[v4,2/4] mailbox: Hi6220: add mailbox driver

Message ID 1444667535-16948-3-git-send-email-leo.yan@linaro.org
State New
Headers show

Commit Message

Leo Yan Oct. 12, 2015, 4:32 p.m.
Add driver for Hi6220 mailbox, the mailbox communicates with MCU; for
sending data, it can support two methods for low level implementation:
one is to use interrupt as acknowledge, another is automatic mode which
without any acknowledge. These two methods have been supported in the
driver. For receiving data, it will depend on the interrupt to notify
the channel has incoming message.

Now mailbox driver is used to send message to MCU to control dynamic
voltage and frequency scaling for CPU, GPU and DDR.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 drivers/mailbox/Kconfig          |   8 +
 drivers/mailbox/Makefile         |   2 +
 drivers/mailbox/hi6220-mailbox.c | 371 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 381 insertions(+)
 create mode 100644 drivers/mailbox/hi6220-mailbox.c

Comments

Jassi Brar Oct. 16, 2015, 5:13 a.m. | #1
On Mon, Oct 12, 2015 at 10:02 PM, Leo Yan <leo.yan@linaro.org> wrote:

> +
> +#define MBOX_CHAN_MAX                  32
> +#define MBOX_CHAN_NUM                  2
> +
You mean the hardware has 32 channels but this driver can not manage
more than 2 ?

OR, there are 32 interfaces but only 2 physical 'floating' links, so
no more than 2 interfaces can be active at any time?
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Leo Yan Oct. 16, 2015, 5:29 a.m. | #2
On Fri, Oct 16, 2015 at 10:43:00AM +0530, Jassi Brar wrote:
> On Mon, Oct 12, 2015 at 10:02 PM, Leo Yan <leo.yan@linaro.org> wrote:
> 
> > +
> > +#define MBOX_CHAN_MAX                  32
> > +#define MBOX_CHAN_NUM                  2
> > +
> You mean the hardware has 32 channels but this driver can not manage
> more than 2 ?
> 
> OR, there are 32 interfaces but only 2 physical 'floating' links, so
> no more than 2 interfaces can be active at any time?

For the later case. Mailbox also can be used by other modules, such
like audio hifi; later need add links for them if want to enable
audio. But so far only uses first 2 channels.

Thanks,
Leo Yan
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Jassi Brar Oct. 16, 2015, 5:47 a.m. | #3
On Fri, Oct 16, 2015 at 10:59 AM, Leo Yan <leo.yan@linaro.org> wrote:
> On Fri, Oct 16, 2015 at 10:43:00AM +0530, Jassi Brar wrote:
>> On Mon, Oct 12, 2015 at 10:02 PM, Leo Yan <leo.yan@linaro.org> wrote:
>>
>> > +
>> > +#define MBOX_CHAN_MAX                  32
>> > +#define MBOX_CHAN_NUM                  2
>> > +
>> You mean the hardware has 32 channels but this driver can not manage
>> more than 2 ?
>>
>> OR, there are 32 interfaces but only 2 physical 'floating' links, so
>> no more than 2 interfaces can be active at any time?
>
> For the later case.
Former is a s/w limitation and latter is h/w limitation. From what you
write below, it seems former to be the case.

> Mailbox also can be used by other modules, such
> like audio hifi; later need add links for them if want to enable
> audio. But so far only uses first 2 channels.
>
You mean every time your platform needs another channel, you'll update
the driver? Not sure about that. It should be simpler to assign which
ever and as many channels as the client asks via DT.
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Leo Yan Oct. 16, 2015, 6:08 a.m. | #4
On Fri, Oct 16, 2015 at 11:17:32AM +0530, Jassi Brar wrote:
> On Fri, Oct 16, 2015 at 10:59 AM, Leo Yan <leo.yan@linaro.org> wrote:
> > On Fri, Oct 16, 2015 at 10:43:00AM +0530, Jassi Brar wrote:
> >> On Mon, Oct 12, 2015 at 10:02 PM, Leo Yan <leo.yan@linaro.org> wrote:
> >>
> >> > +
> >> > +#define MBOX_CHAN_MAX                  32
> >> > +#define MBOX_CHAN_NUM                  2
> >> > +
> >> You mean the hardware has 32 channels but this driver can not manage
> >> more than 2 ?
> >>
> >> OR, there are 32 interfaces but only 2 physical 'floating' links, so
> >> no more than 2 interfaces can be active at any time?
> >
> > For the later case.
> Former is a s/w limitation and latter is h/w limitation. From what you
> write below, it seems former to be the case.

