[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 <mach/mailbox.h>

static int enable_seq_bit;
module_param(enable_seq_bit, bool, 0);
MODULE_PARM_DESC(enable_seq_bit, "Enable sequence bit checking.");

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

/*
 * Mailbox sequence bit API
 */

/* seq_rcv should be initialized with any value other than
 * 0 and 1 << 31, to allow either value for the first
 * message.  */
static inline void mbox_seq_init(struct omap_mbox *mbox)
{
	if (!enable_seq_bit)
		return;

	/* any value other than 0 and 1 << 31 */
	mbox->seq_rcv = 0xffffffff;
}

static inline void mbox_seq_toggle(struct omap_mbox *mbox, mbox_msg_t * msg)
{
	if (!enable_seq_bit)
		return;

	/* add seq_snd to msg */
	*msg = (*msg & 0x7fffffff) | mbox->seq_snd;
	/* flip seq_snd */
	mbox->seq_snd ^= 1 << 31;
}

static inline int mbox_seq_test(struct omap_mbox *mbox, mbox_msg_t msg)
{
	mbox_msg_t seq;

	if (!enable_seq_bit)
		return 0;

	seq = msg & (1 << 31);
	if (seq == mbox->seq_rcv)
		return -1;
	mbox->seq_rcv = seq;
	return 0;
}

/* 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 enable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
	mbox->ops->enable_irq(mbox, irq);
}
static inline void disable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
	mbox->ops->disable_irq(mbox, irq);
}
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);
}

/* Mailbox Sequence Bit function */
void omap_mbox_init_seq(struct omap_mbox *mbox)
{
	mbox_seq_init(mbox);
}
EXPORT_SYMBOL(omap_mbox_init_seq);

/*
 * message sender
 */
static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void *arg)
{
	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);
	}

	if (arg && mbox->txq->callback) {
		ret = mbox->txq->callback(arg);
		if (ret)
			goto out;
	}

	mbox_seq_toggle(mbox, &msg);
	mbox_fifo_write(mbox, msg);
 out:
	return ret;
}

int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void* arg)
{
	struct request *rq;
	struct request_queue *q = mbox->txq->queue;
	int ret = 0;

	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	if (unlikely(!rq)) {
		ret = -ENOMEM;
		goto fail;
	}

	rq->data = (void *)msg;
	blk_insert_request(q, rq, 0, arg);

	schedule_work(&mbox->txq->work);
 fail:
	return ret;
}
EXPORT_SYMBOL(omap_mbox_msg_send);

static void mbox_tx_work(struct work_struct *work)
{
	int ret;
	struct request *rq;
	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->txq->queue;

	while (1) {
		spin_lock(q->queue_lock);
		rq = elv_next_request(q);
		spin_unlock(q->queue_lock);

		if (!rq)
			break;

		ret = __mbox_msg_send(mbox, (mbox_msg_t) rq->data, rq->special);
		if (ret) {
			enable_mbox_irq(mbox, IRQ_TX);
			return;
		}

		spin_lock(q->queue_lock);
		__blk_end_request_all(rq, 0);
		spin_unlock(q->queue_lock);
	}
}

/*
 * 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;

	if (mbox->rxq->callback == NULL) {
		sysfs_notify(&mbox->dev->kobj, NULL, "mbox");
		return;
	}

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

		msg = (mbox_msg_t) rq->data;
		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)
{
	disable_mbox_irq(mbox, IRQ_TX);
	ack_mbox_irq(mbox, IRQ_TX);
	schedule_work(&mbox->txq->work);
}

static void __mbox_rx_interrupt(struct omap_mbox *mbox)
{
	struct request *rq;
	mbox_msg_t msg;
	struct request_queue *q = mbox->rxq->queue;

	disable_mbox_irq(mbox, IRQ_RX);

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

		msg = mbox_fifo_read(mbox);
		rq->data = (void *)msg;

		if (unlikely(mbox_seq_test(mbox, msg))) {
			pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
			if (mbox->err_notify)
				mbox->err_notify();
		}

		blk_insert_request(q, rq, 0, NULL);
		if (mbox->ops->type == OMAP_MBOX_TYPE1)
			break;
	}

	/* no more messages in the fifo. clear IRQ source. */
	ack_mbox_irq(mbox, IRQ_RX);
	enable_mbox_irq(mbox, IRQ_RX);
nomem:
	schedule_work(&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;
}

