1 // SPDX-License-Identifier: GPL-2.0-only
3  * Mailbox: Common code for Mailbox controllers and users
5  * Copyright (C) 2013-2014 Linaro Ltd.
22 #include "mailbox.h"
32 	spin_lock_irqsave(&chan->lock, flags);  in add_to_rbuf()
35 	if (chan->msg_count == MBOX_TX_QUEUE_LEN) {  in add_to_rbuf()
36 		spin_unlock_irqrestore(&chan->lock, flags);  in add_to_rbuf()
37 		return -ENOBUFS;  in add_to_rbuf()
40 	idx = chan->msg_free;  in add_to_rbuf()
41 	chan->msg_data[idx] = mssg;  in add_to_rbuf()
42 	chan->msg_count++;  in add_to_rbuf()
44 	if (idx == MBOX_TX_QUEUE_LEN - 1)  in add_to_rbuf()
45 		chan->msg_free = 0;  in add_to_rbuf()
47 		chan->msg_free++;  in add_to_rbuf()
49 	spin_unlock_irqrestore(&chan->lock, flags);  in add_to_rbuf()
56 	unsigned count, idx;  in msg_submit()  local
59 	int err = -EBUSY;  in msg_submit()
61 	spin_lock_irqsave(&chan->lock, flags);  in msg_submit()
63 	if (!chan->msg_count || chan->active_req)  in msg_submit()
66 	count = chan->msg_count;  in msg_submit()
67 	idx = chan->msg_free;  in msg_submit()
68 	if (idx >= count)  in msg_submit()
69 		idx -= count;  in msg_submit()
71 		idx += MBOX_TX_QUEUE_LEN - count;  in msg_submit()
73 	data = chan->msg_data[idx];  in msg_submit()
75 	if (chan->cl->tx_prepare)  in msg_submit()
76 		chan->cl->tx_prepare(chan->cl, data);  in msg_submit()
78 	err = chan->mbox->ops->send_data(chan, data);  in msg_submit()
80 		chan->active_req = data;  in msg_submit()
81 		chan->msg_count--;  in msg_submit()
84 	spin_unlock_irqrestore(&chan->lock, flags);  in msg_submit()
86 	if (!err && (chan->txdone_method & TXDONE_BY_POLL)) {  in msg_submit()
88 		spin_lock_irqsave(&chan->mbox->poll_hrt_lock, flags);  in msg_submit()
89 		hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL);  in msg_submit()
90 		spin_unlock_irqrestore(&chan->mbox->poll_hrt_lock, flags);  in msg_submit()
99 	spin_lock_irqsave(&chan->lock, flags);  in tx_tick()
100 	mssg = chan->active_req;  in tx_tick()
101 	chan->active_req = NULL;  in tx_tick()
102 	spin_unlock_irqrestore(&chan->lock, flags);  in tx_tick()
111 	if (chan->cl->tx_done)  in tx_tick()
112 		chan->cl->tx_done(chan->cl, mssg, r);  in tx_tick()
114 	if (r != -ETIME && chan->cl->tx_block)  in tx_tick()
115 		complete(&chan->tx_complete);  in tx_tick()
126 	for (i = 0; i < mbox->num_chans; i++) {  in txdone_hrtimer()
127 		struct mbox_chan *chan = &mbox->chans[i];  in txdone_hrtimer()
129 		if (chan->active_req && chan->cl) {  in txdone_hrtimer()
130 			txdone = chan->mbox->ops->last_tx_done(chan);  in txdone_hrtimer()
139 		spin_lock_irqsave(&mbox->poll_hrt_lock, flags);  in txdone_hrtimer()
141 			hrtimer_forward_now(hrtimer, ms_to_ktime(mbox->txpoll_period));  in txdone_hrtimer()
142 		spin_unlock_irqrestore(&mbox->poll_hrt_lock, flags);  in txdone_hrtimer()
150  * mbox_chan_received_data - A way for controller driver to push data
152  * @chan: Pointer to the mailbox channel on which RX happened.
162 	if (chan->cl->rx_callback)  in mbox_chan_received_data()
163 		chan->cl->rx_callback(chan->cl, mssg);  in mbox_chan_received_data()
168  * mbox_chan_txdone - A way for controller driver to notify the
169  *			framework that the last TX has completed.
170  * @chan: Pointer to the mailbox chan on which TX happened.
171  * @r: Status of last TX - OK or ERROR
173  * The controller that has IRQ for TX ACK calls this atomic API
174  * to tick the TX state machine. It works only if txdone_irq
179 	if (unlikely(!(chan->txdone_method & TXDONE_BY_IRQ))) {  in mbox_chan_txdone()
180 		dev_err(chan->mbox->dev,  in mbox_chan_txdone()
181 		       "Controller can't run the TX ticker\n");  in mbox_chan_txdone()
190  * mbox_client_txdone - The way for a client to run the TX state machine.