Sorry, i misunderstood the question. It's a s/w limitation.

> > Mailbox also can be used by other modules, such
> > like audio hifi; later need add links for them if want to enable
> > audio. But so far only uses first 2 channels.
> >
> You mean every time your platform needs another channel, you'll update
> the driver? Not sure about that. It should be simpler to assign which
> ever and as many channels as the client asks via DT.

For hi6220, every channel is fixed to specific purpose; so i can
register all of them in driver, such like hifi related channels;
Though i cannot test them currently, but this will avoid extra
efforts for enabling channels anymore, do you think this is okay?
Or you prefer to bind with DT?

Thanks,
Leo Yan
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Jassi Brar Oct. 16, 2015, 6:12 a.m. | #5
On 16 October 2015 at 11:38, Leo Yan <leo.yan@linaro.org> wrote:
> On Fri, Oct 16, 2015 at 11:17:32AM +0530, Jassi Brar wrote:
>> On Fri, Oct 16, 2015 at 10:59 AM, Leo Yan <leo.yan@linaro.org> wrote:
>> > On Fri, Oct 16, 2015 at 10:43:00AM +0530, Jassi Brar wrote:
>> >> On Mon, Oct 12, 2015 at 10:02 PM, Leo Yan <leo.yan@linaro.org> wrote:
>> >>
>> >> > +
>> >> > +#define MBOX_CHAN_MAX                  32
>> >> > +#define MBOX_CHAN_NUM                  2
>> >> > +
>> >> You mean the hardware has 32 channels but this driver can not manage
>> >> more than 2 ?
>> >>
>> >> OR, there are 32 interfaces but only 2 physical 'floating' links, so
>> >> no more than 2 interfaces can be active at any time?
>> >
>> > For the later case.
>> Former is a s/w limitation and latter is h/w limitation. From what you
>> write below, it seems former to be the case.
>
> Sorry, i misunderstood the question. It's a s/w limitation.
>
>> > Mailbox also can be used by other modules, such
>> > like audio hifi; later need add links for them if want to enable
>> > audio. But so far only uses first 2 channels.
>> >
>> You mean every time your platform needs another channel, you'll update
>> the driver? Not sure about that. It should be simpler to assign which
>> ever and as many channels as the client asks via DT.
>
> For hi6220, every channel is fixed to specific purpose;
on different platform the purposes may be different, so ....

> so i can
> register all of them in driver, such like hifi related channels;
> Though i cannot test them currently, but this will avoid extra
> efforts for enabling channels anymore, do you think this is okay?
> Or you prefer to bind with DT?
>
.... DT please.
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Leo Yan Oct. 16, 2015, 6:18 a.m. | #6
On Fri, Oct 16, 2015 at 11:42:54AM +0530, Jassi Brar wrote:
> On 16 October 2015 at 11:38, Leo Yan <leo.yan@linaro.org> wrote:
> > On Fri, Oct 16, 2015 at 11:17:32AM +0530, Jassi Brar wrote:
> >> On Fri, Oct 16, 2015 at 10:59 AM, Leo Yan <leo.yan@linaro.org> wrote:
> >> > On Fri, Oct 16, 2015 at 10:43:00AM +0530, Jassi Brar wrote:
> >> >> On Mon, Oct 12, 2015 at 10:02 PM, Leo Yan <leo.yan@linaro.org> wrote:
> >> >>
> >> >> > +
> >> >> > +#define MBOX_CHAN_MAX                  32
> >> >> > +#define MBOX_CHAN_NUM                  2
> >> >> > +
> >> >> You mean the hardware has 32 channels but this driver can not manage
> >> >> more than 2 ?
> >> >>
> >> >> OR, there are 32 interfaces but only 2 physical 'floating' links, so
> >> >> no more than 2 interfaces can be active at any time?
> >> >
> >> > For the later case.
> >> Former is a s/w limitation and latter is h/w limitation. From what you
> >> write below, it seems former to be the case.
> >
> > Sorry, i misunderstood the question. It's a s/w limitation.
> >
> >> > Mailbox also can be used by other modules, such
> >> > like audio hifi; later need add links for them if want to enable
> >> > audio. But so far only uses first 2 channels.
> >> >
> >> You mean every time your platform needs another channel, you'll update
> >> the driver? Not sure about that. It should be simpler to assign which
> >> ever and as many channels as the client asks via DT.
> >
> > For hi6220, every channel is fixed to specific purpose;
> on different platform the purposes may be different, so ....
> 
> > so i can
> > register all of them in driver, such like hifi related channels;
> > Though i cannot test them currently, but this will avoid extra
> > efforts for enabling channels anymore, do you think this is okay?
> > Or you prefer to bind with DT?
> >
> .... DT please.