/*
 * sysfs files
 */
static ssize_t
omap_mbox_write(struct device *dev, struct device_attribute *attr,
		const char * buf, size_t count)
{
	int ret;
	mbox_msg_t *p = (mbox_msg_t *)buf;
	struct omap_mbox *mbox = dev_get_drvdata(dev);

	for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) {
		ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL);
		if (ret)
			return -EAGAIN;
		p++;
	}

	return (size_t)((char *)p - buf);
}

static ssize_t
omap_mbox_read(struct device *dev, struct device_attribute *attr, char *buf)
{
	unsigned long flags;
	struct request *rq;
	mbox_msg_t *p = (mbox_msg_t *) buf;
	struct omap_mbox *mbox = dev_get_drvdata(dev);
	struct request_queue *q = mbox->rxq->queue;

	while (1) {
		spin_lock_irqsave(q->queue_lock, flags);
		rq = elv_next_request(q);
		spin_unlock_irqrestore(q->queue_lock, flags);

		if (!rq)
			break;

		*p = (mbox_msg_t) rq->data;

		blk_end_request_all(rq, 0);

		if (unlikely(mbox_seq_test(mbox, *p))) {
			pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
			continue;
		}
		p++;
	}

	pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]);

	return (size_t) ((char *)p - buf);
}

static DEVICE_ATTR(mbox, S_IRUGO | S_IWUSR, omap_mbox_read, omap_mbox_write);

static ssize_t mbox_show(struct class *class, char *buf)
{
	return sprintf(buf, "mbox");
}

static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);

static struct class omap_mbox_class = {
	.name = "omap-mailbox",
};

static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
					request_fn_proc * proc,
					void (*work) (struct work_struct *))
{
	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;

	INIT_WORK(&mq->work, work);

	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_init(struct omap_mbox *mbox)
{
	int ret;
	struct omap_mbox_queue *mq;

	if (likely(mbox->ops->startup)) {
		ret = mbox->ops->startup(mbox);
		if (unlikely(ret))
			return ret;
	}

	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED,
				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, mbox_tx_work);
	if (!mq) {
		ret = -ENOMEM;
		goto fail_alloc_txq;
	}
	mbox->txq = mq;

	mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
	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))
		mbox->ops->shutdown(mbox);
}

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_init(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;

	mbox->dev = device_create(&omap_mbox_class,
				  parent, 0, mbox, "%s", mbox->name);
	if (IS_ERR(mbox->dev))
		return PTR_ERR(mbox->dev);

	ret = device_create_file(mbox->dev, &dev_attr_mbox);
	if (ret)
		goto err_sysfs;

	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:
	device_remove_file(mbox->dev, &dev_attr_mbox);
err_sysfs:
	device_unregister(mbox->dev);
	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);
			device_remove_file(mbox->dev, &dev_attr_mbox);
			device_unregister(mbox->dev);
			return 0;
		}
		tmp = &(*tmp)->next;
	}
	write_unlock(&mboxes_lock);

	return -EINVAL;
}
EXPORT_SYMBOL(omap_mbox_unregister);

static int __init omap_mbox_class_init(void)
{
	int ret = class_register(&omap_mbox_class);
	if (!ret)
		ret = class_create_file(&omap_mbox_class, &class_attr_mbox);

	return ret;
}

static void __exit omap_mbox_class_exit(void)
{
	class_remove_file(&omap_mbox_class, &class_attr_mbox);
	class_unregister(&omap_mbox_class);
}

