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Commit 7be35c72 authored by Matthew Garrett's avatar Matthew Garrett Committed by Richard Purdie
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backlight: Add Nvidia-based Apple Macbook Pro backlight driver 



Nvidia-based Apple Macbook Pros don't appear to handle backlight control
through the graphics card registers or ACPI, but instead trigger changes
via SMI calls. This driver registers a generic backlight device that
lets existing userspace deal with it. Code derived from Julien Blache's
Pommed application.

Signed-off-by: default avatarJulien Blache <jb@jblache.org>
Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
Signed-off-by: default avatarRichard Purdie <rpurdie@rpsys.net>
parent c010b2f7

drivers/video/backlight/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -119,3 +119,12 @@ config BACKLIGHT_PWM 
	help

	  If you have a LCD backlight adjustable by PWM, say Y to enable

	  this driver.



config BACKLIGHT_MBP_NVIDIA

       tristate "MacBook Pro Nvidia Backlight Driver"

       depends on BACKLIGHT_CLASS_DEVICE && X86

       default n

       help

         If you have an Apple Macbook Pro with Nvidia graphics hardware say Y

	 to enable a driver for its backlight

drivers/video/backlight/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -11,3 +11,5 @@ obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o 
obj-$(CONFIG_BACKLIGHT_PROGEAR) += progear_bl.o

obj-$(CONFIG_BACKLIGHT_CARILLO_RANCH) += cr_bllcd.o

obj-$(CONFIG_BACKLIGHT_PWM)	+= pwm_bl.o

obj-$(CONFIG_BACKLIGHT_MBP_NVIDIA) += mbp_nvidia_bl.o

drivers/video/backlight/mbp_nvidia_bl.c

0 → 100644
+116 −0
Original line number Diff line number Diff line 
/*

 *  Backlight Driver for Nvidia 8600 in Macbook Pro

 *

 *  Copyright (c) Red Hat <mjg@redhat.com>

 *  Based on code from Pommed:

 *  Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>

 *  Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>

 *  Copyright (C) 2007 Julien BLACHE <jb@jblache.org>

 *

 *  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 driver triggers SMIs which cause the firmware to change the

 *  backlight brightness. This is icky in many ways, but it's impractical to

 *  get at the firmware code in order to figure out what it's actually doing.

 */



#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/platform_device.h>

#include <linux/backlight.h>

#include <linux/err.h>

#include <linux/dmi.h>

#include <linux/io.h>



static struct backlight_device *mbp_backlight_device;



static struct dmi_system_id __initdata mbp_device_table[] = {

	{

		.ident = "3,1",

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),

			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,1"),

		},

	},

	{

		.ident = "3,2",

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),

			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,2"),

		},

	},

	{

		.ident = "4,1",

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),

			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro4,1"),

		},

	},

	{ }

};



static int mbp_send_intensity(struct backlight_device *bd)

{

	int intensity = bd->props.brightness;



	outb(0x04 | (intensity << 4), 0xb3);

	outb(0xbf, 0xb2);



	return 0;

}



static int mbp_get_intensity(struct backlight_device *bd)

{

	outb(0x03, 0xb3);

	outb(0xbf, 0xb2);

	return inb(0xb3) >> 4;

}



static struct backlight_ops mbp_ops = {

	.get_brightness = mbp_get_intensity,

	.update_status  = mbp_send_intensity,

};



static int __init mbp_init(void)

{

	if (!dmi_check_system(mbp_device_table))

		return -ENODEV;



	if (!request_region(0xb2, 2, "Macbook Pro backlight"))

		return -ENXIO;



	mbp_backlight_device = backlight_device_register("mbp_backlight",

							 NULL, NULL,

							 &mbp_ops);

	if (IS_ERR(mbp_backlight_device)) {

		release_region(0xb2, 2);

		return PTR_ERR(mbp_backlight_device);

	}



	mbp_backlight_device->props.max_brightness = 15;

	mbp_backlight_device->props.brightness =

		mbp_get_intensity(mbp_backlight_device);

	backlight_update_status(mbp_backlight_device);



	return 0;

}



static void __exit mbp_exit(void)

{

	backlight_device_unregister(mbp_backlight_device);



	release_region(0xb2, 2);

}



module_init(mbp_init);

module_exit(mbp_exit);



MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");

MODULE_DESCRIPTION("Nvidia-based Macbook Pro Backlight Driver");

MODULE_LICENSE("GPL");

MODULE_ALIAS("svnAppleInc.:pnMacBookPro3,1");

MODULE_ALIAS("svnAppleInc.:pnMacBookPro3,2");

MODULE_ALIAS("svnAppleInc.:pnMacBookPro4,1");