[mirror_ubuntu-artful-kernel.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 <linux/slab.h>

#include <plat/mailbox.h>

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

static int mbox_configured;
static DEFINE_MUTEX(mbox_configured_lock);

/* 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);
		if (mbox->rxq->callback)
			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)) {
		mutex_lock(&mbox_configured_lock);
		if (!mbox_configured)
			ret = mbox->ops->startup(mbox);

		if (unlikely(ret)) {
			mutex_unlock(&mbox_configured_lock);
			return ret;
		}
		mbox_configured++;
		mutex_unlock(&mbox_configured_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)
{
	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 (unlikely(mbox->ops->shutdown)) {
		mutex_lock(&mbox_configured_lock);
		if (mbox_configured > 0)
			mbox_configured--;
		if (!mbox_configured)
			mbox->ops->shutdown(mbox);
		mutex_unlock(&mbox_configured_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>
5a0e3ad6	28	#include <linux/slab.h>
8dff0fa5	29
ce491cf8	30	#include <plat/mailbox.h>
340a614a	31
8250a5c3	32	static struct workqueue_struct *mboxd;
340a614a HD	33	static struct omap_mbox *mboxes;
	34	static DEFINE_RWLOCK(mboxes_lock);
	35
5f00ec64	36	static int mbox_configured;
72b917ef	37	static DEFINE_MUTEX(mbox_configured_lock);
5f00ec64	38
9ae0ee00 HD	39	/* Mailbox FIFO handle functions */
	40	static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
	41	{
	42	return mbox->ops->fifo_read(mbox);
	43	}
	44	static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
	45	{
	46	mbox->ops->fifo_write(mbox, msg);
	47	}
	48	static inline int mbox_fifo_empty(struct omap_mbox *mbox)
	49	{
	50	return mbox->ops->fifo_empty(mbox);
	51	}
	52	static inline int mbox_fifo_full(struct omap_mbox *mbox)
	53	{
	54	return mbox->ops->fifo_full(mbox);
	55	}
	56
	57	/* Mailbox IRQ handle functions */
9ae0ee00 HD	58	static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	59	{
	60	if (mbox->ops->ack_irq)
	61	mbox->ops->ack_irq(mbox, irq);
	62	}
	63	static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	64	{
	65	return mbox->ops->is_irq(mbox, irq);
	66	}
	67
340a614a HD	68	/*
	69	* message sender
	70	*/
c7c158e5	71	static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
340a614a HD	72	{
	73	int ret = 0, i = 1000;
	74
	75	while (mbox_fifo_full(mbox)) {
	76	if (mbox->ops->type == OMAP_MBOX_TYPE2)
	77	return -1;
	78	if (--i == 0)
	79	return -1;
	80	udelay(1);
	81	}
340a614a	82	mbox_fifo_write(mbox, msg);
340a614a HD	83	return ret;
	84	}
	85
ec24751a	86
b2b6362e	87	int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
340a614a	88	{
5ed8d32e	89
340a614a HD	90	struct request *rq;
340a614a HD	91	struct request_queue *q = mbox->txq->queue;
ec24751a	92
340a614a	93	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
5ed8d32e	94	if (unlikely(!rq))
ec24751a	95	return -ENOMEM;
340a614a	96
5ed8d32e S	97	blk_insert_request(q, rq, 0, (void *) msg);
5ed8d32e S	98	tasklet_schedule(&mbox->txq->tasklet);
340a614a	99
ec24751a	100	return 0;
340a614a HD	101	}
	102	EXPORT_SYMBOL(omap_mbox_msg_send);
	103
5ed8d32e	104	static void mbox_tx_tasklet(unsigned long tx_data)
340a614a HD	105	{
	106	int ret;
	107	struct request *rq;
5ed8d32e	108	struct omap_mbox mbox = (struct omap_mbox )tx_data;
340a614a HD	109	struct request_queue *q = mbox->txq->queue;
	110
	111	while (1) {
ec24751a	112
9934c8c0	113	rq = blk_fetch_request(q);
340a614a HD	114
	115	if (!rq)
	116	break;
	117
5ed8d32e	118	ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
340a614a	119	if (ret) {
eb18858e	120	omap_mbox_enable_irq(mbox, IRQ_TX);
296b2f6a	121	blk_requeue_request(q, rq);
340a614a HD	122	return;
340a614a HD	123	}
