[linux-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 <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;
}

struct omap_msg_tx_data {
	mbox_msg_t	msg;
	void		*arg;
};

static void omap_msg_tx_end_io(struct request *rq, int error)
{
	kfree(rq->special);
	__blk_put_request(rq->q, rq);
}

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

	tx_data = kmalloc(sizeof(*tx_data), GFP_ATOMIC);
	if (unlikely(!tx_data))
		return -ENOMEM;

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

	tx_data->msg = msg;
	tx_data->arg = arg;
	rq->end_io = omap_msg_tx_end_io;
	blk_insert_request(q, rq, 0, tx_data);

	schedule_work(&mbox->txq->work);
	return 0;
}
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) {
		struct omap_msg_tx_data *tx_data;

		spin_lock(q->queue_lock);
		rq = blk_fetch_request(q);
		spin_unlock(q->queue_lock);

		if (!rq)
			break;

		tx_data = rq->special;

		ret = __mbox_msg_send(mbox, tx_data->msg, tx_data->arg);
		if (ret) {
			enable_mbox_irq(mbox, IRQ_TX);
			spin_lock(q->queue_lock);
			blk_requeue_request(q, rq);
			spin_unlock(q->queue_lock);
			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 = 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)
{
	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);

		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, (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);
	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 = blk_fetch_request(q);
		spin_unlock_irqrestore(q->queue_lock, flags);

		if (!rq)
			break;

		*p = (mbox_msg_t)rq->special;

