[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/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/delay.h>

#include <plat/mailbox.h>

static struct workqueue_struct *mboxd;
static struct omap_mbox *mboxes;
static DEFINE_RWLOCK(mboxes_lock);

static int mbox_configured;

/* 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_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
{
	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);
	}
	mbox_fifo_write(mbox, msg);
	return ret;
}


int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
{

	struct request *rq;
	struct request_queue *q = mbox->txq->queue;

	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	if (unlikely(!rq))
		return -ENOMEM;

	blk_insert_request(q, rq, 0, (void *) msg);
	tasklet_schedule(&mbox->txq->tasklet);

	return 0;
}
EXPORT_SYMBOL(omap_mbox_msg_send);

static void mbox_tx_tasklet(unsigned long tx_data)
{
	int ret;
	struct request *rq;
	struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
	struct request_queue *q = mbox->txq->queue;

	while (1) {

		rq = blk_fetch_request(q);

		if (!rq)
			break;

		ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
		if (ret) {
			omap_mbox_enable_irq(mbox, IRQ_TX);
			blk_requeue_request(q, rq);
			return;
		}
		blk_end_request_all(rq, 0);
	}
}

/*
 * 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);
	struct omap_mbox *mbox = mq->queue->queuedata;
	struct request_queue *q = mbox->rxq->queue;
	struct request *rq;
	mbox_msg_t msg;
	unsigned long flags;

	while (1) {
		spin_lock_irqsave(q->queue_lock, flags);
		rq = blk_fetch_request(q);
		spin_unlock_irqrestore(q->queue_lock, flags);
		if (!rq)
			break;

		msg = (mbox_msg_t)rq->special;
		blk_end_request_all(rq, 0);
		mbox->rxq->callback((void *)msg);
	}
}

/*
 * Mailbox interrupt handler
 */
static void mbox_txq_fn(struct request_queue *q)
{
}

static void mbox_rxq_fn(struct request_queue *q)
{
}

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 request *rq;
	mbox_msg_t msg;
	struct request_queue *q = mbox->rxq->queue;

	while (!mbox_fifo_empty(mbox)) {
		rq = blk_get_request(q, WRITE, GFP_ATOMIC);
		if (unlikely(!rq))
			goto nomem;

		msg = mbox_fifo_read(mbox);


		blk_insert_request(q, rq, 0, (void *)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,
					request_fn_proc *proc,
					void (*work) (struct work_struct *),
					void (*tasklet)(unsigned long))
{
	struct request_queue *q;
	struct omap_mbox_queue *mq;

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

	spin_lock_init(&mq->lock);

	q = blk_init_queue(proc, &mq->lock);
	if (!q)
		goto error;
	q->queuedata = mbox;
	mq->queue = q;

	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)
{
	blk_cleanup_queue(q->queue);
	kfree(q);
}

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

	if (likely(mbox->ops->startup)) {
		write_lock(&mboxes_lock);
		if (!mbox_configured)
			ret = mbox->ops->startup(mbox);

		if (unlikely(ret)) {
			write_unlock(&mboxes_lock);
			return ret;
		}
		mbox_configured++;
		write_unlock(&mboxes_lock);
	}

	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
				mbox->name, mbox);
	if (unlikely(ret)) {
		printk(KERN_ERR
			"failed to register mailbox interrupt:%d\n", ret);
		goto fail_request_irq;
	}

	mq = mbox_queue_alloc(mbox, mbox_txq_fn, NULL, mbox_tx_tasklet);
	if (!mq) {
		ret = -ENOMEM;
		goto fail_alloc_txq;
	}
	mbox->txq = mq;

	mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work, NULL);
	if (!mq) {
		ret = -ENOMEM;
		goto fail_alloc_rxq;
	}
	mbox->rxq = mq;

	return 0;

 fail_alloc_rxq:
	mbox_queue_free(mbox->txq);
 fail_alloc_txq:
	free_irq(mbox->irq, mbox);
 fail_request_irq:
	if (unlikely(mbox->ops->shutdown))
		mbox->ops->shutdown(mbox);

	return ret;
}

static void omap_mbox_fini(struct omap_mbox *mbox)
{
	mbox_queue_free(mbox->txq);
	mbox_queue_free(mbox->rxq);

