[linux-2.6-block.git] / arch / arm / plat-omap / mailbox.c

/*
 * OMAP mailbox driver
 *
 * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
 *
 * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/kfifo.h>
#include <linux/err.h>
#include <linux/notifier.h>

#include <plat/mailbox.h>

static struct workqueue_struct *mboxd;
static struct omap_mbox **mboxes;

static int mbox_configured;
static DEFINE_MUTEX(mbox_configured_lock);

static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
module_param(mbox_kfifo_size, uint, S_IRUGO);
MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");

/* Mailbox FIFO handle functions */
static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
{
	return mbox->ops->fifo_read(mbox);
}
static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
{
	mbox->ops->fifo_write(mbox, msg);
}
static inline int mbox_fifo_empty(struct omap_mbox *mbox)
{
	return mbox->ops->fifo_empty(mbox);
}
static inline int mbox_fifo_full(struct omap_mbox *mbox)
{
	return mbox->ops->fifo_full(mbox);
}

/* Mailbox IRQ handle functions */
static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
	if (mbox->ops->ack_irq)
		mbox->ops->ack_irq(mbox, irq);
}
static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
	return mbox->ops->is_irq(mbox, irq);
}

/*
 * message sender
 */
static int __mbox_poll_for_space(struct omap_mbox *mbox)
{
	int ret = 0, i = 1000;

	while (mbox_fifo_full(mbox)) {
		if (mbox->ops->type == OMAP_MBOX_TYPE2)
			return -1;
		if (--i == 0)
			return -1;
		udelay(1);
	}
	return ret;
}

int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
{
	struct omap_mbox_queue *mq = mbox->txq;
	int ret = 0, len;

	spin_lock_bh(&mq->lock);

	if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
		ret = -ENOMEM;
		goto out;
	}

	if (kfifo_is_empty(&mq->fifo) && !__mbox_poll_for_space(mbox)) {
		mbox_fifo_write(mbox, msg);
		goto out;
	}

	len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
	WARN_ON(len != sizeof(msg));

	tasklet_schedule(&mbox->txq->tasklet);

out:
	spin_unlock_bh(&mq->lock);
	return ret;
}
EXPORT_SYMBOL(omap_mbox_msg_send);

static void mbox_tx_tasklet(unsigned long tx_data)
{
	struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
	struct omap_mbox_queue *mq = mbox->txq;
	mbox_msg_t msg;
	int ret;

	while (kfifo_len(&mq->fifo)) {
		if (__mbox_poll_for_space(mbox)) {
			omap_mbox_enable_irq(mbox, IRQ_TX);
			break;
		}

		ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
								sizeof(msg));
		WARN_ON(ret != sizeof(msg));

		mbox_fifo_write(mbox, msg);
	}
}

/*
 * Message receiver(workqueue)
 */
static void mbox_rx_work(struct work_struct *work)
{
	struct omap_mbox_queue *mq =
			container_of(work, struct omap_mbox_queue, work);
	mbox_msg_t msg;
	int len;

	while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
		len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
		WARN_ON(len != sizeof(msg));

		blocking_notifier_call_chain(&mq->mbox->notifier, len,
								(void *)msg);
		spin_lock_irq(&mq->lock);
		if (mq->full) {
			mq->full = false;
			omap_mbox_enable_irq(mq->mbox, IRQ_RX);
		}
		spin_unlock_irq(&mq->lock);
	}
}

/*
 * Mailbox interrupt handler
 */
static void __mbox_tx_interrupt(struct omap_mbox *mbox)
{
	omap_mbox_disable_irq(mbox, IRQ_TX);
	ack_mbox_irq(mbox, IRQ_TX);
	tasklet_schedule(&mbox->txq->tasklet);
}

static void __mbox_rx_interrupt(struct omap_mbox *mbox)
{
	struct omap_mbox_queue *mq = mbox->rxq;
	mbox_msg_t msg;
	int len;

	while (!mbox_fifo_empty(mbox)) {
		if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
			omap_mbox_disable_irq(mbox, IRQ_RX);
			mq->full = true;
			goto nomem;
		}

		msg = mbox_fifo_read(mbox);

		len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
		WARN_ON(len != sizeof(msg));

		if (mbox->ops->type == OMAP_MBOX_TYPE1)
			break;
	}

	/* no more messages in the fifo. clear IRQ source. */
	ack_mbox_irq(mbox, IRQ_RX);
nomem:
	queue_work(mboxd, &mbox->rxq->work);
}

static irqreturn_t mbox_interrupt(int irq, void *p)
{
	struct omap_mbox *mbox = p;

	if (is_mbox_irq(mbox, IRQ_TX))
		__mbox_tx_interrupt(mbox);

	if (is_mbox_irq(mbox, IRQ_RX))
		__mbox_rx_interrupt(mbox);

	return IRQ_HANDLED;
}

static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
					void (*work) (struct work_struct *),
					void (*tasklet)(unsigned long))
{
	struct omap_mbox_queue *mq;

