[PATCH v2] Platform: Samsung Q10 backlight driver

[PATCH v2] Platform: Samsung Q10 backlight driver

[Frederick van der Wyck]

This adds backlight control on the Samsung Q10 laptop, which does not support 
the SABI interface. Also tested successfully on the Dell Latitude X200.

Signed-off-by: Frederick van der Wyck <fvanderwyck@gmail.com>
---
 drivers/platform/x86/Kconfig       |    7 ++
 drivers/platform/x86/Makefile      |    1 +
 drivers/platform/x86/samsung-q10.c |  185 ++++++++++++++++++++++++++++++++++++
 3 files changed, 193 insertions(+), 0 deletions(-)
 create mode 100644 drivers/platform/x86/samsung-q10.c

I've made all the changes suggested by Greg and Dmitry in response to v1. 
Main changes:
(1) use i8042_command instead of port IO;
(2) DMI detect to auto-load and to restrict to supported hardware.
Description of v1:
The Samsung Q10 is an old model, which does not support the SABI interface, so
the samsung-laptop driver does not work. Backlight control is not exposed via
ACPI either. This driver works in the same way as the SMI handler triggered by 
pressing the brightness function keys.

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index faec777..c390727 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -639,4 +639,11 @@ config XO1_RFKILL
 	  Support for enabling/disabling the WLAN interface on the OLPC XO-1
 	  laptop.
 
+config SAMSUNG_Q10
+	tristate "Samsung Q10 Extras"
+	select BACKLIGHT_CLASS_DEVICE
+	---help---
+          This driver provides support for backlight control on Samsung Q10
+          and some other laptops, including Dell Latitude X200.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 9950ccc..2cd3e52 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
 obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
 obj-$(CONFIG_XO1_RFKILL)	+= xo1-rfkill.o
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
+obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
diff --git a/drivers/platform/x86/samsung-q10.c b/drivers/platform/x86/samsung-q10.c
new file mode 100644
index 0000000..c2b6647
--- /dev/null
+++ b/drivers/platform/x86/samsung-q10.c
@@ -0,0 +1,185 @@
+/*
+ *  Driver for Samsung Q10: controls the backlight
+ *
+ *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/i8042.h>
+#include <linux/dmi.h>
+
+#define SAMSUNGQ10_BL_MAX_INTENSITY      255
+#define SAMSUNGQ10_BL_DEFAULT_INTENSITY  185
+
+#define SAMSUNGQ10_BL_8042_CMD           0xbe
+#define SAMSUNGQ10_BL_8042_DATA          { 0x89, 0x91 }
+
+static bool samsungq10_suspended;
+static int samsungq10_bl_brightness;
+
+static int force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force,
+		"Disable the DMI check and force the driver to be loaded");
+
+static int samsungq10_bl_set_intensity(struct backlight_device *bd)
+{
+
+	int brightness = bd->props.brightness;
+	unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
+
+	if (!samsungq10_suspended) {
+		c[2] = (unsigned char)brightness;
+		i8042_lock_chip();
+		i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
+		i8042_unlock_chip();
+		samsungq10_bl_brightness = brightness;
+	}
+	return 0;
+}
+
+static int samsungq10_bl_get_intensity(struct backlight_device *bd)
+{
+	return samsungq10_bl_brightness;
+}
+
+static const struct backlight_ops samsungq10_bl_ops = {
+	.get_brightness = samsungq10_bl_get_intensity,
+	.update_status	= samsungq10_bl_set_intensity,
+};
+
+#ifdef CONFIG_PM
+static int samsungq10_suspend(struct device *dev)
+{
+	samsungq10_suspended = true;
+	return 0;
+}
+
+static int samsungq10_resume(struct device *dev)
+{
+
+	struct backlight_device *bd = dev_get_drvdata(dev);
+
+	samsungq10_suspended = false;
+	samsungq10_bl_set_intensity(bd);
+	return 0;
+}
+#else
+#define samsungq10_suspend NULL
+#define samsungq10_resume  NULL
+#endif
+
+static const struct dev_pm_ops samsungq10_pm_ops = {
+	.suspend	= samsungq10_suspend,
+	.resume		= samsungq10_resume,
+};
+
+static int __devinit samsungq10_probe(struct platform_device *pdev)
+{
+
+	struct backlight_properties props;
+	struct backlight_device *bd;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
+	bd = backlight_device_register("samsung", &pdev->dev, NULL,
+				       &samsungq10_bl_ops, &props);
+	if (IS_ERR(bd))
+		return PTR_ERR(bd);
+
+	platform_set_drvdata(pdev, bd);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	return 0;
+}
+
+static int __devexit samsungq10_remove(struct platform_device *pdev)
+{
+
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver samsungq10_driver = {
+	.driver		= {
+		.name	= "samsung",
+		.owner	= THIS_MODULE,
+		.pm	= &samsungq10_pm_ops,
+	},
+	.probe		= samsungq10_probe,
+	.remove		= __devexit_p(samsungq10_remove),
+};
+
+static struct platform_device *samsungq10_device;
+
+static int __init dmi_check_callback(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
+	return 0;
+}
+
+static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
+	{
+		.ident = "Samsung Q10",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{
+		.ident = "Dell Latitude X200",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
+
+static int __init samsungq10_init(void)
+{
+	if (!force && !dmi_check_system(samsungq10_dmi_table))
+		return -ENODEV;
+
+	samsungq10_device = platform_create_bundle(&samsungq10_driver,
+						   samsungq10_probe,
+						   NULL, 0, NULL, 0);
+
+	if (IS_ERR(samsungq10_device))
+		return PTR_ERR(samsungq10_device);
+
+	return 0;
+}
+
+static void __exit samsungq10_exit(void)
+{
+	platform_device_unregister(samsungq10_device);
+	platform_driver_unregister(&samsungq10_driver);
+}
+
+module_init(samsungq10_init);
+module_exit(samsungq10_exit);
+
+MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
+MODULE_DESCRIPTION("Samsung Q10 Driver");
+MODULE_LICENSE("GPL");
-- 

