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/module.h>
33 #include <linux/of_device.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 #include <linux/mailbox_controller.h>
39 #include <linux/mailbox_client.h>
40 
41 #include "mailbox.h"
42 
43 #define MAILBOX_REVISION		0x000
44 #define MAILBOX_MESSAGE(m)		(0x040 + 4 * (m))
45 #define MAILBOX_FIFOSTATUS(m)		(0x080 + 4 * (m))
46 #define MAILBOX_MSGSTATUS(m)		(0x0c0 + 4 * (m))
47 
48 #define OMAP2_MAILBOX_IRQSTATUS(u)	(0x100 + 8 * (u))
49 #define OMAP2_MAILBOX_IRQENABLE(u)	(0x104 + 8 * (u))
50 
51 #define OMAP4_MAILBOX_IRQSTATUS(u)	(0x104 + 0x10 * (u))
52 #define OMAP4_MAILBOX_IRQENABLE(u)	(0x108 + 0x10 * (u))
53 #define OMAP4_MAILBOX_IRQENABLE_CLR(u)	(0x10c + 0x10 * (u))
54 
55 #define MAILBOX_IRQSTATUS(type, u)	(type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
56 						OMAP2_MAILBOX_IRQSTATUS(u))
57 #define MAILBOX_IRQENABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE(u) : \
58 						OMAP2_MAILBOX_IRQENABLE(u))
59 #define MAILBOX_IRQDISABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
60 						: OMAP2_MAILBOX_IRQENABLE(u))
61 
62 #define MAILBOX_IRQ_NEWMSG(m)		(1 << (2 * (m)))
63 #define MAILBOX_IRQ_NOTFULL(m)		(1 << (2 * (m) + 1))
64 
65 #define MBOX_REG_SIZE			0x120
66 
67 #define OMAP4_MBOX_REG_SIZE		0x130
68 
69 #define MBOX_NR_REGS			(MBOX_REG_SIZE / sizeof(u32))
70 #define OMAP4_MBOX_NR_REGS		(OMAP4_MBOX_REG_SIZE / sizeof(u32))
71 
72 struct omap_mbox_fifo {
73 	unsigned long msg;
74 	unsigned long fifo_stat;
75 	unsigned long msg_stat;
76 	unsigned long irqenable;
77 	unsigned long irqstatus;
78 	unsigned long irqdisable;
79 	u32 intr_bit;
80 };
81 
82 struct omap_mbox_queue {
83 	spinlock_t		lock;
84 	struct kfifo		fifo;
85 	struct work_struct	work;
86 	struct omap_mbox	*mbox;
87 	bool full;
88 };
89 
90 struct omap_mbox_device {
91 	struct device *dev;
92 	struct mutex cfg_lock;
93 	void __iomem *mbox_base;
94 	u32 num_users;
95 	u32 num_fifos;
96 	struct omap_mbox **mboxes;
97 	struct mbox_controller controller;
98 	struct list_head elem;
99 };
100 
101 struct omap_mbox_fifo_info {
102 	int tx_id;
103 	int tx_usr;
104 	int tx_irq;
105 
106 	int rx_id;
107 	int rx_usr;
108 	int rx_irq;
109 
110 	const char *name;
111 	bool send_no_irq;
112 };
113 
114 struct omap_mbox {
115 	const char		*name;
116 	int			irq;
117 	struct omap_mbox_queue	*rxq;
118 	struct device		*dev;
119 	struct omap_mbox_device *parent;
120 	struct omap_mbox_fifo	tx_fifo;
121 	struct omap_mbox_fifo	rx_fifo;
122 	u32			ctx[OMAP4_MBOX_NR_REGS];
123 	u32			intr_type;
124 	struct mbox_chan	*chan;
125 	bool			send_no_irq;
126 };
127 
128 /* global variables for the mailbox devices */
129 static DEFINE_MUTEX(omap_mbox_devices_lock);
130 static LIST_HEAD(omap_mbox_devices);
131 
132 static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
133 module_param(mbox_kfifo_size, uint, S_IRUGO);
134 MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
135 
136 static struct omap_mbox *mbox_chan_to_omap_mbox(struct mbox_chan *chan)
137 {
138 	if (!chan || !chan->con_priv)
139 		return NULL;
140 
141 	return (struct omap_mbox *)chan->con_priv;
142 }
143 
144 static inline
145 unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
146 {
147 	return __raw_readl(mdev->mbox_base + ofs);
148 }
149 
150 static inline
151 void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
152 {
153 	__raw_writel(val, mdev->mbox_base + ofs);
154 }
155 
156 /* Mailbox FIFO handle functions */
