[PATCH 1/1] gpio_mouse driver

[PATCH 1/1] gpio_mouse driver

[Hans-Christian Egtvedt]

This patch adds support for simulating a mouse using GPIO lines.

The driver needs a platform_data struct to be defined and registered with the
appropriate platform_device.

The driver has been tested on AT32AP7000 microprocessor using the ATSTK1000
development board.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
---
 drivers/input/mouse/Kconfig      |   15 ++
 drivers/input/mouse/Makefile     |    1 +
 drivers/input/mouse/gpio_mouse.c |  281 ++++++++++++++++++++++++++++++++++++++
 include/linux/gpio_mouse.h       |   53 +++++++
 4 files changed, 350 insertions(+), 0 deletions(-)

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 35d998c..a3c7057 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -125,4 +125,19 @@ config MOUSE_HIL
 	help
 	  Say Y here to support HIL pointers.
 
+config MOUSE_GPIO
+	tristate "GPIO mouse"
+	depends on GENERIC_GPIO
+	help
+	  This driver simulates a mouse on GPIO lines of various CPUs (and some
+	  other chips).
+
+	  Say Y here if your device has buttons or a simple joystick connected
+	  directly to GPIO lines. Your board-specific setup logic must also
+	  provide a platform device and platform data saying which GPIOs are
+	  used.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called gpio_mouse.
+
 endif
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 21a1de6..5d0fc43 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -13,5 +13,6 @@ obj-$(CONFIG_MOUSE_PS2)		+= psmouse.o
 obj-$(CONFIG_MOUSE_SERIAL)	+= sermouse.o
 obj-$(CONFIG_MOUSE_HIL)		+= hil_ptr.o
 obj-$(CONFIG_MOUSE_VSXXXAA)	+= vsxxxaa.o
+obj-$(CONFIG_MOUSE_GPIO)	+= gpio_mouse.o
 