	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
	if (!mq)
		return NULL;

	spin_lock_init(&mq->lock);

	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
		goto error;

	if (work)
		INIT_WORK(&mq->work, work);

	if (tasklet)
		tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
	return mq;
error:
	kfree(mq);
	return NULL;
}

static void mbox_queue_free(struct omap_mbox_queue *q)
{
	kfifo_free(&q->fifo);
	kfree(q);
}

static int omap_mbox_startup(struct omap_mbox *mbox)
{
	int ret = 0;
	struct omap_mbox_queue *mq;

	mutex_lock(&mbox_configured_lock);
	if (!mbox_configured++) {
		if (likely(mbox->ops->startup)) {
			ret = mbox->ops->startup(mbox);
			if (unlikely(ret))
				goto fail_startup;
		} else
			goto fail_startup;
	}

	if (!mbox->use_count++) {
		ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
							mbox->name, mbox);
		if (unlikely(ret)) {
			pr_err("failed to register mailbox interrupt:%d\n",
									ret);
			goto fail_request_irq;
		}
		mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
		if (!mq) {
			ret = -ENOMEM;
			goto fail_alloc_txq;
		}
		mbox->txq = mq;

		mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
		if (!mq) {
			ret = -ENOMEM;
			goto fail_alloc_rxq;
		}
		mbox->rxq = mq;
		mq->mbox = mbox;
	}
	mutex_unlock(&mbox_configured_lock);
	return 0;

fail_alloc_rxq:
	mbox_queue_free(mbox->txq);
fail_alloc_txq:
	free_irq(mbox->irq, mbox);
fail_request_irq:
	if (mbox->ops->shutdown)
		mbox->ops->shutdown(mbox);
	mbox->use_count--;
fail_startup:
	mbox_configured--;
	mutex_unlock(&mbox_configured_lock);
	return ret;
}

static void omap_mbox_fini(struct omap_mbox *mbox)
{
	mutex_lock(&mbox_configured_lock);

	if (!--mbox->use_count) {
		free_irq(mbox->irq, mbox);
		tasklet_kill(&mbox->txq->tasklet);
		flush_work(&mbox->rxq->work);
		mbox_queue_free(mbox->txq);
		mbox_queue_free(mbox->rxq);
	}

	if (likely(mbox->ops->shutdown)) {
		if (!--mbox_configured)
			mbox->ops->shutdown(mbox);
	}

	mutex_unlock(&mbox_configured_lock);
}

struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
{
	struct omap_mbox *mbox;
	int ret;

	if (!mboxes)
		return ERR_PTR(-EINVAL);

	for (mbox = *mboxes; mbox; mbox++)
		if (!strcmp(mbox->name, name))
			break;

	if (!mbox)
		return ERR_PTR(-ENOENT);

	ret = omap_mbox_startup(mbox);
	if (ret)
		return ERR_PTR(-ENODEV);

	if (nb)
		blocking_notifier_chain_register(&mbox->notifier, nb);

	return mbox;
}
EXPORT_SYMBOL(omap_mbox_get);

void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&mbox->notifier, nb);
	omap_mbox_fini(mbox);
}
EXPORT_SYMBOL(omap_mbox_put);

static struct class omap_mbox_class = { .name = "mbox", };

int omap_mbox_register(struct device *parent, struct omap_mbox **list)
{
	int ret;
	int i;

	mboxes = list;
	if (!mboxes)
		return -EINVAL;

	for (i = 0; mboxes[i]; i++) {
		struct omap_mbox *mbox = mboxes[i];
		mbox->dev = device_create(&omap_mbox_class,
				parent, 0, mbox, "%s", mbox->name);
		if (IS_ERR(mbox->dev)) {
			ret = PTR_ERR(mbox->dev);
			goto err_out;
		}

		BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
	}
	return 0;

err_out:
	while (i--)
		device_unregister(mboxes[i]->dev);
	return ret;
}
EXPORT_SYMBOL(omap_mbox_register);

int omap_mbox_unregister(void)
{
	int i;

	if (!mboxes)
		return -EINVAL;

	for (i = 0; mboxes[i]; i++)
		device_unregister(mboxes[i]->dev);
	mboxes = NULL;
	return 0;
}
EXPORT_SYMBOL(omap_mbox_unregister);

static int __init omap_mbox_init(void)
{
	int err;

	err = class_register(&omap_mbox_class);
	if (err)
		return err;

	mboxd = create_workqueue("mboxd");
	if (!mboxd)
		return -ENOMEM;

	/* kfifo size sanity check: alignment and minimal size */
	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
							sizeof(mbox_msg_t));

	return 0;
}
subsys_initcall(omap_mbox_init);

static void __exit omap_mbox_exit(void)
{
	destroy_workqueue(mboxd);
	class_unregister(&omap_mbox_class);
}
module_exit(omap_mbox_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
MODULE_AUTHOR("Toshihiro Kobayashi");
MODULE_AUTHOR("Hiroshi DOYU");
Commit	Line	Data
340a614a HD	1	/*
	2	* OMAP mailbox driver
	3	*
f48cca87	4	* Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
340a614a	5	*
f48cca87	6	* Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
340a614a HD	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* version 2 as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	20	* 02110-1301 USA
	21	*
	22	*/
	23
340a614a	24	#include <linux/interrupt.h>
b3e69146 FC	25	#include <linux/spinlock.h>
b3e69146 FC	26	#include <linux/mutex.h>
340a614a	27	#include <linux/delay.h>
5a0e3ad6	28	#include <linux/slab.h>
b5bebe41 OBC	29	#include <linux/kfifo.h>
b5bebe41 OBC	30	#include <linux/err.h>
58256307	31	#include <linux/notifier.h>
8dff0fa5	32
ce491cf8	33	#include <plat/mailbox.h>
340a614a	34
8250a5c3	35	static struct workqueue_struct *mboxd;
9c80c8cd	36	static struct omap_mbox **mboxes;
340a614a	37
5f00ec64	38	static int mbox_configured;
72b917ef	39	static DEFINE_MUTEX(mbox_configured_lock);
5f00ec64	40
b5bebe41 OBC	41	static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
	42	module_param(mbox_kfifo_size, uint, S_IRUGO);
	43	MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
	44
9ae0ee00 HD	45	/* Mailbox FIFO handle functions */
	46	static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
	47	{
	48	return mbox->ops->fifo_read(mbox);
	49	}
	50	static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
	51	{
	52	mbox->ops->fifo_write(mbox, msg);
	53	}
	54	static inline int mbox_fifo_empty(struct omap_mbox *mbox)
	55	{
	56	return mbox->ops->fifo_empty(mbox);
	57	}
	58	static inline int mbox_fifo_full(struct omap_mbox *mbox)
	59	{
	60	return mbox->ops->fifo_full(mbox);
	61	}
	62
	63	/* Mailbox IRQ handle functions */
9ae0ee00 HD	64	static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	65	{
	66	if (mbox->ops->ack_irq)
	67	mbox->ops->ack_irq(mbox, irq);
	68	}
	69	static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	70	{
	71	return mbox->ops->is_irq(mbox, irq);
	72	}
	73
340a614a HD	74	/*
	75	* message sender
	76	*/
b5bebe41	77	static int __mbox_poll_for_space(struct omap_mbox *mbox)
340a614a HD	78	{
	79	int ret = 0, i = 1000;
	80
	81	while (mbox_fifo_full(mbox)) {
	82	if (mbox->ops->type == OMAP_MBOX_TYPE2)
	83	return -1;
	84	if (--i == 0)
	85	return -1;
	86	udelay(1);
	87	}
340a614a HD	88	return ret;
