1 /*
2  * OMAP mailbox driver
3  *
4  * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
5  * Copyright (C) 2013-2014 Texas Instruments Inc.
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  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  *
24  */
25 
26 #include <linux/interrupt.h>
27 #include <linux/spinlock.h>
28 #include <linux/mutex.h>
29 #include <linux/slab.h>
30 #include <linux/kfifo.h>
31 #include <linux/err.h>
32 #include <linux/notifier.h>
33 #include <linux/module.h>
34 #include <linux/of_device.h>
35 #include <linux/platform_device.h>
36 #include <linux/pm_runtime.h>
37 #include <linux/platform_data/mailbox-omap.h>
38 #include <linux/omap-mailbox.h>
39 
40 #define MAILBOX_REVISION		0x000
41 #define MAILBOX_MESSAGE(m)		(0x040 + 4 * (m))
42 #define MAILBOX_FIFOSTATUS(m)		(0x080 + 4 * (m))
43 #define MAILBOX_MSGSTATUS(m)		(0x0c0 + 4 * (m))
44 
45 #define OMAP2_MAILBOX_IRQSTATUS(u)	(0x100 + 8 * (u))
46 #define OMAP2_MAILBOX_IRQENABLE(u)	(0x104 + 8 * (u))
47 
48 #define OMAP4_MAILBOX_IRQSTATUS(u)	(0x104 + 0x10 * (u))
49 #define OMAP4_MAILBOX_IRQENABLE(u)	(0x108 + 0x10 * (u))
50 #define OMAP4_MAILBOX_IRQENABLE_CLR(u)	(0x10c + 0x10 * (u))
51 
52 #define MAILBOX_IRQSTATUS(type, u)	(type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
53 						OMAP2_MAILBOX_IRQSTATUS(u))
54 #define MAILBOX_IRQENABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE(u) : \
55 						OMAP2_MAILBOX_IRQENABLE(u))
56 #define MAILBOX_IRQDISABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
57 						: OMAP2_MAILBOX_IRQENABLE(u))
58 
59 #define MAILBOX_IRQ_NEWMSG(m)		(1 << (2 * (m)))
60 #define MAILBOX_IRQ_NOTFULL(m)		(1 << (2 * (m) + 1))
61 
62 #define MBOX_REG_SIZE			0x120
63 
64 #define OMAP4_MBOX_REG_SIZE		0x130
65 
66 #define MBOX_NR_REGS			(MBOX_REG_SIZE / sizeof(u32))
67 #define OMAP4_MBOX_NR_REGS		(OMAP4_MBOX_REG_SIZE / sizeof(u32))
68 
69 struct omap_mbox_fifo {
70 	unsigned long msg;
71 	unsigned long fifo_stat;
72 	unsigned long msg_stat;
73 	unsigned long irqenable;
74 	unsigned long irqstatus;
75 	unsigned long irqdisable;
76 	u32 intr_bit;
77 };
78 
79 struct omap_mbox_queue {
80 	spinlock_t		lock;
81 	struct kfifo		fifo;
82 	struct work_struct	work;
83 	struct tasklet_struct	tasklet;
84 	struct omap_mbox	*mbox;
85 	bool full;
86 };
87 
88 struct omap_mbox_device {
89 	struct device *dev;
90 	struct mutex cfg_lock;
91 	void __iomem *mbox_base;
92 	u32 num_users;
93 	u32 num_fifos;
94 	struct omap_mbox **mboxes;
95 	struct list_head elem;
96 };
97 
98 struct omap_mbox_fifo_info {
99 	int tx_id;
100 	int tx_usr;
101 	int tx_irq;
102 
103 	int rx_id;
104 	int rx_usr;
105 	int rx_irq;
106 
107 	const char *name;
108 };
109 
110 struct omap_mbox {
111 	const char		*name;
112 	int			irq;
113 	struct omap_mbox_queue	*txq, *rxq;
114 	struct device		*dev;
115 	struct omap_mbox_device *parent;
116 	struct omap_mbox_fifo	tx_fifo;
117 	struct omap_mbox_fifo	rx_fifo;
118 	u32			ctx[OMAP4_MBOX_NR_REGS];
119 	u32			intr_type;
120 	int			use_count;
121 	struct blocking_notifier_head	notifier;
122 };
123 
124 /* global variables for the mailbox devices */
125 static DEFINE_MUTEX(omap_mbox_devices_lock);
126 static LIST_HEAD(omap_mbox_devices);
127 
128 static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
129 module_param(mbox_kfifo_size, uint, S_IRUGO);
130 MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
131 
132 static inline
133 unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
134 {
135 	return __raw_readl(mdev->mbox_base + ofs);
136 }
137 
138 static inline
139 void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
140 {
141 	__raw_writel(val, mdev->mbox_base + ofs);
142 }
143 
144 /* Mailbox FIFO handle functions */
145 static mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
146 {
147 	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
148 	return (mbox_msg_t) mbox_read_reg(mbox->parent, fifo->msg);