 psmouse-objs  := psmouse-base.o alps.o logips2pp.o synaptics.o lifebook.o trackpoint.o
diff --git a/drivers/input/mouse/gpio_mouse.c b/drivers/input/mouse/gpio_mouse.c
new file mode 100644
index 0000000..7a95185
--- /dev/null
+++ b/drivers/input/mouse/gpio_mouse.c
@@ -0,0 +1,281 @@
+/*
+ * Driver for simulating a mouse on GPIO lines.
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/gpio_mouse.h>
+
+#include <asm/gpio.h>
+
+/*
+ * Timer function which is run every scan_ms ms when the device is opened. The
+ * dev input varaible is set to the the input_dev pointer.
+ */
+static void gpio_mouse_scan(unsigned long _dev)
+{
+	struct input_dev *input = (struct input_dev *)_dev;
+	struct gpio_mouse_platform_data *gpio = input->private;
+	int x, y;
+
+	if (gpio->bleft >= 0)
+		input_report_key(input, BTN_LEFT,
+				gpio_get_value(gpio->bleft) ^ gpio->polarity);
+	if (gpio->bmiddle >= 0)
+		input_report_key(input, BTN_MIDDLE,
+				gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
+	if (gpio->bright >= 0)
+		input_report_key(input, BTN_RIGHT,
+				gpio_get_value(gpio->bright) ^ gpio->polarity);
+
+	x = (gpio_get_value(gpio->right) ^ gpio->polarity)
+		- (gpio_get_value(gpio->left) ^ gpio->polarity);
+	y = (gpio_get_value(gpio->down) ^ gpio->polarity)
+		- (gpio_get_value(gpio->up) ^ gpio->polarity);
+
+	input_report_rel(input, REL_X, x);
+	input_report_rel(input, REL_Y, y);
+	input_sync(input);
+
+	mod_timer(&gpio->timer, jiffies + msecs_to_jiffies(gpio->scan_ms));
+}
+
+/* Only start the timer when the device is actually in use, i.e. opened. */
+static int gpio_mouse_open(struct input_dev *input)
+{
+	struct gpio_mouse_platform_data *gpio = input->private;
+	gpio->timer.expires = jiffies + msecs_to_jiffies(gpio->scan_ms);
+	gpio->timer.data = (unsigned long)input;
+	add_timer(&gpio->timer);
+	return 0;
+}
+
+static void gpio_mouse_close(struct input_dev *input)
+{
+	struct gpio_mouse_platform_data *gpio = input->private;
+	del_timer_sync(&gpio->timer);
+}
+
+static int __init gpio_mouse_probe(struct platform_device *pdev)
+{
+	struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
+	struct input_dev *input;
+	int ret;
+
+	if (!pdata) {
+		dev_dbg(&pdev->dev, "no platform data\n");
+		ret = -ENXIO;
+		goto out;
+	}
+
+	if (pdata->up < 0 || pdata->down < 0 || pdata->right < 0
+			|| pdata->left < 0) {
+		dev_dbg(&pdev->dev, "missing GPIO for directions\n");
+		ret = -EINVAL;
+		goto out;
+	}
+	if (pdata->scan_ms < 0) {
+		dev_dbg(&pdev->dev, "invalid scan time\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Mouse direction, required. */
+	ret = gpio_request(pdata->up, "gpio_mouse_up");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail up pin\n");
+		goto out_gpio_up;
+	}
+	ret = gpio_request(pdata->down, "gpio_mouse_down");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail down pin\n");
+		goto out_gpio_down;
+	}
+	ret = gpio_request(pdata->left, "gpio_mouse_left");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail left pin\n");
+		goto out_gpio_left;
+	}
+	ret = gpio_request(pdata->right, "gpio_mouse_right");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail right pin\n");
+		goto out_gpio_right;
+	}
+
+	gpio_direction_input(pdata->up);
+	gpio_direction_input(pdata->down);
+	gpio_direction_input(pdata->left);
+	gpio_direction_input(pdata->right);
+
+	/* Mouse buttons, not required, but should at least have bleft. */
+	if (pdata->bleft >= 0) {
+		ret = gpio_request(pdata->bleft, "gpio_mouse_bleft");
+		if (ret) {
+			dev_dbg(&pdev->dev, "fail bleft pin\n");
+			goto out_gpio_bleft;
+		}
+		gpio_direction_input(pdata->bleft);
+	} else {
+		dev_dbg(&pdev->dev, "no left button defined\n");
+	}
+	if (pdata->bmiddle >= 0) {
+		ret = gpio_request(pdata->bmiddle, "gpio_mouse_bmiddle");
+		if (ret) {
+			dev_dbg(&pdev->dev, "fail bmiddle pin\n");
+			goto out_gpio_bmiddle;
+		}
+		gpio_direction_input(pdata->bmiddle);
+	}
+	if (pdata->bright >= 0) {
+		ret = gpio_request(pdata->bright, "gpio_mouse_bright");
+		if (ret) {
+			dev_dbg(&pdev->dev, "fail bright pin\n");
+			goto out_gpio_bright;
+		}
+		gpio_direction_input(pdata->bright);
+	}
+
+	input = input_allocate_device();
+	if (!input) {
+		dev_dbg(&pdev->dev, "not enough memory for input device\n");
+		ret = -ENOMEM;
+		goto out_input_allocate;
+	}
+
+	platform_set_drvdata(pdev, input);
+
+	input->name = pdev->name;
+	input->cdev.dev = &pdev->dev;
+	input->private = pdata;