		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
ec24751a TH	150	struct omap_msg_tx_data {
	151	mbox_msg_t msg;
	152	void *arg;
	153	};
	154
	155	static void omap_msg_tx_end_io(struct request *rq, int error)
	156	{
	157	kfree(rq->special);
	158	__blk_put_request(rq->q, rq);
	159	}
	160
340a614a HD	161	int omap_mbox_msg_send(struct omap_mbox mbox, mbox_msg_t msg, void arg)
340a614a HD	162	{
ec24751a	163	struct omap_msg_tx_data *tx_data;
340a614a HD	164	struct request *rq;
340a614a HD	165	struct request_queue *q = mbox->txq->queue;
ec24751a TH	166
	167	tx_data = kmalloc(sizeof(*tx_data), GFP_ATOMIC);
	168	if (unlikely(!tx_data))
	169	return -ENOMEM;
340a614a HD	170
	171	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	172	if (unlikely(!rq)) {
ec24751a TH	173	kfree(tx_data);
ec24751a TH	174	return -ENOMEM;
340a614a HD	175	}
340a614a HD	176
ec24751a TH	177	tx_data->msg = msg;
	178	tx_data->arg = arg;
	179	rq->end_io = omap_msg_tx_end_io;
	180	blk_insert_request(q, rq, 0, tx_data);
340a614a HD	181
340a614a HD	182	schedule_work(&mbox->txq->work);
ec24751a	183	return 0;
340a614a HD	184	}
	185	EXPORT_SYMBOL(omap_mbox_msg_send);
	186
	187	static void mbox_tx_work(struct work_struct *work)
	188	{
	189	int ret;
	190	struct request *rq;
	191	struct omap_mbox_queue *mq = container_of(work,
	192	struct omap_mbox_queue, work);
	193	struct omap_mbox *mbox = mq->queue->queuedata;
	194	struct request_queue *q = mbox->txq->queue;
	195
	196	while (1) {
ec24751a TH	197	struct omap_msg_tx_data *tx_data;
ec24751a TH	198
340a614a	199	spin_lock(q->queue_lock);
9934c8c0	200	rq = blk_fetch_request(q);
340a614a HD	201	spin_unlock(q->queue_lock);
	202
	203	if (!rq)
	204	break;
	205
ec24751a TH	206	tx_data = rq->special;
	207
	208	ret = __mbox_msg_send(mbox, tx_data->msg, tx_data->arg);
340a614a HD	209	if (ret) {
340a614a HD	210	enable_mbox_irq(mbox, IRQ_TX);
296b2f6a TH	211	spin_lock(q->queue_lock);
	212	blk_requeue_request(q, rq);
	213	spin_unlock(q->queue_lock);
340a614a HD	214	return;
	215	}
	216
	217	spin_lock(q->queue_lock);
40cbbb78	218	__blk_end_request_all(rq, 0);
340a614a HD	219	spin_unlock(q->queue_lock);
	220	}
	221	}
	222
	223	/*
	224	* Message receiver(workqueue)
	225	*/
	226	static void mbox_rx_work(struct work_struct *work)
	227	{
	228	struct omap_mbox_queue *mq =
	229	container_of(work, struct omap_mbox_queue, work);
	230	struct omap_mbox *mbox = mq->queue->queuedata;
	231	struct request_queue *q = mbox->rxq->queue;
	232	struct request *rq;
	233	mbox_msg_t msg;
	234	unsigned long flags;
	235
	236	if (mbox->rxq->callback == NULL) {
f48cca87	237	sysfs_notify(&mbox->dev->kobj, NULL, "mbox");
340a614a HD	238	return;
	239	}
	240
	241	while (1) {
	242	spin_lock_irqsave(q->queue_lock, flags);
9934c8c0	243	rq = blk_fetch_request(q);
340a614a HD	244	spin_unlock_irqrestore(q->queue_lock, flags);
	245	if (!rq)
	246	break;
	247
ec24751a	248	msg = (mbox_msg_t)rq->special;
40cbbb78	249	blk_end_request_all(rq, 0);
340a614a HD	250	mbox->rxq->callback((void *)msg);
	251	}
	252	}
	253
	254	/*
	255	* Mailbox interrupt handler
	256	*/
165125e1	257	static void mbox_txq_fn(struct request_queue * q)
340a614a HD	258	{
	259	}
	260
165125e1	261	static void mbox_rxq_fn(struct request_queue * q)
340a614a HD	262	{
	263	}
	264
	265	static void __mbox_tx_interrupt(struct omap_mbox *mbox)
	266	{
	267	disable_mbox_irq(mbox, IRQ_TX);
	268	ack_mbox_irq(mbox, IRQ_TX);
	269	schedule_work(&mbox->txq->work);
	270	}
	271
	272	static void __mbox_rx_interrupt(struct omap_mbox *mbox)
	273	{
	274	struct request *rq;
	275	mbox_msg_t msg;
165125e1	276	struct request_queue *q = mbox->rxq->queue;
340a614a HD	277
	278	disable_mbox_irq(mbox, IRQ_RX);
	279
	280	while (!mbox_fifo_empty(mbox)) {
	281	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
	282	if (unlikely(!rq))
	283	goto nomem;
	284
	285	msg = mbox_fifo_read(mbox);
