ARM: OMAP: Add mailbox support for IVA

This patch adds a generic mailbox interface for for DSP and IVA
(Image Video Accelerator). This patch itself doesn't contain
any IVA driver.

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

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 000000000000..de7e6ef48bd0
--- /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");