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Dmitry Torokhov]

Hi Fredetick,
On Mon, Feb 21, 2011 at 10:37:43PM +0000, Frederick van der Wyck wrote:
> This adds backlight control on the Samsung Q10 laptop, which does not support 
> the SABI interface. Also tested successfully on the Dell Latitude X200.
> 

Thanks for making the changes, looks mostly good now.

> +
> +static int force;

If it is a bool the call it so.

> +module_param(force, bool, 0);
> +MODULE_PARM_DESC(force,
> +		"Disable the DMI check and force the driver to be loaded");
> +
> +static int samsungq10_bl_set_intensity(struct backlight_device *bd)
> +{
> +
> +	int brightness = bd->props.brightness;
> +	unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
> +
> +	if (!samsungq10_suspended) {

Hmm, if samsungq10_bl_set_intensity() can indeed run simultaneously with
suspend/resume then you'd need to protect it with spinlock or mutex.

> +		c[2] = (unsigned char)brightness;
> +		i8042_lock_chip();
> +		i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
> +		i8042_unlock_chip();
> +		samsungq10_bl_brightness = brightness;
> +	}
> +	return 0;
> +}
> +
> +static int samsungq10_bl_get_intensity(struct backlight_device *bd)
> +{
> +	return samsungq10_bl_brightness;
> +}
> +
> +static const struct backlight_ops samsungq10_bl_ops = {
> +	.get_brightness = samsungq10_bl_get_intensity,
> +	.update_status	= samsungq10_bl_set_intensity,
> +};
> +
> +#ifdef CONFIG_PM
> +static int samsungq10_suspend(struct device *dev)
> +{
> +	samsungq10_suspended = true;
> +	return 0;
> +}
> +
> +static int samsungq10_resume(struct device *dev)
> +{
> +
> +	struct backlight_device *bd = dev_get_drvdata(dev);
> +
> +	samsungq10_suspended = false;
> +	samsungq10_bl_set_intensity(bd);
> +	return 0;
> +}
> +#else
> +#define samsungq10_suspend NULL
> +#define samsungq10_resume  NULL
> +#endif
> +
> +static const struct dev_pm_ops samsungq10_pm_ops = {
> +	.suspend	= samsungq10_suspend,
> +	.resume		= samsungq10_resume,
> +};

Don't you need to restore backlight when resuming from hibernate? I
think you need to guard you methods with CONFIG_PM_SLEEP and then
use SIMPLE_DEV_PM_OPS().

