mailbox/omap: move the OMAP mailbox framework to drivers

The mailbox hardware (in OMAP) uses a queued mailbox interrupt
mechanism that provides a communication channel between processors
through a set of registers and their associated interrupt signals
by sending and receiving messages.

The OMAP mailbox framework/driver code is moved to be under
drivers/mailbox, in preparation for adapting to a common mailbox
driver framework. This allows the build for OMAP mailbox to be
enabled (it was disabled during the multi-platform support).

As part of the migration from plat and mach code:
- Kconfig symbols have been renamed to build OMAP1 or OMAP2+ drivers.
- mailbox.h under plat-omap/plat/include has been split into a public
  and private header files. The public header has only the API related
  functions and types.
- The module name mailbox.ko from plat-omap is changed to
  omap-mailbox.ko
- The module name mailbox_mach.ko from mach-omapX is changed as
    mailbox_omap1.ko for OMAP1
    mailbox_omap2.ko for OMAP2+

Cc: Tony Lindgren <tony@atomide.com>
[gregkh@linuxfoundation.org: ack for staging part]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Omar Ramirez Luna <omar.ramirez@copitl.com>
Signed-off-by: Suman Anna <s-anna@ti.com>

6 files changed, 1137 insertions, 0 deletions

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 9545c9f0380..c8b5c13bcd0 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -16,4 +16,38 @@ config PL320_MBOX
 	  Management Engine, primarily for cpufreq. Say Y here if you want
 	  to use the PL320 IPCM support.
 
+config OMAP_MBOX
+	tristate
+	help
+	  This option is selected by any OMAP architecture specific mailbox
+	  driver such as CONFIG_OMAP1_MBOX or CONFIG_OMAP2PLUS_MBOX. This
+	  enables the common OMAP mailbox framework code.
+
+config OMAP1_MBOX
+	tristate "OMAP1 Mailbox framework support"
+	depends on ARCH_OMAP1
+	select OMAP_MBOX
+	help
+	  Mailbox implementation for OMAP chips with hardware for
+	  interprocessor communication involving DSP in OMAP1. Say Y here
+	  if you want to use OMAP1 Mailbox framework support.
+
+config OMAP2PLUS_MBOX
+	tristate "OMAP2+ Mailbox framework support"
+	depends on ARCH_OMAP2PLUS
+	select OMAP_MBOX
+	help
+	  Mailbox implementation for OMAP family chips with hardware for
+	  interprocessor communication involving DSP, IVA1.0 and IVA2 in
+	  OMAP2/3; or IPU, IVA HD and DSP in OMAP4/5. Say Y here if you
+	  want to use OMAP2+ Mailbox framework support.
+
+config OMAP_MBOX_KFIFO_SIZE
+	int "Mailbox kfifo default buffer size (bytes)"
+	depends on OMAP2PLUS_MBOX || OMAP1_MBOX
+	default 256
+	help
+	  Specify the default size of mailbox's kfifo buffers (bytes).
+	  This can also be changed at runtime (via the mbox_kfifo_size
+	  module parameter).
