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421 lines
8.3 KiB
421 lines
8.3 KiB
/*
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* OMAP mailbox driver
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*
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* Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
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*
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* Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*
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*/
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/device.h>
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#include <linux/delay.h>
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#include <plat/mailbox.h>
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static struct workqueue_struct *mboxd;
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static struct omap_mbox *mboxes;
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static DEFINE_RWLOCK(mboxes_lock);
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static int mbox_configured;
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/* Mailbox FIFO handle functions */
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static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
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{
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return mbox->ops->fifo_read(mbox);
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}
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static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
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{
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mbox->ops->fifo_write(mbox, msg);
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}
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static inline int mbox_fifo_empty(struct omap_mbox *mbox)
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{
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return mbox->ops->fifo_empty(mbox);
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}
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static inline int mbox_fifo_full(struct omap_mbox *mbox)
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{
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return mbox->ops->fifo_full(mbox);
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}
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/* Mailbox IRQ handle functions */
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static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
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{
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if (mbox->ops->ack_irq)
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mbox->ops->ack_irq(mbox, irq);
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}
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static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
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{
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return mbox->ops->is_irq(mbox, irq);
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}
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/*
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* message sender
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*/
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static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
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{
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int ret = 0, i = 1000;
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while (mbox_fifo_full(mbox)) {
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if (mbox->ops->type == OMAP_MBOX_TYPE2)
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return -1;
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if (--i == 0)
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return -1;
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udelay(1);
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}
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mbox_fifo_write(mbox, msg);
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return ret;
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}
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int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
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{
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struct request *rq;
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struct request_queue *q = mbox->txq->queue;
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rq = blk_get_request(q, WRITE, GFP_ATOMIC);
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if (unlikely(!rq))
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return -ENOMEM;
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blk_insert_request(q, rq, 0, (void *) msg);
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tasklet_schedule(&mbox->txq->tasklet);
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return 0;
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}
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EXPORT_SYMBOL(omap_mbox_msg_send);
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static void mbox_tx_tasklet(unsigned long tx_data)
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{
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int ret;
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struct request *rq;
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struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
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struct request_queue *q = mbox->txq->queue;
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while (1) {
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rq = blk_fetch_request(q);
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if (!rq)
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break;
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ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
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if (ret) {
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omap_mbox_enable_irq(mbox, IRQ_TX);
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blk_requeue_request(q, rq);
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return;
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}
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blk_end_request_all(rq, 0);
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}
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}
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/*
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* Message receiver(workqueue)
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*/
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static void mbox_rx_work(struct work_struct *work)
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{
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struct omap_mbox_queue *mq =
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container_of(work, struct omap_mbox_queue, work);
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struct omap_mbox *mbox = mq->queue->queuedata;
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struct request_queue *q = mbox->rxq->queue;
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struct request *rq;
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mbox_msg_t msg;
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unsigned long flags;
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while (1) {
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spin_lock_irqsave(q->queue_lock, flags);
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rq = blk_fetch_request(q);
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spin_unlock_irqrestore(q->queue_lock, flags);
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if (!rq)
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break;
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msg = (mbox_msg_t)rq->special;
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blk_end_request_all(rq, 0);
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mbox->rxq->callback((void *)msg);
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}
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}
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/*
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* Mailbox interrupt handler
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*/
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static void mbox_txq_fn(struct request_queue *q)
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{
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}
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static void mbox_rxq_fn(struct request_queue *q)
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{
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}
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static void __mbox_tx_interrupt(struct omap_mbox *mbox)
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{
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omap_mbox_disable_irq(mbox, IRQ_TX);
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ack_mbox_irq(mbox, IRQ_TX);
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tasklet_schedule(&mbox->txq->tasklet);
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}
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static void __mbox_rx_interrupt(struct omap_mbox *mbox)
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{
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struct request *rq;
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mbox_msg_t msg;
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struct request_queue *q = mbox->rxq->queue;
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while (!mbox_fifo_empty(mbox)) {
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rq = blk_get_request(q, WRITE, GFP_ATOMIC);
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if (unlikely(!rq))
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goto nomem;
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msg = mbox_fifo_read(mbox);
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blk_insert_request(q, rq, 0, (void *)msg);
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if (mbox->ops->type == OMAP_MBOX_TYPE1)
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break;
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}
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/* no more messages in the fifo. clear IRQ source. */
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ack_mbox_irq(mbox, IRQ_RX);
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nomem:
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queue_work(mboxd, &mbox->rxq->work);
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}
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static irqreturn_t mbox_interrupt(int irq, void *p)
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{
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struct omap_mbox *mbox = p;
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if (is_mbox_irq(mbox, IRQ_TX))
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__mbox_tx_interrupt(mbox);
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if (is_mbox_irq(mbox, IRQ_RX))
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__mbox_rx_interrupt(mbox);
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return IRQ_HANDLED;
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}
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static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
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request_fn_proc *proc,
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void (*work) (struct work_struct *),
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void (*tasklet)(unsigned long))
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{
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struct request_queue *q;