> +
> +static int __devinit samsungq10_probe(struct platform_device *pdev)
> +{
> +
> +	struct backlight_properties props;
> +	struct backlight_device *bd;
> +
> +	memset(&props, 0, sizeof(struct backlight_properties));
> +	props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
> +	bd = backlight_device_register("samsung", &pdev->dev, NULL,
> +				       &samsungq10_bl_ops, &props);
> +	if (IS_ERR(bd))
> +		return PTR_ERR(bd);
> +
> +	platform_set_drvdata(pdev, bd);
> +
> +	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
> +	samsungq10_bl_set_intensity(bd);
> +
> +	return 0;
> +}
> +
> +static int __devexit samsungq10_remove(struct platform_device *pdev)
> +{
> +
> +	struct backlight_device *bd = platform_get_drvdata(pdev);
> +
> +	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
> +	samsungq10_bl_set_intensity(bd);
> +
> +	backlight_device_unregister(bd);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver samsungq10_driver = {
> +	.driver		= {
> +		.name	= "samsung",

Samsung is way too generic for driver name, maybe call it
KBUILD_MODNAME?

Thanks.

-- 
Dmitry

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Frederick van der Wyck]

Hi Dmitry,

Thanks for the further comments.

> If it is a bool the call it so.

Fixed.

> Hmm, if samsungq10_bl_set_intensity() can indeed run simultaneously with
> suspend/resume then you'd need to protect it with spinlock or mutex.

I guess it's OK to assume samsungq10_bl_set_intensity() will not be called
during suspend/resume so I've removed the check.

> Don't you need to restore backlight when resuming from hibernate? I
> think you need to guard you methods with CONFIG_PM_SLEEP and then
> use SIMPLE_DEV_PM_OPS().

You're right, thanks, I've made the change.

> Samsung is way too generic for driver name, maybe call it
> KBUILD_MODNAME?

I changed it from "samsung-q10" to "samsung" in reponse to Greg's feedback, 
but OK, I've made it KBUILD_MODNAME as you suggest.

Here's a new version of the patch.

Thanks,
Frederick

Signed-off-by: Frederick van der Wyck <fvanderwyck@gmail.com>
---
 drivers/platform/x86/Kconfig       |    7 ++
 drivers/platform/x86/Makefile      |    1 +
 drivers/platform/x86/samsung-q10.c |  179 ++++++++++++++++++++++++++++++++++++
 3 files changed, 187 insertions(+), 0 deletions(-)
 create mode 100644 drivers/platform/x86/samsung-q10.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index faec777..c390727 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -639,4 +639,11 @@ config XO1_RFKILL
 	  Support for enabling/disabling the WLAN interface on the OLPC XO-1
 	  laptop.
 
