1 // SPDX-License-Identifier: GPL-2.0-only
5  * Copyright (C) 2013-2014 Linaro Ltd.
31 	spin_lock_irqsave(&chan->lock, flags);  in add_to_rbuf()
34 	if (chan->msg_count == MBOX_TX_QUEUE_LEN) {  in add_to_rbuf()
35 		spin_unlock_irqrestore(&chan->lock, flags);  in add_to_rbuf()
36 		return -ENOBUFS;  in add_to_rbuf()
39 	idx = chan->msg_free;  in add_to_rbuf()
40 	chan->msg_data[idx] = mssg;  in add_to_rbuf()
41 	chan->msg_count++;  in add_to_rbuf()
43 	if (idx == MBOX_TX_QUEUE_LEN - 1)  in add_to_rbuf()
44 		chan->msg_free = 0;  in add_to_rbuf()
46 		chan->msg_free++;  in add_to_rbuf()
48 	spin_unlock_irqrestore(&chan->lock, flags);  in add_to_rbuf()
58 	int err = -EBUSY;  in msg_submit()
60 	spin_lock_irqsave(&chan->lock, flags);  in msg_submit()
62 	if (!chan->msg_count || chan->active_req)  in msg_submit()
65 	count = chan->msg_count;  in msg_submit()
66 	idx = chan->msg_free;  in msg_submit()
68 		idx -= count;  in msg_submit()
70 		idx += MBOX_TX_QUEUE_LEN - count;  in msg_submit()
72 	data = chan->msg_data[idx];  in msg_submit()
74 	if (chan->cl->tx_prepare)  in msg_submit()
75 		chan->cl->tx_prepare(chan->cl, data);  in msg_submit()
77 	err = chan->mbox->ops->send_data(chan, data);  in msg_submit()
79 		chan->active_req = data;  in msg_submit()
80 		chan->msg_count--;  in msg_submit()
83 	spin_unlock_irqrestore(&chan->lock, flags);  in msg_submit()
85 	if (!err && (chan->txdone_method & TXDONE_BY_POLL)) {  in msg_submit()
87 		spin_lock_irqsave(&chan->mbox->poll_hrt_lock, flags);  in msg_submit()
88 		hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL);  in msg_submit()
89 		spin_unlock_irqrestore(&chan->mbox->poll_hrt_lock, flags);  in msg_submit()
98 	spin_lock_irqsave(&chan->lock, flags);  in tx_tick()
99 	mssg = chan->active_req;  in tx_tick()
100 	chan->active_req = NULL;  in tx_tick()
101 	spin_unlock_irqrestore(&chan->lock, flags);  in tx_tick()
110 	if (chan->cl->tx_done)  in tx_tick()
111 		chan->cl->tx_done(chan->cl, mssg, r);  in tx_tick()
113 	if (r != -ETIME && chan->cl->tx_block)  in tx_tick()
114 		complete(&chan->tx_complete);  in tx_tick()
125 	for (i = 0; i < mbox->num_chans; i++) {  in txdone_hrtimer()
126 		struct mbox_chan *chan = &mbox->chans[i];  in txdone_hrtimer()
128 		if (chan->active_req && chan->cl) {  in txdone_hrtimer()
129 			txdone = chan->mbox->ops->last_tx_done(chan);  in txdone_hrtimer()
138 		spin_lock_irqsave(&mbox->poll_hrt_lock, flags);  in txdone_hrtimer()
140 			hrtimer_forward_now(hrtimer, ms_to_ktime(mbox->txpoll_period));  in txdone_hrtimer()
141 		spin_unlock_irqrestore(&mbox->poll_hrt_lock, flags);  in txdone_hrtimer()
149  * mbox_chan_received_data - A way for controller driver to push data
161 	if (chan->cl->rx_callback)  in mbox_chan_received_data()
162 		chan->cl->rx_callback(chan->cl, mssg);  in mbox_chan_received_data()
167  * mbox_chan_txdone - A way for controller driver to notify the
170  * @r: Status of last TX - OK or ERROR
178 	if (unlikely(!(chan->txdone_method & TXDONE_BY_IRQ))) {  in mbox_chan_txdone()
179 		dev_err(chan->mbox->dev,  in mbox_chan_txdone()
189  * mbox_client_txdone - The way for a client to run the TX state machine.