	free_irq(mbox->irq, mbox);

	if (unlikely(mbox->ops->shutdown)) {
		write_lock(&mboxes_lock);
		if (mbox_configured > 0)
			mbox_configured--;
		if (!mbox_configured)
			mbox->ops->shutdown(mbox);
		write_unlock(&mboxes_lock);
	}
}

static struct omap_mbox **find_mboxes(const char *name)
{
	struct omap_mbox **p;

	for (p = &mboxes; *p; p = &(*p)->next) {
		if (strcmp((*p)->name, name) == 0)
			break;
	}

	return p;
}

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

	read_lock(&mboxes_lock);
	mbox = *(find_mboxes(name));
	if (mbox == NULL) {
		read_unlock(&mboxes_lock);
		return ERR_PTR(-ENOENT);
	}

	read_unlock(&mboxes_lock);

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

	return mbox;
}
EXPORT_SYMBOL(omap_mbox_get);

void omap_mbox_put(struct omap_mbox *mbox)
{
	omap_mbox_fini(mbox);
}
EXPORT_SYMBOL(omap_mbox_put);

int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
{
	int ret = 0;
	struct omap_mbox **tmp;

	if (!mbox)
		return -EINVAL;
	if (mbox->next)
		return -EBUSY;

	write_lock(&mboxes_lock);
	tmp = find_mboxes(mbox->name);
	if (*tmp) {
		ret = -EBUSY;
		write_unlock(&mboxes_lock);
		goto err_find;
	}
	*tmp = mbox;
	write_unlock(&mboxes_lock);

	return 0;

err_find:
	return ret;
}
EXPORT_SYMBOL(omap_mbox_register);

int omap_mbox_unregister(struct omap_mbox *mbox)
{
	struct omap_mbox **tmp;

	write_lock(&mboxes_lock);
	tmp = &mboxes;
	while (*tmp) {
		if (mbox == *tmp) {
			*tmp = mbox->next;
			mbox->next = NULL;
			write_unlock(&mboxes_lock);
			return 0;
		}
		tmp = &(*tmp)->next;
	}
	write_unlock(&mboxes_lock);

	return -EINVAL;
}
EXPORT_SYMBOL(omap_mbox_unregister);

static int __init omap_mbox_init(void)
{
	mboxd = create_workqueue("mboxd");
	if (!mboxd)
		return -ENOMEM;

	return 0;
}
module_init(omap_mbox_init);