157 static mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
158 {
159 	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
160 	return (mbox_msg_t) mbox_read_reg(mbox->parent, fifo->msg);
161 }
162 
163 static void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
164 {
165 	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
166 	mbox_write_reg(mbox->parent, msg, fifo->msg);
167 }
168 
169 static int mbox_fifo_empty(struct omap_mbox *mbox)
170 {
171 	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
172 	return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
173 }
174 
175 static int mbox_fifo_full(struct omap_mbox *mbox)
176 {
177 	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
178 	return mbox_read_reg(mbox->parent, fifo->fifo_stat);
179 }
180 
181 /* Mailbox IRQ handle functions */
182 static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
183 {
184 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
185 				&mbox->tx_fifo : &mbox->rx_fifo;
186 	u32 bit = fifo->intr_bit;
187 	u32 irqstatus = fifo->irqstatus;
188 
189 	mbox_write_reg(mbox->parent, bit, irqstatus);
190 
191 	/* Flush posted write for irq status to avoid spurious interrupts */
192 	mbox_read_reg(mbox->parent, irqstatus);
193 }
194 
195 static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
196 {
197 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
198 				&mbox->tx_fifo : &mbox->rx_fifo;
199 	u32 bit = fifo->intr_bit;
200 	u32 irqenable = fifo->irqenable;
201 	u32 irqstatus = fifo->irqstatus;
202 
203 	u32 enable = mbox_read_reg(mbox->parent, irqenable);
204 	u32 status = mbox_read_reg(mbox->parent, irqstatus);
205 
206 	return (int)(enable & status & bit);
207 }
208 
209 void omap_mbox_save_ctx(struct mbox_chan *chan)
210 {
211 	int i;
212 	int nr_regs;
213 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
214 
215 	if (WARN_ON(!mbox))
216 		return;
217 
218 	if (mbox->intr_type)
219 		nr_regs = OMAP4_MBOX_NR_REGS;
220 	else
221 		nr_regs = MBOX_NR_REGS;
222 	for (i = 0; i < nr_regs; i++) {
223 		mbox->ctx[i] = mbox_read_reg(mbox->parent, i * sizeof(u32));
224 
225 		dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
226 			i, mbox->ctx[i]);
227 	}
228 }
229 EXPORT_SYMBOL(omap_mbox_save_ctx);
230 
231 void omap_mbox_restore_ctx(struct mbox_chan *chan)
232 {
233 	int i;
234 	int nr_regs;
235 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
236 
237 	if (WARN_ON(!mbox))
238 		return;
239 
240 	if (mbox->intr_type)
241 		nr_regs = OMAP4_MBOX_NR_REGS;
242 	else
243 		nr_regs = MBOX_NR_REGS;
244 	for (i = 0; i < nr_regs; i++) {
245 		mbox_write_reg(mbox->parent, mbox->ctx[i], i * sizeof(u32));
246 		dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
247 			i, mbox->ctx[i]);
248 	}
249 }
250 EXPORT_SYMBOL(omap_mbox_restore_ctx);
251 
252 static void _omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
253 {
254 	u32 l;
255 	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
256 				&mbox->tx_fifo : &mbox->rx_fifo;
257 	u32 bit = fifo->intr_bit;
258 	u32 irqenable = fifo->irqenable;
259 
260 	l = mbox_read_reg(mbox->parent, irqenable);
261 	l |= bit;
262 	mbox_write_reg(mbox->parent, l, irqenable);
263 }
264 
265 static 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 
282 void omap_mbox_enable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
283 {
284 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
285 
286 	if (WARN_ON(!mbox))
287 		return;
288 
289 	_omap_mbox_enable_irq(mbox, irq);