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struct omap_mbox_queue *mq;
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mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
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if (!mq)
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return NULL;
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spin_lock_init(&mq->lock);
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q = blk_init_queue(proc, &mq->lock);
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if (!q)
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goto error;
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q->queuedata = mbox;
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mq->queue = q;
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if (work)
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INIT_WORK(&mq->work, work);
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if (tasklet)
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tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
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return mq;
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error:
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kfree(mq);
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return NULL;
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}
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static void mbox_queue_free(struct omap_mbox_queue *q)
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{
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blk_cleanup_queue(q->queue);
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kfree(q);
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}
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static int omap_mbox_startup(struct omap_mbox *mbox)
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{
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int ret = 0;
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struct omap_mbox_queue *mq;
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if (likely(mbox->ops->startup)) {
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write_lock(&mboxes_lock);
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if (!mbox_configured)
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ret = mbox->ops->startup(mbox);
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if (unlikely(ret)) {
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write_unlock(&mboxes_lock);
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return ret;
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}
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mbox_configured++;
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write_unlock(&mboxes_lock);
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}
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ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
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mbox->name, mbox);
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if (unlikely(ret)) {
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printk(KERN_ERR
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"failed to register mailbox interrupt:%d\n", ret);
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goto fail_request_irq;
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}
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mq = mbox_queue_alloc(mbox, mbox_txq_fn, NULL, mbox_tx_tasklet);
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if (!mq) {
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ret = -ENOMEM;
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goto fail_alloc_txq;
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}
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mbox->txq = mq;
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mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work, NULL);
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if (!mq) {
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ret = -ENOMEM;
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goto fail_alloc_rxq;
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}
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mbox->rxq = mq;
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return 0;
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fail_alloc_rxq:
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mbox_queue_free(mbox->txq);
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fail_alloc_txq:
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free_irq(mbox->irq, mbox);
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fail_request_irq:
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if (unlikely(mbox->ops->shutdown))
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mbox->ops->shutdown(mbox);
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return ret;
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}
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static void omap_mbox_fini(struct omap_mbox *mbox)
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{
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mbox_queue_free(mbox->txq);
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mbox_queue_free(mbox->rxq);
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free_irq(mbox->irq, mbox);
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if (unlikely(mbox->ops->shutdown)) {
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write_lock(&mboxes_lock);
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if (mbox_configured > 0)
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mbox_configured--;
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if (!mbox_configured)
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mbox->ops->shutdown(mbox);
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write_unlock(&mboxes_lock);
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}
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}
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static struct omap_mbox **find_mboxes(const char *name)
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{
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struct omap_mbox **p;
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for (p = &mboxes; *p; p = &(*p)->next) {
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if (strcmp((*p)->name, name) == 0)
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break;
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}
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return p;
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}
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struct omap_mbox *omap_mbox_get(const char *name)
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{
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struct omap_mbox *mbox;
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int ret;
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read_lock(&mboxes_lock);
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mbox = *(find_mboxes(name));
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if (mbox == NULL) {
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read_unlock(&mboxes_lock);
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return ERR_PTR(-ENOENT);
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}
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read_unlock(&mboxes_lock);
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ret = omap_mbox_startup(mbox);
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if (ret)
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return ERR_PTR(-ENODEV);
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return mbox;
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}
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EXPORT_SYMBOL(omap_mbox_get);
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void omap_mbox_put(struct omap_mbox *mbox)
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{
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omap_mbox_fini(mbox);
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}
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EXPORT_SYMBOL(omap_mbox_put);
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int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
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{
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int ret = 0;
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struct omap_mbox **tmp;
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if (!mbox)
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return -EINVAL;
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if (mbox->next)
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return -EBUSY;
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write_lock(&mboxes_lock);
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tmp = find_mboxes(mbox->name);
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if (*tmp) {
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ret = -EBUSY;
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write_unlock(&mboxes_lock);
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goto err_find;
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}
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*tmp = mbox;
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write_unlock(&mboxes_lock);
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return 0;
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err_find:
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return ret;
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}
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EXPORT_SYMBOL(omap_mbox_register);
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int omap_mbox_unregister(struct omap_mbox *mbox)
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{
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struct omap_mbox **tmp;
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write_lock(&mboxes_lock);
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tmp = &mboxes;
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while (*tmp) {
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if (mbox == *tmp) {
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*tmp = mbox->next;
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mbox->next = NULL;
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write_unlock(&mboxes_lock);
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return 0;
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}
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tmp = &(*tmp)->next;
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}
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write_unlock(&mboxes_lock);
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return -EINVAL;
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}
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EXPORT_SYMBOL(omap_mbox_unregister);
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static int __init omap_mbox_init(void)
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{
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mboxd = create_workqueue("mboxd");
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if (!mboxd)
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return -ENOMEM;
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return 0;
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}
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module_init(omap_mbox_init);
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static void __exit omap_mbox_exit(void)
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{
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destroy_workqueue(mboxd);
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}
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module_exit(omap_mbox_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
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MODULE_AUTHOR("Toshihiro Kobayashi and Hiroshi DOYU");
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