1 /*
2  * OMAP mailbox driver
3  *
4  * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
5  * Copyright (C) 2013-2016 Texas Instruments Incorporated - http://www.ti.com
6  *
7  * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
8  *          Suman Anna <s-anna@ti.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  */
19 
20 #include <linux/interrupt.h>
21 #include <linux/spinlock.h>
22 #include <linux/mutex.h>
23 #include <linux/slab.h>
24 #include <linux/kfifo.h>
25 #include <linux/err.h>
26 #include <linux/module.h>
27 #include <linux/of_device.h>
28 #include <linux/platform_device.h>
29 #include <linux/pm_runtime.h>
30 #include <linux/omap-mailbox.h>
31 #include <linux/mailbox_controller.h>
32 #include <linux/mailbox_client.h>
33 
34 #include "mailbox.h"
35 
36 #define MAILBOX_REVISION		0x000
37 #define MAILBOX_MESSAGE(m)		(0x040 + 4 * (m))
38 #define MAILBOX_FIFOSTATUS(m)		(0x080 + 4 * (m))
39 #define MAILBOX_MSGSTATUS(m)		(0x0c0 + 4 * (m))
40 
41 #define OMAP2_MAILBOX_IRQSTATUS(u)	(0x100 + 8 * (u))
42 #define OMAP2_MAILBOX_IRQENABLE(u)	(0x104 + 8 * (u))
43 
44 #define OMAP4_MAILBOX_IRQSTATUS(u)	(0x104 + 0x10 * (u))
45 #define OMAP4_MAILBOX_IRQENABLE(u)	(0x108 + 0x10 * (u))
46 #define OMAP4_MAILBOX_IRQENABLE_CLR(u)	(0x10c + 0x10 * (u))
47 
48 #define MAILBOX_IRQSTATUS(type, u)	(type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
49 						OMAP2_MAILBOX_IRQSTATUS(u))
50 #define MAILBOX_IRQENABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE(u) : \
51 						OMAP2_MAILBOX_IRQENABLE(u))
52 #define MAILBOX_IRQDISABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
53 						: OMAP2_MAILBOX_IRQENABLE(u))
54 
55 #define MAILBOX_IRQ_NEWMSG(m)		(1 << (2 * (m)))
56 #define MAILBOX_IRQ_NOTFULL(m)		(1 << (2 * (m) + 1))
57 
58 /* Interrupt register configuration types */
59 #define MBOX_INTR_CFG_TYPE1		0
60 #define MBOX_INTR_CFG_TYPE2		1
61 
62 struct omap_mbox_fifo {
63 	unsigned long msg;
64 	unsigned long fifo_stat;
65 	unsigned long msg_stat;
66 	unsigned long irqenable;
67 	unsigned long irqstatus;
68 	unsigned long irqdisable;
69 	u32 intr_bit;
70 };
71 
72 struct omap_mbox_queue {
73 	spinlock_t		lock;
74 	struct kfifo		fifo;
75 	struct work_struct	work;
76 	struct omap_mbox	*mbox;
77 	bool full;
78 };
79 
80 struct omap_mbox_device {
81 	struct device *dev;
82 	struct mutex cfg_lock;
83 	void __iomem *mbox_base;
84 	u32 *irq_ctx;
85 	u32 num_users;
86 	u32 num_fifos;
87 	u32 intr_type;
88 	struct omap_mbox **mboxes;
89 	struct mbox_controller controller;
90 	struct list_head elem;
91 };
92 
93 struct omap_mbox_fifo_info {
94 	int tx_id;
95 	int tx_usr;
96 	int tx_irq;
97 
98 	int rx_id;
99 	int rx_usr;
100 	int rx_irq;
101 
102 	const char *name;
103 	bool send_no_irq;
104 };
105 
106 struct omap_mbox {
107 	const char		*name;
108 	int			irq;
109 	struct omap_mbox_queue	*rxq;
110 	struct device		*dev;
111 	struct omap_mbox_device *parent;
112 	struct omap_mbox_fifo	tx_fifo;
113 	struct omap_mbox_fifo	rx_fifo;
114 	u32			intr_type;
115 	struct mbox_chan	*chan;
116 	bool			send_no_irq;
117 };
118 
119 /* global variables for the mailbox devices */
120 static DEFINE_MUTEX(omap_mbox_devices_lock);
121 static LIST_HEAD(omap_mbox_devices);
122 
