mailbox/omap: consolidate OMAP mailbox driver

There is no need for a separate common OMAP mailbox module
now that the OMAP1 mailbox driver has been removed. So,
consolidate the two individual OMAP mailbox modules into a
single driver. This streamlines the driver for converting
to mailbox framework.

The following are the main changes:
- collapse mailbox-omap2.c into omap-mailbox.c
- remove omap_mbox_ops and replace the ops calls with
  the equivalent functionality.
- simplify the sub-mailbox startup/shutdown functionality,
  the one-time operations are moved into probe, and the
  pm_runtime_get_sync and pm_runtime_put_sync can be invoked
  without using a configuration counter.
- move all definitions from private omap_mbox.h into the
  source code, and eliminate this internal header.
- rename some variables that used the omap2_mbox prefix with
  a generic omap_mbox prefix.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 282 insertions, 49 deletions

diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
index eab72276ffab..66b02ab00b19 100644
--- a/drivers/mailbox/omap-mailbox.c
+++ b/drivers/mailbox/omap-mailbox.c
@@ -2,8 +2,10 @@
  * OMAP mailbox driver
  *
  * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
+ * Copyright (C) 2013-2014 Texas Instruments Inc.
  *
  * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *          Suman Anna <s-anna@ti.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -29,45 +31,145 @@
 #include <linux/err.h>
 #include <linux/notifier.h>
 #include <linux/module.h>
-
-#include "omap-mbox.h"
-
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_data/mailbox-omap.h>
+#include <linux/omap-mailbox.h>
+
+#define MAILBOX_REVISION		0x000
+#define MAILBOX_MESSAGE(m)		(0x040 + 4 * (m))
+#define MAILBOX_FIFOSTATUS(m)		(0x080 + 4 * (m))
+#define MAILBOX_MSGSTATUS(m)		(0x0c0 + 4 * (m))
+
+#define OMAP2_MAILBOX_IRQSTATUS(u)	(0x100 + 8 * (u))
+#define OMAP2_MAILBOX_IRQENABLE(u)	(0x104 + 8 * (u))
+
+#define OMAP4_MAILBOX_IRQSTATUS(u)	(0x104 + 0x10 * (u))
+#define OMAP4_MAILBOX_IRQENABLE(u)	(0x108 + 0x10 * (u))
+#define OMAP4_MAILBOX_IRQENABLE_CLR(u)	(0x10c + 0x10 * (u))
+
+#define MAILBOX_IRQSTATUS(type, u)	(type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
+						OMAP2_MAILBOX_IRQSTATUS(u))
+#define MAILBOX_IRQENABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE(u) : \
+						OMAP2_MAILBOX_IRQENABLE(u))
+#define MAILBOX_IRQDISABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
+						: OMAP2_MAILBOX_IRQENABLE(u))
+
+#define MAILBOX_IRQ_NEWMSG(m)		(1 << (2 * (m)))
+#define MAILBOX_IRQ_NOTFULL(m)		(1 << (2 * (m) + 1))
+
+#define MBOX_REG_SIZE			0x120
+
+#define OMAP4_MBOX_REG_SIZE		0x130
+
+#define MBOX_NR_REGS			(MBOX_REG_SIZE / sizeof(u32))
+#define OMAP4_MBOX_NR_REGS		(OMAP4_MBOX_REG_SIZE / sizeof(u32))
+
+struct omap_mbox_fifo {
+	unsigned long msg;
+	unsigned long fifo_stat;
+	unsigned long msg_stat;
+};
+
+struct omap_mbox_priv {
+	struct omap_mbox_fifo tx_fifo;
+	struct omap_mbox_fifo rx_fifo;
+	unsigned long irqenable;
+	unsigned long irqstatus;
+	u32 newmsg_bit;
+	u32 notfull_bit;
+	u32 ctx[OMAP4_MBOX_NR_REGS];
+	unsigned long irqdisable;
+	u32 intr_type;
+};
+
+struct omap_mbox_queue {
+	spinlock_t		lock;
+	struct kfifo		fifo;
+	struct work_struct	work;
+	struct tasklet_struct	tasklet;
+	struct omap_mbox	*mbox;
+	bool full;
+};
+
+struct omap_mbox {
+	const char		*name;
+	int			irq;
+	struct omap_mbox_queue	*txq, *rxq;
+	struct device		*dev;
+	void			*priv;
+	int			use_count;
+	struct blocking_notifier_head	notifier;
+};
+
+static void __iomem *mbox_base;
 static struct omap_mbox **mboxes;
 
