OMAP4 Mailbox driver - Includes Hiroshi's changes on mailbox driver along with...

OMAP4 Mailbox driver - Includes Hiroshi's changes on mailbox driver along with API changes introducted in the 2.6.31 kernel

This patch cleans up the mailbox driver module and adds the
following changes:
	- Remove sequence bit checking (protocol logic not
		required in the driver)
	- Remove class interface (not used presently)
	- Remove disalbe_/enable_mbox_irq in isr (No irqs
		happen in the isr)
	- Remove unnecessary arg for omap_mbox_msg_send
	- Expose omap_mbox_enable()/disable_irq()

NOTE::
For OMAP4 the tx work queue does not ssem to function
properly. Hence, calling __mbox_msg_send for now.
Signed-off-by: C A Subramaniam <subramaniam.ca@ti.com>
Signed-off-by: Ramesh Gupta G <grgupta@ti.com>

arch/arm/plat-omap/include/mach/mailbox.h

@@ -8,7 +8,6 @@
 #include <linux/blkdev.h>
 
 typedef u32 mbox_msg_t;
-typedef void (mbox_receiver_t)(mbox_msg_t msg);
 struct omap_mbox;
 
 typedef int __bitwise omap_mbox_irq_t;
@@ -29,8 +28,10 @@ struct omap_mbox_ops {
 	int		(*fifo_empty)(struct omap_mbox *mbox);
 	int		(*fifo_full)(struct omap_mbox *mbox);
 	/* irq */
-	void		(*enable_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
-	void		(*disable_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
+	void		(*enable_irq)(struct omap_mbox *mbox,
+						omap_mbox_irq_t irq);
+	void		(*disable_irq)(struct omap_mbox *mbox,
+						omap_mbox_irq_t irq);
 	void		(*ack_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
 	int		(*is_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
 	/* ctx */
@@ -64,7 +65,7 @@ struct omap_mbox {
 	void			(*err_notify)(void);
 };
 
-int omap_mbox_msg_send(struct omap_mbox *, mbox_msg_t msg, void *);
+int omap_mbox_msg_send(struct omap_mbox *, mbox_msg_t msg);
 void omap_mbox_init_seq(struct omap_mbox *);
 
 struct omap_mbox *omap_mbox_get(const char *);
@@ -93,4 +94,16 @@ static inline void omap_mbox_restore_ctx(struct omap_mbox *mbox)
 	mbox->ops->restore_ctx(mbox);
 }
 
+static inline void omap_mbox_enable_irq(struct omap_mbox *mbox,
+					omap_mbox_irq_t irq)
+{
+	mbox->ops->enable_irq(mbox, irq);
+}
+
+static inline void omap_mbox_disable_irq(struct omap_mbox *mbox,
+					 omap_mbox_irq_t irq)
+{
+	mbox->ops->disable_irq(mbox, irq);
+}
+
 #endif /* MAILBOX_H */

arch/arm/plat-omap/mailbox.c

@@ -28,54 +28,9 @@
 
 #include <mach/mailbox.h>
 
-static int enable_seq_bit;
-module_param(enable_seq_bit, bool, 0);
-MODULE_PARM_DESC(enable_seq_bit, "Enable sequence bit checking.");
-
 static struct omap_mbox *mboxes;
 static DEFINE_RWLOCK(mboxes_lock);
 
-/*
- * Mailbox sequence bit API
- */
-
-/* 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)
-{
-	if (!enable_seq_bit)
-		return;
-
-	/* 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)
-{
-	if (!enable_seq_bit)
-		return;
-
-	/* 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;
-
-	if (!enable_seq_bit)
-		return 0;
-
-	seq = msg & (1 << 31);
-	if (seq == mbox->seq_rcv)
-		return -1;
-	mbox->seq_rcv = seq;
-	return 0;
-}
-
 /* Mailbox FIFO handle functions */
 static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
 {
@@ -95,14 +50,6 @@ static inline int mbox_fifo_full(struct omap_mbox *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)
@@ -113,17 +60,10 @@ static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
 	return mbox->ops->is_irq(mbox, irq);
 }
 
-/* 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)
+static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
 {
 	int ret = 0, i = 1000;
 
@@ -134,53 +74,43 @@ static int __mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void *arg)
 			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;
 }
 
-struct omap_msg_tx_data {
-	mbox_msg_t	msg;
-	void		*arg;
-};
-
+#if 0
 static void omap_msg_tx_end_io(struct request *rq, int error)
 {
 	kfree(rq->special);
 	__blk_put_request(rq->q, rq);
 }
+#endif
 
-int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg, void* arg)
+int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
 {
-	struct omap_msg_tx_data *tx_data;
+	return __mbox_msg_send(mbox, msg);
+
+	/* FIXME Work queue is not used to send mailbox messages.
+	 Directly calling __mbox_msg_send() */
+#if 0
 	struct request *rq;
 	struct request_queue *q = mbox->txq->queue;
-
-	tx_data = kmalloc(sizeof(*tx_data), GFP_ATOMIC);
-	if (unlikely(!tx_data))
-		return -ENOMEM;
-
+	int ret = 0;
 	rq = blk_get_request(q, WRITE, GFP_ATOMIC);
 	if (unlikely(!rq)) {
-		kfree(tx_data);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto fail;
 	}
 
-	tx_data->msg = msg;
-	tx_data->arg = arg;
 	rq->end_io = omap_msg_tx_end_io;
-	blk_insert_request(q, rq, 0, tx_data);
+
+	blk_insert_request(q, rq, 0, (void *)msg);
 
 	schedule_work(&mbox->txq->work);
-	return 0;
+
+ fail:
+	return ret;
+#endif
 }
 EXPORT_SYMBOL(omap_mbox_msg_send);
 