290 }
291 EXPORT_SYMBOL(omap_mbox_enable_irq);
292 
293 void omap_mbox_disable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
294 {
295 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
296 
297 	if (WARN_ON(!mbox))
298 		return;
299 
300 	_omap_mbox_disable_irq(mbox, irq);
301 }
302 EXPORT_SYMBOL(omap_mbox_disable_irq);
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 		mbox_chan_received_data(mq->mbox->chan, (void *)msg);
319 		spin_lock_irq(&mq->lock);
320 		if (mq->full) {
321 			mq->full = false;
322 			_omap_mbox_enable_irq(mq->mbox, IRQ_RX);
323 		}
324 		spin_unlock_irq(&mq->lock);
325 	}
326 }
327 
328 /*
329  * Mailbox interrupt handler
330  */
331 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
332 {
333 	_omap_mbox_disable_irq(mbox, IRQ_TX);
334 	ack_mbox_irq(mbox, IRQ_TX);
335 	mbox_chan_txdone(mbox->chan, 0);
336 }
337 
338 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
339 {
340 	struct omap_mbox_queue *mq = mbox->rxq;
341 	mbox_msg_t msg;
342 	int len;
343 
344 	while (!mbox_fifo_empty(mbox)) {
345 		if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
346 			_omap_mbox_disable_irq(mbox, IRQ_RX);
347 			mq->full = true;
348 			goto nomem;
349 		}
350 
351 		msg = mbox_fifo_read(mbox);
352 
353 		len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
354 		WARN_ON(len != sizeof(msg));
355 	}
356 
357 	/* no more messages in the fifo. clear IRQ source. */
358 	ack_mbox_irq(mbox, IRQ_RX);
359 nomem:
360 	schedule_work(&mbox->rxq->work);
361 }
362 
363 static irqreturn_t mbox_interrupt(int irq, void *p)
364 {
365 	struct omap_mbox *mbox = p;
366 
367 	if (is_mbox_irq(mbox, IRQ_TX))
368 		__mbox_tx_interrupt(mbox);
369 
370 	if (is_mbox_irq(mbox, IRQ_RX))
371 		__mbox_rx_interrupt(mbox);
372 
373 	return IRQ_HANDLED;
374 }
375 
376 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
377 					void (*work)(struct work_struct *))
378 {
379 	struct omap_mbox_queue *mq;
380 
381 	if (!work)
382 		return NULL;
383 
384 	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
385 	if (!mq)
386 		return NULL;
387 
388 	spin_lock_init(&mq->lock);
389 
390 	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
391 		goto error;
392 
393 	INIT_WORK(&mq->work, work);
394 	return mq;
395 
396 error:
397 	kfree(mq);
398 	return NULL;
399 }
400 
401 static void mbox_queue_free(struct omap_mbox_queue *q)
402 {
403 	kfifo_free(&q->fifo);
404 	kfree(q);
405 }
406 
407 static int omap_mbox_startup(struct omap_mbox *mbox)
408 {
409 	int ret = 0;
410 	struct omap_mbox_queue *mq;
411 
412 	mq = mbox_queue_alloc(mbox, mbox_rx_work);
413 	if (!mq)
414 		return -ENOMEM;
415 	mbox->rxq = mq;
416 	mq->mbox = mbox;
417 
418 	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
419 			  mbox->name, mbox);
420 	if (unlikely(ret)) {
421 		pr_err("failed to register mailbox interrupt:%d\n", ret);
422 		goto fail_request_irq;
423 	}
424 
425 	if (mbox->send_no_irq)
426 		mbox->chan->txdone_method = TXDONE_BY_ACK;
427 
428 	_omap_mbox_enable_irq(mbox, IRQ_RX);
429 
430 	return 0;
431 
432 fail_request_irq:
433 	mbox_queue_free(mbox->rxq);
434 	return ret;
435 }
436 
437 static void omap_mbox_fini(struct omap_mbox *mbox)
438 {
439 	_omap_mbox_disable_irq(mbox, IRQ_RX);
440 	free_irq(mbox->irq, mbox);
441 	flush_work(&mbox->rxq->work);
442 	mbox_queue_free(mbox->rxq);
443 }
444 
445 static struct omap_mbox *omap_mbox_device_find(struct omap_mbox_device *mdev,
446 					       const char *mbox_name)
447 {
