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581 lines
12 KiB
C
581 lines
12 KiB
C
/*
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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 <mach/mailbox.h>
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static int enable_seq_bit;
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module_param(enable_seq_bit, bool, 0);
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MODULE_PARM_DESC(enable_seq_bit, "Enable sequence bit checking.");
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static struct omap_mbox *mboxes;
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static DEFINE_RWLOCK(mboxes_lock);
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/*
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* Mailbox sequence bit API
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*/
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/* seq_rcv should be initialized with any value other than
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* 0 and 1 << 31, to allow either value for the first
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* message. */
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static inline void mbox_seq_init(struct omap_mbox *mbox)
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{
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if (!enable_seq_bit)
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return;
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/* any value other than 0 and 1 << 31 */
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mbox->seq_rcv = 0xffffffff;
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}
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static inline void mbox_seq_toggle(struct omap_mbox *mbox, mbox_msg_t * msg)
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{
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if (!enable_seq_bit)
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return;
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/* add seq_snd to msg */
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*msg = (*msg & 0x7fffffff) | mbox->seq_snd;
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/* flip seq_snd */
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mbox->seq_snd ^= 1 << 31;
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}
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static inline int mbox_seq_test(struct omap_mbox *mbox, mbox_msg_t msg)
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{
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mbox_msg_t seq;
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if (!enable_seq_bit)
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return 0;
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seq = msg & (1 << 31);
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if (seq == mbox->seq_rcv)
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return -1;
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mbox->seq_rcv = seq;
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return 0;
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}
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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 enable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
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{
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mbox->ops->enable_irq(mbox, irq);
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}
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static inline void disable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
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{
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mbox->ops->disable_irq(mbox, irq);
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}
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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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/* Mailbox Sequence Bit function */
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void omap_mbox_init_seq(struct omap_mbox *mbox)
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{
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mbox_seq_init(mbox);
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}
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EXPORT_SYMBOL(omap_mbox_init_seq);
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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, void *arg)
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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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if (arg && mbox->txq->callback) {
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ret = mbox->txq->callback(arg);
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if (ret)
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goto out;
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}
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mbox_seq_toggle(mbox, &msg);
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mbox_fifo_write(mbox, msg);
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out:
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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, void* arg)
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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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int ret = 0;
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rq = blk_get_request(q, WRITE, GFP_ATOMIC);
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if (unlikely(!rq)) {
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ret = -ENOMEM;
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goto fail;
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}
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rq->data = (void *)msg;
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blk_insert_request(q, rq, 0, arg);
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schedule_work(&mbox->txq->work);
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fail:
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return ret;
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}
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EXPORT_SYMBOL(omap_mbox_msg_send);
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static void mbox_tx_work(struct work_struct *work)
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{
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int ret;
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struct request *rq;
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struct omap_mbox_queue *mq = container_of(work,
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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->txq->queue;
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while (1) {
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spin_lock(q->queue_lock);
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rq = elv_next_request(q);
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spin_unlock(q->queue_lock);
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if (!rq)
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break;
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ret = __mbox_msg_send(mbox, (mbox_msg_t) rq->data, rq->special);
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if (ret) {
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enable_mbox_irq(mbox, IRQ_TX);
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return;
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}
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spin_lock(q->queue_lock);
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if (__blk_end_request(rq, 0, 0))
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BUG();
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spin_unlock(q->queue_lock);
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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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if (mbox->rxq->callback == NULL) {
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sysfs_notify(&mbox->dev->kobj, NULL, "mbox");
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return;
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}
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while (1) {
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spin_lock_irqsave(q->queue_lock, flags);
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rq = elv_next_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->data;
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if (blk_end_request(rq, 0, 0))
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BUG();
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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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disable_mbox_irq(mbox, IRQ_TX);
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ack_mbox_irq(mbox, IRQ_TX);
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schedule_work(&mbox->txq->work);
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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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disable_mbox_irq(mbox, IRQ_RX);