-static int mbox_configured;
 static DEFINE_MUTEX(mbox_configured_lock);
 
 static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
 module_param(mbox_kfifo_size, uint, S_IRUGO);
 MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
 
+static inline unsigned int mbox_read_reg(size_t ofs)
+{
+	return __raw_readl(mbox_base + ofs);
+}
+
+static inline void mbox_write_reg(u32 val, size_t ofs)
+{
+	__raw_writel(val, mbox_base + ofs);
+}
+
 /* Mailbox FIFO handle functions */
-static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
+static mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
 {
-	return mbox->ops->fifo_read(mbox);
+	struct omap_mbox_fifo *fifo =
+		&((struct omap_mbox_priv *)mbox->priv)->rx_fifo;
+	return (mbox_msg_t) mbox_read_reg(fifo->msg);
 }
-static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
+
+static void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
 {
-	mbox->ops->fifo_write(mbox, msg);
+	struct omap_mbox_fifo *fifo =
+		&((struct omap_mbox_priv *)mbox->priv)->tx_fifo;
+	mbox_write_reg(msg, fifo->msg);
 }
-static inline int mbox_fifo_empty(struct omap_mbox *mbox)
+
+static int mbox_fifo_empty(struct omap_mbox *mbox)
 {
-	return mbox->ops->fifo_empty(mbox);
+	struct omap_mbox_fifo *fifo =
+		&((struct omap_mbox_priv *)mbox->priv)->rx_fifo;
+	return (mbox_read_reg(fifo->msg_stat) == 0);
 }
-static inline int mbox_fifo_full(struct omap_mbox *mbox)
+
+static int mbox_fifo_full(struct omap_mbox *mbox)
 {
-	return mbox->ops->fifo_full(mbox);
+	struct omap_mbox_fifo *fifo =
+		&((struct omap_mbox_priv *)mbox->priv)->tx_fifo;
+	return mbox_read_reg(fifo->fifo_stat);
 }
 
 /* Mailbox IRQ handle functions */
-static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
 {
-	if (mbox->ops->ack_irq)
-		mbox->ops->ack_irq(mbox, irq);
+	struct omap_mbox_priv *p = mbox->priv;
+	u32 bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
+
+	mbox_write_reg(bit, p->irqstatus);
+
+	/* Flush posted write for irq status to avoid spurious interrupts */
+	mbox_read_reg(p->irqstatus);
 }
-static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+
+static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
 {
-	return mbox->ops->is_irq(mbox, irq);
+	struct omap_mbox_priv *p = mbox->priv;
+	u32 bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
+	u32 enable = mbox_read_reg(p->irqenable);
+	u32 status = mbox_read_reg(p->irqstatus);
+
+	return (int)(enable & status & bit);
 }
 
 /*
@@ -103,35 +205,66 @@ EXPORT_SYMBOL(omap_mbox_msg_send);
 
 void omap_mbox_save_ctx(struct omap_mbox *mbox)
 {
-	if (!mbox->ops->save_ctx) {
-		dev_err(mbox->dev, "%s:\tno save\n", __func__);
-		return;
+	int i;
+	struct omap_mbox_priv *p = mbox->priv;
+	int nr_regs;
+
+	if (p->intr_type)
+		nr_regs = OMAP4_MBOX_NR_REGS;
+	else
+		nr_regs = MBOX_NR_REGS;
+	for (i = 0; i < nr_regs; i++) {
+		p->ctx[i] = mbox_read_reg(i * sizeof(u32));
+
+		dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
+			i, p->ctx[i]);
 	}
-
-	mbox->ops->save_ctx(mbox);
 }
 EXPORT_SYMBOL(omap_mbox_save_ctx);
 
