linux/arch/arm/plat-omap/mailbox.c

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/*
* OMAP mailbox driver
*
* Copyright (C) 2006 Nokia Corporation. All rights reserved.
*
* Contact: Toshihiro Kobayashi <toshihiro.kobayashi@nokia.com>
* Restructured by 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/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/blkdev.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/arch/mailbox.h>
#include "mailbox.h"
static struct omap_mbox *mboxes;
static DEFINE_RWLOCK(mboxes_lock);
/* 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);
blkdev_dequeue_request(rq);
end_that_request_last(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;
spin_lock_irqsave(q->queue_lock, flags);
blkdev_dequeue_request(rq);
end_that_request_last(rq, 0);
spin_unlock_irqrestore(q->queue_lock, flags);
mbox->rxq->callback((void *)msg);
}
}
/*
* Mailbox interrupt handler
*/
static void mbox_txq_fn(request_queue_t * q)
{
}
static void mbox_rxq_fn(request_queue_t * 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;
request_queue_t *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 = (struct omap_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;
spin_lock_irqsave(q->queue_lock, flags);
blkdev_dequeue_request(rq);
end_that_request_last(rq, 0);
spin_unlock_irqrestore(q->queue_lock, flags);
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_mbox",
};
static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
request_fn_proc * proc,
void (*work) (struct work_struct *))
{
request_queue_t *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;
}
mbox->dev.class = &omap_mbox_class;
strlcpy(mbox->dev.bus_id, mbox->name, KOBJ_NAME_LEN);
dev_set_drvdata(&mbox->dev, mbox);
ret = device_register(&mbox->dev);
if (unlikely(ret))
goto fail_device_reg;
ret = device_create_file(&mbox->dev, &dev_attr_mbox);
if (unlikely(ret)) {
printk(KERN_ERR
"device_create_file failed: %d\n", ret);
goto fail_create_mbox;
}
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;
}
enable_mbox_irq(mbox, IRQ_RX);
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:
device_remove_file(&mbox->dev, &dev_attr_mbox);
fail_create_mbox:
device_unregister(&mbox->dev);
fail_device_reg:
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);
device_remove_file(&mbox->dev, &dev_attr_mbox);
class_unregister(&omap_mbox_class);
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 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;
else
*tmp = mbox;
write_unlock(&mboxes_lock);
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_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");