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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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rq->data = (void *)msg;
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if (unlikely(mbox_seq_test(mbox, msg))) {
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pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
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if (mbox->err_notify)
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mbox->err_notify();
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}
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blk_insert_request(q, rq, 0, NULL);
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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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enable_mbox_irq(mbox, IRQ_RX);
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nomem:
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schedule_work(&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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/*
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* sysfs files
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*/
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static ssize_t
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omap_mbox_write(struct device *dev, struct device_attribute *attr,
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const char * buf, size_t count)
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{
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int ret;
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mbox_msg_t *p = (mbox_msg_t *)buf;
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struct omap_mbox *mbox = dev_get_drvdata(dev);
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for (; count >= sizeof(mbox_msg_t); count -= sizeof(mbox_msg_t)) {
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ret = omap_mbox_msg_send(mbox, be32_to_cpu(*p), NULL);
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if (ret)
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return -EAGAIN;
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p++;
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}
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return (size_t)((char *)p - buf);
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}
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static ssize_t
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omap_mbox_read(struct device *dev, struct device_attribute *attr, char *buf)
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{
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unsigned long flags;
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struct request *rq;
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mbox_msg_t *p = (mbox_msg_t *) buf;
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struct omap_mbox *mbox = dev_get_drvdata(dev);
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struct request_queue *q = mbox->rxq->queue;
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while (1) {
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spin_lock_irqsave(q->queue_lock, flags);
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rq = elv_next_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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*p = (mbox_msg_t) rq->data;
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if (blk_end_request(rq, 0, 0))
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BUG();
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if (unlikely(mbox_seq_test(mbox, *p))) {
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pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
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continue;
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}
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p++;
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}
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pr_debug("%02x %02x %02x %02x\n", buf[0], buf[1], buf[2], buf[3]);
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return (size_t) ((char *)p - buf);
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}
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static DEVICE_ATTR(mbox, S_IRUGO | S_IWUSR, omap_mbox_read, omap_mbox_write);
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static ssize_t mbox_show(struct class *class, char *buf)
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{
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return sprintf(buf, "mbox");
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}
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static CLASS_ATTR(mbox, S_IRUGO, mbox_show, NULL);
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static struct class omap_mbox_class = {
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.name = "omap-mailbox",
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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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{
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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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INIT_WORK(&mq->work, work);
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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_init(struct omap_mbox *mbox)
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{
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int ret;
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struct omap_mbox_queue *mq;
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if (likely(mbox->ops->startup)) {
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ret = mbox->ops->startup(mbox);
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if (unlikely(ret))
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return ret;
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}
|
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ret = request_irq(mbox->irq, mbox_interrupt, IRQF_DISABLED,
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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, mbox_tx_work);
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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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|
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mq = mbox_queue_alloc(mbox, mbox_rxq_fn, mbox_rx_work);
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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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|
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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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mbox->ops->shutdown(mbox);
|
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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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struct omap_mbox *omap_mbox_get(const char *name)
|
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{
|
|
struct omap_mbox *mbox;
|
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int ret;
|
|
|
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read_lock(&mboxes_lock);
|
|
mbox = *(find_mboxes(name));
|
|
if (mbox == NULL) {
|
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read_unlock(&mboxes_lock);
|
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return ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
read_unlock(&mboxes_lock);
|
|
|
|
ret = omap_mbox_init(mbox);
|
|
if (ret)
|
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return ERR_PTR(-ENODEV);
|
|
|
|
return mbox;
|
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}
|
|
EXPORT_SYMBOL(omap_mbox_get);
|
|
|
|
void omap_mbox_put(struct omap_mbox *mbox)
|
|
{
|
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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);
|
|
|
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static int __init omap_mbox_class_init(void)
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{
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int ret = class_register(&omap_mbox_class);
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if (!ret)
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ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
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return ret;
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}
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static void __exit omap_mbox_class_exit(void)
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{
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class_remove_file(&omap_mbox_class, &class_attr_mbox);
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class_unregister(&omap_mbox_class);
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}
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subsys_initcall(omap_mbox_class_init);
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module_exit(omap_mbox_class_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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