subsys_initcall(omap_mbox_class_init);
module_exit(omap_mbox_class_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
a09e64fb	29	#include <mach/mailbox.h>
340a614a	30
7a781afd HD	31	static int enable_seq_bit;
	32	module_param(enable_seq_bit, bool, 0);
	33	MODULE_PARM_DESC(enable_seq_bit, "Enable sequence bit checking.");
	34
340a614a HD	35	static struct omap_mbox *mboxes;
	36	static DEFINE_RWLOCK(mboxes_lock);
	37
9ae0ee00 HD	38	/*
	39	* Mailbox sequence bit API
	40	*/
9ae0ee00	41
9ae0ee00 HD	42	/* seq_rcv should be initialized with any value other than
	43	* 0 and 1 << 31, to allow either value for the first
	44	* message. */
	45	static inline void mbox_seq_init(struct omap_mbox *mbox)
	46	{
7a781afd HD	47	if (!enable_seq_bit)
	48	return;
	49
9ae0ee00 HD	50	/* any value other than 0 and 1 << 31 */
	51	mbox->seq_rcv = 0xffffffff;
	52	}
	53
	54	static inline void mbox_seq_toggle(struct omap_mbox mbox, mbox_msg_t msg)
	55	{
7a781afd HD	56	if (!enable_seq_bit)
	57	return;
	58
9ae0ee00 HD	59	/* add seq_snd to msg */
	60	msg = (msg & 0x7fffffff) \| mbox->seq_snd;
	61	/* flip seq_snd */
	62	mbox->seq_snd ^= 1 << 31;
	63	}
	64
	65	static inline int mbox_seq_test(struct omap_mbox *mbox, mbox_msg_t msg)
	66	{
7a781afd HD	67	mbox_msg_t seq;
	68
	69	if (!enable_seq_bit)
	70	return 0;
	71
	72	seq = msg & (1 << 31);
9ae0ee00 HD	73	if (seq == mbox->seq_rcv)
	74	return -1;
	75	mbox->seq_rcv = seq;
	76	return 0;
	77	}
9ae0ee00 HD	78
	79	/* Mailbox FIFO handle functions */
	80	static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
	81	{
	82	return mbox->ops->fifo_read(mbox);
	83	}
	84	static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
	85	{
	86	mbox->ops->fifo_write(mbox, msg);
	87	}
	88	static inline int mbox_fifo_empty(struct omap_mbox *mbox)
	89	{
	90	return mbox->ops->fifo_empty(mbox);
	91	}
	92	static inline int mbox_fifo_full(struct omap_mbox *mbox)
	93	{
	94	return mbox->ops->fifo_full(mbox);
	95	}
	96
	97	/* Mailbox IRQ handle functions */
	98	static inline void enable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	99	{
	100	mbox->ops->enable_irq(mbox, irq);
	101	}
	102	static inline void disable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	103	{
	104	mbox->ops->disable_irq(mbox, irq);
	105	}
	106	static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	107	{
	108	if (mbox->ops->ack_irq)
	109	mbox->ops->ack_irq(mbox, irq);
	110	}
	111	static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
	112	{
	113	return mbox->ops->is_irq(mbox, irq);
	114	}
	115
340a614a HD	116	/* Mailbox Sequence Bit function */
	117	void omap_mbox_init_seq(struct omap_mbox *mbox)
	118	{
	119	mbox_seq_init(mbox);
	120	}
	121	EXPORT_SYMBOL(omap_mbox_init_seq);
	122
	123	/*
	124	* message sender
	125	*/
	126	static int __mbox_msg_send(struct omap_mbox mbox, mbox_msg_t msg, void arg)
	127	{
	128	int ret = 0, i = 1000;
	129
	130	while (mbox_fifo_full(mbox)) {
	131	if (mbox->ops->type == OMAP_MBOX_TYPE2)
	132	return -1;
	133	if (--i == 0)
	134	return -1;
	135	udelay(1);
	136	}
	137
	138	if (arg && mbox->txq->callback) {
	139	ret = mbox->txq->callback(arg);
	140	if (ret)
	141	goto out;
	142	}
	143
	144	mbox_seq_toggle(mbox, &msg);
	145	mbox_fifo_write(mbox, msg);
	146	out:
	147	return ret;
	148	}
	149
	150	int omap_mbox_msg_send(struct omap_mbox mbox, mbox_msg_t msg, void arg)
	151	{
	152	struct request *rq;
	153	struct request_queue *q = mbox->txq->queue;
	154	int ret = 0;
	155