@@ -194,8 +124,6 @@ static void mbox_tx_work(struct work_struct *work)
 	struct request_queue *q = mbox->txq->queue;
 
 	while (1) {
-		struct omap_msg_tx_data *tx_data;
-
 		spin_lock(q->queue_lock);
 		rq = blk_fetch_request(q);
 		spin_unlock(q->queue_lock);
@@ -203,11 +131,9 @@ static void mbox_tx_work(struct work_struct *work)
 		if (!rq)
 			break;
 
-		tx_data = rq->special;
-
-		ret = __mbox_msg_send(mbox, tx_data->msg, tx_data->arg);
+		ret = __mbox_msg_send(mbox, (mbox_msg_t)rq->special);
 		if (ret) {
-			enable_mbox_irq(mbox, IRQ_TX);
+			omap_mbox_enable_irq(mbox, IRQ_TX);
 			spin_lock(q->queue_lock);
 			blk_requeue_request(q, rq);
 			spin_unlock(q->queue_lock);
@@ -215,7 +141,7 @@ static void mbox_tx_work(struct work_struct *work)
 		}
 
 		spin_lock(q->queue_lock);
-		__blk_end_request_all(rq, 0);
+		blk_end_request_all(rq, 0);
 		spin_unlock(q->queue_lock);
 	}
 }
@@ -233,11 +159,6 @@ static void mbox_rx_work(struct work_struct *work)
 	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 = blk_fetch_request(q);
@@ -245,7 +166,8 @@ static void mbox_rx_work(struct work_struct *work)
 		if (!rq)
 			break;
 
-		msg = (mbox_msg_t)rq->special;
+		msg = (mbox_msg_t) rq->special;
+
 		blk_end_request_all(rq, 0);
 		mbox->rxq->callback((void *)msg);
 	}
@@ -254,17 +176,17 @@ static void mbox_rx_work(struct work_struct *work)
 /*
  * Mailbox interrupt handler
  */
-static void mbox_txq_fn(struct request_queue * q)
+static void mbox_txq_fn(struct request_queue *q)
 {
 }
 
-static void mbox_rxq_fn(struct request_queue * q)
+static void mbox_rxq_fn(struct request_queue *q)
 {
 }
 
 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
 {
-	disable_mbox_irq(mbox, IRQ_TX);
+	omap_mbox_disable_irq(mbox, IRQ_TX);
 	ack_mbox_irq(mbox, IRQ_TX);
 	schedule_work(&mbox->txq->work);
 }
@@ -275,20 +197,13 @@ static void __mbox_rx_interrupt(struct omap_mbox *mbox)
 	mbox_msg_t msg;
 	struct request_queue *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);
-
-		if (unlikely(mbox_seq_test(mbox, msg))) {
-			pr_info("mbox: Illegal seq bit!(%08x)\n", msg);
-			if (mbox->err_notify)
-				mbox->err_notify();
-		}
+		rq->special = (void *)msg;
 
 		blk_insert_request(q, rq, 0, (void *)msg);
 		if (mbox->ops->type == OMAP_MBOX_TYPE1)
@@ -297,7 +212,6 @@ static void __mbox_rx_interrupt(struct omap_mbox *mbox)
 
 	/* 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);
 }
@@ -315,75 +229,8 @@ static irqreturn_t mbox_interrupt(int irq, void *p)
 	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 = blk_fetch_request(q);
-		spin_unlock_irqrestore(q->queue_lock, flags);
-
-		if (!rq)
-			break;
-
-		*p = (mbox_msg_t)rq->special;
-
-		blk_end_request_all(rq, 0);
-
-		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-mailbox",
-};
-
 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
-					request_fn_proc * proc,
+					request_fn_proc *proc,
 					void (*work) (struct work_struct *))
 {
 	struct request_queue *q;
@@ -415,7 +262,7 @@ static void mbox_queue_free(struct omap_mbox_queue *q)
 	kfree(q);
 }
 
-static int omap_mbox_init(struct omap_mbox *mbox)
+static int omap_mbox_startup(struct omap_mbox *mbox)
 {
 	int ret;
 	struct omap_mbox_queue *mq;
@@ -498,7 +345,7 @@ struct omap_mbox *omap_mbox_get(const char *name)
 
 	read_unlock(&mboxes_lock);
 
-	ret = omap_mbox_init(mbox);
+	ret = omap_mbox_startup(mbox);
 	if (ret)
 		return ERR_PTR(-ENODEV);
 
@@ -522,15 +369,6 @@ int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
 	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) {
@@ -544,9 +382,6 @@ int omap_mbox_register(struct device *parent, struct omap_mbox *mbox)
 	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);
@@ -562,8 +397,6 @@ int omap_mbox_unregister(struct omap_mbox *mbox)
 			*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;
@@ -574,23 +407,16 @@ int omap_mbox_unregister(struct omap_mbox *mbox)
 }
 EXPORT_SYMBOL(omap_mbox_unregister);
 
-static int __init omap_mbox_class_init(void)
+static int __init omap_mbox_init(void)
 {
-	int ret = class_register(&omap_mbox_class);
-	if (!ret)
-		ret = class_create_file(&omap_mbox_class, &class_attr_mbox);
-
-	return ret;
+	return 0;
 }
+module_init(omap_mbox_init);
 
-static void __exit omap_mbox_class_exit(void)
+static void __exit omap_mbox_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_exit(omap_mbox_exit);
 
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");