Ok, will do this.

Thansk,
Leo Yan
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Patch

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index bbec500..41fb7fa 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -71,4 +71,12 @@  config BCM2835_MBOX
 	  the services of the Videocore. Say Y here if you want to use the
 	  BCM2835 Mailbox.
 
+config HI6220_MBOX
+	tristate "Hi6220 Mailbox"
+	depends on ARCH_HISI
+	help
+	  An implementation of the hi6220 mailbox. It is used to send message
+	  between application processors and MCU. Say Y here if you want to build
+	  the Hi6220 mailbox controller driver.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 8e6d822..4ba9f5f 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -13,3 +13,5 @@  obj-$(CONFIG_PCC)		+= pcc.o
 obj-$(CONFIG_ALTERA_MBOX)	+= mailbox-altera.o
 
 obj-$(CONFIG_BCM2835_MBOX)	+= bcm2835-mailbox.o
+
+obj-$(CONFIG_HI6220_MBOX)	+= hi6220-mailbox.o
diff --git a/drivers/mailbox/hi6220-mailbox.c b/drivers/mailbox/hi6220-mailbox.c
new file mode 100644
index 0000000..c0e19d5
--- /dev/null
+++ b/drivers/mailbox/hi6220-mailbox.c
@@ -0,0 +1,371 @@ 
+/*
+ * Hisilicon's Hi6220 mailbox driver
+ *
+ * Copyright (c) 2015 Hisilicon Limited.
+ * Copyright (c) 2015 Linaro Limited.
+ *
+ * Author: Leo Yan <leo.yan@linaro.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kfifo.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define MBOX_CHAN_MAX			32
+#define MBOX_CHAN_NUM			2
+
+#define MBOX_RX				0x0
+#define MBOX_TX				0x1
+
+/* Mailbox message length: 8 words */
+#define MBOX_MSG_LEN			8
+
+/* Mailbox Registers */
+#define MBOX_OFF(m)			(0x40 * (m))
+#define MBOX_MODE_REG(m)		(MBOX_OFF(m) + 0x0)
+#define MBOX_DATA_REG(m)		(MBOX_OFF(m) + 0x4)
+
+#define MBOX_STATE_MASK			(0xF << 4)
+#define MBOX_STATE_IDLE			(0x1 << 4)
+#define MBOX_STATE_TX			(0x2 << 4)
+#define MBOX_STATE_RX			(0x4 << 4)
+#define MBOX_STATE_ACK			(0x8 << 4)
+#define MBOX_ACK_CONFIG_MASK		(0x1 << 0)
+#define MBOX_ACK_AUTOMATIC		(0x1 << 0)
+#define MBOX_ACK_IRQ			(0x0 << 0)
+
+/* IPC registers */
+#define ACK_INT_RAW_REG(i)		((i) + 0x400)
+#define ACK_INT_MSK_REG(i)		((i) + 0x404)
+#define ACK_INT_STAT_REG(i)		((i) + 0x408)
+#define ACK_INT_CLR_REG(i)		((i) + 0x40c)
+#define ACK_INT_ENA_REG(i)		((i) + 0x500)
+#define ACK_INT_DIS_REG(i)		((i) + 0x504)
+#define DST_INT_RAW_REG(i)		((i) + 0x420)
+
+
+struct hi6220_mbox_chan {
+
+	/*
+	 * Description for channel's hardware info:
+	 *  - direction: tx or rx
+	 *  - dst irq: peer core's irq number
+	 *  - ack irq: local irq number
+	 *  - slot number
+	 */
+	unsigned int dir, dst_irq, ack_irq;
+	unsigned int slot;
+
+	struct hi6220_mbox *parent;
+};
+
+struct hi6220_mbox {
+	struct device *dev;
+
+	int irq;
+
+	/* flag of enabling tx's irq mode */
+	bool tx_irq_mode;
+
+	/* region for ipc event */
+	void __iomem *ipc;
+
+	/* region for mailbox */
+	void __iomem *base;
+
+	unsigned int chan_num;
+	struct hi6220_mbox_chan *mchan;
+
+	void *irq_map_chan[MBOX_CHAN_MAX];
+	struct mbox_chan *chan;
+	struct mbox_controller controller;
+};
+
+static void mbox_set_state(struct hi6220_mbox *mbox,
+			   unsigned int slot, u32 val)
+{
+	u32 status;
+
+	status = readl(mbox->base + MBOX_MODE_REG(slot));