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 543ad6a7950..e0facb34084 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -1 +1,7 @@
 obj-$(CONFIG_PL320_MBOX)	+= pl320-ipc.o
+
+obj-$(CONFIG_OMAP_MBOX)		+= omap-mailbox.o
+obj-$(CONFIG_OMAP1_MBOX)	+= mailbox_omap1.o
+mailbox_omap1-objs		:= mailbox-omap1.o
+obj-$(CONFIG_OMAP2PLUS_MBOX)	+= mailbox_omap2.o
+mailbox_omap2-objs		:= mailbox-omap2.o
diff --git a/drivers/mailbox/mailbox-omap1.c b/drivers/mailbox/mailbox-omap1.c
new file mode 100644
index 00000000000..9001b7633f1
--- /dev/null
+++ b/drivers/mailbox/mailbox-omap1.c
@@ -0,0 +1,203 @@
+/*
+ * Mailbox reservation modules for OMAP1
+ *
+ * Copyright (C) 2006-2009 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.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include "omap-mbox.h"
+
+#define MAILBOX_ARM2DSP1		0x00
+#define MAILBOX_ARM2DSP1b		0x04
+#define MAILBOX_DSP2ARM1		0x08
+#define MAILBOX_DSP2ARM1b		0x0c
+#define MAILBOX_DSP2ARM2		0x10
+#define MAILBOX_DSP2ARM2b		0x14
+#define MAILBOX_ARM2DSP1_Flag		0x18
+#define MAILBOX_DSP2ARM1_Flag		0x1c
+#define MAILBOX_DSP2ARM2_Flag		0x20
+
+static void __iomem *mbox_base;
+
+struct omap_mbox1_fifo {
+	unsigned long cmd;
+	unsigned long data;
+	unsigned long flag;
+};
+
+struct omap_mbox1_priv {
+	struct omap_mbox1_fifo tx_fifo;
+	struct omap_mbox1_fifo rx_fifo;
+};
+
+static inline int mbox_read_reg(size_t ofs)
+{
+	return __raw_readw(mbox_base + ofs);
+}
+
+static inline void mbox_write_reg(u32 val, size_t ofs)
+{
+	__raw_writew(val, mbox_base + ofs);
+}
+
+/* msg */
+static mbox_msg_t omap1_mbox_fifo_read(struct omap_mbox *mbox)
+{
+	struct omap_mbox1_fifo *fifo =
+		&((struct omap_mbox1_priv *)mbox->priv)->rx_fifo;
+	mbox_msg_t msg;
+
+	msg = mbox_read_reg(fifo->data);
+	msg |= ((mbox_msg_t) mbox_read_reg(fifo->cmd)) << 16;
+
+	return msg;
+}
+
+static void
+omap1_mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+	struct omap_mbox1_fifo *fifo =
+		&((struct omap_mbox1_priv *)mbox->priv)->tx_fifo;
+
+	mbox_write_reg(msg & 0xffff, fifo->data);
+	mbox_write_reg(msg >> 16, fifo->cmd);
+}
+
+static int omap1_mbox_fifo_empty(struct omap_mbox *mbox)
+{
+	return 0;
+}
+
+static int omap1_mbox_fifo_full(struct omap_mbox *mbox)
+{
+	struct omap_mbox1_fifo *fifo =
+		&((struct omap_mbox1_priv *)mbox->priv)->rx_fifo;
+
+	return mbox_read_reg(fifo->flag);
+}
+
+/* irq */
+static void
+omap1_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	if (irq == IRQ_RX)
+		enable_irq(mbox->irq);
+}
+
+static void
+omap1_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	if (irq == IRQ_RX)
+		disable_irq(mbox->irq);
+}
+
+static int
+omap1_mbox_is_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	if (irq == IRQ_TX)
+		return 0;
+	return 1;
+}
+
+static struct omap_mbox_ops omap1_mbox_ops = {
+	.type		= OMAP_MBOX_TYPE1,
+	.fifo_read	= omap1_mbox_fifo_read,
+	.fifo_write	= omap1_mbox_fifo_write,
+	.fifo_empty	= omap1_mbox_fifo_empty,
+	.fifo_full	= omap1_mbox_fifo_full,
+	.enable_irq	= omap1_mbox_enable_irq,
+	.disable_irq	= omap1_mbox_disable_irq,
+	.is_irq		= omap1_mbox_is_irq,
+};
+
+/* FIXME: the following struct should be created automatically by the user id */
+
+/* DSP */
+static struct omap_mbox1_priv omap1_mbox_dsp_priv = {
+	.tx_fifo = {
+		.cmd	= MAILBOX_ARM2DSP1b,
+		.data	= MAILBOX_ARM2DSP1,
+		.flag	= MAILBOX_ARM2DSP1_Flag,
+	},
+	.rx_fifo = {
+		.cmd	= MAILBOX_DSP2ARM1b,
+		.data	= MAILBOX_DSP2ARM1,
+		.flag	= MAILBOX_DSP2ARM1_Flag,
+	},
+};
+
+static struct omap_mbox mbox_dsp_info = {
+	.name	= "dsp",