195  * if the controller can't sense TX-Done.
199 	if (unlikely(!(chan->txdone_method & TXDONE_BY_ACK))) {  in mbox_client_txdone()
200 		dev_err(chan->mbox->dev, "Client can't run the TX ticker\n");  in mbox_client_txdone()
209  * mbox_client_peek_data - A way for client driver to pull data
225 	if (chan->mbox->ops->peek_data)  in mbox_client_peek_data()
226 		return chan->mbox->ops->peek_data(chan);  in mbox_client_peek_data()
233  * mbox_send_message -	For client to submit a message to be
242  *  In non-blocking mode, the requests are buffered by the API and a
243  * non-negative token is returned for each queued request. If the request
244  * is not queued, a negative token is returned. Upon failure or successful
252  * Return: Non-negative integer for successful submission (non-blocking mode)
254  *	Negative value denotes failure.
260 	if (!chan || !chan->cl)  in mbox_send_message()
261 		return -EINVAL;  in mbox_send_message()
265 		dev_err(chan->mbox->dev, "Try increasing MBOX_TX_QUEUE_LEN\n");  in mbox_send_message()
271 	if (chan->cl->tx_block) {  in mbox_send_message()
275 		if (!chan->cl->tx_tout) /* wait forever */  in mbox_send_message()
278 			wait = msecs_to_jiffies(chan->cl->tx_tout);  in mbox_send_message()
280 		ret = wait_for_completion_timeout(&chan->tx_complete, wait);  in mbox_send_message()
282 			t = -ETIME;  in mbox_send_message()
292  * mbox_flush - flush a mailbox channel
297  * ->flush() callback to busy loop until a transmission has been completed.
303  * Returns: 0 on success or a negative error code on failure.
309 	if (!chan->mbox->ops->flush)  in mbox_flush()
310 		return -ENOTSUPP;  in mbox_flush()
312 	ret = chan->mbox->ops->flush(chan, timeout);  in mbox_flush()
321  * mbox_request_channel - Request a mailbox channel.
339 	struct device *dev = cl->dev;  in mbox_request_channel()
346 	if (!dev || !dev->of_node) {  in mbox_request_channel()
348 		return ERR_PTR(-ENODEV);  in mbox_request_channel()
353 	if (of_parse_phandle_with_args(dev->of_node, "mboxes",  in mbox_request_channel()
354 				       "#mbox-cells", index, &spec)) {  in mbox_request_channel()
357 		return ERR_PTR(-ENODEV);  in mbox_request_channel()
360 	chan = ERR_PTR(-EPROBE_DEFER);  in mbox_request_channel()
362 		if (mbox->dev->of_node == spec.np) {  in mbox_request_channel()
363 			chan = mbox->of_xlate(mbox, &spec);  in mbox_request_channel()
375 	if (chan->cl || !try_module_get(mbox->dev->driver->owner)) {  in mbox_request_channel()
378 		return ERR_PTR(-EBUSY);  in mbox_request_channel()
381 	spin_lock_irqsave(&chan->lock, flags);  in mbox_request_channel()
382 	chan->msg_free = 0;  in mbox_request_channel()
383 	chan->msg_count = 0;  in mbox_request_channel()
384 	chan->active_req = NULL;  in mbox_request_channel()
385 	chan->cl = cl;  in mbox_request_channel()
386 	init_completion(&chan->tx_complete);  in mbox_request_channel()
388 	if (chan->txdone_method	== TXDONE_BY_POLL && cl->knows_txdone)  in mbox_request_channel()
389 		chan->txdone_method = TXDONE_BY_ACK;  in mbox_request_channel()
391 	spin_unlock_irqrestore(&chan->lock, flags);  in mbox_request_channel()
393 	if (chan->mbox->ops->startup) {  in mbox_request_channel()
394 		ret = chan->mbox->ops->startup(chan);  in mbox_request_channel()
411 	struct device_node *np = cl->dev->of_node;  in mbox_request_channel_byname()
417 		dev_err(cl->dev, "%s() currently only supports DT\n", __func__);  in mbox_request_channel_byname()
418 		return ERR_PTR(-EINVAL);  in mbox_request_channel_byname()
421 	if (!of_get_property(np, "mbox-names", NULL)) {  in mbox_request_channel_byname()
422 		dev_err(cl->dev,  in mbox_request_channel_byname()