123 static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
124 module_param(mbox_kfifo_size, uint, S_IRUGO);
125 MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
126 
127 static struct omap_mbox *mbox_chan_to_omap_mbox(struct mbox_chan *chan)
128 {
129 	if (!chan || !chan->con_priv)
130 		return NULL;
131 
132 	return (struct omap_mbox *)chan->con_priv;
133 }
134 
135 static inline
136 unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
137 {
138 	return __raw_readl(mdev->mbox_base + ofs);
139 }
140 
141 static inline
142 void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
143 {
144 	__raw_writel(val, mdev->mbox_base + ofs);
145 }
146 
147 /* Mailbox FIFO handle functions */
148 static mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
149 {
150 	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
151 
152 	return (mbox_msg_t)mbox_read_reg(mbox->parent, fifo->msg);
153 }
154 
155 static void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
156 {
157 	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
158 
159 	mbox_write_reg(mbox->parent, msg, fifo->msg);
160 }
161 
162 static int mbox_fifo_empty(struct omap_mbox *mbox)
163 {
164 	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
165 
166 	return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
167 }
168 
169 static int mbox_fifo_full(struct omap_mbox *mbox)
170 {
171 	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
172 
173 	return mbox_read_reg(mbox->parent, fifo->fifo_stat);
174 }
175 
176 /* Mailbox IRQ handle functions */
177 static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
178 {
179 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
180 				&mbox->tx_fifo : &mbox->rx_fifo;
181 	u32 bit = fifo->intr_bit;
182 	u32 irqstatus = fifo->irqstatus;
183 
184 	mbox_write_reg(mbox->parent, bit, irqstatus);
185 
186 	/* Flush posted write for irq status to avoid spurious interrupts */
187 	mbox_read_reg(mbox->parent, irqstatus);
188 }
189 
190 static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
191 {
192 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
193 				&mbox->tx_fifo : &mbox->rx_fifo;
194 	u32 bit = fifo->intr_bit;
195 	u32 irqenable = fifo->irqenable;
196 	u32 irqstatus = fifo->irqstatus;
197 
198 	u32 enable = mbox_read_reg(mbox->parent, irqenable);
199 	u32 status = mbox_read_reg(mbox->parent, irqstatus);
200 
201 	return (int)(enable & status & bit);
202 }
203 
204 static void _omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
205 {
206 	u32 l;
207 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
208 				&mbox->tx_fifo : &mbox->rx_fifo;
209 	u32 bit = fifo->intr_bit;
210 	u32 irqenable = fifo->irqenable;
211 
212 	l = mbox_read_reg(mbox->parent, irqenable);
213 	l |= bit;
214 	mbox_write_reg(mbox->parent, l, irqenable);
215 }
216 
217 static void _omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
218 {
219 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
220 				&mbox->tx_fifo : &mbox->rx_fifo;
221 	u32 bit = fifo->intr_bit;
222 	u32 irqdisable = fifo->irqdisable;
223 
224 	/*
225 	 * Read and update the interrupt configuration register for pre-OMAP4.
226 	 * OMAP4 and later SoCs have a dedicated interrupt disabling register.