+
+	/*
+	 * Revisit: is bustype, vendor, product and version needed to
+	 * input->id? And if they should be present, what values should they
+	 * have?
+	 */
+
+	input->evbit[0] = BIT(EV_REL);
+	if (pdata->bleft >= 0 || pdata->bmiddle >= 0 || pdata->bright >= 0) {
+		input->evbit[0] |= BIT(EV_KEY);
+
+		if (pdata->bleft >= 0)
+			input->keybit[LONG(BTN_MOUSE)] = BIT(BTN_LEFT);
+		if (pdata->bmiddle >= 0)
+			input->keybit[LONG(BTN_MOUSE)] |= BIT(BTN_MIDDLE);
+		if (pdata->bright >= 0)
+			input->keybit[LONG(BTN_MOUSE)] |= BIT(BTN_RIGHT);
+	}
+	input->relbit[0] = BIT(REL_X) | BIT(REL_Y);
+
+	input->open = gpio_mouse_open;
+	input->close = gpio_mouse_close;
+
+	/* Init the scan timer. */
+	pdata->timer.function = gpio_mouse_scan;
+	pdata->timer.base = &boot_tvec_bases;
+
+	ret = input_register_device(input);
+	if (ret) {
+		dev_dbg(&pdev->dev, "could not register input device\n");
+		goto out_reg_dev;
+	}
+
+	dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
+			pdata->scan_ms,
+			pdata->bleft < 0 ? "" : "left ",
+			pdata->bmiddle < 0 ? "" : "middle ",
+			pdata->bright < 0 ? "" : "right");
+
+	return 0;
+
+out_reg_dev:
+	input_free_device(input);
+	platform_set_drvdata(pdev, NULL);
+out_input_allocate:
+	if (pdata->bright >= 0)
+		gpio_free(pdata->bright);
+out_gpio_bright:
+	if (pdata->bmiddle >= 0)
+		gpio_free(pdata->bmiddle);
+out_gpio_bmiddle:
+	if (pdata->bleft >= 0)
+		gpio_free(pdata->bleft);
+out_gpio_bleft:
+	if (pdata->right >= 0)
+		gpio_free(pdata->right);
+out_gpio_right:
+	if (pdata->left >= 0)
+		gpio_free(pdata->left);
+out_gpio_left:
+	if (pdata->down >= 0)
+		gpio_free(pdata->down);
+out_gpio_down:
+	if (pdata->up >= 0)
+		gpio_free(pdata->up);
+out_gpio_up:
+out:
+	return ret;
+}
+
+static int __exit gpio_mouse_remove(struct platform_device *pdev)
+{
+	struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
+	struct input_dev *input = platform_get_drvdata(pdev);
+
+	if (input)
+		input_unregister_device(input);
+
+	if (pdata->up >= 0)
+		gpio_free(pdata->up);
+	if (pdata->down >= 0)
+		gpio_free(pdata->down);
+	if (pdata->left >= 0)
+		gpio_free(pdata->left);
+	if (pdata->right >= 0)
+		gpio_free(pdata->right);
+	if (pdata->bleft >= 0)
+		gpio_free(pdata->bleft);
+	if (pdata->bmiddle >= 0)
+		gpio_free(pdata->bmiddle);
+	if (pdata->bright >= 0)
+		gpio_free(pdata->bright);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+struct platform_driver gpio_mouse_device_driver = {
+	.remove		= __exit_p(gpio_mouse_remove),
+	.driver		= {
+		.name	= "gpio_mouse",
+	}
+};
+
+static int __init gpio_mouse_init(void)
+{
+	return platform_driver_probe(&gpio_mouse_device_driver,
+			gpio_mouse_probe);
+}
+module_init(gpio_mouse_init);
+
+static void __exit gpio_mouse_exit(void)
+{
+	platform_driver_unregister(&gpio_mouse_device_driver);
+}
+module_exit(gpio_mouse_exit);
+
+MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
+MODULE_DESCRIPTION("GPIO mouse driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/gpio_mouse.h b/include/linux/gpio_mouse.h
new file mode 100644
index 0000000..8b01950
--- /dev/null
+++ b/include/linux/gpio_mouse.h
@@ -0,0 +1,53 @@
+/*
+ * Driver for simulating a mouse on GPIO lines.
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * 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 _GPIO_MOUSE_H
+#define _GPIO_MOUSE_H
+
+#include <linux/timer.h>
+
+#define GPIO_MOUSE_POLARITY_ACT_HIGH	0x00
+#define GPIO_MOUSE_POLARITY_ACT_LOW	0x01
+
+/**
+ * struct gpio_mouse_platform_data
+ * @scan_ms: integer in ms specifying the scan periode.
+ * @polarity: Pin polarity, active high or low.
+ * @up: GPIO line for up value.
+ * @down: GPIO line for down value.
+ * @left: GPIO line for left value.
+ * @right: GPIO line for right value.
+ * @bleft: GPIO line for left button.
+ * @bright: GPIO line for right button.
+ * @bmiddle: GPIO line for middle button.
+ * @timer: placeholder for struct timer_list initialized in the driver.
+ *
+ * This struct must be added to the platform_device in the board code. It is
+ * used by the gpio_mouse driver to setup GPIO lines, calculate mouse movement
+ * and have a reference to the timer used for scanning.
+ */
+struct gpio_mouse_platform_data {
+	int scan_ms;
+	int polarity;
+
+	int up;
+	int down;
+	int left;
+	int right;
+
+	int bleft;
+	int bmiddle;
+	int bright;
+
+	/* private */
+	struct timer_list timer;
+};
+
+#endif /* _GPIO_MOUSE_H */
-- 
1.4.4.2