	156	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	157	if (unlikely(!rq)) {
	158	ret = -ENOMEM;
	159	goto fail;
	160	}
	161
	162	rq->data = (void *)msg;
	163	blk_insert_request(q, rq, 0, arg);
	164
	165	schedule_work(&mbox->txq->work);
	166	fail:
	167	return ret;
	168	}
	169	EXPORT_SYMBOL(omap_mbox_msg_send);
	170
	171	static void mbox_tx_work(struct work_struct *work)
	172	{
	173	int ret;
	174	struct request *rq;
	175	struct omap_mbox_queue *mq = container_of(work,
	176	struct omap_mbox_queue, work);
	177	struct omap_mbox *mbox = mq->queue->queuedata;
	178	struct request_queue *q = mbox->txq->queue;
	179
180	while (1) {
181	spin_lock(q->queue_lock);
182	rq = elv_next_request(q);
183	spin_unlock(q->queue_lock);
184
185	if (!rq)
186	break;
187
188	ret = __mbox_msg_send(mbox, (mbox_msg_t) rq->data, rq->special);
189	if (ret) {
190	enable_mbox_irq(mbox, IRQ_TX);
191	return;
192	}
193
194	spin_lock(q->queue_lock);
40cbbb78	195	__blk_end_request_all(rq, 0);
340a614a HD	196	spin_unlock(q->queue_lock);
	197	}
	198	}
	199
	200	/*
	201	* Message receiver(workqueue)
	202	*/
	203	static void mbox_rx_work(struct work_struct *work)
	204	{
	205	struct omap_mbox_queue *mq =
	206	container_of(work, struct omap_mbox_queue, work);
	207	struct omap_mbox *mbox = mq->queue->queuedata;
	208	struct request_queue *q = mbox->rxq->queue;
	209	struct request *rq;
	210	mbox_msg_t msg;
	211	unsigned long flags;
	212
	213	if (mbox->rxq->callback == NULL) {
f48cca87	214	sysfs_notify(&mbox->dev->kobj, NULL, "mbox");
340a614a HD	215	return;
	216	}
	217
	218	while (1) {
	219	spin_lock_irqsave(q->queue_lock, flags);
	220	rq = elv_next_request(q);
	221	spin_unlock_irqrestore(q->queue_lock, flags);
	222	if (!rq)
	223	break;
	224
	225	msg = (mbox_msg_t) rq->data;
40cbbb78	226	blk_end_request_all(rq, 0);
340a614a HD	227	mbox->rxq->callback((void *)msg);
	228	}
	229	}
	230
	231	/*
	232	* Mailbox interrupt handler
	233	*/
165125e1	234	static void mbox_txq_fn(struct request_queue * q)
340a614a HD	235	{
	236	}
	237
165125e1	238	static void mbox_rxq_fn(struct request_queue * q)
340a614a HD	239	{
	240	}
	241
	242	static void __mbox_tx_interrupt(struct omap_mbox *mbox)
	243	{
	244	disable_mbox_irq(mbox, IRQ_TX);
	245	ack_mbox_irq(mbox, IRQ_TX);
	246	schedule_work(&mbox->txq->work);
	247	}
	248
	249	static void __mbox_rx_interrupt(struct omap_mbox *mbox)
	250	{
	251	struct request *rq;
	252	mbox_msg_t msg;
165125e1	253	struct request_queue *q = mbox->rxq->queue;
340a614a HD	254
	255	disable_mbox_irq(mbox, IRQ_RX);
	256
	257	while (!mbox_fifo_empty(mbox)) {
	258	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	259	if (unlikely(!rq))
	260	goto nomem;
	261
	262	msg = mbox_fifo_read(mbox);
	263	rq->data = (void *)msg;
	264
	265	if (unlikely(mbox_seq_test(mbox, msg))) {
	266	pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
	267	if (mbox->err_notify)
	268	mbox->err_notify();
	269	}
	270
	271	blk_insert_request(q, rq, 0, NULL);
	272	if (mbox->ops->type == OMAP_MBOX_TYPE1)
	273	break;
	274	}
	275
	276	/* no more messages in the fifo. clear IRQ source. */
	277	ack_mbox_irq(mbox, IRQ_RX);
	278	enable_mbox_irq(mbox, IRQ_RX);
f48cca87	279	nomem:
340a614a HD	280	schedule_work(&mbox->rxq->work);
	281	}
	282
	283	static irqreturn_t mbox_interrupt(int irq, void *p)
	284	{
2a7057e3	285	struct omap_mbox *mbox = p;
340a614a HD	286
	287	if (is_mbox_irq(mbox, IRQ_TX))
	288	__mbox_tx_interrupt(mbox);
	289
	290	if (is_mbox_irq(mbox, IRQ_RX))