227 	 */
228 	if (!mbox->intr_type)
229 		bit = mbox_read_reg(mbox->parent, irqdisable) & ~bit;
230 
231 	mbox_write_reg(mbox->parent, bit, irqdisable);
232 }
233 
234 void omap_mbox_enable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
235 {
236 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
237 
238 	if (WARN_ON(!mbox))
239 		return;
240 
241 	_omap_mbox_enable_irq(mbox, irq);
242 }
243 EXPORT_SYMBOL(omap_mbox_enable_irq);
244 
245 void omap_mbox_disable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
246 {
247 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
248 
249 	if (WARN_ON(!mbox))
250 		return;
251 
252 	_omap_mbox_disable_irq(mbox, irq);
253 }
254 EXPORT_SYMBOL(omap_mbox_disable_irq);
255 
256 /*
257  * Message receiver(workqueue)
258  */
259 static void mbox_rx_work(struct work_struct *work)
260 {
261 	struct omap_mbox_queue *mq =
262 			container_of(work, struct omap_mbox_queue, work);
263 	mbox_msg_t msg;
264 	int len;
265 
266 	while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
267 		len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
268 		WARN_ON(len != sizeof(msg));
269 
270 		mbox_chan_received_data(mq->mbox->chan, (void *)msg);
271 		spin_lock_irq(&mq->lock);
272 		if (mq->full) {
273 			mq->full = false;
274 			_omap_mbox_enable_irq(mq->mbox, IRQ_RX);
275 		}
276 		spin_unlock_irq(&mq->lock);
277 	}
278 }
279 
280 /*
281  * Mailbox interrupt handler
282  */
283 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
284 {
285 	_omap_mbox_disable_irq(mbox, IRQ_TX);
286 	ack_mbox_irq(mbox, IRQ_TX);
287 	mbox_chan_txdone(mbox->chan, 0);
288 }
289 
290 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
291 {
292 	struct omap_mbox_queue *mq = mbox->rxq;
293 	mbox_msg_t msg;
294 	int len;
295 
296 	while (!mbox_fifo_empty(mbox)) {
297 		if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
298 			_omap_mbox_disable_irq(mbox, IRQ_RX);
299 			mq->full = true;
300 			goto nomem;
301 		}
302 
303 		msg = mbox_fifo_read(mbox);
304 
305 		len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
306 		WARN_ON(len != sizeof(msg));
307 	}
308 
309 	/* no more messages in the fifo. clear IRQ source. */
310 	ack_mbox_irq(mbox, IRQ_RX);
311 nomem:
312 	schedule_work(&mbox->rxq->work);
313 }
314 
315 static irqreturn_t mbox_interrupt(int irq, void *p)
316 {
317 	struct omap_mbox *mbox = p;
318 
319 	if (is_mbox_irq(mbox, IRQ_TX))
320 		__mbox_tx_interrupt(mbox);
321 
322 	if (is_mbox_irq(mbox, IRQ_RX))
323 		__mbox_rx_interrupt(mbox);
324 
325 	return IRQ_HANDLED;
326 }
327 
328 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
329 					void (*work)(struct work_struct *))
330 {
331 	struct omap_mbox_queue *mq;
332 
333 	if (!work)
334 		return NULL;
335 
336 	mq = kzalloc(sizeof(*mq), GFP_KERNEL);
337 	if (!mq)
338 		return NULL;
339 
340 	spin_lock_init(&mq->lock);
341 
342 	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
343 		goto error;
344 
345 	INIT_WORK(&mq->work, work);
346 	return mq;
347 
348 error:
349 	kfree(mq);
350 	return NULL;
351 }
352 
353 static void mbox_queue_free(struct omap_mbox_queue *q)
354 {
355 	kfifo_free(&q->fifo);