 void omap_mbox_restore_ctx(struct omap_mbox *mbox)
 {
-	if (!mbox->ops->restore_ctx) {
-		dev_err(mbox->dev, "%s:\tno restore\n", __func__);
-		return;
+	int i;
+	struct omap_mbox_priv *p = mbox->priv;
+	int nr_regs;
+
+	if (p->intr_type)
+		nr_regs = OMAP4_MBOX_NR_REGS;
+	else
+		nr_regs = MBOX_NR_REGS;
+	for (i = 0; i < nr_regs; i++) {
+		mbox_write_reg(p->ctx[i], i * sizeof(u32));
+
+		dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
+			i, p->ctx[i]);
 	}
-
-	mbox->ops->restore_ctx(mbox);
 }
 EXPORT_SYMBOL(omap_mbox_restore_ctx);
 
 void omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
 {
-	mbox->ops->enable_irq(mbox, irq);
+	struct omap_mbox_priv *p = mbox->priv;
+	u32 l, bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
+
+	l = mbox_read_reg(p->irqenable);
+	l |= bit;
+	mbox_write_reg(l, p->irqenable);
 }
 EXPORT_SYMBOL(omap_mbox_enable_irq);
 
 void omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
 {
-	mbox->ops->disable_irq(mbox, irq);
+	struct omap_mbox_priv *p = mbox->priv;
+	u32 bit = (irq == IRQ_TX) ? p->notfull_bit : p->newmsg_bit;
+
+	/*
+	 * Read and update the interrupt configuration register for pre-OMAP4.
+	 * OMAP4 and later SoCs have a dedicated interrupt disabling register.
+	 */
+	if (!p->intr_type)
+		bit = mbox_read_reg(p->irqdisable) & ~bit;
+
+	mbox_write_reg(bit, p->irqdisable);
 }
 EXPORT_SYMBOL(omap_mbox_disable_irq);
 
@@ -267,14 +400,9 @@ static int omap_mbox_startup(struct omap_mbox *mbox)
 	struct omap_mbox_queue *mq;
 
 	mutex_lock(&mbox_configured_lock);
-	if (!mbox_configured++) {
-		if (likely(mbox->ops->startup)) {
-			ret = mbox->ops->startup(mbox);
-			if (unlikely(ret))
-				goto fail_startup;
-		} else
-			goto fail_startup;
-	}
+	ret = pm_runtime_get_sync(mbox->dev->parent);
+	if (unlikely(ret < 0))
+		goto fail_startup;
 
 	if (!mbox->use_count++) {
 		mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
@@ -309,11 +437,9 @@ fail_request_irq:
 fail_alloc_rxq:
 	mbox_queue_free(mbox->txq);
 fail_alloc_txq:
-	if (mbox->ops->shutdown)
-		mbox->ops->shutdown(mbox);
+	pm_runtime_put_sync(mbox->dev->parent);
 	mbox->use_count--;
 fail_startup:
-	mbox_configured--;
 	mutex_unlock(&mbox_configured_lock);
 	return ret;
 }
@@ -331,10 +457,7 @@ static void omap_mbox_fini(struct omap_mbox *mbox)
 		mbox_queue_free(mbox->rxq);
 	}
 
-	if (likely(mbox->ops->shutdown)) {
-		if (!--mbox_configured)
-			mbox->ops->shutdown(mbox);
-	}
+	pm_runtime_put_sync(mbox->dev->parent);
 
 	mutex_unlock(&mbox_configured_lock);
 }
@@ -379,7 +502,7 @@ EXPORT_SYMBOL(omap_mbox_put);
 
 static struct class omap_mbox_class = { .name = "mbox", };
 
-int omap_mbox_register(struct device *parent, struct omap_mbox **list)
+static int omap_mbox_register(struct device *parent, struct omap_mbox **list)
 {
 	int ret;
 	int i;
@@ -406,9 +529,8 @@ err_out:
 		device_unregister(mboxes[i]->dev);
 	return ret;
 }
-EXPORT_SYMBOL(omap_mbox_register);
 
-int omap_mbox_unregister(void)
+static int omap_mbox_unregister(void)
 {
 	int i;
 