+	.ops	= &omap1_mbox_ops,
+	.priv	= &omap1_mbox_dsp_priv,
+};
+
+static struct omap_mbox *omap1_mboxes[] = { &mbox_dsp_info, NULL };
+
+static int omap1_mbox_probe(struct platform_device *pdev)
+{
+	struct resource *mem;
+	int ret;
+	struct omap_mbox **list;
+
+	list = omap1_mboxes;
+	list[0]->irq = platform_get_irq_byname(pdev, "dsp");
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem)
+		return -ENOENT;
+
+	mbox_base = ioremap(mem->start, resource_size(mem));
+	if (!mbox_base)
+		return -ENOMEM;
+
+	ret = omap_mbox_register(&pdev->dev, list);
+	if (ret) {
+		iounmap(mbox_base);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int omap1_mbox_remove(struct platform_device *pdev)
+{
+	omap_mbox_unregister();
+	iounmap(mbox_base);
+	return 0;
+}
+
+static struct platform_driver omap1_mbox_driver = {
+	.probe	= omap1_mbox_probe,
+	.remove	= omap1_mbox_remove,
+	.driver	= {
+		.name	= "omap-mailbox",
+	},
+};
+
+static int __init omap1_mbox_init(void)
+{
+	return platform_driver_register(&omap1_mbox_driver);
+}
+
+static void __exit omap1_mbox_exit(void)
+{
+	platform_driver_unregister(&omap1_mbox_driver);
+}
+
+module_init(omap1_mbox_init);
+module_exit(omap1_mbox_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("omap mailbox: omap1 architecture specific functions");
+MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
+MODULE_ALIAS("platform:omap1-mailbox");
diff --git a/drivers/mailbox/mailbox-omap2.c b/drivers/mailbox/mailbox-omap2.c
new file mode 100644
index 00000000000..eba380d7b17
--- /dev/null
+++ b/drivers/mailbox/mailbox-omap2.c
@@ -0,0 +1,358 @@
+/*
+ * Mailbox reservation modules for OMAP2/3
+ *
+ * Copyright (C) 2006-2009 Nokia Corporation
+ * Written by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *        and  Paul Mundt
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_data/mailbox-omap.h>
+
+#include "omap-mbox.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 MAILBOX_IRQSTATUS(u)		(0x100 + 8 * (u))
+#define 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_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))
+
+static void __iomem *mbox_base;
+
+struct omap_mbox2_fifo {
+	unsigned long msg;
+	unsigned long fifo_stat;
+	unsigned long msg_stat;
+};
+
+struct omap_mbox2_priv {
+	struct omap_mbox2_fifo tx_fifo;
+	struct omap_mbox2_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;
+};
+
+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 H/W preparations */
+static int omap2_mbox_startup(struct omap_mbox *mbox)
+{
+	u32 l;
+
+	pm_runtime_enable(mbox->dev->parent);
+	pm_runtime_get_sync(mbox->dev->parent);
+
+	l = mbox_read_reg(MAILBOX_REVISION);
+	pr_debug("omap mailbox rev %d.%d\n", (l & 0xf0) >> 4, (l & 0x0f));
+
+	return 0;
+}
+
+static void omap2_mbox_shutdown(struct omap_mbox *mbox)
+{
+	pm_runtime_put_sync(mbox->dev->parent);
+	pm_runtime_disable(mbox->dev->parent);
+}
+
+/* Mailbox FIFO handle functions */
+static mbox_msg_t omap2_mbox_fifo_read(struct omap_mbox *mbox)
+{
+	struct omap_mbox2_fifo *fifo =
+		&((struct omap_mbox2_priv *)mbox->priv)->rx_fifo;
+	return (mbox_msg_t) mbox_read_reg(fifo->msg);
+}
+
+static void omap2_mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+	struct omap_mbox2_fifo *fifo =
+		&((struct omap_mbox2_priv *)mbox->priv)->tx_fifo;
+	mbox_write_reg(msg, fifo->msg);
+}
+
+static int omap2_mbox_fifo_empty(struct omap_mbox *mbox)
+{
+	struct omap_mbox2_fifo *fifo =
+		&((struct omap_mbox2_priv *)mbox->priv)->rx_fifo;
+	return (mbox_read_reg(fifo->msg_stat) == 0);
+}
+