149 }
150 
151 static void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
152 {
153 	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
154 	mbox_write_reg(mbox->parent, msg, fifo->msg);
155 }
156 
157 static int mbox_fifo_empty(struct omap_mbox *mbox)
158 {
159 	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
160 	return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
161 }
162 
163 static int mbox_fifo_full(struct omap_mbox *mbox)
164 {
165 	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
166 	return mbox_read_reg(mbox->parent, fifo->fifo_stat);
167 }
168 
169 /* Mailbox IRQ handle functions */
170 static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
171 {
172 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
173 				&mbox->tx_fifo : &mbox->rx_fifo;
174 	u32 bit = fifo->intr_bit;
175 	u32 irqstatus = fifo->irqstatus;
176 
177 	mbox_write_reg(mbox->parent, bit, irqstatus);
178 
179 	/* Flush posted write for irq status to avoid spurious interrupts */
180 	mbox_read_reg(mbox->parent, irqstatus);
181 }
182 
183 static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
184 {
185 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
186 				&mbox->tx_fifo : &mbox->rx_fifo;
187 	u32 bit = fifo->intr_bit;
188 	u32 irqenable = fifo->irqenable;
189 	u32 irqstatus = fifo->irqstatus;
190 
191 	u32 enable = mbox_read_reg(mbox->parent, irqenable);
192 	u32 status = mbox_read_reg(mbox->parent, irqstatus);
193 
194 	return (int)(enable & status & bit);
195 }
196 
197 /*
198  * message sender
199  */
200 int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
201 {
202 	struct omap_mbox_queue *mq = mbox->txq;
203 	int ret = 0, len;
204 
205 	spin_lock_bh(&mq->lock);
206 
207 	if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
208 		ret = -ENOMEM;
209 		goto out;
210 	}
211 
212 	if (kfifo_is_empty(&mq->fifo) && !mbox_fifo_full(mbox)) {
213 		mbox_fifo_write(mbox, msg);
214 		goto out;
215 	}
216 
217 	len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
218 	WARN_ON(len != sizeof(msg));
219 
220 	tasklet_schedule(&mbox->txq->tasklet);
221 
222 out:
223 	spin_unlock_bh(&mq->lock);
224 	return ret;
225 }
226 EXPORT_SYMBOL(omap_mbox_msg_send);
227 
228 void omap_mbox_save_ctx(struct omap_mbox *mbox)
229 {
230 	int i;
231 	int nr_regs;
232 
233 	if (mbox->intr_type)
234 		nr_regs = OMAP4_MBOX_NR_REGS;
235 	else
236 		nr_regs = MBOX_NR_REGS;
237 	for (i = 0; i < nr_regs; i++) {
238 		mbox->ctx[i] = mbox_read_reg(mbox->parent, i * sizeof(u32));
239 
240 		dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
241 			i, mbox->ctx[i]);
242 	}
243 }
244 EXPORT_SYMBOL(omap_mbox_save_ctx);
245 
246 void omap_mbox_restore_ctx(struct omap_mbox *mbox)
247 {
248 	int i;
249 	int nr_regs;
250 
251 	if (mbox->intr_type)
252 		nr_regs = OMAP4_MBOX_NR_REGS;
253 	else
254 		nr_regs = MBOX_NR_REGS;
255 	for (i = 0; i < nr_regs; i++) {
256 		mbox_write_reg(mbox->parent, mbox->ctx[i], i * sizeof(u32));
257 
258 		dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
259 			i, mbox->ctx[i]);
260 	}
261 }
262 EXPORT_SYMBOL(omap_mbox_restore_ctx);
263 
264 void omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
265 {
266 	u32 l;
267 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
268 				&mbox->tx_fifo : &mbox->rx_fifo;
269 	u32 bit = fifo->intr_bit;
270 	u32 irqenable = fifo->irqenable;
271 
272 	l = mbox_read_reg(mbox->parent, irqenable);
273 	l |= bit;
274 	mbox_write_reg(mbox->parent, l, irqenable);
275 }
276 EXPORT_SYMBOL(omap_mbox_enable_irq);
277 
278 void omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
279 {
280 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
281 				&mbox->tx_fifo : &mbox->rx_fifo;
282 	u32 bit = fifo->intr_bit;
283 	u32 irqdisable = fifo->irqdisable;
284 
285 	/*
286 	 * Read and update the interrupt configuration register for pre-OMAP4.