+config SAMSUNG_Q10
+	tristate "Samsung Q10 Extras"
+	select BACKLIGHT_CLASS_DEVICE
+	---help---
+          This driver provides support for backlight control on Samsung Q10
+          and some other laptops, including Dell Latitude X200.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 9950ccc..2cd3e52 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -33,3 +33,4 @@ obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
 obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
 obj-$(CONFIG_XO1_RFKILL)	+= xo1-rfkill.o
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
+obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
diff --git a/drivers/platform/x86/samsung-q10.c b/drivers/platform/x86/samsung-q10.c
new file mode 100644
index 0000000..7b60c67
--- /dev/null
+++ b/drivers/platform/x86/samsung-q10.c
@@ -0,1 +1,179 @@
+/*
+ *  Driver for Samsung Q10: controls the backlight
+ *
+ *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/i8042.h>
+#include <linux/dmi.h>
+
+#define SAMSUNGQ10_BL_MAX_INTENSITY      255
+#define SAMSUNGQ10_BL_DEFAULT_INTENSITY  185
+
+#define SAMSUNGQ10_BL_8042_CMD           0xbe
+#define SAMSUNGQ10_BL_8042_DATA          { 0x89, 0x91 }
+
+static int samsungq10_bl_brightness;
+
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force,
+		"Disable the DMI check and force the driver to be loaded");
+
+static int samsungq10_bl_set_intensity(struct backlight_device *bd)
+{
+
+	int brightness = bd->props.brightness;
+	unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
+
+	c[2] = (unsigned char)brightness;
+	i8042_lock_chip();
+	i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
+	i8042_unlock_chip();
+	samsungq10_bl_brightness = brightness;
+
+	return 0;
+}
+
+static int samsungq10_bl_get_intensity(struct backlight_device *bd)
+{
+	return samsungq10_bl_brightness;
+}
+
+static const struct backlight_ops samsungq10_bl_ops = {
+	.get_brightness = samsungq10_bl_get_intensity,
+	.update_status	= samsungq10_bl_set_intensity,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int samsungq10_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int samsungq10_resume(struct device *dev)
+{
+
+	struct backlight_device *bd = dev_get_drvdata(dev);
+
+	samsungq10_bl_set_intensity(bd);
+	return 0;
+}
+#else
+#define samsungq10_suspend NULL
+#define samsungq10_resume  NULL
+#endif
+
+static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
+			  samsungq10_suspend, samsungq10_resume);
+
+static int __devinit samsungq10_probe(struct platform_device *pdev)
+{
+
+	struct backlight_properties props;
+	struct backlight_device *bd;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
+	bd = backlight_device_register("samsung", &pdev->dev, NULL,
+				       &samsungq10_bl_ops, &props);
+	if (IS_ERR(bd))
+		return PTR_ERR(bd);
+
+	platform_set_drvdata(pdev, bd);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	return 0;
+}
+
+static int __devexit samsungq10_remove(struct platform_device *pdev)
+{
+
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver samsungq10_driver = {
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+		.pm	= &samsungq10_pm_ops,
+	},
+	.probe		= samsungq10_probe,
+	.remove		= __devexit_p(samsungq10_remove),
+};
+
+static struct platform_device *samsungq10_device;
+
+static int __init dmi_check_callback(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
+	return 0;
+}
+
+static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
+	{
+		.ident = "Samsung Q10",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{
+		.ident = "Dell Latitude X200",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
+
+static int __init samsungq10_init(void)
+{
+	if (!force && !dmi_check_system(samsungq10_dmi_table))
+		return -ENODEV;
+
+	samsungq10_device = platform_create_bundle(&samsungq10_driver,
+						   samsungq10_probe,
+						   NULL, 0, NULL, 0);
+
+	if (IS_ERR(samsungq10_device))
+		return PTR_ERR(samsungq10_device);
+
+	return 0;
+}
+
+static void __exit samsungq10_exit(void)
+{
+	platform_device_unregister(samsungq10_device);
+	platform_driver_unregister(&samsungq10_driver);
+}
+
+module_init(samsungq10_init);
+module_exit(samsungq10_exit);
+
+MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
+MODULE_DESCRIPTION("Samsung Q10 Driver");
+MODULE_LICENSE("GPL");
-- 

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Matthew Garrett]

Thanks, I'll merge this. Any idea if the same interface is present on 
the Q15/X300?

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Matthew Garrett]

Hm. This patch makes both git-am and patch very unhappy, in that they 
fail to create samsung-q10.c despite it not already existing. How did 
you generate it?

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Frederick van der Wyck]

Hi Matthew,

> Hm. This patch makes both git-am and patch very unhappy, in that they 
> fail to create samsung-q10.c despite it not already existing. How did 
> you generate it?

I used git format-patch. I guess I must have done something wrong
- I'm sorry about that. Here's a version made using diff.

Signed-off-by: Frederick van der Wyck <fvanderwyck@gmail.com>

diff -uprN -X platform-drivers-x86/Documentation/dontdiff platform-drivers-x86-vanilla/drivers/platform/x86/Kconfig platform-drivers-x86/drivers/platform/x86/Kconfig
--- platform-drivers-x86-vanilla/drivers/platform/x86/Kconfig	2011-03-11 23:56:46.000000000 +0000
+++ platform-drivers-x86/drivers/platform/x86/Kconfig	2011-03-12 00:08:03.000000000 +0000
@@ -654,4 +654,11 @@ config XO1_RFKILL
 	  Support for enabling/disabling the WLAN interface on the OLPC XO-1
 	  laptop.
 