356 	kfree(q);
357 }
358 
359 static int omap_mbox_startup(struct omap_mbox *mbox)
360 {
361 	int ret = 0;
362 	struct omap_mbox_queue *mq;
363 
364 	mq = mbox_queue_alloc(mbox, mbox_rx_work);
365 	if (!mq)
366 		return -ENOMEM;
367 	mbox->rxq = mq;
368 	mq->mbox = mbox;
369 
370 	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
371 			  mbox->name, mbox);
372 	if (unlikely(ret)) {
373 		pr_err("failed to register mailbox interrupt:%d\n", ret);
374 		goto fail_request_irq;
375 	}
376 
377 	if (mbox->send_no_irq)
378 		mbox->chan->txdone_method = TXDONE_BY_ACK;
379 
380 	_omap_mbox_enable_irq(mbox, IRQ_RX);
381 
382 	return 0;
383 
384 fail_request_irq:
385 	mbox_queue_free(mbox->rxq);
386 	return ret;
387 }
388 
389 static void omap_mbox_fini(struct omap_mbox *mbox)
390 {
391 	_omap_mbox_disable_irq(mbox, IRQ_RX);
392 	free_irq(mbox->irq, mbox);
393 	flush_work(&mbox->rxq->work);
394 	mbox_queue_free(mbox->rxq);
395 }
396 
397 static struct omap_mbox *omap_mbox_device_find(struct omap_mbox_device *mdev,
398 					       const char *mbox_name)
399 {
400 	struct omap_mbox *_mbox, *mbox = NULL;
401 	struct omap_mbox **mboxes = mdev->mboxes;
402 	int i;
403 
404 	if (!mboxes)
405 		return NULL;
406 
407 	for (i = 0; (_mbox = mboxes[i]); i++) {
408 		if (!strcmp(_mbox->name, mbox_name)) {
409 			mbox = _mbox;
410 			break;
411 		}
412 	}
413 	return mbox;
414 }
415 
416 struct mbox_chan *omap_mbox_request_channel(struct mbox_client *cl,
417 					    const char *chan_name)
418 {
419 	struct device *dev = cl->dev;
420 	struct omap_mbox *mbox = NULL;
421 	struct omap_mbox_device *mdev;
422 	struct mbox_chan *chan;
423 	unsigned long flags;
424 	int ret;
425 
426 	if (!dev)
427 		return ERR_PTR(-ENODEV);
428 
429 	if (dev->of_node) {
430 		pr_err("%s: please use mbox_request_channel(), this API is supported only for OMAP non-DT usage\n",
431 		       __func__);
432 		return ERR_PTR(-ENODEV);
433 	}
434 
435 	mutex_lock(&omap_mbox_devices_lock);
436 	list_for_each_entry(mdev, &omap_mbox_devices, elem) {
437 		mbox = omap_mbox_device_find(mdev, chan_name);
438 		if (mbox)
439 			break;
440 	}
441 	mutex_unlock(&omap_mbox_devices_lock);
442 
443 	if (!mbox || !mbox->chan)
444 		return ERR_PTR(-ENOENT);
445 
446 	chan = mbox->chan;
447 	spin_lock_irqsave(&chan->lock, flags);
448 	chan->msg_free = 0;
449 	chan->msg_count = 0;
450 	chan->active_req = NULL;
451 	chan->cl = cl;
452 	init_completion(&chan->tx_complete);
453 	spin_unlock_irqrestore(&chan->lock, flags);
454 
455 	ret = chan->mbox->ops->startup(chan);
456 	if (ret) {
457 		pr_err("Unable to startup the chan (%d)\n", ret);
458 		mbox_free_channel(chan);
459 		chan = ERR_PTR(ret);
460 	}
461 
462 	return chan;
463 }
464 EXPORT_SYMBOL(omap_mbox_request_channel);
465 
466 static struct class omap_mbox_class = { .name = "mbox", };
467 
468 static int omap_mbox_register(struct omap_mbox_device *mdev)
469 {
470 	int ret;
471 	int i;
472 	struct omap_mbox **mboxes;
473 
474 	if (!mdev || !mdev->mboxes)
475 		return -EINVAL;
476 
477 	mboxes = mdev->mboxes;
478 	for (i = 0; mboxes[i]; i++) {
479 		struct omap_mbox *mbox = mboxes[i];
480 