Re: [PATCH 1/1] gpio_mouse driver

[Dmitry Torokhov]

Hi,

On 5/29/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
> This patch adds support for simulating a mouse using GPIO lines.
>
> The driver needs a platform_data struct to be defined and registered with the
> appropriate platform_device.
>
> The driver has been tested on AT32AP7000 microprocessor using the ATSTK1000
> development board.
>

It looks sane although I would recommend switching to input-polldev
when implementing a polled input device.

> +
> +       input->name = pdev->name;
> +       input->cdev.dev = &pdev->dev;

Please use input->dev.parent = &pdev->dev. Input devices are being
moved from class_device to struct device.

> +       input->private = pdata;
> +
> +       /*
> +        * Revisit: is bustype, vendor, product and version needed to
> +        * input->id? And if they should be present, what values should they
> +        * have?
> +        */

BUS_HOST seems to be most suitable here. The rest may stay 0.

> +
> +       /* private */
> +       struct timer_list timer;
> +};

I don't think it is a good idea to have timer structure in platform
data which should really be constant. Timer shoudl be part of the
stucture created when driver binds to a device. I can see you may not
want to introduce extra complexity in the driver; however if you use
input-polldev it will handle timer for you.

-- 
Dmitry

Re: [PATCH 1/1] gpio_mouse driver

[Hans-Christian Egtvedt]

[-- Attachment #1: Type: text/plain, Size: 2023 bytes --]

On Tue, 2007-05-29 at 11:36 -0400, Dmitry Torokhov wrote:
> Hi,
> 
> On 5/29/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
> > This patch adds support for simulating a mouse using GPIO lines.
> >
> > The driver needs a platform_data struct to be defined and registered with the
> > appropriate platform_device.
> >
> > The driver has been tested on AT32AP7000 microprocessor using the ATSTK1000
> > development board.
> >
> 
> It looks sane although I would recommend switching to input-polldev
> when implementing a polled input device.

Oh, I was not aware about this, it seems like just the thing I need.

Could it be scheduled for after the official kernel has this included?
AFAICT it will be released with 2.6.22?

I have attached a new patch with some minor modifications.

> > +
> > +       input->name = pdev->name;
> > +       input->cdev.dev = &pdev->dev;
> 
> Please use input->dev.parent = &pdev->dev. Input devices are being
> moved from class_device to struct device.

This is not present in 2.6.21.1, could I schedule it for the next update
of the driver as above?

> > +       input->private = pdata;
> > +
> > +       /*
> > +        * Revisit: is bustype, vendor, product and version needed to
> > +        * input->id? And if they should be present, what values should they
> > +        * have?
> > +        */
> 
> BUS_HOST seems to be most suitable here. The rest may stay 0.

Thanks, applied.

> > +
> > +       /* private */
> > +       struct timer_list timer;
> > +};
> 
> I don't think it is a good idea to have timer structure in platform
> data which should really be constant. Timer shoudl be part of the
> stucture created when driver binds to a device. I can see you may not
> want to introduce extra complexity in the driver; however if you use
> input-polldev it will handle timer for you.

I was a bit unsure about this before submitting. I have moved the
timer_list into a struct in the driver and added the usual
kmalloc/kfree.

-- 
Best regards
Hans-Christian Egtvedt

[-- Attachment #2: 0001-gpio_mouse-driver.txt --]
[-- Type: application/mbox, Size: 11812 bytes --]

Re: [PATCH 1/1] gpio_mouse driver

[Hans-Christian Egtvedt]

On Wed, 2007-05-30 at 08:23 +0200, Hans-Christian Egtvedt wrote:
> On Tue, 2007-05-29 at 11:36 -0400, Dmitry Torokhov wrote:

<cut other fixes and comments>

> > I don't think it is a good idea to have timer structure in platform
> > data which should really be constant. Timer shoudl be part of the
> > stucture created when driver binds to a device. I can see you may not
> > want to introduce extra complexity in the driver; however if you use
> > input-polldev it will handle timer for you.
> 
> I was a bit unsure about this before submitting. I have moved the
> timer_list into a struct in the driver and added the usual
> kmalloc/kfree.

Oops, this introduced a bug when calling add_timer, since kmalloc does
not zero the memory.