287 	 * OMAP4 and later SoCs have a dedicated interrupt disabling register.
288 	 */
289 	if (!mbox->intr_type)
290 		bit = mbox_read_reg(mbox->parent, irqdisable) & ~bit;
291 
292 	mbox_write_reg(mbox->parent, bit, irqdisable);
293 }
294 EXPORT_SYMBOL(omap_mbox_disable_irq);
295 
296 static void mbox_tx_tasklet(unsigned long tx_data)
297 {
298 	struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
299 	struct omap_mbox_queue *mq = mbox->txq;
300 	mbox_msg_t msg;
301 	int ret;
302 
303 	while (kfifo_len(&mq->fifo)) {
304 		if (mbox_fifo_full(mbox)) {
305 			omap_mbox_enable_irq(mbox, IRQ_TX);
306 			break;
307 		}
308 
309 		ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
310 								sizeof(msg));
311 		WARN_ON(ret != sizeof(msg));
312 
313 		mbox_fifo_write(mbox, msg);
314 	}
315 }
316 
317 /*
318  * Message receiver(workqueue)
319  */
320 static void mbox_rx_work(struct work_struct *work)
321 {
322 	struct omap_mbox_queue *mq =
323 			container_of(work, struct omap_mbox_queue, work);
324 	mbox_msg_t msg;
325 	int len;
326 
327 	while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
328 		len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
329 		WARN_ON(len != sizeof(msg));
330 
331 		blocking_notifier_call_chain(&mq->mbox->notifier, len,
332 								(void *)msg);
333 		spin_lock_irq(&mq->lock);
334 		if (mq->full) {
335 			mq->full = false;
336 			omap_mbox_enable_irq(mq->mbox, IRQ_RX);
337 		}
338 		spin_unlock_irq(&mq->lock);
339 	}
340 }
341 
342 /*
343  * Mailbox interrupt handler
344  */
345 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
346 {
347 	omap_mbox_disable_irq(mbox, IRQ_TX);
348 	ack_mbox_irq(mbox, IRQ_TX);
349 	tasklet_schedule(&mbox->txq->tasklet);
350 }
351 
352 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
353 {
354 	struct omap_mbox_queue *mq = mbox->rxq;
355 	mbox_msg_t msg;
356 	int len;
357 
358 	while (!mbox_fifo_empty(mbox)) {
359 		if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
360 			omap_mbox_disable_irq(mbox, IRQ_RX);
361 			mq->full = true;
362 			goto nomem;
363 		}
364 
365 		msg = mbox_fifo_read(mbox);
366 
367 		len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
368 		WARN_ON(len != sizeof(msg));
369 	}
370 
371 	/* no more messages in the fifo. clear IRQ source. */
372 	ack_mbox_irq(mbox, IRQ_RX);
373 nomem:
374 	schedule_work(&mbox->rxq->work);
375 }
376 
377 static irqreturn_t mbox_interrupt(int irq, void *p)
378 {
379 	struct omap_mbox *mbox = p;
380 
381 	if (is_mbox_irq(mbox, IRQ_TX))
382 		__mbox_tx_interrupt(mbox);
383 
384 	if (is_mbox_irq(mbox, IRQ_RX))
385 		__mbox_rx_interrupt(mbox);
386 
387 	return IRQ_HANDLED;
388 }
389 
390 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
391 					void (*work) (struct work_struct *),
392 					void (*tasklet)(unsigned long))
393 {
394 	struct omap_mbox_queue *mq;
395 
396 	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
397 	if (!mq)
398 		return NULL;
399 
400 	spin_lock_init(&mq->lock);
401 
402 	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