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

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
MODULE_AUTHOR("Toshihiro Kobayashi and 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/module.h>
340a614a HD	25	#include <linux/interrupt.h>
340a614a HD	26	#include <linux/device.h>
340a614a	27	#include <linux/delay.h>
8dff0fa5	28
ce491cf8	29	#include <plat/mailbox.h>
340a614a	30
8250a5c3	31	static struct workqueue_struct *mboxd;
340a614a HD	32	static struct omap_mbox *mboxes;
	33	static DEFINE_RWLOCK(mboxes_lock);
	34
5f00ec64 S	35	static int mbox_configured;
5f00ec64 S	36
9ae0ee00 HD	37	/* Mailbox FIFO handle functions */
	38	static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
	39	{
	40	return mbox->ops->fifo_read(mbox);
	41	}
	42	static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
	43	{
	44	mbox->ops->fifo_write(mbox, msg);
	45	}
	46	static inline int mbox_fifo_empty(struct omap_mbox *mbox)
	47	{
	48	return mbox->ops->fifo_empty(mbox);
	49	}
	50	static inline int mbox_fifo_full(struct omap_mbox *mbox)
	51	{
	52	return mbox->ops->fifo_full(mbox);
	53	}
	54
	55	/* Mailbox IRQ handle functions */
9ae0ee00 HD	56	static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	57	{
	58	if (mbox->ops->ack_irq)
	59	mbox->ops->ack_irq(mbox, irq);
	60	}
	61	static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	62	{
	63	return mbox->ops->is_irq(mbox, irq);
	64	}
	65
340a614a HD	66	/*
	67	* message sender
	68	*/
c7c158e5	69	static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
340a614a HD	70	{
	71	int ret = 0, i = 1000;
	72
	73	while (mbox_fifo_full(mbox)) {
	74	if (mbox->ops->type == OMAP_MBOX_TYPE2)
	75	return -1;
	76	if (--i == 0)
	77	return -1;
	78	udelay(1);
	79	}
340a614a	80	mbox_fifo_write(mbox, msg);
340a614a HD	81	return ret;
	82	}
	83
ec24751a	84
b2b6362e	85	int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
340a614a	86	{
5ed8d32e	87
340a614a HD	88	struct request *rq;
340a614a HD	89	struct request_queue *q = mbox->txq->queue;
ec24751a	90
340a614a	91	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
5ed8d32e	92	if (unlikely(!rq))
ec24751a	93	return -ENOMEM;
340a614a	94
5ed8d32e S	95	blk_insert_request(q, rq, 0, (void *) msg);
5ed8d32e S	96	tasklet_schedule(&mbox->txq->tasklet);
340a614a	97
ec24751a	98	return 0;
340a614a HD	99	}
	100	EXPORT_SYMBOL(omap_mbox_msg_send);
	101
5ed8d32e	102	static void mbox_tx_tasklet(unsigned long tx_data)
340a614a HD	103	{
	104	int ret;
	105	struct request *rq;
5ed8d32e	106	struct omap_mbox mbox = (struct omap_mbox )tx_data;
340a614a HD	107	struct request_queue *q = mbox->txq->queue;
	108
	109	while (1) {
ec24751a	110
9934c8c0	111	rq = blk_fetch_request(q);
340a614a HD	112
	113	if (!rq)
	114	break;
	115
5ed8d32e	116	ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
340a614a	117	if (ret) {
eb18858e	118	omap_mbox_enable_irq(mbox, IRQ_TX);
296b2f6a	119	blk_requeue_request(q, rq);
340a614a HD	120	return;
340a614a HD	121	}
5ed8d32e	122	blk_end_request_all(rq, 0);
340a614a HD	123	}
	124	}
	125
	126	/*
	127	* Message receiver(workqueue)
	128	*/
	129	static void mbox_rx_work(struct work_struct *work)
	130	{
	131	struct omap_mbox_queue *mq =
	132	container_of(work, struct omap_mbox_queue, work);
	133	struct omap_mbox *mbox = mq->queue->queuedata;
	134	struct request_queue *q = mbox->rxq->queue;
	135	struct request *rq;
	136	mbox_msg_t msg;
	137	unsigned long flags;
	138
340a614a HD	139	while (1) {
340a614a HD	140	spin_lock_irqsave(q->queue_lock, flags);
9934c8c0	141	rq = blk_fetch_request(q);