481 		mbox->dev = device_create(&omap_mbox_class, mdev->dev,
482 					0, mbox, "%s", mbox->name);
483 		if (IS_ERR(mbox->dev)) {
484 			ret = PTR_ERR(mbox->dev);
485 			goto err_out;
486 		}
487 	}
488 
489 	mutex_lock(&omap_mbox_devices_lock);
490 	list_add(&mdev->elem, &omap_mbox_devices);
491 	mutex_unlock(&omap_mbox_devices_lock);
492 
493 	ret = mbox_controller_register(&mdev->controller);
494 
495 err_out:
496 	if (ret) {
497 		while (i--)
498 			device_unregister(mboxes[i]->dev);
499 	}
500 	return ret;
501 }
502 
503 static int omap_mbox_unregister(struct omap_mbox_device *mdev)
504 {
505 	int i;
506 	struct omap_mbox **mboxes;
507 
508 	if (!mdev || !mdev->mboxes)
509 		return -EINVAL;
510 
511 	mutex_lock(&omap_mbox_devices_lock);
512 	list_del(&mdev->elem);
513 	mutex_unlock(&omap_mbox_devices_lock);
514 
515 	mbox_controller_unregister(&mdev->controller);
516 
517 	mboxes = mdev->mboxes;
518 	for (i = 0; mboxes[i]; i++)
519 		device_unregister(mboxes[i]->dev);
520 	return 0;
521 }
522 
523 static int omap_mbox_chan_startup(struct mbox_chan *chan)
524 {
525 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
526 	struct omap_mbox_device *mdev = mbox->parent;
527 	int ret = 0;
528 
529 	mutex_lock(&mdev->cfg_lock);
530 	pm_runtime_get_sync(mdev->dev);
531 	ret = omap_mbox_startup(mbox);
532 	if (ret)
533 		pm_runtime_put_sync(mdev->dev);
534 	mutex_unlock(&mdev->cfg_lock);
535 	return ret;
536 }
537 
538 static void omap_mbox_chan_shutdown(struct mbox_chan *chan)
539 {
540 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
541 	struct omap_mbox_device *mdev = mbox->parent;
542 
543 	mutex_lock(&mdev->cfg_lock);
544 	omap_mbox_fini(mbox);
545 	pm_runtime_put_sync(mdev->dev);
546 	mutex_unlock(&mdev->cfg_lock);
547 }
548 
549 static int omap_mbox_chan_send_noirq(struct omap_mbox *mbox, void *data)
550 {
551 	int ret = -EBUSY;
552 
553 	if (!mbox_fifo_full(mbox)) {
554 		_omap_mbox_enable_irq(mbox, IRQ_RX);
555 		mbox_fifo_write(mbox, (mbox_msg_t)data);
556 		ret = 0;
557 		_omap_mbox_disable_irq(mbox, IRQ_RX);
558 
559 		/* we must read and ack the interrupt directly from here */
560 		mbox_fifo_read(mbox);
561 		ack_mbox_irq(mbox, IRQ_RX);
562 	}
563 
564 	return ret;
565 }
566 
567 static int omap_mbox_chan_send(struct omap_mbox *mbox, void *data)
568 {
569 	int ret = -EBUSY;
570 
571 	if (!mbox_fifo_full(mbox)) {
572 		mbox_fifo_write(mbox, (mbox_msg_t)data);
573 		ret = 0;
574 	}
575 
576 	/* always enable the interrupt */
577 	_omap_mbox_enable_irq(mbox, IRQ_TX);
578 	return ret;
579 }
580 
581 static int omap_mbox_chan_send_data(struct mbox_chan *chan, void *data)
582 {
583 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
584 	int ret;
585 
586 	if (!mbox)
587 		return -EINVAL;
588 
589 	if (mbox->send_no_irq)
590 		ret = omap_mbox_chan_send_noirq(mbox, data);
591 	else
592 		ret = omap_mbox_chan_send(mbox, data);
593 
594 	return ret;
595 }
596 
597 static const struct mbox_chan_ops omap_mbox_chan_ops = {
598 	.startup        = omap_mbox_chan_startup,
599 	.send_data      = omap_mbox_chan_send_data,
600 	.shutdown       = omap_mbox_chan_shutdown,
601 };
602 
603 #ifdef CONFIG_PM_SLEEP