448 	struct omap_mbox *_mbox, *mbox = NULL;
449 	struct omap_mbox **mboxes = mdev->mboxes;
450 	int i;
451 
452 	if (!mboxes)
453 		return NULL;
454 
455 	for (i = 0; (_mbox = mboxes[i]); i++) {
456 		if (!strcmp(_mbox->name, mbox_name)) {
457 			mbox = _mbox;
458 			break;
459 		}
460 	}
461 	return mbox;
462 }
463 
464 struct mbox_chan *omap_mbox_request_channel(struct mbox_client *cl,
465 					    const char *chan_name)
466 {
467 	struct device *dev = cl->dev;
468 	struct omap_mbox *mbox = NULL;
469 	struct omap_mbox_device *mdev;
470 	struct mbox_chan *chan;
471 	unsigned long flags;
472 	int ret;
473 
474 	if (!dev)
475 		return ERR_PTR(-ENODEV);
476 
477 	if (dev->of_node) {
478 		pr_err("%s: please use mbox_request_channel(), this API is supported only for OMAP non-DT usage\n",
479 		       __func__);
480 		return ERR_PTR(-ENODEV);
481 	}
482 
483 	mutex_lock(&omap_mbox_devices_lock);
484 	list_for_each_entry(mdev, &omap_mbox_devices, elem) {
485 		mbox = omap_mbox_device_find(mdev, chan_name);
486 		if (mbox)
487 			break;
488 	}
489 	mutex_unlock(&omap_mbox_devices_lock);
490 
491 	if (!mbox || !mbox->chan)
492 		return ERR_PTR(-ENOENT);
493 
494 	chan = mbox->chan;
495 	spin_lock_irqsave(&chan->lock, flags);
496 	chan->msg_free = 0;
497 	chan->msg_count = 0;
498 	chan->active_req = NULL;
499 	chan->cl = cl;
500 	init_completion(&chan->tx_complete);
501 	spin_unlock_irqrestore(&chan->lock, flags);
502 
503 	ret = chan->mbox->ops->startup(chan);
504 	if (ret) {
505 		pr_err("Unable to startup the chan (%d)\n", ret);
506 		mbox_free_channel(chan);
507 		chan = ERR_PTR(ret);
508 	}
509 
510 	return chan;
511 }
512 EXPORT_SYMBOL(omap_mbox_request_channel);
513 
514 static struct class omap_mbox_class = { .name = "mbox", };
515 
516 static int omap_mbox_register(struct omap_mbox_device *mdev)
517 {
518 	int ret;
519 	int i;
520 	struct omap_mbox **mboxes;
521 
522 	if (!mdev || !mdev->mboxes)
523 		return -EINVAL;
524 
525 	mboxes = mdev->mboxes;
526 	for (i = 0; mboxes[i]; i++) {
527 		struct omap_mbox *mbox = mboxes[i];
528 		mbox->dev = device_create(&omap_mbox_class, mdev->dev,
529 					0, mbox, "%s", mbox->name);
530 		if (IS_ERR(mbox->dev)) {
531 			ret = PTR_ERR(mbox->dev);
532 			goto err_out;
533 		}
534 	}
535 
536 	mutex_lock(&omap_mbox_devices_lock);
537 	list_add(&mdev->elem, &omap_mbox_devices);
538 	mutex_unlock(&omap_mbox_devices_lock);
539 
540 	ret = mbox_controller_register(&mdev->controller);
541 
542 err_out:
543 	if (ret) {
544 		while (i--)
545 			device_unregister(mboxes[i]->dev);
546 	}
547 	return ret;
548 }
549 
550 static int omap_mbox_unregister(struct omap_mbox_device *mdev)
551 {
552 	int i;
553 	struct omap_mbox **mboxes;
554 
555 	if (!mdev || !mdev->mboxes)
556 		return -EINVAL;
557 
558 	mutex_lock(&omap_mbox_devices_lock);
559 	list_del(&mdev->elem);
560 	mutex_unlock(&omap_mbox_devices_lock);
561 
562 	mbox_controller_unregister(&mdev->controller);
563 
564 	mboxes = mdev->mboxes;
565 	for (i = 0; mboxes[i]; i++)
566 		device_unregister(mboxes[i]->dev);
567 	return 0;
568 }
569 
570 static int omap_mbox_chan_startup(struct mbox_chan *chan)
571 {
572 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
573 	struct omap_mbox_device *mdev = mbox->parent;
574 	int ret = 0;
575 
576 	mutex_lock(&mdev->cfg_lock);
577 	pm_runtime_get_sync(mdev->dev);
578 	ret = omap_mbox_startup(mbox);
579 	if (ret)
580 		pm_runtime_put_sync(mdev->dev);
581 	mutex_unlock(&mdev->cfg_lock);
582 	return ret;
583 }