403 		goto error;
404 
405 	if (work)
406 		INIT_WORK(&mq->work, work);
407 
408 	if (tasklet)
409 		tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
410 	return mq;
411 error:
412 	kfree(mq);
413 	return NULL;
414 }
415 
416 static void mbox_queue_free(struct omap_mbox_queue *q)
417 {
418 	kfifo_free(&q->fifo);
419 	kfree(q);
420 }
421 
422 static int omap_mbox_startup(struct omap_mbox *mbox)
423 {
424 	int ret = 0;
425 	struct omap_mbox_queue *mq;
426 	struct omap_mbox_device *mdev = mbox->parent;
427 
428 	mutex_lock(&mdev->cfg_lock);
429 	ret = pm_runtime_get_sync(mdev->dev);
430 	if (unlikely(ret < 0))
431 		goto fail_startup;
432 
433 	if (!mbox->use_count++) {
434 		mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
435 		if (!mq) {
436 			ret = -ENOMEM;
437 			goto fail_alloc_txq;
438 		}
439 		mbox->txq = mq;
440 
441 		mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
442 		if (!mq) {
443 			ret = -ENOMEM;
444 			goto fail_alloc_rxq;
445 		}
446 		mbox->rxq = mq;
447 		mq->mbox = mbox;
448 		ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
449 							mbox->name, mbox);
450 		if (unlikely(ret)) {
451 			pr_err("failed to register mailbox interrupt:%d\n",
452 									ret);
453 			goto fail_request_irq;
454 		}
455 
456 		omap_mbox_enable_irq(mbox, IRQ_RX);
457 	}
458 	mutex_unlock(&mdev->cfg_lock);
459 	return 0;
460 
461 fail_request_irq:
462 	mbox_queue_free(mbox->rxq);
463 fail_alloc_rxq:
464 	mbox_queue_free(mbox->txq);
465 fail_alloc_txq:
466 	pm_runtime_put_sync(mdev->dev);
467 	mbox->use_count--;
468 fail_startup:
469 	mutex_unlock(&mdev->cfg_lock);
470 	return ret;
471 }
472 
473 static void omap_mbox_fini(struct omap_mbox *mbox)
474 {
475 	struct omap_mbox_device *mdev = mbox->parent;
476 
477 	mutex_lock(&mdev->cfg_lock);
478 
479 	if (!--mbox->use_count) {
480 		omap_mbox_disable_irq(mbox, IRQ_RX);
481 		free_irq(mbox->irq, mbox);
482 		tasklet_kill(&mbox->txq->tasklet);
483 		flush_work(&mbox->rxq->work);
484 		mbox_queue_free(mbox->txq);
485 		mbox_queue_free(mbox->rxq);
486 	}
487 
488 	pm_runtime_put_sync(mdev->dev);
489 
490 	mutex_unlock(&mdev->cfg_lock);
491 }
492 
493 static struct omap_mbox *omap_mbox_device_find(struct omap_mbox_device *mdev,
494 					       const char *mbox_name)
495 {
496 	struct omap_mbox *_mbox, *mbox = NULL;
497 	struct omap_mbox **mboxes = mdev->mboxes;
498 	int i;
499 
500 	if (!mboxes)
501 		return NULL;
502 
503 	for (i = 0; (_mbox = mboxes[i]); i++) {
504 		if (!strcmp(_mbox->name, mbox_name)) {
505 			mbox = _mbox;
506 			break;
507 		}
508 	}
509 	return mbox;
510 }
511 
512 struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
513 {
514 	struct omap_mbox *mbox = NULL;
515 	struct omap_mbox_device *mdev;
516 	int ret;
517 
518 	mutex_lock(&omap_mbox_devices_lock);
519 	list_for_each_entry(mdev, &omap_mbox_devices, elem) {
520 		mbox = omap_mbox_device_find(mdev, name);
521 		if (mbox)
522 			break;
523 	}
524 	mutex_unlock(&omap_mbox_devices_lock);
525 
526 	if (!mbox)
527 		return ERR_PTR(-ENOENT);
528 
529 	if (nb)