	89	}
	90
b2b6362e	91	int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
340a614a	92	{
b5bebe41 OBC	93	struct omap_mbox_queue *mq = mbox->txq;
b5bebe41 OBC	94	int ret = 0, len;
5ed8d32e	95
a42743c2	96	spin_lock_bh(&mq->lock);
ec24751a	97
b5bebe41 OBC	98	if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
	99	ret = -ENOMEM;
	100	goto out;
	101	}
	102
a42743c2 KH	103	if (kfifo_is_empty(&mq->fifo) && !__mbox_poll_for_space(mbox)) {
	104	mbox_fifo_write(mbox, msg);
	105	goto out;
	106	}
	107
b5bebe41 OBC	108	len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
b5bebe41 OBC	109	WARN_ON(len != sizeof(msg));
340a614a	110
5ed8d32e	111	tasklet_schedule(&mbox->txq->tasklet);
340a614a	112
b5bebe41	113	out:
a42743c2	114	spin_unlock_bh(&mq->lock);
b5bebe41	115	return ret;
340a614a HD	116	}
	117	EXPORT_SYMBOL(omap_mbox_msg_send);
	118
5ed8d32e	119	static void mbox_tx_tasklet(unsigned long tx_data)
340a614a	120	{
5ed8d32e	121	struct omap_mbox mbox = (struct omap_mbox )tx_data;
b5bebe41 OBC	122	struct omap_mbox_queue *mq = mbox->txq;
	123	mbox_msg_t msg;
	124	int ret;
340a614a	125
b5bebe41 OBC	126	while (kfifo_len(&mq->fifo)) {
b5bebe41 OBC	127	if (__mbox_poll_for_space(mbox)) {
eb18858e	128	omap_mbox_enable_irq(mbox, IRQ_TX);
b5bebe41	129	break;
340a614a	130	}
b5bebe41 OBC	131
	132	ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
	133	sizeof(msg));
	134	WARN_ON(ret != sizeof(msg));
	135
	136	mbox_fifo_write(mbox, msg);
340a614a HD	137	}
	138	}
	139
	140	/*
	141	* Message receiver(workqueue)
	142	*/
	143	static void mbox_rx_work(struct work_struct *work)
	144	{
	145	struct omap_mbox_queue *mq =
	146	container_of(work, struct omap_mbox_queue, work);
340a614a	147	mbox_msg_t msg;
b5bebe41 OBC	148	int len;
	149
	150	while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
	151	len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
	152	WARN_ON(len != sizeof(msg));
340a614a	153
58256307 KH	154	blocking_notifier_call_chain(&mq->mbox->notifier, len,
58256307 KH	155	(void *)msg);
d2295042 FGL	156	spin_lock_irq(&mq->lock);
	157	if (mq->full) {
	158	mq->full = false;
	159	omap_mbox_enable_irq(mq->mbox, IRQ_RX);
	160	}
	161	spin_unlock_irq(&mq->lock);
340a614a HD	162	}
	163	}
	164
	165	/*
	166	* Mailbox interrupt handler
	167	*/
340a614a HD	168	static void __mbox_tx_interrupt(struct omap_mbox *mbox)
340a614a HD	169	{
eb18858e	170	omap_mbox_disable_irq(mbox, IRQ_TX);
340a614a	171	ack_mbox_irq(mbox, IRQ_TX);
5ed8d32e	172	tasklet_schedule(&mbox->txq->tasklet);
340a614a HD	173	}
	174
	175	static void __mbox_rx_interrupt(struct omap_mbox *mbox)
	176	{
b5bebe41	177	struct omap_mbox_queue *mq = mbox->rxq;
340a614a	178	mbox_msg_t msg;
b5bebe41	179	int len;
340a614a	180
340a614a	181	while (!mbox_fifo_empty(mbox)) {
b5bebe41	182	if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
1ea5d6d1	183	omap_mbox_disable_irq(mbox, IRQ_RX);
d2295042	184	mq->full = true;
340a614a	185	goto nomem;
1ea5d6d1	186	}
340a614a HD	187
340a614a HD	188	msg = mbox_fifo_read(mbox);
340a614a	189
b5bebe41 OBC	190	len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
b5bebe41 OBC	191	WARN_ON(len != sizeof(msg));
340a614a	192
340a614a HD	193	if (mbox->ops->type == OMAP_MBOX_TYPE1)
	194	break;
	195	}
	196
	197	/* no more messages in the fifo. clear IRQ source. */
	198	ack_mbox_irq(mbox, IRQ_RX);
f48cca87	199	nomem:
8250a5c3	200	queue_work(mboxd, &mbox->rxq->work);
340a614a HD	201	}
	202
	203	static irqreturn_t mbox_interrupt(int irq, void *p)
	204	{
2a7057e3	205	struct omap_mbox *mbox = p;
340a614a HD	206
	207	if (is_mbox_irq(mbox, IRQ_TX))
	208	__mbox_tx_interrupt(mbox);
	209
	210	if (is_mbox_irq(mbox, IRQ_RX))
	211	__mbox_rx_interrupt(mbox);
	212
	213	return IRQ_HANDLED;
	214	}
	215
340a614a	216	static struct omap_mbox_queue mbox_queue_alloc(struct omap_mbox mbox,
5ed8d32e S	217	void (work) (struct work_struct ),
5ed8d32e S	218	void (*tasklet)(unsigned long))
340a614a	219	{
340a614a HD	220	struct omap_mbox_queue *mq;
	221
	222	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
	223	if (!mq)
	224	return NULL;
	225
	226	spin_lock_init(&mq->lock);
	227
b5bebe41	228	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
340a614a	229	goto error;
340a614a	230
5ed8d32e S	231	if (work)
5ed8d32e S	232	INIT_WORK(&mq->work, work);
340a614a	233
5ed8d32e S	234	if (tasklet)
5ed8d32e S	235	tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
340a614a HD	236	return mq;
	237	error:
	238	kfree(mq);
	239	return NULL;
	240	}
	241
	242	static void mbox_queue_free(struct omap_mbox_queue *q)
	243	{
b5bebe41	244	kfifo_free(&q->fifo);
340a614a HD	245	kfree(q);
	246	}
	247
c7c158e5	248	static int omap_mbox_startup(struct omap_mbox *mbox)
340a614a	249	{
5f00ec64	250	int ret = 0;
340a614a HD	251	struct omap_mbox_queue *mq;
340a614a HD	252
58256307 KH	253	mutex_lock(&mbox_configured_lock);
	254	if (!mbox_configured++) {
	255	if (likely(mbox->ops->startup)) {
5f00ec64	256	ret = mbox->ops->startup(mbox);
58256307 KH	257	if (unlikely(ret))
	258	goto fail_startup;
	259	} else
	260	goto fail_startup;
340a614a HD	261	}
340a614a HD	262
58256307 KH	263	if (!mbox->use_count++) {
	264	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
	265	mbox->name, mbox);
	266	if (unlikely(ret)) {
	267	pr_err("failed to register mailbox interrupt:%d\n",
	268	ret);
	269	goto fail_request_irq;
	270	}
	271	mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
	272	if (!mq) {
	273	ret = -ENOMEM;
	274	goto fail_alloc_txq;
	275	}
	276	mbox->txq = mq;
340a614a	277
58256307 KH	278	mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
	279	if (!mq) {
	280	ret = -ENOMEM;
	281	goto fail_alloc_rxq;
	282	}
	283	mbox->rxq = mq;
	284	mq->mbox = mbox;
340a614a	285	}
58256307	286	mutex_unlock(&mbox_configured_lock);
340a614a HD	287	return 0;
340a614a HD	288
ab66ac30	289	fail_alloc_rxq:
340a614a	290	mbox_queue_free(mbox->txq);
ab66ac30	291	fail_alloc_txq:
340a614a	292	free_irq(mbox->irq, mbox);
ab66ac30	293	fail_request_irq:
01072d8f	294	if (mbox->ops->shutdown)
340a614a	295	mbox->ops->shutdown(mbox);
58256307 KH	296	mbox->use_count--;
	297	fail_startup:
	298	mbox_configured--;
	299	mutex_unlock(&mbox_configured_lock);
340a614a HD	300	return ret;
	301	}
	302
	303	static void omap_mbox_fini(struct omap_mbox *mbox)
	304	{
58256307 KH	305	mutex_lock(&mbox_configured_lock);
	306
	307	if (!--mbox->use_count) {
	308	free_irq(mbox->irq, mbox);
	309	tasklet_kill(&mbox->txq->tasklet);
	310	flush_work(&mbox->rxq->work);
	311	mbox_queue_free(mbox->txq);
	312	mbox_queue_free(mbox->rxq);
	313	}
340a614a	314
58256307 KH	315	if (likely(mbox->ops->shutdown)) {
58256307 KH	316	if (!--mbox_configured)
5f00ec64	317	mbox->ops->shutdown(mbox);
5f00ec64	318	}