5ed8d32e	124	blk_end_request_all(rq, 0);
340a614a HD	125	}
	126	}
	127
	128	/*
	129	* Message receiver(workqueue)
	130	*/
	131	static void mbox_rx_work(struct work_struct *work)
	132	{
	133	struct omap_mbox_queue *mq =
	134	container_of(work, struct omap_mbox_queue, work);
	135	struct omap_mbox *mbox = mq->queue->queuedata;
	136	struct request_queue *q = mbox->rxq->queue;
	137	struct request *rq;
	138	mbox_msg_t msg;
	139	unsigned long flags;
	140
340a614a HD	141	while (1) {
340a614a HD	142	spin_lock_irqsave(q->queue_lock, flags);
9934c8c0	143	rq = blk_fetch_request(q);
340a614a HD	144	spin_unlock_irqrestore(q->queue_lock, flags);
	145	if (!rq)
	146	break;
	147
ec24751a	148	msg = (mbox_msg_t)rq->special;
40cbbb78	149	blk_end_request_all(rq, 0);
9caae4d8 FGL	150	if (mbox->rxq->callback)
9caae4d8 FGL	151	mbox->rxq->callback((void *)msg);
340a614a HD	152	}
	153	}
	154
	155	/*
	156	* Mailbox interrupt handler
	157	*/
bfe1f6ac	158	static void mbox_txq_fn(struct request_queue *q)
340a614a HD	159	{
	160	}
	161
bfe1f6ac	162	static void mbox_rxq_fn(struct request_queue *q)
340a614a HD	163	{
	164	}
	165
	166	static void __mbox_tx_interrupt(struct omap_mbox *mbox)
	167	{
eb18858e	168	omap_mbox_disable_irq(mbox, IRQ_TX);
340a614a	169	ack_mbox_irq(mbox, IRQ_TX);
5ed8d32e	170	tasklet_schedule(&mbox->txq->tasklet);
340a614a HD	171	}
	172
	173	static void __mbox_rx_interrupt(struct omap_mbox *mbox)
	174	{
	175	struct request *rq;
	176	mbox_msg_t msg;
165125e1	177	struct request_queue *q = mbox->rxq->queue;
340a614a	178
340a614a HD	179	while (!mbox_fifo_empty(mbox)) {
	180	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	181	if (unlikely(!rq))
	182	goto nomem;
	183
	184	msg = mbox_fifo_read(mbox);
340a614a	185
340a614a	186
ec24751a	187	blk_insert_request(q, rq, 0, (void *)msg);
340a614a HD	188	if (mbox->ops->type == OMAP_MBOX_TYPE1)
	189	break;
	190	}
	191
	192	/* no more messages in the fifo. clear IRQ source. */
	193	ack_mbox_irq(mbox, IRQ_RX);
f48cca87	194	nomem:
8250a5c3	195	queue_work(mboxd, &mbox->rxq->work);
340a614a HD	196	}
	197
	198	static irqreturn_t mbox_interrupt(int irq, void *p)
	199	{
2a7057e3	200	struct omap_mbox *mbox = p;
340a614a HD	201
	202	if (is_mbox_irq(mbox, IRQ_TX))
	203	__mbox_tx_interrupt(mbox);
	204
	205	if (is_mbox_irq(mbox, IRQ_RX))
	206	__mbox_rx_interrupt(mbox);
	207
	208	return IRQ_HANDLED;
	209	}
	210
340a614a	211	static struct omap_mbox_queue mbox_queue_alloc(struct omap_mbox mbox,
bfe1f6ac	212	request_fn_proc *proc,
5ed8d32e S	213	void (work) (struct work_struct ),
5ed8d32e S	214	void (*tasklet)(unsigned long))
340a614a	215	{
165125e1	216	struct request_queue *q;
340a614a HD	217	struct omap_mbox_queue *mq;
	218
	219	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
	220	if (!mq)
	221	return NULL;
	222
	223	spin_lock_init(&mq->lock);
	224
	225	q = blk_init_queue(proc, &mq->lock);
	226	if (!q)
	227	goto error;
	228	q->queuedata = mbox;
	229	mq->queue = q;
	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	{
	244	blk_cleanup_queue(q->queue);
	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;
	252
	253	if (likely(mbox->ops->startup)) {
72b917ef	254	mutex_lock(&mbox_configured_lock);
5f00ec64 S	255	if (!mbox_configured)
	256	ret = mbox->ops->startup(mbox);
	257
	258	if (unlikely(ret)) {
72b917ef	259	mutex_unlock(&mbox_configured_lock);
340a614a	260	return ret;
5f00ec64 S	261	}
5f00ec64 S	262	mbox_configured++;
72b917ef	263	mutex_unlock(&mbox_configured_lock);
340a614a HD	264	}
340a614a HD	265
5e683825	266	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
340a614a HD	267	mbox->name, mbox);
	268	if (unlikely(ret)) {
	269	printk(KERN_ERR
	270	"failed to register mailbox interrupt:%d\n", ret);
	271	goto fail_request_irq;
	272	}
340a614a	273