604 static int omap_mbox_suspend(struct device *dev)
605 {
606 	struct omap_mbox_device *mdev = dev_get_drvdata(dev);
607 	u32 usr, fifo, reg;
608 
609 	if (pm_runtime_status_suspended(dev))
610 		return 0;
611 
612 	for (fifo = 0; fifo < mdev->num_fifos; fifo++) {
613 		if (mbox_read_reg(mdev, MAILBOX_MSGSTATUS(fifo))) {
614 			dev_err(mdev->dev, "fifo %d has unexpected unread messages\n",
615 				fifo);
616 			return -EBUSY;
617 		}
618 	}
619 
620 	for (usr = 0; usr < mdev->num_users; usr++) {
621 		reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
622 		mdev->irq_ctx[usr] = mbox_read_reg(mdev, reg);
623 	}
624 
625 	return 0;
626 }
627 
628 static int omap_mbox_resume(struct device *dev)
629 {
630 	struct omap_mbox_device *mdev = dev_get_drvdata(dev);
631 	u32 usr, reg;
632 
633 	if (pm_runtime_status_suspended(dev))
634 		return 0;
635 
636 	for (usr = 0; usr < mdev->num_users; usr++) {
637 		reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
638 		mbox_write_reg(mdev, mdev->irq_ctx[usr], reg);
639 	}
640 
641 	return 0;
642 }
643 #endif
644 
645 static const struct dev_pm_ops omap_mbox_pm_ops = {
646 	SET_SYSTEM_SLEEP_PM_OPS(omap_mbox_suspend, omap_mbox_resume)
647 };
648 
649 static const struct of_device_id omap_mailbox_of_match[] = {
650 	{
651 		.compatible	= "ti,omap2-mailbox",
652 		.data		= (void *)MBOX_INTR_CFG_TYPE1,
653 	},
654 	{
655 		.compatible	= "ti,omap3-mailbox",
656 		.data		= (void *)MBOX_INTR_CFG_TYPE1,
657 	},
658 	{
659 		.compatible	= "ti,omap4-mailbox",
660 		.data		= (void *)MBOX_INTR_CFG_TYPE2,
661 	},
662 	{
663 		/* end */
664 	},
665 };
666 MODULE_DEVICE_TABLE(of, omap_mailbox_of_match);
667 
668 static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
669 					    const struct of_phandle_args *sp)
670 {
671 	phandle phandle = sp->args[0];
672 	struct device_node *node;
673 	struct omap_mbox_device *mdev;
674 	struct omap_mbox *mbox;
675 
676 	mdev = container_of(controller, struct omap_mbox_device, controller);
677 	if (WARN_ON(!mdev))
678 		return ERR_PTR(-EINVAL);
679 
680 	node = of_find_node_by_phandle(phandle);
681 	if (!node) {
682 		pr_err("%s: could not find node phandle 0x%x\n",
683 		       __func__, phandle);
684 		return ERR_PTR(-ENODEV);
685 	}
686 
687 	mbox = omap_mbox_device_find(mdev, node->name);
688 	of_node_put(node);
689 	return mbox ? mbox->chan : ERR_PTR(-ENOENT);
690 }
691 
692 static int omap_mbox_probe(struct platform_device *pdev)
693 {
694 	struct resource *mem;
695 	int ret;
696 	struct mbox_chan *chnls;
697 	struct omap_mbox **list, *mbox, *mboxblk;
698 	struct omap_mbox_fifo_info *finfo, *finfoblk;
699 	struct omap_mbox_device *mdev;
700 	struct omap_mbox_fifo *fifo;
701 	struct device_node *node = pdev->dev.of_node;
702 	struct device_node *child;
703 	const struct of_device_id *match;
704 	u32 intr_type, info_count;
705 	u32 num_users, num_fifos;
706 	u32 tmp[3];
707 	u32 l;
708 	int i;
709 
710 	if (!node) {
711 		pr_err("%s: only DT-based devices are supported\n", __func__);
712 		return -ENODEV;
713 	}
714 
715 	match = of_match_device(omap_mailbox_of_match, &pdev->dev);
716 	if (!match)
717 		return -ENODEV;