+	status = (status & ~MBOX_STATE_MASK) | val;
+	writel(status, mbox->base + MBOX_MODE_REG(slot));
+}
+
+static void mbox_set_mode(struct hi6220_mbox *mbox,
+			  unsigned int slot, u32 val)
+{
+	u32 mode;
+
+	mode = readl(mbox->base + MBOX_MODE_REG(slot));
+	mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
+	writel(mode, mbox->base + MBOX_MODE_REG(slot));
+}
+
+static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+	u32 state;
+
+	/* Only set idle state for polling mode */
+	BUG_ON(mbox->tx_irq_mode);
+
+	state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
+	return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
+}
+
+static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+	unsigned int slot = mchan->slot;
+	u32 *buf = msg;
+	int i;
+
+	mbox_set_state(mbox, slot, MBOX_STATE_TX);
+
+	if (mbox->tx_irq_mode)
+		mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
+	else
+		mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
+
+	for (i = 0; i < MBOX_MSG_LEN; i++)
+		writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
+
+	/* trigger remote request */
+	writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
+	return 0;
+}
+
+static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
+{
+	struct hi6220_mbox *mbox = p;
+	struct hi6220_mbox_chan *mchan;
+	struct mbox_chan *chan;
+	unsigned int state, intr_bit, i;
+	u32 msg[MBOX_MSG_LEN];
+
+	state = readl(ACK_INT_STAT_REG(mbox->ipc));
+	if (!state) {
+		dev_warn(mbox->dev, "%s: spurious interrupt\n",
+			 __func__);
+		return IRQ_HANDLED;
+	}
+
+	while (state) {
+		intr_bit = __ffs(state);
+		state &= (state - 1);
+
+		chan = mbox->irq_map_chan[intr_bit];
+		if (!chan) {
+			dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
+				 __func__, intr_bit);
+			continue;
+		}
+
+		mchan = chan->con_priv;
+		if (mchan->dir == MBOX_TX)
+			mbox_chan_txdone(chan, 0);
+		else {
+			for (i = 0; i < MBOX_MSG_LEN; i++)
+				msg[i] = readl(mbox->base +
+					MBOX_DATA_REG(mchan->slot) + i * 4);
+
+			mbox_chan_received_data(chan, (void *)msg);
+		}
+
+		/* clear IRQ source */
+		writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
+		mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int hi6220_mbox_startup(struct mbox_chan *chan)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+
+	mbox->irq_map_chan[mchan->ack_irq] = (void *)chan;
+
+	/* enable interrupt */
+	writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
+	return 0;
+}
+
+static void hi6220_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+
+	/* disable interrupt */
+	writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
+	mbox->irq_map_chan[mchan->ack_irq] = NULL;
+}
+
+static struct mbox_chan_ops hi6220_mbox_chan_ops = {
+	.send_data    = hi6220_mbox_send_data,
+	.startup      = hi6220_mbox_startup,
+	.shutdown     = hi6220_mbox_shutdown,
+	.last_tx_done = hi6220_mbox_last_tx_done,
+};
+
+static void hi6220_mbox_init_hw(struct hi6220_mbox *mbox)
+{
+	struct hi6220_mbox_chan init_data[MBOX_CHAN_NUM] = {
+		{ MBOX_RX, 1, 10 },
+		{ MBOX_TX, 0, 11 },
+	};
+	struct hi6220_mbox_chan *mchan = mbox->mchan;
+	int i;
+
+	for (i = 0; i < MBOX_CHAN_NUM; i++) {