340a614a HD	286
	287	if (unlikely(mbox_seq_test(mbox, msg))) {
	288	pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
	289	if (mbox->err_notify)
	290	mbox->err_notify();
	291	}
	292
ec24751a	293	blk_insert_request(q, rq, 0, (void *)msg);
340a614a HD	294	if (mbox->ops->type == OMAP_MBOX_TYPE1)
	295	break;
	296	}
	297
	298	/* no more messages in the fifo. clear IRQ source. */
	299	ack_mbox_irq(mbox, IRQ_RX);
	300	enable_mbox_irq(mbox, IRQ_RX);
f48cca87	301	nomem:
340a614a HD	302	schedule_work(&mbox->rxq->work);
	303	}
	304
	305	static irqreturn_t mbox_interrupt(int irq, void *p)
	306	{
2a7057e3	307	struct omap_mbox *mbox = p;
340a614a HD	308
	309	if (is_mbox_irq(mbox, IRQ_TX))
	310	__mbox_tx_interrupt(mbox);
	311
	312	if (is_mbox_irq(mbox, IRQ_RX))
	313	__mbox_rx_interrupt(mbox);
	314
	315	return IRQ_HANDLED;
	316	}
	317
	318	/*
	319	* sysfs files
	320	*/
	321	static ssize_t
	322	omap_mbox_write(struct device dev, struct device_attribute attr,
	323	const char * buf, size_t count)
	324	{
	325	int ret;
	326	mbox_msg_t p = (mbox_msg_t )buf;
	327	struct omap_mbox *mbox = dev_get_drvdata(dev);
	328
	329	for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) {
	330	ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL);
	331	if (ret)
	332	return -EAGAIN;
	333	p++;
	334	}
	335
	336	return (size_t)((char *)p - buf);
	337	}
	338
	339	static ssize_t
	340	omap_mbox_read(struct device dev, struct device_attribute attr, char *buf)
	341	{
	342	unsigned long flags;
	343	struct request *rq;
	344	mbox_msg_t p = (mbox_msg_t ) buf;
	345	struct omap_mbox *mbox = dev_get_drvdata(dev);
	346	struct request_queue *q = mbox->rxq->queue;
	347
	348	while (1) {
	349	spin_lock_irqsave(q->queue_lock, flags);
9934c8c0	350	rq = blk_fetch_request(q);
340a614a HD	351	spin_unlock_irqrestore(q->queue_lock, flags);
	352
	353	if (!rq)
	354	break;
	355
ec24751a	356	*p = (mbox_msg_t)rq->special;
340a614a	357
40cbbb78	358	blk_end_request_all(rq, 0);
340a614a HD	359
	360	if (unlikely(mbox_seq_test(mbox, *p))) {
	361	pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
	362	continue;
	363	}
	364	p++;
	365	}
	366
	367	pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]);
	368
	369	return (size_t) ((char *)p - buf);
	370	}
	371
	372	static DEVICE_ATTR(mbox, S_IRUGO \| S_IWUSR, omap_mbox_read, omap_mbox_write);
	373
	374	static ssize_t mbox_show(struct class class, char buf)
	375	{
	376	return sprintf(buf, "mbox");
	377	}
	378
	379	static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);
	380
	381	static struct class omap_mbox_class = {
f48cca87	382	.name = "omap-mailbox",
340a614a HD	383	};
	384
	385	static struct omap_mbox_queue mbox_queue_alloc(struct omap_mbox mbox,
	386	request_fn_proc * proc,
	387	void (work) (struct work_struct ))
	388	{
165125e1	389	struct request_queue *q;
340a614a HD	390	struct omap_mbox_queue *mq;
	391
	392	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
	393	if (!mq)
	394	return NULL;
	395
	396	spin_lock_init(&mq->lock);
	397
	398	q = blk_init_queue(proc, &mq->lock);
	399	if (!q)
	400	goto error;
	401	q->queuedata = mbox;
	402	mq->queue = q;
	403
	404	INIT_WORK(&mq->work, work);
	405
	406	return mq;
	407	error:
	408	kfree(mq);
	409	return NULL;
	410	}
	411
	412	static void mbox_queue_free(struct omap_mbox_queue *q)
	413	{
	414	blk_cleanup_queue(q->queue);
	415	kfree(q);
	416	}
	417
	418	static int omap_mbox_init(struct omap_mbox *mbox)
	419	{
	420	int ret;
	421	struct omap_mbox_queue *mq;
	422
	423	if (likely(mbox->ops->startup)) {
	424	ret = mbox->ops->startup(mbox);
	425	if (unlikely(ret))
	426	return ret;
	427	}
	428
340a614a HD	429	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED,
	430	mbox->name, mbox);
	431	if (unlikely(ret)) {
	432	printk(KERN_ERR
	433	"failed to register mailbox interrupt:%d\n", ret);
	434	goto fail_request_irq;
	435	}
340a614a HD	436