+config SAMSUNG_Q10
+	tristate "Samsung Q10 Extras"
+	select BACKLIGHT_CLASS_DEVICE
+	---help---
+          This driver provides support for backlight control on Samsung Q10
+          and some other laptops, including Dell Latitude X200.
+
 endif # X86_PLATFORM_DEVICES
diff -uprN -X platform-drivers-x86/Documentation/dontdiff platform-drivers-x86-vanilla/drivers/platform/x86/Makefile platform-drivers-x86/drivers/platform/x86/Makefile
--- platform-drivers-x86-vanilla/drivers/platform/x86/Makefile	2011-03-11 23:56:46.000000000 +0000
+++ platform-drivers-x86/drivers/platform/x86/Makefile	2011-03-12 00:07:13.000000000 +0000
@@ -34,3 +34,4 @@ obj-$(CONFIG_INTEL_IPS)		+= intel_ips.o
 obj-$(CONFIG_GPIO_INTEL_PMIC)	+= intel_pmic_gpio.o
 obj-$(CONFIG_XO1_RFKILL)	+= xo1-rfkill.o
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
+obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
diff -uprN -X platform-drivers-x86/Documentation/dontdiff platform-drivers-x86-vanilla/drivers/platform/x86/samsung-q10.c platform-drivers-x86/drivers/platform/x86/samsung-q10.c
--- platform-drivers-x86-vanilla/drivers/platform/x86/samsung-q10.c	1970-01-01 01:00:00.000000000 +0100
+++ platform-drivers-x86/drivers/platform/x86/samsung-q10.c	2011-03-12 00:00:03.000000000 +0000
@@ -0,0 +1,179 @@
+/*
+ *  Driver for Samsung Q10: controls the backlight
+ *
+ *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/i8042.h>
+#include <linux/dmi.h>
+
+#define SAMSUNGQ10_BL_MAX_INTENSITY      255
+#define SAMSUNGQ10_BL_DEFAULT_INTENSITY  185
+
+#define SAMSUNGQ10_BL_8042_CMD           0xbe
+#define SAMSUNGQ10_BL_8042_DATA          { 0x89, 0x91 }
+
+static int samsungq10_bl_brightness;
+
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force,
+		"Disable the DMI check and force the driver to be loaded");
+
+static int samsungq10_bl_set_intensity(struct backlight_device *bd)
+{
+
+	int brightness = bd->props.brightness;
+	unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
+
+	c[2] = (unsigned char)brightness;
+	i8042_lock_chip();
+	i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
+	i8042_unlock_chip();
+	samsungq10_bl_brightness = brightness;
+
+	return 0;
+}
+
+static int samsungq10_bl_get_intensity(struct backlight_device *bd)
+{
+	return samsungq10_bl_brightness;
+}
+
+static const struct backlight_ops samsungq10_bl_ops = {
+	.get_brightness = samsungq10_bl_get_intensity,
+	.update_status	= samsungq10_bl_set_intensity,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int samsungq10_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int samsungq10_resume(struct device *dev)
+{
+
+	struct backlight_device *bd = dev_get_drvdata(dev);
+
+	samsungq10_bl_set_intensity(bd);
+	return 0;
+}
+#else
+#define samsungq10_suspend NULL
+#define samsungq10_resume  NULL
+#endif
+
+static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
+			  samsungq10_suspend, samsungq10_resume);
+
+static int __devinit samsungq10_probe(struct platform_device *pdev)
+{
+
+	struct backlight_properties props;
+	struct backlight_device *bd;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
+	bd = backlight_device_register("samsung", &pdev->dev, NULL,
+				       &samsungq10_bl_ops, &props);
+	if (IS_ERR(bd))
+		return PTR_ERR(bd);
+
+	platform_set_drvdata(pdev, bd);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	return 0;
+}
+
+static int __devexit samsungq10_remove(struct platform_device *pdev)
+{
+
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver samsungq10_driver = {
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+		.pm	= &samsungq10_pm_ops,
+	},
+	.probe		= samsungq10_probe,
+	.remove		= __devexit_p(samsungq10_remove),
+};
+
+static struct platform_device *samsungq10_device;
+
+static int __init dmi_check_callback(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
+	return 0;
+}
+
+static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
+	{
+		.ident = "Samsung Q10",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{
+		.ident = "Dell Latitude X200",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
+
+static int __init samsungq10_init(void)
+{
+	if (!force && !dmi_check_system(samsungq10_dmi_table))
+		return -ENODEV;
+
+	samsungq10_device = platform_create_bundle(&samsungq10_driver,
+						   samsungq10_probe,
+						   NULL, 0, NULL, 0);
+
+	if (IS_ERR(samsungq10_device))
+		return PTR_ERR(samsungq10_device);
+
+	return 0;
+}
+
+static void __exit samsungq10_exit(void)
+{
+	platform_device_unregister(samsungq10_device);
+	platform_driver_unregister(&samsungq10_driver);
+}
+
+module_init(samsungq10_init);
+module_exit(samsungq10_exit);
+
+MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
+MODULE_DESCRIPTION("Samsung Q10 Driver");
+MODULE_LICENSE("GPL");