191  * @chan: Mailbox channel assigned to this client.
196  * if the controller can't sense TX-Done.
200 	if (unlikely(!(chan->txdone_method & TXDONE_BY_ACK))) {  in mbox_client_txdone()
201 		dev_err(chan->mbox->dev, "Client can't run the TX ticker\n");  in mbox_client_txdone()
210  * mbox_client_peek_data - A way for client driver to pull data
212  * @chan: Mailbox channel assigned to this client.
226 	if (chan->mbox->ops->peek_data)  in mbox_client_peek_data()
227 		return chan->mbox->ops->peek_data(chan);  in mbox_client_peek_data()
234  * mbox_send_message -	For client to submit a message to be
236  * @chan: Mailbox channel assigned to this client.
243  *  In non-blocking mode, the requests are buffered by the API and a
244  * non-negative token is returned for each queued request. If the request
246  * TX, the API calls 'tx_done' from atomic context, from which the client
253  * Return: Non-negative integer for successful submission (non-blocking mode)
261 	if (!chan || !chan->cl)  in mbox_send_message()
262 		return -EINVAL;  in mbox_send_message()
266 		dev_err(chan->mbox->dev, "Try increasing MBOX_TX_QUEUE_LEN\n");  in mbox_send_message()
272 	if (chan->cl->tx_block) {  in mbox_send_message()
276 		if (!chan->cl->tx_tout) /* wait forever */  in mbox_send_message()
279 			wait = msecs_to_jiffies(chan->cl->tx_tout);  in mbox_send_message()
281 		ret = wait_for_completion_timeout(&chan->tx_complete, wait);  in mbox_send_message()
283 			t = -ETIME;  in mbox_send_message()
293  * mbox_flush - flush a mailbox channel
294  * @chan: mailbox channel to flush
297  * Mailbox controllers that need to work in atomic context can implement the
298  * ->flush() callback to busy loop until a transmission has been completed.
301  * flush the transmission. After the function returns success, the mailbox
310 	if (!chan->mbox->ops->flush)  in mbox_flush()
311 		return -ENOTSUPP;  in mbox_flush()
313 	ret = chan->mbox->ops->flush(chan, timeout);  in mbox_flush()
323 	struct device *dev = cl->dev;  in __mbox_bind_client()
327 	if (chan->cl || !try_module_get(chan->mbox->dev->driver->owner)) {  in __mbox_bind_client()
328 		dev_dbg(dev, "%s: mailbox not free\n", __func__);  in __mbox_bind_client()
329 		return -EBUSY;  in __mbox_bind_client()
332 	spin_lock_irqsave(&chan->lock, flags);  in __mbox_bind_client()
333 	chan->msg_free = 0;  in __mbox_bind_client()
334 	chan->msg_count = 0;  in __mbox_bind_client()
335 	chan->active_req = NULL;  in __mbox_bind_client()
336 	chan->cl = cl;  in __mbox_bind_client()
337 	init_completion(&chan->tx_complete);  in __mbox_bind_client()
339 	if (chan->txdone_method	== TXDONE_BY_POLL && cl->knows_txdone)  in __mbox_bind_client()
340 		chan->txdone_method = TXDONE_BY_ACK;  in __mbox_bind_client()
342 	spin_unlock_irqrestore(&chan->lock, flags);  in __mbox_bind_client()
344 	if (chan->mbox->ops->startup) {  in __mbox_bind_client()
345 		ret = chan->mbox->ops->startup(chan);  in __mbox_bind_client()
358  * mbox_bind_client - Request a mailbox channel.
359  * @chan: The mailbox channel to bind the client to.
363  * a mailbox channel. It can't be called from atomic context.
387  * mbox_request_channel - Request a mailbox channel.
389  * @index: Index of mailbox specifier in 'mboxes' property.
392  * a mailbox channel. It can't be called from atomic context.
405 	struct device *dev = cl->dev;  in mbox_request_channel()
411 	if (!dev || !dev->of_node) {  in mbox_request_channel()
413 		return ERR_PTR(-ENODEV);  in mbox_request_channel()
418 	if (of_parse_phandle_with_args(dev->of_node, "mboxes",  in mbox_request_channel()
419 				       "#mbox-cells", index, &spec)) {  in mbox_request_channel()
422 		return ERR_PTR(-ENODEV);  in mbox_request_channel()
425 	chan = ERR_PTR(-EPROBE_DEFER);  in mbox_request_channel()
427 		if (mbox->dev->of_node == spec.np) {  in mbox_request_channel()
428 			chan = mbox->of_xlate(mbox, &spec);  in mbox_request_channel()
452 	struct device_node *np = cl->dev->of_node;  in mbox_request_channel_byname()
456 		dev_err(cl->dev, "%s() currently only supports DT\n", __func__);  in mbox_request_channel_byname()
457 		return ERR_PTR(-EINVAL);  in mbox_request_channel_byname()
460 	index = of_property_match_string(np, "mbox-names", name);  in mbox_request_channel_byname()
462 		dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",  in mbox_request_channel_byname()
464 		return ERR_PTR(-EINVAL);  in mbox_request_channel_byname()
471  * mbox_free_channel - The client relinquishes control of a mailbox
473  * @chan: The mailbox channel to be freed.