340a614a HD	142	spin_unlock_irqrestore(q->queue_lock, flags);
	143	if (!rq)
	144	break;
	145
ec24751a	146	msg = (mbox_msg_t)rq->special;
40cbbb78	147	blk_end_request_all(rq, 0);
340a614a HD	148	mbox->rxq->callback((void *)msg);
	149	}
	150	}
	151
	152	/*
	153	* Mailbox interrupt handler
	154	*/
bfe1f6ac	155	static void mbox_txq_fn(struct request_queue *q)
340a614a HD	156	{
	157	}
	158
bfe1f6ac	159	static void mbox_rxq_fn(struct request_queue *q)
340a614a HD	160	{
	161	}
	162
	163	static void __mbox_tx_interrupt(struct omap_mbox *mbox)
	164	{
eb18858e	165	omap_mbox_disable_irq(mbox, IRQ_TX);
340a614a	166	ack_mbox_irq(mbox, IRQ_TX);
5ed8d32e	167	tasklet_schedule(&mbox->txq->tasklet);
340a614a HD	168	}
	169
	170	static void __mbox_rx_interrupt(struct omap_mbox *mbox)
	171	{
	172	struct request *rq;
	173	mbox_msg_t msg;
165125e1	174	struct request_queue *q = mbox->rxq->queue;
340a614a	175
340a614a HD	176	while (!mbox_fifo_empty(mbox)) {
	177	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	178	if (unlikely(!rq))
	179	goto nomem;
	180
	181	msg = mbox_fifo_read(mbox);
340a614a	182
340a614a	183
ec24751a	184	blk_insert_request(q, rq, 0, (void *)msg);
340a614a HD	185	if (mbox->ops->type == OMAP_MBOX_TYPE1)
	186	break;
	187	}
	188
	189	/* no more messages in the fifo. clear IRQ source. */
	190	ack_mbox_irq(mbox, IRQ_RX);
f48cca87	191	nomem:
8250a5c3	192	queue_work(mboxd, &mbox->rxq->work);
340a614a HD	193	}
	194
	195	static irqreturn_t mbox_interrupt(int irq, void *p)
	196	{
2a7057e3	197	struct omap_mbox *mbox = p;
340a614a HD	198
	199	if (is_mbox_irq(mbox, IRQ_TX))
	200	__mbox_tx_interrupt(mbox);
	201
	202	if (is_mbox_irq(mbox, IRQ_RX))
	203	__mbox_rx_interrupt(mbox);
	204
	205	return IRQ_HANDLED;
	206	}
	207
340a614a	208	static struct omap_mbox_queue mbox_queue_alloc(struct omap_mbox mbox,
bfe1f6ac	209	request_fn_proc *proc,
5ed8d32e S	210	void (work) (struct work_struct ),
5ed8d32e S	211	void (*tasklet)(unsigned long))
340a614a	212	{
165125e1	213	struct request_queue *q;
340a614a HD	214	struct omap_mbox_queue *mq;
	215
	216	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
	217	if (!mq)
	218	return NULL;
	219
	220	spin_lock_init(&mq->lock);
	221
	222	q = blk_init_queue(proc, &mq->lock);
	223	if (!q)
	224	goto error;
	225	q->queuedata = mbox;
	226	mq->queue = q;
	227
5ed8d32e S	228	if (work)
5ed8d32e S	229	INIT_WORK(&mq->work, work);
340a614a	230
5ed8d32e S	231	if (tasklet)
5ed8d32e S	232	tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
340a614a HD	233	return mq;
	234	error:
	235	kfree(mq);
	236	return NULL;
	237	}
	238
	239	static void mbox_queue_free(struct omap_mbox_queue *q)
	240	{
	241	blk_cleanup_queue(q->queue);
	242	kfree(q);
	243	}
	244
c7c158e5	245	static int omap_mbox_startup(struct omap_mbox *mbox)
340a614a	246	{
5f00ec64	247	int ret = 0;
340a614a HD	248	struct omap_mbox_queue *mq;
	249
	250	if (likely(mbox->ops->startup)) {
5f00ec64 S	251	write_lock(&mboxes_lock);
	252	if (!mbox_configured)
	253	ret = mbox->ops->startup(mbox);
	254
	255	if (unlikely(ret)) {
	256	write_unlock(&mboxes_lock);
340a614a	257	return ret;
5f00ec64 S	258	}
	259	mbox_configured++;
	260	write_unlock(&mboxes_lock);
340a614a HD	261	}
340a614a HD	262
5e683825	263	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
340a614a HD	264	mbox->name, mbox);
	265	if (unlikely(ret)) {
	266	printk(KERN_ERR
	267	"failed to register mailbox interrupt:%d\n", ret);
	268	goto fail_request_irq;
	269	}
340a614a	270
5ed8d32e	271	mq = mbox_queue_alloc(mbox, mbox_txq_fn, NULL, mbox_tx_tasklet);