@@ -420,7 +542,117 @@ int omap_mbox_unregister(void)
 	mboxes = NULL;
 	return 0;
 }
-EXPORT_SYMBOL(omap_mbox_unregister);
+
+static int omap_mbox_probe(struct platform_device *pdev)
+{
+	struct resource *mem;
+	int ret;
+	struct omap_mbox **list, *mbox, *mboxblk;
+	struct omap_mbox_priv *priv, *privblk;
+	struct omap_mbox_pdata *pdata = pdev->dev.platform_data;
+	struct omap_mbox_dev_info *info;
+	u32 intr_type;
+	u32 l;
+	int i;
+
+	if (!pdata || !pdata->info_cnt || !pdata->info) {
+		pr_err("%s: platform not supported\n", __func__);
+		return -ENODEV;
+	}
+
+	/* allocate one extra for marking end of list */
+	list = devm_kzalloc(&pdev->dev, (pdata->info_cnt + 1) * sizeof(*list),
+			    GFP_KERNEL);
+	if (!list)
+		return -ENOMEM;
+
+	mboxblk = devm_kzalloc(&pdev->dev, pdata->info_cnt * sizeof(*mbox),
+			       GFP_KERNEL);
+	if (!mboxblk)
+		return -ENOMEM;
+
+	privblk = devm_kzalloc(&pdev->dev, pdata->info_cnt * sizeof(*priv),
+			       GFP_KERNEL);
+	if (!privblk)
+		return -ENOMEM;
+
+	info = pdata->info;
+	intr_type = pdata->intr_type;
+	mbox = mboxblk;
+	priv = privblk;
+	for (i = 0; i < pdata->info_cnt; i++, info++, priv++) {
+		priv->tx_fifo.msg = MAILBOX_MESSAGE(info->tx_id);
+		priv->tx_fifo.fifo_stat = MAILBOX_FIFOSTATUS(info->tx_id);
+		priv->rx_fifo.msg =  MAILBOX_MESSAGE(info->rx_id);
+		priv->rx_fifo.msg_stat =  MAILBOX_MSGSTATUS(info->rx_id);
+		priv->notfull_bit = MAILBOX_IRQ_NOTFULL(info->tx_id);
+		priv->newmsg_bit = MAILBOX_IRQ_NEWMSG(info->rx_id);
+		priv->irqenable = MAILBOX_IRQENABLE(intr_type, info->usr_id);
+		priv->irqstatus = MAILBOX_IRQSTATUS(intr_type, info->usr_id);
+		priv->irqdisable = MAILBOX_IRQDISABLE(intr_type, info->usr_id);
+		priv->intr_type = intr_type;
+
+		mbox->priv = priv;
+		mbox->name = info->name;
+		mbox->irq = platform_get_irq(pdev, info->irq_id);
+		if (mbox->irq < 0)
+			return mbox->irq;
+		list[i] = mbox++;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mbox_base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(mbox_base))
+		return PTR_ERR(mbox_base);
+
+	ret = omap_mbox_register(&pdev->dev, list);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, list);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		goto unregister;
+	}
+
+	/*
+	 * just print the raw revision register, the format is not
+	 * uniform across all SoCs
+	 */
+	l = mbox_read_reg(MAILBOX_REVISION);
+	dev_info(&pdev->dev, "omap mailbox rev 0x%x\n", l);
+
+	ret = pm_runtime_put_sync(&pdev->dev);
+	if (ret < 0)
+		goto unregister;
+
+	return 0;
+
+unregister:
+	pm_runtime_disable(&pdev->dev);
+	omap_mbox_unregister();
+	return ret;
+}
+
+static int omap_mbox_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+	omap_mbox_unregister();
+
+	return 0;
+}
+
+static struct platform_driver omap_mbox_driver = {
+	.probe	= omap_mbox_probe,
+	.remove	= omap_mbox_remove,
+	.driver	= {
+		.name = "omap-mailbox",
+		.owner = THIS_MODULE,
+	},
+};
 
 static int __init omap_mbox_init(void)
 {
@@ -435,12 +667,13 @@ static int __init omap_mbox_init(void)
 	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
 							sizeof(mbox_msg_t));
 
-	return 0;
+	return platform_driver_register(&omap_mbox_driver);
 }
 subsys_initcall(omap_mbox_init);
 
 static void __exit omap_mbox_exit(void)
 {
+	platform_driver_unregister(&omap_mbox_driver);
 	class_unregister(&omap_mbox_class);
 }
 module_exit(omap_mbox_exit);