	437	mq = mbox_queue_alloc(mbox, mbox_txq_fn, mbox_tx_work);
	438	if (!mq) {
	439	ret = -ENOMEM;
	440	goto fail_alloc_txq;
	441	}
	442	mbox->txq = mq;
	443
	444	mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
	445	if (!mq) {
	446	ret = -ENOMEM;
	447	goto fail_alloc_rxq;
	448	}
	449	mbox->rxq = mq;
	450
	451	return 0;
	452
	453	fail_alloc_rxq:
	454	mbox_queue_free(mbox->txq);
	455	fail_alloc_txq:
	456	free_irq(mbox->irq, mbox);
	457	fail_request_irq:
340a614a HD	458	if (unlikely(mbox->ops->shutdown))
	459	mbox->ops->shutdown(mbox);
	460
	461	return ret;
	462	}
	463
	464	static void omap_mbox_fini(struct omap_mbox *mbox)
	465	{
	466	mbox_queue_free(mbox->txq);
	467	mbox_queue_free(mbox->rxq);
	468
	469	free_irq(mbox->irq, mbox);
340a614a HD	470
	471	if (unlikely(mbox->ops->shutdown))
	472	mbox->ops->shutdown(mbox);
	473	}
	474
	475	static struct omap_mbox *find_mboxes(const char name)
	476	{
	477	struct omap_mbox **p;
	478
	479	for (p = &mboxes; p; p = &(p)->next) {
	480	if (strcmp((*p)->name, name) == 0)
	481	break;
	482	}
	483
	484	return p;
	485	}
	486
	487	struct omap_mbox omap_mbox_get(const char name)
	488	{
	489	struct omap_mbox *mbox;
	490	int ret;
	491
	492	read_lock(&mboxes_lock);
	493	mbox = *(find_mboxes(name));
	494	if (mbox == NULL) {
	495	read_unlock(&mboxes_lock);
	496	return ERR_PTR(-ENOENT);
	497	}
	498
	499	read_unlock(&mboxes_lock);
	500
	501	ret = omap_mbox_init(mbox);
	502	if (ret)
	503	return ERR_PTR(-ENODEV);
	504
	505	return mbox;
	506	}
	507	EXPORT_SYMBOL(omap_mbox_get);
	508
	509	void omap_mbox_put(struct omap_mbox *mbox)
	510	{
	511	omap_mbox_fini(mbox);
	512	}
	513	EXPORT_SYMBOL(omap_mbox_put);
	514
f48cca87	515	int omap_mbox_register(struct device parent, struct omap_mbox mbox)
340a614a HD	516	{
	517	int ret = 0;
	518	struct omap_mbox **tmp;
	519
	520	if (!mbox)
	521	return -EINVAL;
	522	if (mbox->next)
	523	return -EBUSY;
	524
f48cca87 HD	525	mbox->dev = device_create(&omap_mbox_class,
	526	parent, 0, mbox, "%s", mbox->name);
	527	if (IS_ERR(mbox->dev))
	528	return PTR_ERR(mbox->dev);
	529
	530	ret = device_create_file(mbox->dev, &dev_attr_mbox);
	531	if (ret)
	532	goto err_sysfs;
	533
340a614a HD	534	write_lock(&mboxes_lock);
340a614a HD	535	tmp = find_mboxes(mbox->name);
f48cca87	536	if (*tmp) {
340a614a	537	ret = -EBUSY;
f48cca87 HD	538	write_unlock(&mboxes_lock);
	539	goto err_find;
	540	}
	541	*tmp = mbox;
340a614a HD	542	write_unlock(&mboxes_lock);
340a614a HD	543
f48cca87 HD	544	return 0;
	545
	546	err_find:
	547	device_remove_file(mbox->dev, &dev_attr_mbox);
	548	err_sysfs:
	549	device_unregister(mbox->dev);
340a614a HD	550	return ret;
	551	}
	552	EXPORT_SYMBOL(omap_mbox_register);
	553
	554	int omap_mbox_unregister(struct omap_mbox *mbox)
	555	{
	556	struct omap_mbox **tmp;
	557
	558	write_lock(&mboxes_lock);
	559	tmp = &mboxes;
	560	while (*tmp) {
	561	if (mbox == *tmp) {
	562	*tmp = mbox->next;
	563	mbox->next = NULL;
	564	write_unlock(&mboxes_lock);
f48cca87 HD	565	device_remove_file(mbox->dev, &dev_attr_mbox);
f48cca87 HD	566	device_unregister(mbox->dev);
340a614a HD	567	return 0;
	568	}
	569	tmp = &(*tmp)->next;
	570	}
	571	write_unlock(&mboxes_lock);
	572
	573	return -EINVAL;
	574	}
	575	EXPORT_SYMBOL(omap_mbox_unregister);
	576
	577	static int __init omap_mbox_class_init(void)
	578	{
	579	int ret = class_register(&omap_mbox_class);
	580	if (!ret)
	581	ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
	582
	583	return ret;
	584	}
	585
	586	static void __exit omap_mbox_class_exit(void)
	587	{
	588	class_remove_file(&omap_mbox_class, &class_attr_mbox);
	589	class_unregister(&omap_mbox_class);
	590	}
	591
	592	subsys_initcall(omap_mbox_class_init);
	593	module_exit(omap_mbox_class_exit);
	594
f48cca87 HD	595	MODULE_LICENSE("GPL v2");
	596	MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
	597	MODULE_AUTHOR("Toshihiro Kobayashi and Hiroshi DOYU");