530 		blocking_notifier_chain_register(&mbox->notifier, nb);
531 
532 	ret = omap_mbox_startup(mbox);
533 	if (ret) {
534 		blocking_notifier_chain_unregister(&mbox->notifier, nb);
535 		return ERR_PTR(-ENODEV);
536 	}
537 
538 	return mbox;
539 }
540 EXPORT_SYMBOL(omap_mbox_get);
541 
542 void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
543 {
544 	blocking_notifier_chain_unregister(&mbox->notifier, nb);
545 	omap_mbox_fini(mbox);
546 }
547 EXPORT_SYMBOL(omap_mbox_put);
548 
549 static struct class omap_mbox_class = { .name = "mbox", };
550 
551 static int omap_mbox_register(struct omap_mbox_device *mdev)
552 {
553 	int ret;
554 	int i;
555 	struct omap_mbox **mboxes;
556 
557 	if (!mdev || !mdev->mboxes)
558 		return -EINVAL;
559 
560 	mboxes = mdev->mboxes;
561 	for (i = 0; mboxes[i]; i++) {
562 		struct omap_mbox *mbox = mboxes[i];
563 		mbox->dev = device_create(&omap_mbox_class,
564 				mdev->dev, 0, mbox, "%s", mbox->name);
565 		if (IS_ERR(mbox->dev)) {
566 			ret = PTR_ERR(mbox->dev);
567 			goto err_out;
568 		}
569 
570 		BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
571 	}
572 
573 	mutex_lock(&omap_mbox_devices_lock);
574 	list_add(&mdev->elem, &omap_mbox_devices);
575 	mutex_unlock(&omap_mbox_devices_lock);
576 
577 	return 0;
578 
579 err_out:
580 	while (i--)
581 		device_unregister(mboxes[i]->dev);
582 	return ret;
583 }
584 
585 static int omap_mbox_unregister(struct omap_mbox_device *mdev)
586 {
587 	int i;
588 	struct omap_mbox **mboxes;
589 
590 	if (!mdev || !mdev->mboxes)
591 		return -EINVAL;
592 
593 	mutex_lock(&omap_mbox_devices_lock);
594 	list_del(&mdev->elem);
595 	mutex_unlock(&omap_mbox_devices_lock);
596 
597 	mboxes = mdev->mboxes;
598 	for (i = 0; mboxes[i]; i++)
599 		device_unregister(mboxes[i]->dev);
600 	return 0;
601 }
602 
603 static const struct of_device_id omap_mailbox_of_match[] = {
604 	{
605 		.compatible	= "ti,omap2-mailbox",
606 		.data		= (void *)MBOX_INTR_CFG_TYPE1,
607 	},
608 	{
609 		.compatible	= "ti,omap3-mailbox",
610 		.data		= (void *)MBOX_INTR_CFG_TYPE1,
611 	},
612 	{
613 		.compatible	= "ti,omap4-mailbox",
614 		.data		= (void *)MBOX_INTR_CFG_TYPE2,
615 	},
616 	{
617 		/* end */
618 	},
619 };
620 MODULE_DEVICE_TABLE(of, omap_mailbox_of_match);
621 
622 static int omap_mbox_probe(struct platform_device *pdev)
623 {
624 	struct resource *mem;
625 	int ret;
626 	struct omap_mbox **list, *mbox, *mboxblk;
627 	struct omap_mbox_pdata *pdata = pdev->dev.platform_data;
628 	struct omap_mbox_dev_info *info = NULL;
629 	struct omap_mbox_fifo_info *finfo, *finfoblk;
630 	struct omap_mbox_device *mdev;
631 	struct omap_mbox_fifo *fifo;
632 	struct device_node *node = pdev->dev.of_node;
633 	struct device_node *child;
634 	const struct of_device_id *match;
635 	u32 intr_type, info_count;
636 	u32 num_users, num_fifos;
637 	u32 tmp[3];
638 	u32 l;
639 	int i;
640 
641 	if (!node && (!pdata || !pdata->info_cnt || !pdata->info)) {
642 		pr_err("%s: platform not supported\n", __func__);
643 		return -ENODEV;
644 	}
645 