479 	if (!chan || !chan->cl)  in mbox_free_channel()
482 	if (chan->mbox->ops->shutdown)  in mbox_free_channel()
483 		chan->mbox->ops->shutdown(chan);  in mbox_free_channel()
485 	/* The queued TX requests are simply aborted, no callbacks are made */  in mbox_free_channel()
486 	spin_lock_irqsave(&chan->lock, flags);  in mbox_free_channel()
487 	chan->cl = NULL;  in mbox_free_channel()
488 	chan->active_req = NULL;  in mbox_free_channel()
489 	if (chan->txdone_method == TXDONE_BY_ACK)  in mbox_free_channel()
490 		chan->txdone_method = TXDONE_BY_POLL;  in mbox_free_channel()
492 	module_put(chan->mbox->dev->driver->owner);  in mbox_free_channel()
493 	spin_unlock_irqrestore(&chan->lock, flags);  in mbox_free_channel()
501 	int ind = sp->args[0];  in of_mbox_index_xlate()
503 	if (ind >= mbox->num_chans)  in of_mbox_index_xlate()
504 		return ERR_PTR(-EINVAL);  in of_mbox_index_xlate()
506 	return &mbox->chans[ind];  in of_mbox_index_xlate()
510  * mbox_controller_register - Register the mailbox controller
511  * @mbox:	Pointer to the mailbox controller.
520 	if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans)  in mbox_controller_register()
521 		return -EINVAL;  in mbox_controller_register()
523 	if (mbox->txdone_irq)  in mbox_controller_register()
525 	else if (mbox->txdone_poll)  in mbox_controller_register()
532 		if (!mbox->ops->last_tx_done) {  in mbox_controller_register()
533 			dev_err(mbox->dev, "last_tx_done method is absent\n");  in mbox_controller_register()
534 			return -EINVAL;  in mbox_controller_register()
537 		hrtimer_init(&mbox->poll_hrt, CLOCK_MONOTONIC,  in mbox_controller_register()
539 		mbox->poll_hrt.function = txdone_hrtimer;  in mbox_controller_register()
540 		spin_lock_init(&mbox->poll_hrt_lock);  in mbox_controller_register()
543 	for (i = 0; i < mbox->num_chans; i++) {  in mbox_controller_register()
544 		struct mbox_chan *chan = &mbox->chans[i];  in mbox_controller_register()
546 		chan->cl = NULL;  in mbox_controller_register()
547 		chan->mbox = mbox;  in mbox_controller_register()
548 		chan->txdone_method = txdone;  in mbox_controller_register()
549 		spin_lock_init(&chan->lock);  in mbox_controller_register()
552 	if (!mbox->of_xlate)  in mbox_controller_register()
553 		mbox->of_xlate = of_mbox_index_xlate;  in mbox_controller_register()
556 	list_add_tail(&mbox->node, &mbox_cons);  in mbox_controller_register()
564  * mbox_controller_unregister - Unregister the mailbox controller
565  * @mbox:	Pointer to the mailbox controller.
576 	list_del(&mbox->node);  in mbox_controller_unregister()
578 	for (i = 0; i < mbox->num_chans; i++)  in mbox_controller_unregister()
579 		mbox_free_channel(&mbox->chans[i]);  in mbox_controller_unregister()
581 	if (mbox->txdone_poll)  in mbox_controller_unregister()
582 		hrtimer_cancel(&mbox->poll_hrt);  in mbox_controller_unregister()
606  * devm_mbox_controller_register() - managed mbox_controller_register()
607  * @dev: device owning the mailbox controller being registered
608  * @mbox: mailbox controller being registered
610  * This function adds a device-managed resource that will make sure that the
611  * mailbox controller, which is registered using mbox_controller_register()
613  * device-managed resources upon driver probe failure or driver removal.
626 		return -ENOMEM;  in devm_mbox_controller_register()
642  * devm_mbox_controller_unregister() - managed mbox_controller_unregister()
643  * @dev: device owning the mailbox controller being unregistered
644  * @mbox: mailbox controller being unregistered
646  * This function unregisters the mailbox controller and removes the device-
647  * managed resource that was set up to automatically unregister the mailbox