lock_irqsave(&chan->lock, flags); | |
450 | chan->cl = NULL; | |
451 | chan->active_req = NULL; | |
33cd7123 | 452 | if (chan->txdone_method == TXDONE_BY_ACK) |
2b6d83e2 JB |
453 | chan->txdone_method = TXDONE_BY_POLL; |
454 | ||
455 | module_put(chan->mbox->dev->driver->owner); | |
456 | spin_unlock_irqrestore(&chan->lock, flags); | |
457 | } | |
458 | EXPORT_SYMBOL_GPL(mbox_free_channel); | |
459 | ||
460 | static struct mbox_chan * | |
461 | of_mbox_index_xlate(struct mbox_controller *mbox, | |
462 | const struct of_phandle_args *sp) | |
463 | { | |
464 | int ind = sp->args[0]; | |
465 | ||
466 | if (ind >= mbox->num_chans) | |
2d805fc1 | 467 | return ERR_PTR(-EINVAL); |
2b6d83e2 JB |
468 | |
469 | return &mbox->chans[ind]; | |
470 | } | |
471 | ||
472 | /** | |
473 | * mbox_controller_register - Register the mailbox controller | |
474 | * @mbox: Pointer to the mailbox controller. | |
475 | * | |
476 | * The controller driver registers its communication channels | |
477 | */ | |
478 | int mbox_controller_register(struct mbox_controller *mbox) | |
479 | { | |
480 | int i, txdone; | |
481 | ||
482 | /* Sanity check */ | |
483 | if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans) | |
484 | return -EINVAL; | |
485 | ||
486 | if (mbox->txdone_irq) | |
487 | txdone = TXDONE_BY_IRQ; | |
488 | else if (mbox->txdone_poll) | |
489 | txdone = TXDONE_BY_POLL; | |
490 | else /* It has to be ACK then */ | |
491 | txdone = TXDONE_BY_ACK; | |
492 | ||
493 | if (txdone == TXDONE_BY_POLL) { | |
4605fff0 AK |
494 | |
495 | if (!mbox->ops->last_tx_done) { | |
496 | dev_err(mbox->dev, "last_tx_done method is absent\n"); | |
497 | return -EINVAL; | |
498 | } | |
499 | ||
0cc67945 SH |
500 | hrtimer_init(&mbox->poll_hrt, CLOCK_MONOTONIC, |
501 | HRTIMER_MODE_REL); | |
502 | mbox->poll_hrt.function = txdone_hrtimer; | |
2b6d83e2 JB |
503 | } |
504 | ||
505 | for (i = 0; i < mbox->num_chans; i++) { | |
506 | struct mbox_chan *chan = &mbox->chans[i]; | |
507 | ||
508 | chan->cl = NULL; | |
509 | chan->mbox = mbox; | |
510 | chan->txdone_method = txdone; | |
511 | spin_lock_init(&chan->lock); | |
512 | } | |
513 | ||
514 | if (!mbox->of_xlate) | |
515 | mbox->of_xlate = of_mbox_index_xlate; | |
516 | ||
517 | mutex_lock(&con_mutex); | |
518 | list_add_tail(&mbox->node, &mbox_cons); | |
519 | mutex_unlock(&con_mutex); | |
520 | ||
521 | return 0; | |
522 | } | |
523 | EXPORT_SYMBOL_GPL(mbox_controller_register); | |
524 | ||
525 | /** | |
526 | * mbox_controller_unregister - Unregister the mailbox controller | |
527 | * @mbox: Pointer to the mailbox controller. | |
528 | */ | |
529 | void mbox_controller_unregister(struct mbox_controller *mbox) | |
530 | { | |
531 | int i; | |
532 | ||
533 | if (!mbox) | |
534 | return; | |
535 | ||
536 | mutex_lock(&con_mutex); | |
537 | ||
538 | list_del(&mbox->node); | |
539 | ||
540 | for (i = 0; i < mbox->num_chans; i++) | |
541 | mbox_free_channel(&mbox->chans[i]); | |
542 | ||
543 | if (mbox->txdone_poll) | |
0cc67945 | 544 | hrtimer_cancel(&mbox->poll_hrt); |
2b6d83e2 JB |
545 | |
546 | mutex_unlock(&con_mutex); | |
547 | } | |
548 | EXPORT_SYMBOL_GPL(mbox_controller_unregister); | |
e898d9cd TR |
549 | |
550 | static void __devm_mbox_controller_unregister(struct device *dev, void *res) | |
551 | { | |
552 | struct mbox_controller **mbox = res; | |
553 | ||
554 | mbox_controller_unregister(*mbox); | |
555 | } | |
556 | ||
557 | static int devm_mbox_controller_match(struct device *dev, void *res, void *data) | |
558 | { | |
559 | struct mbox_controller **mbox = res; | |
560 | ||
561 | if (WARN_ON(!mbox || !*mbox)) | |
562 | return 0; | |
563 | ||
564 | return *mbox == data; | |
565 | } | |
566 | ||
567 | /** | |
568 | * devm_mbox_controller_register() - managed mbox_controller_register() | |
569 | * @dev: device owning the mailbox controller being registered | |
570 | * @mbox: mailbox controller being registered | |
571 | * | |
572 | * This function adds a device-managed resource that will make sure that the | |
573 | * mailbox controller, which is registered using mbox_controller_register() | |
574 | * as part of this function, will be unregistered along with the rest of | |
575 | * device-managed resources upon driver probe failure or driver removal. | |
576 | * | |
577 | * Returns 0 on success or a negative error code on failure. | |
578 | */ | |
579 | int devm_mbox_controller_register(struct device *dev, | |
580 | struct mbox_controller *mbox) | |
581 | { | |
582 | struct mbox_controller **ptr; | |
583 | int err; | |
584 | ||
585 | ptr = devres_alloc(__devm_mbox_controller_unregister, sizeof(*ptr), | |
586 | GFP_KERNEL); | |
587 | if (!ptr) | |
588 | return -ENOMEM; | |
589 | ||
590 | err = mbox_controller_register(mbox); | |
591 | if (err < 0) { | |
592 | devres_free(ptr); | |
593 | return err; | |
594 | } | |
595 | ||
596 | devres_add(dev, ptr); | |
597 | *ptr = mbox; | |
598 | ||
599 | return 0; | |
600 | } | |
601 | EXPORT_SYMBOL_GPL(devm_mbox_controller_register); | |
602 | ||
603 | /** | |
604 | * devm_mbox_controller_unregister() - managed mbox_controller_unregister() | |
605 | * @dev: device owning the mailbox controller being unregistered | |
606 | * @mbox: mailbox controller being unregistered | |
607 | * | |
608 | * This function unregisters the mailbox controller and removes the device- | |
609 | * managed resource that was set up to automatically unregister the mailbox | |
610 | * controller on driver probe failure or driver removal. It's typically not | |
611 | * necessary to call this function. | |
612 | */ | |
613 | void devm_mbox_controller_unregister(struct device *dev, struct mbox_controller *mbox) | |
614 | { | |
615 | WARN_ON(devres_release(dev, __devm_mbox_controller_unregister, | |
616 | devm_mbox_controller_match, mbox)); | |
617 | } | |
618 | EXPORT_SYMBOL_GPL(devm_mbox_controller_unregister); |