arch/arm/plat-omap/mailbox.c - kernel/msm-4.19 - Gitiles

 /*
  * 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, *mbox = NULL;
 	int i, ret;

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

 	for (i = 0; (_mbox = mboxes[i]); i++) {
 		if (!strcmp(_mbox->name, name)) {
 			mbox = _mbox;
 			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");
	/*
	* 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, mbox = NULL;
	int i, ret;

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

	for (i = 0; (_mbox = mboxes[i]); i++) {
	if (!strcmp(_mbox->name, name)) {
	mbox = _mbox;
	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");