linux/drivers/mailbox/omap-mailbox.c

470 lines
10 KiB
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/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 <linux/module.h>
#include "omap-mbox.h"
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);
void omap_mbox_save_ctx(struct omap_mbox *mbox)
{
if (!mbox->ops->save_ctx) {
dev_err(mbox->dev, "%s:\tno save\n", __func__);
return;
}
mbox->ops->save_ctx(mbox);
}
EXPORT_SYMBOL(omap_mbox_save_ctx);
void omap_mbox_restore_ctx(struct omap_mbox *mbox)
{
if (!mbox->ops->restore_ctx) {
dev_err(mbox->dev, "%s:\tno restore\n", __func__);
return;
}
mbox->ops->restore_ctx(mbox);
}
EXPORT_SYMBOL(omap_mbox_restore_ctx);
void omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
mbox->ops->enable_irq(mbox, irq);
}
EXPORT_SYMBOL(omap_mbox_enable_irq);
void omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
mbox->ops->disable_irq(mbox, irq);
}
EXPORT_SYMBOL(omap_mbox_disable_irq);
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:
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;
}
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++) {
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;
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;
}
omap_mbox_enable_irq(mbox, IRQ_RX);
}
mutex_unlock(&mbox_configured_lock);
return 0;
fail_request_irq:
mbox_queue_free(mbox->rxq);
fail_alloc_rxq:
mbox_queue_free(mbox->txq);
fail_alloc_txq:
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) {
omap_mbox_disable_irq(mbox, IRQ_RX);
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);
if (nb)
blocking_notifier_chain_register(&mbox->notifier, nb);
ret = omap_mbox_startup(mbox);
if (ret) {
blocking_notifier_chain_unregister(&mbox->notifier, nb);
return ERR_PTR(-ENODEV);
}
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;
/* 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)
{
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");