The fix is:

> +	input->open = gpio_mouse_open;
> +	input->close = gpio_mouse_close;
> +
> +	gmouse->gpio = pdata;
> +	gmouse->input = input;
> +
> +	/* Init the scan timer. TODO: rewrite to use input-polldev in the future */

Add a timer_init(&gmouse->timer); here.

> +	gmouse->timer.function = gpio_mouse_scan;
> +	gmouse->timer.base = &boot_tvec_bases;

Remove this line ^^^

> +
> +	ret = input_register_device(input);

-- 
Mvh
Hans-Christian Egtvedt

Re: [PATCH 1/1] gpio_mouse driver

[Dmitry Torokhov]

On 5/30/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
> On Tue, 2007-05-29 at 11:36 -0400, Dmitry Torokhov wrote:
> > Hi,
> >
> > On 5/29/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
> > > This patch adds support for simulating a mouse using GPIO lines.
> > >
> > > The driver needs a platform_data struct to be defined and registered with the
> > > appropriate platform_device.
> > >
> > > The driver has been tested on AT32AP7000 microprocessor using the ATSTK1000
> > > development board.
> > >
> >
> > It looks sane although I would recommend switching to input-polldev
> > when implementing a polled input device.
>
> Oh, I was not aware about this, it seems like just the thing I need.
>
> Could it be scheduled for after the official kernel has this included?
> AFAICT it will be released with 2.6.22?

Because merge window for 2.6.22 is closed the driver will only be
merged in the mainline when 2.6.23 window opens. For now it will stay
in my tree (and because Andrew pulls form me it will also show up in
-mm). Because of that I would like to get the driver in shape from the
beginning - my tree obviously does have these changes.

Thank you.

-- 
Dmitry

Re: [PATCH 1/1] gpio_mouse driver

[Hans-Christian Egtvedt]

On Wed, 2007-05-30 at 08:30 -0400, Dmitry Torokhov wrote:
> On 5/30/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
> > On Tue, 2007-05-29 at 11:36 -0400, Dmitry Torokhov wrote:
> > > Hi,
> > >
> > > On 5/29/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
> > > > This patch adds support for simulating a mouse using GPIO lines.
> > > >
> > > > The driver needs a platform_data struct to be defined and registered with the
> > > > appropriate platform_device.
> > > >
> > > > The driver has been tested on AT32AP7000 microprocessor using the ATSTK1000
> > > > development board.
> > > >
> > >
> > > It looks sane although I would recommend switching to input-polldev
> > > when implementing a polled input device.
> >
> > Oh, I was not aware about this, it seems like just the thing I need.
> >
> > Could it be scheduled for after the official kernel has this included?
> > AFAICT it will be released with 2.6.22?
> 
> Because merge window for 2.6.22 is closed the driver will only be
> merged in the mainline when 2.6.23 window opens. For now it will stay
> in my tree (and because Andrew pulls form me it will also show up in
> -mm). Because of that I would like to get the driver in shape from the
> beginning - my tree obviously does have these changes.

Ok, I will pull your GIT tree sometime soon(tm), and update the patch to
match the new standard. A bit unsure about when, but in good time before
2.6.23.

Is git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git the
correct tree?

Thanks for the feedback.

-- 
Best regards
Hans-Christian Egtvedt

Re: [PATCH 1/1] gpio_mouse driver

[Dmitry Torokhov]

On 5/30/07, Hans-Christian Egtvedt <hcegtvedt@norway.atmel.com> wrote:
>
> Ok, I will pull your GIT tree sometime soon(tm), and update the patch to
> match the new standard. A bit unsure about when, but in good time before
> 2.6.23.
>

Thank you. A couple of things to remember - the merge window for new
code is 2 weeks after release of 2.6.22 and code that is merged during
that window is expected to be present in -mm for couple -mm releases
to make sure it is solid with regard to different
architectures/.configs.

> Is git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git the
> correct tree?
>

Yes. You may also get any of Linus's 2.6.22-rcX - the new code is there as well.

-- 
Dmitry

[PATCH 1/1] gpio_mouse driver

[Hans-Christian Egtvedt]

From: Hans-Christian Egtvedt <hcegtvedt@atmel.com>

This patch adds support for simulating a mouse using GPIO lines.

The driver needs a platform_data struct to be defined and registered with the
appropriate platform_device.