+static int omap2_mbox_fifo_full(struct omap_mbox *mbox)
+{
+	struct omap_mbox2_fifo *fifo =
+		&((struct omap_mbox2_priv *)mbox->priv)->tx_fifo;
+	return mbox_read_reg(fifo->fifo_stat);
+}
+
+/* Mailbox IRQ handle functions */
+static void omap2_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox2_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);
+}
+
+static void omap2_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox2_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);
+}
+
+static void omap2_mbox_ack_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox2_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 int omap2_mbox_is_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox2_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);
+}
+
+static void omap2_mbox_save_ctx(struct omap_mbox *mbox)
+{
+	int i;
+	struct omap_mbox2_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]);
+	}
+}
+
+static void omap2_mbox_restore_ctx(struct omap_mbox *mbox)
+{
+	int i;
+	struct omap_mbox2_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]);
+	}
+}
+
+static struct omap_mbox_ops omap2_mbox_ops = {
+	.type		= OMAP_MBOX_TYPE2,
+	.startup	= omap2_mbox_startup,
+	.shutdown	= omap2_mbox_shutdown,
+	.fifo_read	= omap2_mbox_fifo_read,
+	.fifo_write	= omap2_mbox_fifo_write,
+	.fifo_empty	= omap2_mbox_fifo_empty,
+	.fifo_full	= omap2_mbox_fifo_full,
+	.enable_irq	= omap2_mbox_enable_irq,
+	.disable_irq	= omap2_mbox_disable_irq,
+	.ack_irq	= omap2_mbox_ack_irq,
+	.is_irq		= omap2_mbox_is_irq,
+	.save_ctx	= omap2_mbox_save_ctx,
+	.restore_ctx	= omap2_mbox_restore_ctx,
+};
+
+static int omap2_mbox_probe(struct platform_device *pdev)
+{
+	struct resource *mem;
+	int ret;
+	struct omap_mbox **list, *mbox, *mboxblk;
+	struct omap_mbox2_priv *priv, *privblk;
+	struct omap_mbox_pdata *pdata = pdev->dev.platform_data;
+	struct omap_mbox_dev_info *info;
+	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 = kzalloc((pdata->info_cnt + 1) * sizeof(*list), GFP_KERNEL);
+	if (!list)
+		return -ENOMEM;
+
+	mboxblk = mbox = kzalloc(pdata->info_cnt * sizeof(*mbox), GFP_KERNEL);
+	if (!mboxblk) {
+		ret = -ENOMEM;
+		goto free_list;
+	}
+
+	privblk = priv = kzalloc(pdata->info_cnt * sizeof(*priv), GFP_KERNEL);
+	if (!privblk) {
+		ret = -ENOMEM;
+		goto free_mboxblk;
+	}
+
+	info = pdata->info;
+	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);
+		if (pdata->intr_type) {
+			priv->irqenable = OMAP4_MAILBOX_IRQENABLE(info->usr_id);
+			priv->irqstatus = OMAP4_MAILBOX_IRQSTATUS(info->usr_id);
+			priv->irqdisable =
+				OMAP4_MAILBOX_IRQENABLE_CLR(info->usr_id);
+		} else {
+			priv->irqenable = MAILBOX_IRQENABLE(info->usr_id);
+			priv->irqstatus = MAILBOX_IRQSTATUS(info->usr_id);
+			priv->irqdisable = MAILBOX_IRQENABLE(info->usr_id);
+		}
+		priv->intr_type = pdata->intr_type;
+
+		mbox->priv = priv;
+		mbox->name = info->name;
+		mbox->ops = &omap2_mbox_ops;
+		mbox->irq = platform_get_irq(pdev, info->irq_id);
+		if (mbox->irq < 0) {
+			ret = mbox->irq;
+			goto free_privblk;
+		}
+		list[i] = mbox++;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		ret = -ENOENT;
+		goto free_privblk;
+	}
+
+	mbox_base = ioremap(mem->start, resource_size(mem));
+	if (!mbox_base) {
+		ret = -ENOMEM;
+		goto free_privblk;
+	}
+
+	ret = omap_mbox_register(&pdev->dev, list);
+	if (ret)
+		goto unmap_mbox;
+	platform_set_drvdata(pdev, list);
+
+	return 0;
+
+unmap_mbox:
+	iounmap(mbox_base);
+free_privblk:
+	kfree(privblk);
+free_mboxblk:
+	kfree(mboxblk);
+free_list:
+	kfree(list);