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Frederick van der Wyck]

On Fri, Mar 11, 2011 at 05:19:05PM +0000, Matthew Garrett wrote:
> Any idea if the same interface is present on the Q15/X300?

I don't know - I don't have one of those to try it, unfortunately. 
I wouldn't be surprised though.

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Frederick van der Wyck]

Hi Matthew,

On Fri, Mar 11, 2011 at 05:43:29PM +0000, Matthew Garrett wrote:
> Hm. This patch makes both git-am and patch very unhappy, in that they 
> fail to create samsung-q10.c despite it not already existing. How did 
> you generate it?

Did you get the chance to try applying the new copy of the Samsung
Q10 patch I sent in response to your message above? I guess you're
waiting to do it along with the next round of patches, but please
let me know if you tried and it still caused problems, so I can
fix it for next time.

Thanks,
Frederick

Re: [PATCH v2] Platform: Samsung Q10 backlight driver

[Frederick van der Wyck]

Hi Matthew,

On Sat, Mar 12, 2011 at 12:39:30AM +0000, Frederick van der Wyck wrote:
> Hi Matthew,
> 
> > Hm. This patch makes both git-am and patch very unhappy, in that they 
> > fail to create samsung-q10.c despite it not already existing. How did 
> > you generate it?
> 
> I used git format-patch. I guess I must have done something wrong
> - I'm sorry about that. Here's a version made using diff.

Has this patch been queued for 2.6.40 release? It missed out in
2.6.39 because there was a problem with it which meant it wouldn't
apply, but the new version I sent fixed that. Here it is again.

Thanks,
Frederick

Signed-off-by: Frederick van der Wyck <fvanderwyck@gmail.com>
---
 drivers/platform/x86/Kconfig       |    7 ++
 drivers/platform/x86/Makefile      |    1 +
 drivers/platform/x86/samsung-q10.c |  179 ++++++++++++++++++++++++++++++++++++
 3 files changed, 187 insertions(+), 0 deletions(-)
 create mode 100644 drivers/platform/x86/samsung-q10.c

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 446f723..532a604 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -762,4 +762,11 @@ config INTEL_OAKTRAIL
 	  enable/disable the Camera, WiFi, BT etc. devices. If in doubt, say Y
 	  here; it will only load on supported platforms.
 