The driver has been tested on AT32AP7000 microprocessor using the ATSTK1000
development board.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
---
 drivers/input/mouse/Kconfig      |   15 ++
 drivers/input/mouse/Makefile     |    1 +
 drivers/input/mouse/gpio_mouse.c |  276 ++++++++++++++++++++++++++++++++++++++
 include/linux/gpio_mouse.h       |   53 +++++++
 4 files changed, 345 insertions(+), 0 deletions(-)

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index 35d998c..a3c7057 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -125,4 +125,19 @@ config MOUSE_HIL
 	help
 	  Say Y here to support HIL pointers.
 
+config MOUSE_GPIO
+	tristate "GPIO mouse"
+	depends on GENERIC_GPIO
+	help
+	  This driver simulates a mouse on GPIO lines of various CPUs (and some
+	  other chips).
+
+	  Say Y here if your device has buttons or a simple joystick connected
+	  directly to GPIO lines. Your board-specific setup logic must also
+	  provide a platform device and platform data saying which GPIOs are
+	  used.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called gpio_mouse.
+
 endif
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 21a1de6..5d0fc43 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -13,5 +13,6 @@ obj-$(CONFIG_MOUSE_PS2)		+= psmouse.o
 obj-$(CONFIG_MOUSE_SERIAL)	+= sermouse.o
 obj-$(CONFIG_MOUSE_HIL)		+= hil_ptr.o
 obj-$(CONFIG_MOUSE_VSXXXAA)	+= vsxxxaa.o
+obj-$(CONFIG_MOUSE_GPIO)	+= gpio_mouse.o
 