	291	__mbox_rx_interrupt(mbox);
	292
	293	return IRQ_HANDLED;
	294	}
	295
	296	/*
	297	* sysfs files
	298	*/
	299	static ssize_t
	300	omap_mbox_write(struct device dev, struct device_attribute attr,
	301	const char * buf, size_t count)
	302	{
	303	int ret;
	304	mbox_msg_t p = (mbox_msg_t )buf;
	305	struct omap_mbox *mbox = dev_get_drvdata(dev);
	306
	307	for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) {
	308	ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL);
	309	if (ret)
	310	return -EAGAIN;
	311	p++;
	312	}
	313
	314	return (size_t)((char *)p - buf);
	315	}
	316
	317	static ssize_t
	318	omap_mbox_read(struct device dev, struct device_attribute attr, char *buf)
	319	{
	320	unsigned long flags;
	321	struct request *rq;
	322	mbox_msg_t p = (mbox_msg_t ) buf;
	323	struct omap_mbox *mbox = dev_get_drvdata(dev);
	324	struct request_queue *q = mbox->rxq->queue;
	325
	326	while (1) {
	327	spin_lock_irqsave(q->queue_lock, flags);
	328	rq = elv_next_request(q);
	329	spin_unlock_irqrestore(q->queue_lock, flags);
	330
	331	if (!rq)
	332	break;
	333
	334	*p = (mbox_msg_t) rq->data;
	335
40cbbb78	336	blk_end_request_all(rq, 0);
340a614a HD	337
	338	if (unlikely(mbox_seq_test(mbox, *p))) {
	339	pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
	340	continue;
	341	}
	342	p++;
	343	}
	344
	345	pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]);
	346
	347	return (size_t) ((char *)p - buf);
	348	}
	349
	350	static DEVICE_ATTR(mbox, S_IRUGO \| S_IWUSR, omap_mbox_read, omap_mbox_write);
	351
	352	static ssize_t mbox_show(struct class class, char buf)
	353	{
	354	return sprintf(buf, "mbox");
	355	}
	356
	357	static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);
	358
	359	static struct class omap_mbox_class = {
f48cca87	360	.name = "omap-mailbox",
340a614a HD	361	};
	362
	363	static struct omap_mbox_queue mbox_queue_alloc(struct omap_mbox mbox,
	364	request_fn_proc * proc,
	365	void (work) (struct work_struct ))
	366	{
165125e1	367	struct request_queue *q;
340a614a HD	368	struct omap_mbox_queue *mq;
	369
	370	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
	371	if (!mq)
	372	return NULL;
	373
	374	spin_lock_init(&mq->lock);
	375
	376	q = blk_init_queue(proc, &mq->lock);
	377	if (!q)
	378	goto error;
	379	q->queuedata = mbox;
	380	mq->queue = q;
	381
	382	INIT_WORK(&mq->work, work);
	383
	384	return mq;
	385	error:
	386	kfree(mq);
	387	return NULL;
	388	}
	389
	390	static void mbox_queue_free(struct omap_mbox_queue *q)
	391	{
	392	blk_cleanup_queue(q->queue);
	393	kfree(q);
	394	}
	395
	396	static int omap_mbox_init(struct omap_mbox *mbox)
	397	{
	398	int ret;
	399	struct omap_mbox_queue *mq;
	400
	401	if (likely(mbox->ops->startup)) {
	402	ret = mbox->ops->startup(mbox);
	403	if (unlikely(ret))
	404	return ret;
	405	}
	406
340a614a HD	407	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED,
	408	mbox->name, mbox);
	409	if (unlikely(ret)) {
	410	printk(KERN_ERR
	411	"failed to register mailbox interrupt:%d\n", ret);
	412	goto fail_request_irq;
	413	}
340a614a HD	414
	415	mq = mbox_queue_alloc(mbox, mbox_txq_fn, mbox_tx_work);
	416	if (!mq) {
	417	ret = -ENOMEM;
	418	goto fail_alloc_txq;
	419	}
	420	mbox->txq = mq;
	421
	422	mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
	423	if (!mq) {
	424	ret = -ENOMEM;
	425	goto fail_alloc_rxq;
	426	}
	427	mbox->rxq = mq;
	428
	429	return 0;
	430
	431	fail_alloc_rxq:
	432	mbox_queue_free(mbox->txq);
	433	fail_alloc_txq:
	434	free_irq(mbox->irq, mbox);
	435	fail_request_irq:
340a614a HD	436	if (unlikely(mbox->ops->shutdown))
	437	mbox->ops->shutdown(mbox);
	438
	439	return ret;
	440	}
	441
	442	static void omap_mbox_fini(struct omap_mbox *mbox)
	443	{
	444	mbox_queue_free(mbox->txq);
	445	mbox_queue_free(mbox->rxq);
	446
	447	free_irq(mbox->irq, mbox);
340a614a HD	448
	449	if (unlikely(mbox->ops->shutdown))
	450	mbox->ops->shutdown(mbox);
	451	}
	452
	453	static struct omap_mbox *find_mboxes(const char name)
	454	{
	455	struct omap_mbox **p;
	456
	457	for (p = &mboxes; p; p = &(p)->next) {
	458	if (strcmp((*p)->name, name) == 0)
	459	break;
	460	}
	461
	462	return p;
	463	}
	464
	465	struct omap_mbox omap_mbox_get(const char name)
	466	{
	467	struct omap_mbox *mbox;
	468	int ret;
	469
	470	read_lock(&mboxes_lock);
	471	mbox = *(find_mboxes(name));
	472	if (mbox == NULL) {
	473	read_unlock(&mboxes_lock);
	474	return ERR_PTR(-ENOENT);
	475	}
	476
	477	read_unlock(&mboxes_lock);
	478
	479	ret = omap_mbox_init(mbox);
	480	if (ret)
	481	return ERR_PTR(-ENODEV);
	482
	483	return mbox;
	484	}
	485	EXPORT_SYMBOL(omap_mbox_get);
	486
	487	void omap_mbox_put(struct omap_mbox *mbox)
	488	{
	489	omap_mbox_fini(mbox);
	490	}
	491	EXPORT_SYMBOL(omap_mbox_put);
	492
f48cca87	493	int omap_mbox_register(struct device parent, struct omap_mbox mbox)
340a614a HD	494	{
	495	int ret = 0;
	496	struct omap_mbox **tmp;
	497
	498	if (!mbox)
	499	return -EINVAL;
	500	if (mbox->next)
	501	return -EBUSY;
	502
f48cca87 HD	503	mbox->dev = device_create(&omap_mbox_class,
	504	parent, 0, mbox, "%s", mbox->name);
	505	if (IS_ERR(mbox->dev))
	506	return PTR_ERR(mbox->dev);
	507
	508	ret = device_create_file(mbox->dev, &dev_attr_mbox);
	509	if (ret)
	510	goto err_sysfs;
	511
340a614a HD	512	write_lock(&mboxes_lock);
340a614a HD	513	tmp = find_mboxes(mbox->name);
f48cca87	514	if (*tmp) {
340a614a	515	ret = -EBUSY;
f48cca87 HD	516	write_unlock(&mboxes_lock);
	517	goto err_find;
	518	}
	519	*tmp = mbox;
340a614a HD	520	write_unlock(&mboxes_lock);
340a614a HD	521
f48cca87 HD	522	return 0;
	523
	524	err_find:
	525	device_remove_file(mbox->dev, &dev_attr_mbox);
	526	err_sysfs:
	527	device_unregister(mbox->dev);
340a614a HD	528	return ret;
	529	}
	530	EXPORT_SYMBOL(omap_mbox_register);
	531
	532	int omap_mbox_unregister(struct omap_mbox *mbox)
	533	{
	534	struct omap_mbox **tmp;
	535
	536	write_lock(&mboxes_lock);
	537	tmp = &mboxes;
	538	while (*tmp) {
	539	if (mbox == *tmp) {
	540	*tmp = mbox->next;
	541	mbox->next = NULL;
	542	write_unlock(&mboxes_lock);
f48cca87 HD	543	device_remove_file(mbox->dev, &dev_attr_mbox);
f48cca87 HD	544	device_unregister(mbox->dev);
340a614a HD	545	return 0;
	546	}
	547	tmp = &(*tmp)->next;
	548	}
	549	write_unlock(&mboxes_lock);
	550
	551	return -EINVAL;
	552	}
	553	EXPORT_SYMBOL(omap_mbox_unregister);
	554
	555	static int __init omap_mbox_class_init(void)
	556	{
	557	int ret = class_register(&omap_mbox_class);
	558	if (!ret)
	559	ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
	560
	561	return ret;
	562	}
	563
	564	static void __exit omap_mbox_class_exit(void)
	565	{
	566	class_remove_file(&omap_mbox_class, &class_attr_mbox);
	567	class_unregister(&omap_mbox_class);
	568	}
	569
	570	subsys_initcall(omap_mbox_class_init);
	571	module_exit(omap_mbox_class_exit);
	572
f48cca87 HD	573	MODULE_LICENSE("GPL v2");
	574	MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
	575	MODULE_AUTHOR("Toshihiro Kobayashi and Hiroshi DOYU");