5ed8d32e	274	mq = mbox_queue_alloc(mbox, mbox_txq_fn, NULL, mbox_tx_tasklet);
340a614a HD	275	if (!mq) {
	276	ret = -ENOMEM;
	277	goto fail_alloc_txq;
	278	}
	279	mbox->txq = mq;
	280
5ed8d32e	281	mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work, NULL);
340a614a HD	282	if (!mq) {
	283	ret = -ENOMEM;
	284	goto fail_alloc_rxq;
	285	}
	286	mbox->rxq = mq;
	287
	288	return 0;
	289
	290	fail_alloc_rxq:
	291	mbox_queue_free(mbox->txq);
	292	fail_alloc_txq:
	293	free_irq(mbox->irq, mbox);
	294	fail_request_irq:
340a614a HD	295	if (unlikely(mbox->ops->shutdown))
	296	mbox->ops->shutdown(mbox);
	297
	298	return ret;
	299	}
	300
	301	static void omap_mbox_fini(struct omap_mbox *mbox)
	302	{
ad6d9627	303	free_irq(mbox->irq, mbox);
0e828e8c FGL	304	tasklet_kill(&mbox->txq->tasklet);
0e828e8c FGL	305	flush_work(&mbox->rxq->work);
340a614a HD	306	mbox_queue_free(mbox->txq);
	307	mbox_queue_free(mbox->rxq);
	308
5f00ec64	309	if (unlikely(mbox->ops->shutdown)) {
72b917ef	310	mutex_lock(&mbox_configured_lock);
5f00ec64 S	311	if (mbox_configured > 0)
	312	mbox_configured--;
	313	if (!mbox_configured)
	314	mbox->ops->shutdown(mbox);
72b917ef	315	mutex_unlock(&mbox_configured_lock);
5f00ec64	316	}
340a614a HD	317	}
	318
	319	static struct omap_mbox *find_mboxes(const char name)
	320	{
	321	struct omap_mbox **p;
	322
	323	for (p = &mboxes; p; p = &(p)->next) {
	324	if (strcmp((*p)->name, name) == 0)
	325	break;
	326	}
	327
	328	return p;
	329	}
	330
	331	struct omap_mbox omap_mbox_get(const char name)
	332	{
	333	struct omap_mbox *mbox;
	334	int ret;
	335
	336	read_lock(&mboxes_lock);
	337	mbox = *(find_mboxes(name));
	338	if (mbox == NULL) {
	339	read_unlock(&mboxes_lock);
	340	return ERR_PTR(-ENOENT);
	341	}
	342
	343	read_unlock(&mboxes_lock);
	344
c7c158e5	345	ret = omap_mbox_startup(mbox);
340a614a HD	346	if (ret)
	347	return ERR_PTR(-ENODEV);
	348
	349	return mbox;
	350	}
	351	EXPORT_SYMBOL(omap_mbox_get);
	352
	353	void omap_mbox_put(struct omap_mbox *mbox)
	354	{
	355	omap_mbox_fini(mbox);
	356	}
	357	EXPORT_SYMBOL(omap_mbox_put);
	358
f48cca87	359	int omap_mbox_register(struct device parent, struct omap_mbox mbox)
340a614a HD	360	{
	361	int ret = 0;
	362	struct omap_mbox **tmp;
	363
	364	if (!mbox)
	365	return -EINVAL;
	366	if (mbox->next)
	367	return -EBUSY;
	368
	369	write_lock(&mboxes_lock);
	370	tmp = find_mboxes(mbox->name);
f48cca87	371	if (*tmp) {
340a614a	372	ret = -EBUSY;
f48cca87 HD	373	write_unlock(&mboxes_lock);
	374	goto err_find;
	375	}
	376	*tmp = mbox;
340a614a HD	377	write_unlock(&mboxes_lock);
340a614a HD	378
f48cca87 HD	379	return 0;
	380
	381	err_find:
340a614a HD	382	return ret;
	383	}
	384	EXPORT_SYMBOL(omap_mbox_register);
	385
	386	int omap_mbox_unregister(struct omap_mbox *mbox)
	387	{
	388	struct omap_mbox **tmp;
	389
	390	write_lock(&mboxes_lock);
	391	tmp = &mboxes;
	392	while (*tmp) {
	393	if (mbox == *tmp) {
	394	*tmp = mbox->next;
	395	mbox->next = NULL;
	396	write_unlock(&mboxes_lock);
	397	return 0;
	398	}
	399	tmp = &(*tmp)->next;
	400	}
	401	write_unlock(&mboxes_lock);
	402
	403	return -EINVAL;
	404	}
	405	EXPORT_SYMBOL(omap_mbox_unregister);
	406
c7c158e5	407	static int __init omap_mbox_init(void)
340a614a	408	{
8250a5c3 RC	409	mboxd = create_workqueue("mboxd");
	410	if (!mboxd)
	411	return -ENOMEM;
	412
c7c158e5	413	return 0;
340a614a	414	}
c7c158e5	415	module_init(omap_mbox_init);
340a614a	416
c7c158e5	417	static void __exit omap_mbox_exit(void)
340a614a	418	{
8250a5c3	419	destroy_workqueue(mboxd);
340a614a	420	}
c7c158e5	421	module_exit(omap_mbox_exit);
340a614a	422
f48cca87 HD	423	MODULE_LICENSE("GPL v2");
	424	MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
	425	MODULE_AUTHOR("Toshihiro Kobayashi and Hiroshi DOYU");