 psmouse-objs  := psmouse-base.o alps.o logips2pp.o synaptics.o lifebook.o trackpoint.o
diff --git a/drivers/input/mouse/gpio_mouse.c b/drivers/input/mouse/gpio_mouse.c
new file mode 100644
index 0000000..3f36b73
--- /dev/null
+++ b/drivers/input/mouse/gpio_mouse.c
@@ -0,0 +1,276 @@
+/*
+ * Driver for simulating a mouse on GPIO lines.
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * 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.
+ */
+
+/*#define DEBUG*/
+
+#include <linux/init.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/gpio_mouse.h>
+
+#include <asm/gpio.h>
+
+/*
+ * Timer function which is run every scan_ms ms when the device is opened. The
+ * dev input varaible is set to the the input_dev pointer.
+ */
+static void gpio_mouse_scan(unsigned long _dev)
+{
+	struct input_dev *input = (struct input_dev *)_dev;
+	struct gpio_mouse_platform_data *gpio = input->private;
+	int x, y;
+
+	if (gpio->bleft >= 0)
+		input_report_key(input, BTN_LEFT,
+				gpio_get_value(gpio->bleft) ^ gpio->polarity);
+	if (gpio->bmiddle >= 0)
+		input_report_key(input, BTN_MIDDLE,
+				gpio_get_value(gpio->bmiddle) ^ gpio->polarity);
+	if (gpio->bright >= 0)
+		input_report_key(input, BTN_RIGHT,
+				gpio_get_value(gpio->bright) ^ gpio->polarity);
+
+	x = (gpio_get_value(gpio->right) ^ gpio->polarity)
+		- (gpio_get_value(gpio->left) ^ gpio->polarity);
+	y = (gpio_get_value(gpio->down) ^ gpio->polarity)
+		- (gpio_get_value(gpio->up) ^ gpio->polarity);
+
+	input_report_rel(input, REL_X, x);
+	input_report_rel(input, REL_Y, y);
+	input_sync(input);
+
+	mod_timer(&gpio->timer, jiffies + msecs_to_jiffies(gpio->scan_ms));
+}
+
+/* Only start the timer when the device is actually in use, i.e. opened */
+static int gpio_mouse_open(struct input_dev *input)
+{
+	struct gpio_mouse_platform_data *gpio = input->private;
+	gpio->timer.expires = jiffies + msecs_to_jiffies(gpio->scan_ms);
+	gpio->timer.data = (unsigned long)input;
+	add_timer(&gpio->timer);
+	return 0;
+}
+
+static void gpio_mouse_close(struct input_dev *input)
+{
+	struct gpio_mouse_platform_data *gpio = input->private;
+	del_timer_sync(&gpio->timer);
+}
+
+static int __init gpio_mouse_probe(struct platform_device *pdev)
+{
+	struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
+	struct input_dev *input;
+	int ret;
+
+	if (!pdata) {
+		dev_dbg(&pdev->dev, "no platform data\n");
+		ret = -ENXIO;
+		goto out;
+	}
+
+	if (pdata->up < 0 || pdata->down < 0 || pdata->right < 0
+			|| pdata->left < 0) {
+		dev_dbg(&pdev->dev, "missing GPIO for directions\n");
+		ret = -EINVAL;
+		goto out_gpio;
+	}
+	if (pdata->scan_ms < 0) {
+		dev_dbg(&pdev->dev, "invalid scan time\n");
+		ret = -EINVAL;
+		goto out_gpio;
+	}
+
+	/* Mouse direction, required */
+	ret = gpio_request(pdata->up, "gpio_mouse_up");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail up pin\n");
+		goto out_gpio;
+	}
+	ret = gpio_request(pdata->down, "gpio_mouse_down");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail down pin\n");
+		goto out_gpio;
+	}
+	ret = gpio_request(pdata->left, "gpio_mouse_left");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail left pin\n");
+		goto out_gpio;
+	}
+	ret = gpio_request(pdata->right, "gpio_mouse_right");
+	if (ret) {
+		dev_dbg(&pdev->dev, "fail right pin\n");
+		goto out_gpio;
+	}
+
+	gpio_direction_input(pdata->up);
+	gpio_direction_input(pdata->down);
+	gpio_direction_input(pdata->left);
+	gpio_direction_input(pdata->right);
+
+	/* Mouse buttons, not required, but should at least have bleft */
+	if (pdata->bleft >= 0) {
+		ret = gpio_request(pdata->bleft, "gpio_mouse_bleft");
+		if (ret) {
+			dev_dbg(&pdev->dev, "fail bleft pin\n");
+			goto out_gpio;
+		}
+		gpio_direction_input(pdata->bleft);
+	} else {
+		dev_dbg(&pdev->dev, "no left button defined\n");
+	}
+	if (pdata->bmiddle >= 0) {
+		ret = gpio_request(pdata->bmiddle, "gpio_mouse_bmiddle");
+		if (ret) {
+			dev_dbg(&pdev->dev, "fail bmiddle pin\n");
+			goto out_gpio;
+		}
+		gpio_direction_input(pdata->bmiddle);
+	}
+	if (pdata->bright >= 0) {
+		ret = gpio_request(pdata->bright, "gpio_mouse_bright");
+		if (ret) {
+			dev_dbg(&pdev->dev, "fail bright pin\n");
+			goto out_gpio;
+		}
+		gpio_direction_input(pdata->bright);
+	}
+
+	input = input_allocate_device();
+	if (!input) {
+		dev_dbg(&pdev->dev, "not enough memory for input device\n");
+		ret = -ENOMEM;
+		goto out_gpio;
+	}
+