423 			"%s() requires an \"mbox-names\" property\n", __func__);  in mbox_request_channel_byname()
424 		return ERR_PTR(-EINVAL);  in mbox_request_channel_byname()
427 	of_property_for_each_string(np, "mbox-names", prop, mbox_name) {  in mbox_request_channel_byname()
433 	dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",  in mbox_request_channel_byname()
435 	return ERR_PTR(-EINVAL);  in mbox_request_channel_byname()
440  * mbox_free_channel - The client relinquishes control of a mailbox
448 	if (!chan || !chan->cl)  in mbox_free_channel()
451 	if (chan->mbox->ops->shutdown)  in mbox_free_channel()
452 		chan->mbox->ops->shutdown(chan);  in mbox_free_channel()
455 	spin_lock_irqsave(&chan->lock, flags);  in mbox_free_channel()
456 	chan->cl = NULL;  in mbox_free_channel()
457 	chan->active_req = NULL;  in mbox_free_channel()
458 	if (chan->txdone_method == TXDONE_BY_ACK)  in mbox_free_channel()
459 		chan->txdone_method = TXDONE_BY_POLL;  in mbox_free_channel()
461 	module_put(chan->mbox->dev->driver->owner);  in mbox_free_channel()
462 	spin_unlock_irqrestore(&chan->lock, flags);  in mbox_free_channel()
470 	int ind = sp->args[0];  in of_mbox_index_xlate()
472 	if (ind >= mbox->num_chans)  in of_mbox_index_xlate()
473 		return ERR_PTR(-EINVAL);  in of_mbox_index_xlate()
475 	return &mbox->chans[ind];  in of_mbox_index_xlate()
479  * mbox_controller_register - Register the mailbox controller
489 	if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans)  in mbox_controller_register()
490 		return -EINVAL;  in mbox_controller_register()
492 	if (mbox->txdone_irq)  in mbox_controller_register()
494 	else if (mbox->txdone_poll)  in mbox_controller_register()
501 		if (!mbox->ops->last_tx_done) {  in mbox_controller_register()
502 			dev_err(mbox->dev, "last_tx_done method is absent\n");  in mbox_controller_register()
503 			return -EINVAL;  in mbox_controller_register()
506 		hrtimer_init(&mbox->poll_hrt, CLOCK_MONOTONIC,  in mbox_controller_register()
508 		mbox->poll_hrt.function = txdone_hrtimer;  in mbox_controller_register()
509 		spin_lock_init(&mbox->poll_hrt_lock);  in mbox_controller_register()
512 	for (i = 0; i < mbox->num_chans; i++) {  in mbox_controller_register()
513 		struct mbox_chan *chan = &mbox->chans[i];  in mbox_controller_register()
515 		chan->cl = NULL;  in mbox_controller_register()
516 		chan->mbox = mbox;  in mbox_controller_register()
517 		chan->txdone_method = txdone;  in mbox_controller_register()
518 		spin_lock_init(&chan->lock);  in mbox_controller_register()
521 	if (!mbox->of_xlate)  in mbox_controller_register()
522 		mbox->of_xlate = of_mbox_index_xlate;  in mbox_controller_register()
525 	list_add_tail(&mbox->node, &mbox_cons);  in mbox_controller_register()
533  * mbox_controller_unregister - Unregister the mailbox controller
545 	list_del(&mbox->node);  in mbox_controller_unregister()
547 	for (i = 0; i < mbox->num_chans; i++)  in mbox_controller_unregister()
548 		mbox_free_channel(&mbox->chans[i]);  in mbox_controller_unregister()
550 	if (mbox->txdone_poll)  in mbox_controller_unregister()
551 		hrtimer_cancel(&mbox->poll_hrt);  in mbox_controller_unregister()
575  * devm_mbox_controller_register() - managed mbox_controller_register()
579  * This function adds a device-managed resource that will make sure that the
582  * device-managed resources upon driver probe failure or driver removal.
584  * Returns 0 on success or a negative error code on failure.
595 		return -ENOMEM;  in devm_mbox_controller_register()
611  * devm_mbox_controller_unregister() - managed mbox_controller_unregister()
615  * This function unregisters the mailbox controller and removes the device-