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>

2 files changed, 609 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");
diff --git a/arch/arm/plat-omap/mailbox.h b/arch/arm/plat-omap/mailbox.h
new file mode 100644
index 000000000000..67c6740b8ad5
--- /dev/null
+++ b/arch/arm/plat-omap/mailbox.h
@@ -0,0 +1,100 @@
+/*
+ * Mailbox internal functions
+ *
+ * Copyright (C) 2006 Nokia Corporation
+ * Written by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef __ARCH_ARM_PLAT_MAILBOX_H
+#define __ARCH_ARM_PLAT_MAILBOX_H
+
+/*
+ * Mailbox sequence bit API
+ */
+#if defined(CONFIG_ARCH_OMAP1)
+#  define MBOX_USE_SEQ_BIT
+#elif defined(CONFIG_ARCH_OMAP2)
+#  define MBOX_USE_SEQ_BIT
+#endif
+
+#ifdef MBOX_USE_SEQ_BIT
+/* seq_rcv should be initialized with any value other than
+ * 0 and 1 << 31, to allow either value for the first
+ * message.  */
+static inline void mbox_seq_init(struct omap_mbox *mbox)
+{
+	/* any value other than 0 and 1 << 31 */
+	mbox->seq_rcv = 0xffffffff;
+}
+
+static inline void mbox_seq_toggle(struct omap_mbox *mbox, mbox_msg_t * msg)
+{
+	/* add seq_snd to msg */
+	*msg = (*msg & 0x7fffffff) | mbox->seq_snd;
+	/* flip seq_snd */
+	mbox->seq_snd ^= 1 << 31;
+}
+
+static inline int mbox_seq_test(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+	mbox_msg_t seq = msg & (1 << 31);
+	if (seq == mbox->seq_rcv)
+		return -1;
+	mbox->seq_rcv = seq;
+	return 0;
+}
+#else
+static inline void mbox_seq_init(struct omap_mbox *mbox)
+{
+}
+static inline void mbox_seq_toggle(struct omap_mbox *mbox, mbox_msg_t * msg)
+{
+}
+static inline int mbox_seq_test(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+	return 0;
+}
+#endif
+
+/* 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 enable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	mbox->ops->enable_irq(mbox, irq);
+}
+static inline void disable_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	mbox->ops->disable_irq(mbox, irq);
+}
+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);
+}
+
+#endif				/* __ARCH_ARM_PLAT_MAILBOX_H */