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