718 	intr_type = (u32)match->data;
719 
720 	if (of_property_read_u32(node, "ti,mbox-num-users", &num_users))
721 		return -ENODEV;
722 
723 	if (of_property_read_u32(node, "ti,mbox-num-fifos", &num_fifos))
724 		return -ENODEV;
725 
726 	info_count = of_get_available_child_count(node);
727 	if (!info_count) {
728 		dev_err(&pdev->dev, "no available mbox devices found\n");
729 		return -ENODEV;
730 	}
731 
732 	finfoblk = devm_kzalloc(&pdev->dev, info_count * sizeof(*finfoblk),
733 				GFP_KERNEL);
734 	if (!finfoblk)
735 		return -ENOMEM;
736 
737 	finfo = finfoblk;
738 	child = NULL;
739 	for (i = 0; i < info_count; i++, finfo++) {
740 		child = of_get_next_available_child(node, child);
741 		ret = of_property_read_u32_array(child, "ti,mbox-tx", tmp,
742 						 ARRAY_SIZE(tmp));
743 		if (ret)
744 			return ret;
745 		finfo->tx_id = tmp[0];
746 		finfo->tx_irq = tmp[1];
747 		finfo->tx_usr = tmp[2];
748 
749 		ret = of_property_read_u32_array(child, "ti,mbox-rx", tmp,
750 						 ARRAY_SIZE(tmp));
751 		if (ret)
752 			return ret;
753 		finfo->rx_id = tmp[0];
754 		finfo->rx_irq = tmp[1];
755 		finfo->rx_usr = tmp[2];
756 
757 		finfo->name = child->name;
758 
759 		if (of_find_property(child, "ti,mbox-send-noirq", NULL))
760 			finfo->send_no_irq = true;
761 
762 		if (finfo->tx_id >= num_fifos || finfo->rx_id >= num_fifos ||
763 		    finfo->tx_usr >= num_users || finfo->rx_usr >= num_users)
764 			return -EINVAL;
765 	}
766 
767 	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
768 	if (!mdev)
769 		return -ENOMEM;
770 
771 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
772 	mdev->mbox_base = devm_ioremap_resource(&pdev->dev, mem);
773 	if (IS_ERR(mdev->mbox_base))
774 		return PTR_ERR(mdev->mbox_base);
775 
776 	mdev->irq_ctx = devm_kzalloc(&pdev->dev, num_users * sizeof(u32),
777 				     GFP_KERNEL);
778 	if (!mdev->irq_ctx)
779 		return -ENOMEM;
780 
781 	/* allocate one extra for marking end of list */
782 	list = devm_kzalloc(&pdev->dev, (info_count + 1) * sizeof(*list),
783 			    GFP_KERNEL);
784 	if (!list)
785 		return -ENOMEM;
786 
787 	chnls = devm_kzalloc(&pdev->dev, (info_count + 1) * sizeof(*chnls),
788 			     GFP_KERNEL);
789 	if (!chnls)
790 		return -ENOMEM;
791 
792 	mboxblk = devm_kzalloc(&pdev->dev, info_count * sizeof(*mbox),
793 			       GFP_KERNEL);
794 	if (!mboxblk)
795 		return -ENOMEM;
796 
797 	mbox = mboxblk;
798 	finfo = finfoblk;
799 	for (i = 0; i < info_count; i++, finfo++) {
800 		fifo = &mbox->tx_fifo;
801 		fifo->msg = MAILBOX_MESSAGE(finfo->tx_id);
802 		fifo->fifo_stat = MAILBOX_FIFOSTATUS(finfo->tx_id);
803 		fifo->intr_bit = MAILBOX_IRQ_NOTFULL(finfo->tx_id);
804 		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->tx_usr);
805 		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->tx_usr);
806 		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->tx_usr);
807 
808 		fifo = &mbox->rx_fifo;
809 		fifo->msg = MAILBOX_MESSAGE(finfo->rx_id);
810 		fifo->msg_stat =  MAILBOX_MSGSTATUS(finfo->rx_id);
811 		fifo->intr_bit = MAILBOX_IRQ_NEWMSG(finfo->rx_id);
812 		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->rx_usr);