584 
585 static void omap_mbox_chan_shutdown(struct mbox_chan *chan)
586 {
587 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
588 	struct omap_mbox_device *mdev = mbox->parent;
589 
590 	mutex_lock(&mdev->cfg_lock);
591 	omap_mbox_fini(mbox);
592 	pm_runtime_put_sync(mdev->dev);
593 	mutex_unlock(&mdev->cfg_lock);
594 }
595 
596 static int omap_mbox_chan_send_noirq(struct omap_mbox *mbox, void *data)
597 {
598 	int ret = -EBUSY;
599 
600 	if (!mbox_fifo_full(mbox)) {
601 		_omap_mbox_enable_irq(mbox, IRQ_RX);
602 		mbox_fifo_write(mbox, (mbox_msg_t)data);
603 		ret = 0;
604 		_omap_mbox_disable_irq(mbox, IRQ_RX);
605 
606 		/* we must read and ack the interrupt directly from here */
607 		mbox_fifo_read(mbox);
608 		ack_mbox_irq(mbox, IRQ_RX);
609 	}
610 
611 	return ret;
612 }
613 
614 static int omap_mbox_chan_send(struct omap_mbox *mbox, void *data)
615 {
616 	int ret = -EBUSY;
617 
618 	if (!mbox_fifo_full(mbox)) {
619 		mbox_fifo_write(mbox, (mbox_msg_t)data);
620 		ret = 0;
621 	}
622 
623 	/* always enable the interrupt */
624 	_omap_mbox_enable_irq(mbox, IRQ_TX);
625 	return ret;
626 }
627 
628 static int omap_mbox_chan_send_data(struct mbox_chan *chan, void *data)
629 {
630 	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
631 	int ret;
632 
633 	if (!mbox)
634 		return -EINVAL;
635 
636 	if (mbox->send_no_irq)
637 		ret = omap_mbox_chan_send_noirq(mbox, data);
638 	else
639 		ret = omap_mbox_chan_send(mbox, data);
640 
641 	return ret;
642 }
643 
644 static const struct mbox_chan_ops omap_mbox_chan_ops = {
645 	.startup        = omap_mbox_chan_startup,
646 	.send_data      = omap_mbox_chan_send_data,
647 	.shutdown       = omap_mbox_chan_shutdown,
648 };
649 
650 static const struct of_device_id omap_mailbox_of_match[] = {
651 	{
652 		.compatible	= "ti,omap2-mailbox",
653 		.data		= (void *)MBOX_INTR_CFG_TYPE1,
654 	},
655 	{
656 		.compatible	= "ti,omap3-mailbox",
657 		.data		= (void *)MBOX_INTR_CFG_TYPE1,
658 	},
659 	{
660 		.compatible	= "ti,omap4-mailbox",
661 		.data		= (void *)MBOX_INTR_CFG_TYPE2,
662 	},
663 	{
664 		/* end */
665 	},
666 };
667 MODULE_DEVICE_TABLE(of, omap_mailbox_of_match);
668 
669 static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
670 					    const struct of_phandle_args *sp)
671 {
672 	phandle phandle = sp->args[0];
673 	struct device_node *node;
674 	struct omap_mbox_device *mdev;
675 	struct omap_mbox *mbox;
676 
677 	mdev = container_of(controller, struct omap_mbox_device, controller);
678 	if (WARN_ON(!mdev))
679 		return ERR_PTR(-EINVAL);
680 
681 	node = of_find_node_by_phandle(phandle);
682 	if (!node) {
683 		pr_err("%s: could not find node phandle 0x%x\n",
684 		       __func__, phandle);
685 		return ERR_PTR(-ENODEV);
686 	}
687 
688 	mbox = omap_mbox_device_find(mdev, node->name);
689 	of_node_put(node);
690 	return mbox ? mbox->chan : ERR_PTR(-ENOENT);
691 }
692 
693 static int omap_mbox_probe(struct platform_device *pdev)
694 {
695 	struct resource *mem;
696 	int ret;
697 	struct mbox_chan *chnls;
698 	struct omap_mbox **list, *mbox, *mboxblk;
699 	struct omap_mbox_pdata *pdata = pdev->dev.platform_data;
700 	struct omap_mbox_dev_info *info = NULL;
701 	struct omap_mbox_fifo_info *finfo, *finfoblk;
702 	struct omap_mbox_device *mdev;
703 	struct omap_mbox_fifo *fifo;
704 	struct device_node *node = pdev->dev.of_node;
705 	struct device_node *child;
706 	const struct of_device_id *match;
707 	u32 intr_type, info_count;
708 	u32 num_users, num_fifos;