340a614a HD	272	if (!mq) {
	273	ret = -ENOMEM;
	274	goto fail_alloc_txq;
	275	}
	276	mbox->txq = mq;
	277
5ed8d32e	278	mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work, NULL);
340a614a HD	279	if (!mq) {
	280	ret = -ENOMEM;
	281	goto fail_alloc_rxq;
	282	}
	283	mbox->rxq = mq;
	284
	285	return 0;
	286
	287	fail_alloc_rxq:
	288	mbox_queue_free(mbox->txq);
	289	fail_alloc_txq:
	290	free_irq(mbox->irq, mbox);
	291	fail_request_irq:
340a614a HD	292	if (unlikely(mbox->ops->shutdown))
	293	mbox->ops->shutdown(mbox);
	294
	295	return ret;
	296	}
	297
	298	static void omap_mbox_fini(struct omap_mbox *mbox)
	299	{
	300	mbox_queue_free(mbox->txq);
	301	mbox_queue_free(mbox->rxq);
	302
	303	free_irq(mbox->irq, mbox);
340a614a	304
5f00ec64 S	305	if (unlikely(mbox->ops->shutdown)) {
	306	write_lock(&mboxes_lock);
	307	if (mbox_configured > 0)
	308	mbox_configured--;
	309	if (!mbox_configured)
	310	mbox->ops->shutdown(mbox);
	311	write_unlock(&mboxes_lock);
	312	}
340a614a HD	313	}
	314
	315	static struct omap_mbox *find_mboxes(const char name)
	316	{
	317	struct omap_mbox **p;
	318
	319	for (p = &mboxes; p; p = &(p)->next) {
	320	if (strcmp((*p)->name, name) == 0)
	321	break;
	322	}
	323
	324	return p;
	325	}
	326
	327	struct omap_mbox omap_mbox_get(const char name)
	328	{
	329	struct omap_mbox *mbox;
	330	int ret;
	331
	332	read_lock(&mboxes_lock);
	333	mbox = *(find_mboxes(name));
	334	if (mbox == NULL) {
	335	read_unlock(&mboxes_lock);
	336	return ERR_PTR(-ENOENT);
	337	}
	338
	339	read_unlock(&mboxes_lock);
	340
c7c158e5	341	ret = omap_mbox_startup(mbox);
340a614a HD	342	if (ret)
	343	return ERR_PTR(-ENODEV);
	344
	345	return mbox;
	346	}
	347	EXPORT_SYMBOL(omap_mbox_get);
	348
	349	void omap_mbox_put(struct omap_mbox *mbox)
	350	{
	351	omap_mbox_fini(mbox);
	352	}
	353	EXPORT_SYMBOL(omap_mbox_put);
	354
f48cca87	355	int omap_mbox_register(struct device parent, struct omap_mbox mbox)
340a614a HD	356	{
	357	int ret = 0;
	358	struct omap_mbox **tmp;
	359
	360	if (!mbox)
	361	return -EINVAL;
	362	if (mbox->next)
	363	return -EBUSY;
	364
	365	write_lock(&mboxes_lock);
	366	tmp = find_mboxes(mbox->name);
f48cca87	367	if (*tmp) {
340a614a	368	ret = -EBUSY;
f48cca87 HD	369	write_unlock(&mboxes_lock);
	370	goto err_find;
	371	}
	372	*tmp = mbox;
340a614a HD	373	write_unlock(&mboxes_lock);
340a614a HD	374
f48cca87 HD	375	return 0;
	376
	377	err_find:
340a614a HD	378	return ret;
	379	}
	380	EXPORT_SYMBOL(omap_mbox_register);
	381
	382	int omap_mbox_unregister(struct omap_mbox *mbox)
	383	{
	384	struct omap_mbox **tmp;
	385
	386	write_lock(&mboxes_lock);
	387	tmp = &mboxes;
	388	while (*tmp) {
	389	if (mbox == *tmp) {
	390	*tmp = mbox->next;
	391	mbox->next = NULL;
	392	write_unlock(&mboxes_lock);
	393	return 0;
	394	}
	395	tmp = &(*tmp)->next;
	396	}
	397	write_unlock(&mboxes_lock);
	398
	399	return -EINVAL;
	400	}
	401	EXPORT_SYMBOL(omap_mbox_unregister);
	402
c7c158e5	403	static int __init omap_mbox_init(void)
340a614a	404	{
8250a5c3 RC	405	mboxd = create_workqueue("mboxd");
	406	if (!mboxd)
	407	return -ENOMEM;
	408
c7c158e5	409	return 0;
340a614a	410	}
c7c158e5	411	module_init(omap_mbox_init);
340a614a	412
c7c158e5	413	static void __exit omap_mbox_exit(void)
340a614a	414	{
8250a5c3	415	destroy_workqueue(mboxd);
340a614a	416	}
c7c158e5	417	module_exit(omap_mbox_exit);
340a614a	418
f48cca87 HD	419	MODULE_LICENSE("GPL v2");
	420	MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
	421	MODULE_AUTHOR("Toshihiro Kobayashi and Hiroshi DOYU");