+	return ret;
+}
+
+static int omap2_mbox_remove(struct platform_device *pdev)
+{
+	struct omap_mbox2_priv *privblk;
+	struct omap_mbox **list = platform_get_drvdata(pdev);
+	struct omap_mbox *mboxblk = list[0];
+
+	privblk = mboxblk->priv;
+	omap_mbox_unregister();
+	iounmap(mbox_base);
+	kfree(privblk);
+	kfree(mboxblk);
+	kfree(list);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver omap2_mbox_driver = {
+	.probe	= omap2_mbox_probe,
+	.remove	= omap2_mbox_remove,
+	.driver	= {
+		.name = "omap-mailbox",
+	},
+};
+
+static int __init omap2_mbox_init(void)
+{
+	return platform_driver_register(&omap2_mbox_driver);
+}
+
+static void __exit omap2_mbox_exit(void)
+{
+	platform_driver_unregister(&omap2_mbox_driver);
+}
+
+module_init(omap2_mbox_init);
+module_exit(omap2_mbox_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("omap mailbox: omap2/3/4 architecture specific functions");
+MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
+MODULE_AUTHOR("Paul Mundt");
+MODULE_ALIAS("platform:omap2-mailbox");
diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
new file mode 100644
index 00000000000..d79a646b904
--- /dev/null
+++ b/drivers/mailbox/omap-mailbox.c
@@ -0,0 +1,469 @@
+/*
+ * OMAP mailbox driver
+ *
+ * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
+ *
+ * Contact: 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/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/kfifo.h>
+#include <linux/err.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+
+#include "omap-mbox.h"
+
+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)");
+
+/* 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 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);
+}
+
+/*
+ * message sender
+ */
+static int __mbox_poll_for_space(struct omap_mbox *mbox)
+{
+	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);
+	}
+	return ret;
+}
+
+int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
+{
+	struct omap_mbox_queue *mq = mbox->txq;
+	int ret = 0, len;
+
+	spin_lock_bh(&mq->lock);
+
+	if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (kfifo_is_empty(&mq->fifo) && !__mbox_poll_for_space(mbox)) {
+		mbox_fifo_write(mbox, msg);
+		goto out;
+	}
+
+	len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+	WARN_ON(len != sizeof(msg));
+
+	tasklet_schedule(&mbox->txq->tasklet);
+
+out:
+	spin_unlock_bh(&mq->lock);
+	return ret;
+}
+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;
+	}
+
+	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;
+	}
+
+	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);
+}
+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);
+}
+EXPORT_SYMBOL(omap_mbox_disable_irq);
+
+static void mbox_tx_tasklet(unsigned long tx_data)
+{
+	struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
+	struct omap_mbox_queue *mq = mbox->txq;
+	mbox_msg_t msg;
+	int ret;
+
+	while (kfifo_len(&mq->fifo)) {
+		if (__mbox_poll_for_space(mbox)) {
+			omap_mbox_enable_irq(mbox, IRQ_TX);
+			break;
+		}
+
+		ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
+								sizeof(msg));
+		WARN_ON(ret != sizeof(msg));
+
+		mbox_fifo_write(mbox, msg);
+	}
+}
+
+/*
+ * 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);
+	mbox_msg_t msg;
+	int len;
+
+	while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
+		len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+		WARN_ON(len != sizeof(msg));
+
+		blocking_notifier_call_chain(&mq->mbox->notifier, len,
+								(void *)msg);
+		spin_lock_irq(&mq->lock);
+		if (mq->full) {