+	platform_set_drvdata(pdev, input);
+
+	input->name = pdev->name;
+	input->cdev.dev = &pdev->dev;
+	input->private = pdata;
+
+	/*
+	 * Revisit: is bustype, vendor, product and version needed to
+	 * input->id? And if they should be present, what values should they
+	 * have?
+	 */
+
+	input->evbit[0] = BIT(EV_REL);
+	if (pdata->bleft >= 0 || pdata->bmiddle >= 0 || pdata->bright >= 0) {
+		input->evbit[0] |= BIT(EV_KEY);
+
+		if (pdata->bleft >= 0)
+			input->keybit[LONG(BTN_MOUSE)] = BIT(BTN_LEFT);
+		if (pdata->bmiddle >= 0)
+			input->keybit[LONG(BTN_MOUSE)] |= BIT(BTN_MIDDLE);
+		if (pdata->bright >= 0)
+			input->keybit[LONG(BTN_MOUSE)] |= BIT(BTN_RIGHT);
+	}
+	input->relbit[0] = BIT(REL_X) | BIT(REL_Y);
+
+	input->open = gpio_mouse_open;
+	input->close = gpio_mouse_close;
+
+	/* init the scan timer */
+	pdata->timer.function = gpio_mouse_scan;
+	pdata->timer.base = &boot_tvec_bases;
+
+	ret = input_register_device(input);
+	if (ret) {
+		dev_dbg(&pdev->dev, "could not register input device\n");
+		goto out_reg_dev;
+	}
+
+	dev_dbg(&pdev->dev, "%d ms scan time, buttons: %s%s%s\n",
+			pdata->scan_ms,
+			pdata->bleft < 0 ? "" : "left ",
+			pdata->bmiddle < 0 ? "" : "middle ",
+			pdata->bright < 0 ? "" : "right");
+
+	return 0;
+
+out_reg_dev:
+	input_free_device(input);
+	platform_set_drvdata(pdev, NULL);
+out_gpio:
+	if (pdata->up >= 0)
+		gpio_free(pdata->up);
+	if (pdata->down >= 0)
+		gpio_free(pdata->down);
+	if (pdata->left >= 0)
+		gpio_free(pdata->left);
+	if (pdata->right >= 0)
+		gpio_free(pdata->right);
+	if (pdata->bleft >= 0)
+		gpio_free(pdata->bleft);
+	if (pdata->bmiddle >= 0)
+		gpio_free(pdata->bmiddle);
+	if (pdata->bright >= 0)
+		gpio_free(pdata->bright);
+out:
+	return ret;
+}
+
+static int __exit gpio_mouse_remove(struct platform_device *pdev)
+{
+	struct gpio_mouse_platform_data *pdata = pdev->dev.platform_data;
+	struct input_dev *input = platform_get_drvdata(pdev);
+
+	if (input)
+		input_unregister_device(input);
+
+	if (pdata->up >= 0)
+		gpio_free(pdata->up);
+	if (pdata->down >= 0)
+		gpio_free(pdata->down);
+	if (pdata->left >= 0)
+		gpio_free(pdata->left);
+	if (pdata->right >= 0)
+		gpio_free(pdata->right);
+	if (pdata->bleft >= 0)
+		gpio_free(pdata->bleft);
+	if (pdata->bmiddle >= 0)
+		gpio_free(pdata->bmiddle);
+	if (pdata->bright >= 0)
+		gpio_free(pdata->bright);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+struct platform_driver gpio_mouse_device_driver = {
+	.remove		= __exit_p(gpio_mouse_remove),
+	.driver		= {
+		.name	= "gpio_mouse",
+	}
+};
+
+static int __init gpio_mouse_init(void)
+{
+	return platform_driver_probe(&gpio_mouse_device_driver,
+			gpio_mouse_probe);
+}
+module_init(gpio_mouse_init);
+
+static void __exit gpio_mouse_exit(void)
+{
+	platform_driver_unregister(&gpio_mouse_device_driver);
+}
+module_exit(gpio_mouse_exit);
+
+MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
+MODULE_DESCRIPTION("GPIO mouse driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/gpio_mouse.h b/include/linux/gpio_mouse.h
new file mode 100644
index 0000000..b63d43f
--- /dev/null
+++ b/include/linux/gpio_mouse.h
@@ -0,0 +1,53 @@
+/*
+ * Driver for simulating a mouse on GPIO lines.
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * 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 _GPIO_MOUSE_H
+#define _GPIO_MOUSE_H
+
+#include <linux/timer.h>
+
+#define GPIO_MOUSE_POLARITY_ACT_HIGH	0x00
+#define GPIO_MOUSE_POLARITY_ACT_LOW	0x01
+
+/**
+ * struct GPIO_mouse_platform_data
+ * @scan_ms: integer in ms specifying the scan periode.
+ * @polarity: Pin polarity, active high or low.
+ * @up: GPIO line for up value.
+ * @down: GPIO line for down value.
+ * @left: GPIO line for left value.
+ * @right: GPIO line for right value.
+ * @bleft: GPIO line for left button.
+ * @bright: GPIO line for right button.
+ * @bmiddle: GPIO line for middle button.
+ * @timer: placeholder for struct timer_list initialized in the driver.
+ *
+ * This struct must be added to the platform_device in the board code. It is
+ * used by the gpio_mouse driver to setup GPIO lines, calculate mouse movement
+ * and have a reference to the timer used for scanning.
+ */
+struct gpio_mouse_platform_data {
+	int scan_ms;
+	int polarity;
+
+	int up;
+	int down;
+	int left;
+	int right;
+
+	int bleft;
+	int bmiddle;
+	int bright;
+
+	/* private */
+	struct timer_list timer;
+};
+
+#endif /* _GPIO_MOUSE_H */
-- 
1.4.4.2