+		memcpy(&mchan[i], &init_data[i], sizeof(*mchan));
+		mchan[i].slot = i;
+		mchan[i].parent = mbox;
+	}
+
+	/* mask and clear all interrupt vectors */
+	writel(0x0,  ACK_INT_MSK_REG(mbox->ipc));
+	writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
+
+	/* use interrupt for tx's ack */
+	mbox->tx_irq_mode = true;
+}
+
+static const struct of_device_id hi6220_mbox_of_match[] = {
+	{ .compatible = "hisilicon,hi6220-mbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
+
+static int hi6220_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct hi6220_mbox *mbox;
+	struct resource *res;
+	int i, err;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	mbox->dev = dev;
+	mbox->chan_num = MBOX_CHAN_NUM;
+	mbox->mchan = devm_kzalloc(dev,
+		mbox->chan_num * sizeof(*mbox->mchan), GFP_KERNEL);
+	if (!mbox->mchan)
+		return -ENOMEM;
+
+	mbox->chan = devm_kzalloc(dev,
+		mbox->chan_num * sizeof(*mbox->chan), GFP_KERNEL);
+	if (!mbox->chan)
+		return -ENOMEM;
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	if (mbox->irq < 0)
+		return mbox->irq;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mbox->ipc = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mbox->ipc)) {
+		dev_err(dev, "ioremap ipc failed\n");
+		return PTR_ERR(mbox->ipc);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	mbox->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(mbox->base)) {
+		dev_err(dev, "ioremap buffer failed\n");
+		return PTR_ERR(mbox->base);
+	}
+
+	err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
+			dev_name(dev), mbox);
+	if (err) {
+		dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
+			err);
+		return -ENODEV;
+	}
+
+	/* init hardware parameters */
+	hi6220_mbox_init_hw(mbox);
+
+	for (i = 0; i < mbox->chan_num; i++) {
+		mbox->chan[i].con_priv = &mbox->mchan[i];
+		mbox->irq_map_chan[i] = NULL;
+	}
+
+	mbox->controller.dev = dev;
+	mbox->controller.chans = &mbox->chan[0];
+	mbox->controller.num_chans = mbox->chan_num;
+	mbox->controller.ops = &hi6220_mbox_chan_ops;
+
+	if (mbox->tx_irq_mode)
+		mbox->controller.txdone_irq = true;
+	else {
+		mbox->controller.txdone_poll = true;
+		mbox->controller.txpoll_period = 5;
+	}
+
+	err = mbox_controller_register(&mbox->controller);
+	if (err) {
+		dev_err(dev, "Failed to register mailbox %d\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	dev_info(dev, "Mailbox enabled\n");
+	return 0;
+}
+
+static int hi6220_mbox_remove(struct platform_device *pdev)
+{
+	struct hi6220_mbox *mbox = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&mbox->controller);
+	return 0;
+}
+
+static struct platform_driver hi6220_mbox_driver = {
+	.driver = {
+		.name = "hi6220-mbox",
+		.owner = THIS_MODULE,
+		.of_match_table = hi6220_mbox_of_match,
+	},
+	.probe	= hi6220_mbox_probe,
+	.remove	= hi6220_mbox_remove,
+};
+
+static int __init hi6220_mbox_init(void)
+{
+	return platform_driver_register(&hi6220_mbox_driver);
+}
+core_initcall(hi6220_mbox_init);
+
+static void __exit hi6220_mbox_exit(void)
+{
+	platform_driver_unregister(&hi6220_mbox_driver);
+}
+module_exit(hi6220_mbox_exit);
+
+MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
+MODULE_DESCRIPTION("Hi6220 mailbox driver");
+MODULE_LICENSE("GPL v2");