+			mq->full = false;
+			omap_mbox_enable_irq(mq->mbox, IRQ_RX);
+		}
+		spin_unlock_irq(&mq->lock);
+	}
+}
+
+/*
+ * Mailbox interrupt handler
+ */
+static void __mbox_tx_interrupt(struct omap_mbox *mbox)
+{
+	omap_mbox_disable_irq(mbox, IRQ_TX);
+	ack_mbox_irq(mbox, IRQ_TX);
+	tasklet_schedule(&mbox->txq->tasklet);
+}
+
+static void __mbox_rx_interrupt(struct omap_mbox *mbox)
+{
+	struct omap_mbox_queue *mq = mbox->rxq;
+	mbox_msg_t msg;
+	int len;
+
+	while (!mbox_fifo_empty(mbox)) {
+		if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
+			omap_mbox_disable_irq(mbox, IRQ_RX);
+			mq->full = true;
+			goto nomem;
+		}
+
+		msg = mbox_fifo_read(mbox);
+
+		len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+		WARN_ON(len != sizeof(msg));
+
+		if (mbox->ops->type == OMAP_MBOX_TYPE1)
+			break;
+	}
+
+	/* no more messages in the fifo. clear IRQ source. */
+	ack_mbox_irq(mbox, IRQ_RX);
+nomem:
+	schedule_work(&mbox->rxq->work);
+}
+
+static irqreturn_t mbox_interrupt(int irq, void *p)
+{
+	struct omap_mbox *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;
+}
+
+static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
+					void (*work) (struct work_struct *),
+					void (*tasklet)(unsigned long))
+{
+	struct omap_mbox_queue *mq;
+
+	mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
+	if (!mq)
+		return NULL;
+
+	spin_lock_init(&mq->lock);
+
+	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
+		goto error;
+
+	if (work)
+		INIT_WORK(&mq->work, work);
+
+	if (tasklet)
+		tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
+	return mq;
+error:
+	kfree(mq);
+	return NULL;
+}
+
+static void mbox_queue_free(struct omap_mbox_queue *q)
+{
+	kfifo_free(&q->fifo);
+	kfree(q);
+}
+
+static int omap_mbox_startup(struct omap_mbox *mbox)
+{
+	int ret = 0;
+	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;
+	}
+
+	if (!mbox->use_count++) {
+		mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
+		if (!mq) {
+			ret = -ENOMEM;
+			goto fail_alloc_txq;
+		}
+		mbox->txq = mq;
+
+		mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
+		if (!mq) {
+			ret = -ENOMEM;
+			goto fail_alloc_rxq;
+		}
+		mbox->rxq = mq;
+		mq->mbox = mbox;
+		ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
+							mbox->name, mbox);
+		if (unlikely(ret)) {
+			pr_err("failed to register mailbox interrupt:%d\n",
+									ret);
+			goto fail_request_irq;
+		}
+
+		omap_mbox_enable_irq(mbox, IRQ_RX);
+	}
+	mutex_unlock(&mbox_configured_lock);
+	return 0;
+
+fail_request_irq:
+	mbox_queue_free(mbox->rxq);
+fail_alloc_rxq:
+	mbox_queue_free(mbox->txq);
+fail_alloc_txq:
+	if (mbox->ops->shutdown)
+		mbox->ops->shutdown(mbox);
+	mbox->use_count--;
+fail_startup:
+	mbox_configured--;
+	mutex_unlock(&mbox_configured_lock);
+	return ret;
+}
+
+static void omap_mbox_fini(struct omap_mbox *mbox)
+{
+	mutex_lock(&mbox_configured_lock);
+
+	if (!--mbox->use_count) {
+		omap_mbox_disable_irq(mbox, IRQ_RX);
+		free_irq(mbox->irq, mbox);
+		tasklet_kill(&mbox->txq->tasklet);
+		flush_work(&mbox->rxq->work);
+		mbox_queue_free(mbox->txq);
+		mbox_queue_free(mbox->rxq);
+	}
+
+	if (likely(mbox->ops->shutdown)) {
+		if (!--mbox_configured)
+			mbox->ops->shutdown(mbox);
+	}
+
+	mutex_unlock(&mbox_configured_lock);
+}
+
+struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
+{
+	struct omap_mbox *_mbox, *mbox = NULL;
+	int i, ret;
+
+	if (!mboxes)
+		return ERR_PTR(-EINVAL);
+
+	for (i = 0; (_mbox = mboxes[i]); i++) {
+		if (!strcmp(_mbox->name, name)) {
+			mbox = _mbox;