709 	u32 tmp[3];
710 	u32 l;
711 	int i;
712 
713 	if (!node && (!pdata || !pdata->info_cnt || !pdata->info)) {
714 		pr_err("%s: platform not supported\n", __func__);
715 		return -ENODEV;
716 	}
717 
718 	if (node) {
719 		match = of_match_device(omap_mailbox_of_match, &pdev->dev);
720 		if (!match)
721 			return -ENODEV;
722 		intr_type = (u32)match->data;
723 
724 		if (of_property_read_u32(node, "ti,mbox-num-users",
725 					 &num_users))
726 			return -ENODEV;
727 
728 		if (of_property_read_u32(node, "ti,mbox-num-fifos",
729 					 &num_fifos))
730 			return -ENODEV;
731 
732 		info_count = of_get_available_child_count(node);
733 		if (!info_count) {
734 			dev_err(&pdev->dev, "no available mbox devices found\n");
735 			return -ENODEV;
736 		}
737 	} else { /* non-DT device creation */
738 		info_count = pdata->info_cnt;
739 		info = pdata->info;
740 		intr_type = pdata->intr_type;
741 		num_users = pdata->num_users;
742 		num_fifos = pdata->num_fifos;
743 	}
744 
745 	finfoblk = devm_kzalloc(&pdev->dev, info_count * sizeof(*finfoblk),
746 				GFP_KERNEL);
747 	if (!finfoblk)
748 		return -ENOMEM;
749 
750 	finfo = finfoblk;
751 	child = NULL;
752 	for (i = 0; i < info_count; i++, finfo++) {
753 		if (node) {
754 			child = of_get_next_available_child(node, child);
755 			ret = of_property_read_u32_array(child, "ti,mbox-tx",
756 							 tmp, ARRAY_SIZE(tmp));
757 			if (ret)
758 				return ret;
759 			finfo->tx_id = tmp[0];
760 			finfo->tx_irq = tmp[1];
761 			finfo->tx_usr = tmp[2];
762 
763 			ret = of_property_read_u32_array(child, "ti,mbox-rx",
764 							 tmp, ARRAY_SIZE(tmp));
765 			if (ret)
766 				return ret;
767 			finfo->rx_id = tmp[0];
768 			finfo->rx_irq = tmp[1];
769 			finfo->rx_usr = tmp[2];
770 
771 			finfo->name = child->name;
772 
773 			if (of_find_property(child, "ti,mbox-send-noirq", NULL))
774 				finfo->send_no_irq = true;
775 		} else {
776 			finfo->tx_id = info->tx_id;
777 			finfo->rx_id = info->rx_id;
778 			finfo->tx_usr = info->usr_id;
779 			finfo->tx_irq = info->irq_id;
780 			finfo->rx_usr = info->usr_id;
781 			finfo->rx_irq = info->irq_id;
782 			finfo->name = info->name;
783 			info++;
784 		}
785 		if (finfo->tx_id >= num_fifos || finfo->rx_id >= num_fifos ||
786 		    finfo->tx_usr >= num_users || finfo->rx_usr >= num_users)
787 			return -EINVAL;
788 	}
789 
790 	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
791 	if (!mdev)
792 		return -ENOMEM;
793 
794 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
795 	mdev->mbox_base = devm_ioremap_resource(&pdev->dev, mem);
796 	if (IS_ERR(mdev->mbox_base))
797 		return PTR_ERR(mdev->mbox_base);
798 
799 	/* allocate one extra for marking end of list */
800 	list = devm_kzalloc(&pdev->dev, (info_count + 1) * sizeof(*list),
801 			    GFP_KERNEL);
802 	if (!list)
803 		return -ENOMEM;
804 
805 	chnls = devm_kzalloc(&pdev->dev, (info_count + 1) * sizeof(*chnls),
806 			     GFP_KERNEL);
807 	if (!chnls)
808 		return -ENOMEM;
809 
810 	mboxblk = devm_kzalloc(&pdev->dev, info_count * sizeof(*mbox),
811 			       GFP_KERNEL);
812 	if (!mboxblk)
813 		return -ENOMEM;
814 
815 	mbox = mboxblk;
816 	finfo = finfoblk;
817 	for (i = 0; i < info_count; i++, finfo++) {
818 		fifo = &mbox->tx_fifo;
819 		fifo->msg = MAILBOX_MESSAGE(finfo->tx_id);
820 		fifo->fifo_stat = MAILBOX_FIFOSTATUS(finfo->tx_id);
821 		fifo->intr_bit = MAILBOX_IRQ_NOTFULL(finfo->tx_id);
822 		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->tx_usr);