646 	if (node) {
647 		match = of_match_device(omap_mailbox_of_match, &pdev->dev);
648 		if (!match)
649 			return -ENODEV;
650 		intr_type = (u32)match->data;
651 
652 		if (of_property_read_u32(node, "ti,mbox-num-users",
653 					 &num_users))
654 			return -ENODEV;
655 
656 		if (of_property_read_u32(node, "ti,mbox-num-fifos",
657 					 &num_fifos))
658 			return -ENODEV;
659 
660 		info_count = of_get_available_child_count(node);
661 		if (!info_count) {
662 			dev_err(&pdev->dev, "no available mbox devices found\n");
663 			return -ENODEV;
664 		}
665 	} else { /* non-DT device creation */
666 		info_count = pdata->info_cnt;
667 		info = pdata->info;
668 		intr_type = pdata->intr_type;
669 		num_users = pdata->num_users;
670 		num_fifos = pdata->num_fifos;
671 	}
672 
673 	finfoblk = devm_kzalloc(&pdev->dev, info_count * sizeof(*finfoblk),
674 				GFP_KERNEL);
675 	if (!finfoblk)
676 		return -ENOMEM;
677 
678 	finfo = finfoblk;
679 	child = NULL;
680 	for (i = 0; i < info_count; i++, finfo++) {
681 		if (node) {
682 			child = of_get_next_available_child(node, child);
683 			ret = of_property_read_u32_array(child, "ti,mbox-tx",
684 							 tmp, ARRAY_SIZE(tmp));
685 			if (ret)
686 				return ret;
687 			finfo->tx_id = tmp[0];
688 			finfo->tx_irq = tmp[1];
689 			finfo->tx_usr = tmp[2];
690 
691 			ret = of_property_read_u32_array(child, "ti,mbox-rx",
692 							 tmp, ARRAY_SIZE(tmp));
693 			if (ret)
694 				return ret;
695 			finfo->rx_id = tmp[0];
696 			finfo->rx_irq = tmp[1];
697 			finfo->rx_usr = tmp[2];
698 
699 			finfo->name = child->name;
700 		} else {
701 			finfo->tx_id = info->tx_id;
702 			finfo->rx_id = info->rx_id;
703 			finfo->tx_usr = info->usr_id;
704 			finfo->tx_irq = info->irq_id;
705 			finfo->rx_usr = info->usr_id;
706 			finfo->rx_irq = info->irq_id;
707 			finfo->name = info->name;
708 			info++;
709 		}
710 		if (finfo->tx_id >= num_fifos || finfo->rx_id >= num_fifos ||
711 		    finfo->tx_usr >= num_users || finfo->rx_usr >= num_users)
712 			return -EINVAL;
713 	}
714 
715 	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
716 	if (!mdev)
717 		return -ENOMEM;
718 
719 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
720 	mdev->mbox_base = devm_ioremap_resource(&pdev->dev, mem);
721 	if (IS_ERR(mdev->mbox_base))
722 		return PTR_ERR(mdev->mbox_base);
723 
724 	/* allocate one extra for marking end of list */
725 	list = devm_kzalloc(&pdev->dev, (info_count + 1) * sizeof(*list),
726 			    GFP_KERNEL);
727 	if (!list)
728 		return -ENOMEM;
729 
730 	mboxblk = devm_kzalloc(&pdev->dev, info_count * sizeof(*mbox),
731 			       GFP_KERNEL);
732 	if (!mboxblk)
733 		return -ENOMEM;
734 
735 	mbox = mboxblk;
736 	finfo = finfoblk;
737 	for (i = 0; i < info_count; i++, finfo++) {
738 		fifo = &mbox->tx_fifo;
739 		fifo->msg = MAILBOX_MESSAGE(finfo->tx_id);
740 		fifo->fifo_stat = MAILBOX_FIFOSTATUS(finfo->tx_id);
741 		fifo->intr_bit = MAILBOX_IRQ_NOTFULL(finfo->tx_id);
742 		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->tx_usr);