+			break;
+		}
+	}
+
+	if (!mbox)
+		return ERR_PTR(-ENOENT);
+
+	if (nb)
+		blocking_notifier_chain_register(&mbox->notifier, nb);
+
+	ret = omap_mbox_startup(mbox);
+	if (ret) {
+		blocking_notifier_chain_unregister(&mbox->notifier, nb);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return mbox;
+}
+EXPORT_SYMBOL(omap_mbox_get);
+
+void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
+{
+	blocking_notifier_chain_unregister(&mbox->notifier, nb);
+	omap_mbox_fini(mbox);
+}
+EXPORT_SYMBOL(omap_mbox_put);
+
+static struct class omap_mbox_class = { .name = "mbox", };
+
+int omap_mbox_register(struct device *parent, struct omap_mbox **list)
+{
+	int ret;
+	int i;
+
+	mboxes = list;
+	if (!mboxes)
+		return -EINVAL;
+
+	for (i = 0; mboxes[i]; i++) {
+		struct omap_mbox *mbox = mboxes[i];
+		mbox->dev = device_create(&omap_mbox_class,
+				parent, 0, mbox, "%s", mbox->name);
+		if (IS_ERR(mbox->dev)) {
+			ret = PTR_ERR(mbox->dev);
+			goto err_out;
+		}
+
+		BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
+	}
+	return 0;
+
+err_out:
+	while (i--)
+		device_unregister(mboxes[i]->dev);
+	return ret;
+}
+EXPORT_SYMBOL(omap_mbox_register);
+
+int omap_mbox_unregister(void)
+{
+	int i;
+
+	if (!mboxes)
+		return -EINVAL;
+
+	for (i = 0; mboxes[i]; i++)
+		device_unregister(mboxes[i]->dev);
+	mboxes = NULL;
+	return 0;
+}
+EXPORT_SYMBOL(omap_mbox_unregister);
+
+static int __init omap_mbox_init(void)
+{
+	int err;
+
+	err = class_register(&omap_mbox_class);
+	if (err)
+		return err;
+
+	/* kfifo size sanity check: alignment and minimal size */
+	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
+	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
+							sizeof(mbox_msg_t));
+
+	return 0;
+}
+subsys_initcall(omap_mbox_init);
+
+static void __exit omap_mbox_exit(void)
+{
+	class_unregister(&omap_mbox_class);
+}
+module_exit(omap_mbox_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
+MODULE_AUTHOR("Toshihiro Kobayashi");
+MODULE_AUTHOR("Hiroshi DOYU");
diff --git a/drivers/mailbox/omap-mbox.h b/drivers/mailbox/omap-mbox.h
new file mode 100644
index 00000000000..6cd38fc6859
--- /dev/null
+++ b/drivers/mailbox/omap-mbox.h
@@ -0,0 +1,67 @@
+/*
+ * omap-mbox.h: OMAP mailbox internal definitions
+ *
+ * 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.
+ */
+
+#ifndef OMAP_MBOX_H
+#define OMAP_MBOX_H
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+#include <linux/omap-mailbox.h>
+
+typedef int __bitwise omap_mbox_type_t;
+#define OMAP_MBOX_TYPE1 ((__force omap_mbox_type_t) 1)
+#define OMAP_MBOX_TYPE2 ((__force omap_mbox_type_t) 2)
+
+struct omap_mbox_ops {
+	omap_mbox_type_t	type;
+	int		(*startup)(struct omap_mbox *mbox);
+	void		(*shutdown)(struct omap_mbox *mbox);
+	/* fifo */
+	mbox_msg_t	(*fifo_read)(struct omap_mbox *mbox);
+	void		(*fifo_write)(struct omap_mbox *mbox, mbox_msg_t msg);
+	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		(*ack_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
+	int		(*is_irq)(struct omap_mbox *mbox, omap_mbox_irq_t irq);
+	/* ctx */
+	void		(*save_ctx)(struct omap_mbox *mbox);
+	void		(*restore_ctx)(struct omap_mbox *mbox);
+};
+
+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;
+	unsigned int		irq;
+	struct omap_mbox_queue	*txq, *rxq;
+	struct omap_mbox_ops	*ops;
+	struct device		*dev;
+	void			*priv;
+	int			use_count;
+	struct blocking_notifier_head	notifier;
+};
+
+int omap_mbox_register(struct device *parent, struct omap_mbox **);
+int omap_mbox_unregister(void);
+
+#endif /* OMAP_MBOX_H */