823 		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->tx_usr);
824 		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->tx_usr);
825 
826 		fifo = &mbox->rx_fifo;
827 		fifo->msg = MAILBOX_MESSAGE(finfo->rx_id);
828 		fifo->msg_stat =  MAILBOX_MSGSTATUS(finfo->rx_id);
829 		fifo->intr_bit = MAILBOX_IRQ_NEWMSG(finfo->rx_id);
830 		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->rx_usr);
831 		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->rx_usr);
832 		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->rx_usr);
833 
834 		mbox->send_no_irq = finfo->send_no_irq;
835 		mbox->intr_type = intr_type;
836 
837 		mbox->parent = mdev;
838 		mbox->name = finfo->name;
839 		mbox->irq = platform_get_irq(pdev, finfo->tx_irq);
840 		if (mbox->irq < 0)
841 			return mbox->irq;
842 		mbox->chan = &chnls[i];
843 		chnls[i].con_priv = mbox;
844 		list[i] = mbox++;
845 	}
846 
847 	mutex_init(&mdev->cfg_lock);
848 	mdev->dev = &pdev->dev;
849 	mdev->num_users = num_users;
850 	mdev->num_fifos = num_fifos;
851 	mdev->mboxes = list;
852 
853 	/* OMAP does not have a Tx-Done IRQ, but rather a Tx-Ready IRQ */
854 	mdev->controller.txdone_irq = true;
855 	mdev->controller.dev = mdev->dev;
856 	mdev->controller.ops = &omap_mbox_chan_ops;
857 	mdev->controller.chans = chnls;
858 	mdev->controller.num_chans = info_count;
859 	mdev->controller.of_xlate = omap_mbox_of_xlate;
860 	ret = omap_mbox_register(mdev);
861 	if (ret)
862 		return ret;
863 
864 	platform_set_drvdata(pdev, mdev);
865 	pm_runtime_enable(mdev->dev);
866 
867 	ret = pm_runtime_get_sync(mdev->dev);
868 	if (ret < 0) {
869 		pm_runtime_put_noidle(mdev->dev);
870 		goto unregister;
871 	}
872 
873 	/*
874 	 * just print the raw revision register, the format is not
875 	 * uniform across all SoCs
876 	 */
877 	l = mbox_read_reg(mdev, MAILBOX_REVISION);
878 	dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);
879 
880 	ret = pm_runtime_put_sync(mdev->dev);
881 	if (ret < 0)
882 		goto unregister;
883 
884 	devm_kfree(&pdev->dev, finfoblk);
885 	return 0;
886 
887 unregister:
888 	pm_runtime_disable(mdev->dev);
889 	omap_mbox_unregister(mdev);
890 	return ret;
891 }
892 
893 static int omap_mbox_remove(struct platform_device *pdev)
894 {
895 	struct omap_mbox_device *mdev = platform_get_drvdata(pdev);
896 
897 	pm_runtime_disable(mdev->dev);
898 	omap_mbox_unregister(mdev);
899 
900 	return 0;
901 }
902 
903 static struct platform_driver omap_mbox_driver = {
904 	.probe	= omap_mbox_probe,
905 	.remove	= omap_mbox_remove,
906 	.driver	= {
907 		.name = "omap-mailbox",
908 		.of_match_table = of_match_ptr(omap_mailbox_of_match),
909 	},
910 };
911 
912 static int __init omap_mbox_init(void)
913 {
914 	int err;
915 
916 	err = class_register(&omap_mbox_class);
917 	if (err)
918 		return err;
919 
920 	/* kfifo size sanity check: alignment and minimal size */
921 	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
922 	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
923 							sizeof(mbox_msg_t));
924 
925 	return platform_driver_register(&omap_mbox_driver);
926 }
927 subsys_initcall(omap_mbox_init);
928 
929 static void __exit omap_mbox_exit(void)
930 {
931 	platform_driver_unregister(&omap_mbox_driver);
932 	class_unregister(&omap_mbox_class);
933 }
934 module_exit(omap_mbox_exit);
935 
936 MODULE_LICENSE("GPL v2");
937 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
938 MODULE_AUTHOR("Toshihiro Kobayashi");
939 MODULE_AUTHOR("Hiroshi DOYU");
940