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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
21#include "mailbox.h"
22
23static LIST_HEAD(mbox_cons);
24static DEFINE_MUTEX(con_mutex);
25
26static 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
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
53static void msg_submit(struct mbox_chan *chan)
54{
55 unsigned count, idx;
56 unsigned long flags;
57 void *data;
58 int err = -EBUSY;
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
74 if (chan->cl->tx_prepare)
75 chan->cl->tx_prepare(chan->cl, data);
76
77 err = chan->mbox->ops->send_data(chan, data);
78 if (!err) {
79 chan->active_req = data;
80 chan->msg_count--;
81 }
82exit:
83 spin_unlock_irqrestore(&chan->lock, flags);
84
85
86 if (!err && (chan->txdone_method & TXDONE_BY_POLL)) {
87
88 if (!hrtimer_active(&chan->mbox->poll_hrt))
89 hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL);
90 }
91}
92
93static 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
104 msg_submit(chan);
105
106 if (!mssg)
107 return;
108
109
110 if (chan->cl->tx_done)
111 chan->cl->tx_done(chan->cl, mssg, r);
112
113 if (r != -ETIME && chan->cl->tx_block)
114 complete(&chan->tx_complete);
115}
116
117static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer)
118{
119 struct mbox_controller *mbox =
120 container_of(hrtimer, struct mbox_controller, poll_hrt);
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) {
128 resched = true;
129 txdone = chan->mbox->ops->last_tx_done(chan);
130 if (txdone)
131 tx_tick(chan, 0);
132 }
133 }
134
135 if (resched) {
136 hrtimer_forward_now(hrtimer, ms_to_ktime(mbox->txpoll_period));
137 return HRTIMER_RESTART;
138 }
139 return HRTIMER_NORESTART;
140}
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151
152void mbox_chan_received_data(struct mbox_chan *chan, void *mssg)
153{
154
155 if (chan->cl->rx_callback)
156 chan->cl->rx_callback(chan->cl, mssg);
157}
158EXPORT_SYMBOL_GPL(mbox_chan_received_data);
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170void 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}
180EXPORT_SYMBOL_GPL(mbox_chan_txdone);
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191void 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}
200EXPORT_SYMBOL_GPL(mbox_client_txdone);
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217bool 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}
224EXPORT_SYMBOL_GPL(mbox_client_peek_data);
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250int 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
265 if (chan->cl->tx_block) {
266 unsigned long wait;
267 int ret;
268
269 if (!chan->cl->tx_tout)
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) {
276 t = -ETIME;
277 tx_tick(chan, t);
278 }
279 }
280
281 return t;
282}
283EXPORT_SYMBOL_GPL(mbox_send_message);
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299int 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}
312EXPORT_SYMBOL_GPL(mbox_flush);
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331struct 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
354 chan = ERR_PTR(-EPROBE_DEFER);
355 list_for_each_entry(mbox, &mbox_cons, node)
356 if (mbox->dev->of_node == spec.np) {
357 chan = mbox->of_xlate(mbox, &spec);
358 if (!IS_ERR(chan))
359 break;
360 }
361
362 of_node_put(spec.np);
363
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)) {
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)
383 chan->txdone_method = TXDONE_BY_ACK;
384
385 spin_unlock_irqrestore(&chan->lock, flags);
386
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 }
395 }
396
397 mutex_unlock(&con_mutex);
398 return chan;
399}
400EXPORT_SYMBOL_GPL(mbox_request_channel);
401
402struct 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__);
412 return ERR_PTR(-EINVAL);
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__);
418 return ERR_PTR(-EINVAL);
419 }
420
421 of_property_for_each_string(np, "mbox-names", prop, mbox_name) {
422 if (!strncmp(name, mbox_name, strlen(name)))
423 return mbox_request_channel(cl, index);
424 index++;
425 }
426
427 dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",
428 __func__, name);
429 return ERR_PTR(-EINVAL);
430}
431EXPORT_SYMBOL_GPL(mbox_request_channel_byname);
432
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438void mbox_free_channel(struct mbox_chan *chan)
439{
440 unsigned long flags;
441
442 if (!chan || !chan->cl)
443 return;
444
445 if (chan->mbox->ops->shutdown)
446 chan->mbox->ops->shutdown(chan);
447
448
449 spin_lock_irqsave(&chan->lock, flags);
450 chan->cl = NULL;
451 chan->active_req = NULL;
452 if (chan->txdone_method == TXDONE_BY_ACK)
453 chan->txdone_method = TXDONE_BY_POLL;
454
455 module_put(chan->mbox->dev->driver->owner);
456 spin_unlock_irqrestore(&chan->lock, flags);
457}
458EXPORT_SYMBOL_GPL(mbox_free_channel);
459
460static struct mbox_chan *
461of_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)
467 return ERR_PTR(-EINVAL);
468
469 return &mbox->chans[ind];
470}
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478int mbox_controller_register(struct mbox_controller *mbox)
479{
480 int i, txdone;
481
482
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
491 txdone = TXDONE_BY_ACK;
492
493 if (txdone == TXDONE_BY_POLL) {
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
500 hrtimer_init(&mbox->poll_hrt, CLOCK_MONOTONIC,
501 HRTIMER_MODE_REL);
502 mbox->poll_hrt.function = txdone_hrtimer;
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}
523EXPORT_SYMBOL_GPL(mbox_controller_register);
524
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529void 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)
544 hrtimer_cancel(&mbox->poll_hrt);
545
546 mutex_unlock(&con_mutex);
547}
548EXPORT_SYMBOL_GPL(mbox_controller_unregister);
549
550static 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
557static 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}
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579int 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}
601EXPORT_SYMBOL_GPL(devm_mbox_controller_register);
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613void 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}
618EXPORT_SYMBOL_GPL(devm_mbox_controller_unregister);
619