813 		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->rx_usr);
814 		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->rx_usr);
815 
816 		mbox->send_no_irq = finfo->send_no_irq;
817 		mbox->intr_type = intr_type;
818 
819 		mbox->parent = mdev;
820 		mbox->name = finfo->name;
821 		mbox->irq = platform_get_irq(pdev, finfo->tx_irq);
822 		if (mbox->irq < 0)
823 			return mbox->irq;
824 		mbox->chan = &chnls[i];
825 		chnls[i].con_priv = mbox;
826 		list[i] = mbox++;
827 	}
828 
829 	mutex_init(&mdev->cfg_lock);
830 	mdev->dev = &pdev->dev;
831 	mdev->num_users = num_users;
832 	mdev->num_fifos = num_fifos;
833 	mdev->intr_type = intr_type;
834 	mdev->mboxes = list;
835 
836 	/* OMAP does not have a Tx-Done IRQ, but rather a Tx-Ready IRQ */
837 	mdev->controller.txdone_irq = true;
838 	mdev->controller.dev = mdev->dev;
839 	mdev->controller.ops = &omap_mbox_chan_ops;
840 	mdev->controller.chans = chnls;
841 	mdev->controller.num_chans = info_count;
842 	mdev->controller.of_xlate = omap_mbox_of_xlate;
843 	ret = omap_mbox_register(mdev);
844 	if (ret)
845 		return ret;
846 
847 	platform_set_drvdata(pdev, mdev);
848 	pm_runtime_enable(mdev->dev);
849 
850 	ret = pm_runtime_get_sync(mdev->dev);
851 	if (ret < 0) {
852 		pm_runtime_put_noidle(mdev->dev);
853 		goto unregister;
854 	}
855 
856 	/*
857 	 * just print the raw revision register, the format is not
858 	 * uniform across all SoCs
859 	 */
860 	l = mbox_read_reg(mdev, MAILBOX_REVISION);
861 	dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);
862 
863 	ret = pm_runtime_put_sync(mdev->dev);
864 	if (ret < 0)
865 		goto unregister;
866 
867 	devm_kfree(&pdev->dev, finfoblk);
868 	return 0;
869 
870 unregister:
871 	pm_runtime_disable(mdev->dev);
872 	omap_mbox_unregister(mdev);
873 	return ret;
874 }
875 
876 static int omap_mbox_remove(struct platform_device *pdev)
877 {
878 	struct omap_mbox_device *mdev = platform_get_drvdata(pdev);
879 
880 	pm_runtime_disable(mdev->dev);
881 	omap_mbox_unregister(mdev);
882 
883 	return 0;
884 }
885 
886 static struct platform_driver omap_mbox_driver = {
887 	.probe	= omap_mbox_probe,
888 	.remove	= omap_mbox_remove,
889 	.driver	= {
890 		.name = "omap-mailbox",
891 		.pm = &omap_mbox_pm_ops,
892 		.of_match_table = of_match_ptr(omap_mailbox_of_match),
893 	},
894 };
895 
896 static int __init omap_mbox_init(void)
897 {
898 	int err;
899 
900 	err = class_register(&omap_mbox_class);
901 	if (err)
902 		return err;
903 
904 	/* kfifo size sanity check: alignment and minimal size */
905 	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
906 	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
907 							sizeof(mbox_msg_t));
908 
909 	return platform_driver_register(&omap_mbox_driver);
910 }
911 subsys_initcall(omap_mbox_init);
912 
913 static void __exit omap_mbox_exit(void)
914 {
915 	platform_driver_unregister(&omap_mbox_driver);
916 	class_unregister(&omap_mbox_class);
917 }
918 module_exit(omap_mbox_exit);
919 
920 MODULE_LICENSE("GPL v2");
921 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
922 MODULE_AUTHOR("Toshihiro Kobayashi");
923 MODULE_AUTHOR("Hiroshi DOYU");
924