58256307 KH	319
58256307 KH	320	mutex_unlock(&mbox_configured_lock);
340a614a HD	321	}
340a614a HD	322
58256307	323	struct omap_mbox omap_mbox_get(const char name, struct notifier_block *nb)
340a614a HD	324	{
	325	struct omap_mbox *mbox;
	326	int ret;
	327
9c80c8cd FC	328	if (!mboxes)
9c80c8cd FC	329	return ERR_PTR(-EINVAL);
340a614a	330
9c80c8cd FC	331	for (mbox = *mboxes; mbox; mbox++)
	332	if (!strcmp(mbox->name, name))
	333	break;
	334
	335	if (!mbox)
	336	return ERR_PTR(-ENOENT);
340a614a	337
c7c158e5	338	ret = omap_mbox_startup(mbox);
340a614a HD	339	if (ret)
	340	return ERR_PTR(-ENODEV);
	341
58256307 KH	342	if (nb)
	343	blocking_notifier_chain_register(&mbox->notifier, nb);
	344
340a614a HD	345	return mbox;
	346	}
	347	EXPORT_SYMBOL(omap_mbox_get);
	348
58256307	349	void omap_mbox_put(struct omap_mbox mbox, struct notifier_block nb)
340a614a	350	{
58256307	351	blocking_notifier_chain_unregister(&mbox->notifier, nb);
340a614a HD	352	omap_mbox_fini(mbox);
	353	}
	354	EXPORT_SYMBOL(omap_mbox_put);
	355
6b233985 HD	356	static struct class omap_mbox_class = { .name = "mbox", };
6b233985 HD	357
9c80c8cd	358	int omap_mbox_register(struct device parent, struct omap_mbox *list)
340a614a	359	{
9c80c8cd FC	360	int ret;
9c80c8cd FC	361	int i;
340a614a	362
9c80c8cd FC	363	mboxes = list;
9c80c8cd FC	364	if (!mboxes)
340a614a	365	return -EINVAL;
340a614a	366
9c80c8cd FC	367	for (i = 0; mboxes[i]; i++) {
	368	struct omap_mbox *mbox = mboxes[i];
	369	mbox->dev = device_create(&omap_mbox_class,
	370	parent, 0, mbox, "%s", mbox->name);
	371	if (IS_ERR(mbox->dev)) {
	372	ret = PTR_ERR(mbox->dev);
	373	goto err_out;
	374	}
58256307 KH	375
58256307 KH	376	BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
9c80c8cd	377	}
f48cca87 HD	378	return 0;
f48cca87 HD	379
9c80c8cd FC	380	err_out:
	381	while (i--)
	382	device_unregister(mboxes[i]->dev);
340a614a HD	383	return ret;
	384	}
	385	EXPORT_SYMBOL(omap_mbox_register);
	386
9c80c8cd	387	int omap_mbox_unregister(void)
340a614a	388	{
9c80c8cd	389	int i;
340a614a	390
9c80c8cd FC	391	if (!mboxes)
	392	return -EINVAL;
	393
	394	for (i = 0; mboxes[i]; i++)
	395	device_unregister(mboxes[i]->dev);
	396	mboxes = NULL;
	397	return 0;
340a614a HD	398	}
	399	EXPORT_SYMBOL(omap_mbox_unregister);
	400
c7c158e5	401	static int __init omap_mbox_init(void)
340a614a	402	{
6b233985 HD	403	int err;
	404
	405	err = class_register(&omap_mbox_class);
	406	if (err)
	407	return err;
	408
8250a5c3 RC	409	mboxd = create_workqueue("mboxd");
	410	if (!mboxd)
	411	return -ENOMEM;
	412
b5bebe41 OBC	413	/* kfifo size sanity check: alignment and minimal size */
b5bebe41 OBC	414	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
ab66ac30 KH	415	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
ab66ac30 KH	416	sizeof(mbox_msg_t));
b5bebe41	417
c7c158e5	418	return 0;
340a614a	419	}
6b233985	420	subsys_initcall(omap_mbox_init);
340a614a	421
c7c158e5	422	static void __exit omap_mbox_exit(void)
340a614a	423	{
8250a5c3	424	destroy_workqueue(mboxd);
6b233985	425	class_unregister(&omap_mbox_class);
340a614a	426	}
c7c158e5	427	module_exit(omap_mbox_exit);
340a614a	428
f48cca87 HD	429	MODULE_LICENSE("GPL v2");
f48cca87 HD	430	MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
f375325a OBC	431	MODULE_AUTHOR("Toshihiro Kobayashi");
f375325a OBC	432	MODULE_AUTHOR("Hiroshi DOYU");