/*
* 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 <linux/slab.h>
#include <plat/mailbox.h>
static struct workqueue_struct *mboxd;
static struct omap_mbox *mboxes;
static DEFINE_RWLOCK(mboxes_lock);
static int mbox_configured;
/* 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_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
{
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);
}
mbox_fifo_write(mbox, msg);
return ret;
}
int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
{
struct request *rq;
struct request_queue *q = mbox->txq->queue;
rq = blk_get_request(q, WRITE, GFP_ATOMIC);
if (unlikely(!rq))
return -ENOMEM;
blk_insert_request(q, rq, 0, (void *) msg);
tasklet_schedule(&mbox->txq->tasklet);
return 0;
}
EXPORT_SYMBOL(omap_mbox_msg_send);
static void mbox_tx_tasklet(unsigned long tx_data)
{
int ret;
struct request *rq;
struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
struct request_queue *q = mbox->txq->queue;
while (1) {
rq = blk_fetch_request(q);
if (!rq)
break;
ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
if (ret) {
omap_mbox_enable_irq(mbox, IRQ_TX);
blk_requeue_request(q, rq);
return;
}
blk_end_request_all(rq, 0);
}
}
/*
* 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;
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)
{
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 request *rq;
mbox_msg_t msg;
struct request_queue *q = mbox->rxq->queue;
while (!mbox_fifo_empty(mbox)) {
rq = blk_get_request(q, WRITE, GFP_ATOMIC);
if (unlikely(!rq))
goto nomem;
msg = mbox_fifo_read(mbox);
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);
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,
request_fn_proc *proc,
void (*work) (struct work_struct *),
void (*tasklet)(unsigned long))
{
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;
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)
{
blk_cleanup_queue(q->queue);
kfree(q);
}
static int omap_mbox_startup(struct omap_mbox *mbox)
{
int ret = 0;
struct omap_mbox_queue *mq;
if (likely(mbox->ops->startup)) {
write_lock(&mboxes_lock);
if (!mbox_configured)
ret = mbox->ops->startup(mbox);
if (unlikely(ret)) {
write_unlock(&mboxes_lock);
return ret;
}
mbox_configured++;
write_unlock(&mboxes_lock);
}
ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
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, NULL, mbox_tx_tasklet);
if (!mq) {
ret = -ENOMEM;
goto fail_alloc_txq;
}
mbox->txq = mq;
mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work, NULL);
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)) {
write_lock(&mboxes_lock);
if (mbox_configured > 0)
mbox_configured--;
if (!mbox_configured)
mbox->ops->shutdown(mbox);
write_unlock(&mboxes_lock);
}
}
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_startup(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;
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:
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_init(void)
{
mboxd = create_workqueue("mboxd");
if (!mboxd)
return -ENOMEM;
return 0;
}
module_init(omap_mbox_init);
static void __exit omap_mbox_exit(void)
{
destroy_workqueue(mboxd);
}
module_exit(omap_mbox_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
MODULE_AUTHOR("Toshihiro Kobayashi and Hiroshi DOYU");