743 		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->tx_usr);
744 		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->tx_usr);
745 
746 		fifo = &mbox->rx_fifo;
747 		fifo->msg = MAILBOX_MESSAGE(finfo->rx_id);
748 		fifo->msg_stat =  MAILBOX_MSGSTATUS(finfo->rx_id);
749 		fifo->intr_bit = MAILBOX_IRQ_NEWMSG(finfo->rx_id);
750 		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->rx_usr);
751 		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->rx_usr);
752 		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->rx_usr);
753 
754 		mbox->intr_type = intr_type;
755 
756 		mbox->parent = mdev;
757 		mbox->name = finfo->name;
758 		mbox->irq = platform_get_irq(pdev, finfo->tx_irq);
759 		if (mbox->irq < 0)
760 			return mbox->irq;
761 		list[i] = mbox++;
762 	}
763 
764 	mutex_init(&mdev->cfg_lock);
765 	mdev->dev = &pdev->dev;
766 	mdev->num_users = num_users;
767 	mdev->num_fifos = num_fifos;
768 	mdev->mboxes = list;
769 	ret = omap_mbox_register(mdev);
770 	if (ret)
771 		return ret;
772 
773 	platform_set_drvdata(pdev, mdev);
774 	pm_runtime_enable(mdev->dev);
775 
776 	ret = pm_runtime_get_sync(mdev->dev);
777 	if (ret < 0) {
778 		pm_runtime_put_noidle(mdev->dev);
779 		goto unregister;
780 	}
781 
782 	/*
783 	 * just print the raw revision register, the format is not
784 	 * uniform across all SoCs
785 	 */
786 	l = mbox_read_reg(mdev, MAILBOX_REVISION);
787 	dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);
788 
789 	ret = pm_runtime_put_sync(mdev->dev);
790 	if (ret < 0)
791 		goto unregister;
792 
793 	devm_kfree(&pdev->dev, finfoblk);
794 	return 0;
795 
796 unregister:
797 	pm_runtime_disable(mdev->dev);
798 	omap_mbox_unregister(mdev);
799 	return ret;
800 }
801 
802 static int omap_mbox_remove(struct platform_device *pdev)
803 {
804 	struct omap_mbox_device *mdev = platform_get_drvdata(pdev);
805 
806 	pm_runtime_disable(mdev->dev);
807 	omap_mbox_unregister(mdev);
808 
809 	return 0;
810 }
811 
812 static struct platform_driver omap_mbox_driver = {
813 	.probe	= omap_mbox_probe,
814 	.remove	= omap_mbox_remove,
815 	.driver	= {
816 		.name = "omap-mailbox",
817 		.owner = THIS_MODULE,
818 		.of_match_table = of_match_ptr(omap_mailbox_of_match),
819 	},
820 };
821 
822 static int __init omap_mbox_init(void)
823 {
824 	int err;
825 
826 	err = class_register(&omap_mbox_class);
827 	if (err)
828 		return err;
829 
830 	/* kfifo size sanity check: alignment and minimal size */
831 	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
832 	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
833 							sizeof(mbox_msg_t));
834 
835 	return platform_driver_register(&omap_mbox_driver);
836 }
837 subsys_initcall(omap_mbox_init);
838 
839 static void __exit omap_mbox_exit(void)
840 {
841 	platform_driver_unregister(&omap_mbox_driver);
842 	class_unregister(&omap_mbox_class);
843 }
844 module_exit(omap_mbox_exit);
845 
846 MODULE_LICENSE("GPL v2");
847 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
848 MODULE_AUTHOR("Toshihiro Kobayashi");
849 MODULE_AUTHOR("Hiroshi DOYU");
850