diff options
Diffstat (limited to 'arch/arm/plat-omap/mailbox.c')
-rw-r--r-- | arch/arm/plat-omap/mailbox.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c new file mode 100644 index 00000000000..de7e6ef48bd --- /dev/null +++ b/arch/arm/plat-omap/mailbox.c @@ -0,0 +1,509 @@ +/* + * 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"); |