+config SAMSUNG_Q10
+	tristate "Samsung Q10 Extras"
+	select BACKLIGHT_CLASS_DEVICE
+	---help---
+          This driver provides support for backlight control on Samsung Q10
+          and some other laptops, including Dell Latitude X200.
+
 endif # X86_PLATFORM_DEVICES
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 9058c72..fe577de 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -43,3 +43,4 @@ obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
 obj-$(CONFIG_SAMSUNG_LAPTOP)	+= samsung-laptop.o
 obj-$(CONFIG_INTEL_MFLD_THERMAL)	+= intel_mid_thermal.o
 obj-$(CONFIG_INTEL_OAKTRAIL)	+= intel_oaktrail.o
+obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
diff --git a/drivers/platform/x86/samsung-q10.c b/drivers/platform/x86/samsung-q10.c
new file mode 100644
index 0000000..7b60c67
--- /dev/null
+++ b/drivers/platform/x86/samsung-q10.c
@@ -0,0 +1,179 @@
+/*
+ *  Driver for Samsung Q10: controls the backlight
+ *
+ *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/backlight.h>
+#include <linux/i8042.h>
+#include <linux/dmi.h>
+
+#define SAMSUNGQ10_BL_MAX_INTENSITY      255
+#define SAMSUNGQ10_BL_DEFAULT_INTENSITY  185
+
+#define SAMSUNGQ10_BL_8042_CMD           0xbe
+#define SAMSUNGQ10_BL_8042_DATA          { 0x89, 0x91 }
+
+static int samsungq10_bl_brightness;
+
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force,
+		"Disable the DMI check and force the driver to be loaded");
+
+static int samsungq10_bl_set_intensity(struct backlight_device *bd)
+{
+
+	int brightness = bd->props.brightness;
+	unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
+
+	c[2] = (unsigned char)brightness;
+	i8042_lock_chip();
+	i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
+	i8042_unlock_chip();
+	samsungq10_bl_brightness = brightness;
+
+	return 0;
+}
+
+static int samsungq10_bl_get_intensity(struct backlight_device *bd)
+{
+	return samsungq10_bl_brightness;
+}
+
+static const struct backlight_ops samsungq10_bl_ops = {
+	.get_brightness = samsungq10_bl_get_intensity,
+	.update_status	= samsungq10_bl_set_intensity,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int samsungq10_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int samsungq10_resume(struct device *dev)
+{
+
+	struct backlight_device *bd = dev_get_drvdata(dev);
+
+	samsungq10_bl_set_intensity(bd);
+	return 0;
+}
+#else
+#define samsungq10_suspend NULL
+#define samsungq10_resume  NULL
+#endif
+
+static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
+			  samsungq10_suspend, samsungq10_resume);
+
+static int __devinit samsungq10_probe(struct platform_device *pdev)
+{
+
+	struct backlight_properties props;
+	struct backlight_device *bd;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
+	bd = backlight_device_register("samsung", &pdev->dev, NULL,
+				       &samsungq10_bl_ops, &props);
+	if (IS_ERR(bd))
+		return PTR_ERR(bd);
+
+	platform_set_drvdata(pdev, bd);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	return 0;
+}
+
+static int __devexit samsungq10_remove(struct platform_device *pdev)
+{
+
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
+	samsungq10_bl_set_intensity(bd);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver samsungq10_driver = {
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+		.pm	= &samsungq10_pm_ops,
+	},
+	.probe		= samsungq10_probe,
+	.remove		= __devexit_p(samsungq10_remove),
+};
+
+static struct platform_device *samsungq10_device;
+
+static int __init dmi_check_callback(const struct dmi_system_id *id)
+{
+	printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
+	return 0;
+}
+
+static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
+	{
+		.ident = "Samsung Q10",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{
+		.ident = "Dell Latitude X200",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
+		},
+		.callback = dmi_check_callback,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
+
+static int __init samsungq10_init(void)
+{
+	if (!force && !dmi_check_system(samsungq10_dmi_table))
+		return -ENODEV;
+
+	samsungq10_device = platform_create_bundle(&samsungq10_driver,
+						   samsungq10_probe,
+						   NULL, 0, NULL, 0);
+
+	if (IS_ERR(samsungq10_device))
+		return PTR_ERR(samsungq10_device);
+
+	return 0;
+}
+
+static void __exit samsungq10_exit(void)
+{
+	platform_device_unregister(samsungq10_device);
+	platform_driver_unregister(&samsungq10_driver);
+}
+
+module_init(samsungq10_init);
+module_exit(samsungq10_exit);
+
+MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
+MODULE_DESCRIPTION("Samsung Q10 Driver");
+MODULE_LICENSE("GPL");