backlight: Add support for MacBook 5, MacBook Air 2, and MacBook Pro 5

This patch adds support for the new Apple models incorporating an Nvidia
chipset.  Apple still uses the same protocol as on older models, but the
registers moved to a different address. To do this, two sets of functions
are added for the Intel/Nvidia chipset models and passed by the DMI_MATCH
function.

The initial code has been contributed by Hu Gang <hugang@soulinfo.com>.

The driver is known to work on MacBook Pro 3, MacBook Pro 4 and MacBook
Pro 5.

Its known to work with limitations on MacBook 5 / MacBook Air 2. Changing
brightness within X doesn't work, if using Nvidia's proprietary graphics
driver with no known fix at present. Changing brightness on a text console
or using the open-source driver does work.

MacBook Pro 5 has a known bug where the initial brightness after bootup is
the last recently used brightness (in Mac OSX), while the firmware reports
maximum. Impossible to fix.

[akpm@linux-foundation.org: build fix]
[rpurdie@linux.intel.com: Rebased the patch against latest git]
Signed-off-by: Mario Schwalbe <schwalbe@inf.tu-dresden.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

drivers/video/backlight/mbp_nvidia_bl.c

@@ -27,52 +27,142 @@
 
 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"),
-		},
-	},
-	{ }
+/* Structure to be passed to the DMI_MATCH function. */
+struct dmi_match_data {
+	/* I/O resource to allocate. */
+	unsigned long iostart;
+	unsigned long iolen;
+	/* Backlight operations structure. */
+	struct backlight_ops backlight_ops;
 };
 
-static int mbp_send_intensity(struct backlight_device *bd)
+/*
+ * Implementation for MacBooks with Intel chipset.
+ */
+static int intel_chipset_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)
+static int intel_chipset_get_intensity(struct backlight_device *bd)
 {
 	outb(0x03, 0xb3);
 	outb(0xbf, 0xb2);
 	return inb(0xb3) >> 4;
 }
 
-static struct backlight_ops mbp_ops = {
-	.options = BL_CORE_SUSPENDRESUME,
-	.get_brightness = mbp_get_intensity,
-	.update_status  = mbp_send_intensity,
+static const struct dmi_match_data intel_chipset_data = {
+	.iostart = 0xb2,
+	.iolen = 2,
+	.backlight_ops	= {
+		.options	= BL_CORE_SUSPENDRESUME,
+		.get_brightness	= intel_chipset_get_intensity,
+		.update_status	= intel_chipset_send_intensity,
+	}
+};
+
+/*
+ * Implementation for MacBooks with Nvidia chipset.
+ */
+static int nvidia_chipset_send_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+
+	outb(0x04 | (intensity << 4), 0x52f);
+	outb(0xbf, 0x52e);
+	return 0;
+}
+
+static int nvidia_chipset_get_intensity(struct backlight_device *bd)
+{
+	outb(0x03, 0x52f);
+	outb(0xbf, 0x52e);
+	return inb(0x52f) >> 4;
+}
+
+static const struct dmi_match_data nvidia_chipset_data = {
+	.iostart = 0x52e,
+	.iolen = 2,
+	.backlight_ops		= {
+		.options	= BL_CORE_SUSPENDRESUME,
+		.get_brightness	= nvidia_chipset_get_intensity,
+		.update_status	= nvidia_chipset_send_intensity
+	}
+};
+
+/*
+ * DMI matching.
+ */
+static /* const */ struct dmi_match_data *driver_data;
+
+static int mbp_dmi_match(const struct dmi_system_id *id)
+{
+	driver_data = id->driver_data;
+
+	printk(KERN_INFO "mbp_nvidia_bl: %s detected\n", id->ident);
+	return 1;
+}
+
+static const struct dmi_system_id __initdata mbp_device_table[] = {
+	{
+		.callback	= mbp_dmi_match,
+		.ident		= "MacBookPro 3,1",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,1"),
+		},
+		.driver_data	= (void *)&intel_chipset_data,
+	},
+	{
+		.callback	= mbp_dmi_match,
+		.ident		= "MacBookPro 3,2",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,2"),
+		},
+		.driver_data	= (void *)&intel_chipset_data,
+	},
+	{
+		.callback	= mbp_dmi_match,
+		.ident		= "MacBookPro 4,1",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro4,1"),
+		},
+		.driver_data	= (void *)&intel_chipset_data,
+	},
+	{
+		.callback	= mbp_dmi_match,
+		.ident		= "MacBook 5,1",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5,1"),
+		},
+		.driver_data	= (void *)&nvidia_chipset_data,
+	},
+	{
+		.callback	= mbp_dmi_match,
+		.ident		= "MacBookAir 2,1",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir2,1"),
+		},
+		.driver_data	= (void *)&nvidia_chipset_data,
+	},
+	{
+		.callback	= mbp_dmi_match,
+		.ident		= "MacBookPro 5,1",
+		.matches	= {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5,1"),
+		},
+		.driver_data	= (void *)&nvidia_chipset_data,
+	},
+	{ }
 };
 
 static int __init mbp_init(void)
@@ -80,20 +170,20 @@ static int __init mbp_init(void)
 	if (!dmi_check_system(mbp_device_table))
 		return -ENODEV;
 
-	if (!request_region(0xb2, 2, "Macbook Pro backlight"))
+	if (!request_region(driver_data->iostart, driver_data->iolen, 
+						"Macbook Pro backlight"))
 		return -ENXIO;
 
 	mbp_backlight_device = backlight_device_register("mbp_backlight",
-							 NULL, NULL,
-							 &mbp_ops);
+					NULL, NULL, &driver_data->backlight_ops);
 	if (IS_ERR(mbp_backlight_device)) {
-		release_region(0xb2, 2);
+		release_region(driver_data->iostart, driver_data->iolen);
 		return PTR_ERR(mbp_backlight_device);
 	}
 
 	mbp_backlight_device->props.max_brightness = 15;
 	mbp_backlight_device->props.brightness =
-		mbp_get_intensity(mbp_backlight_device);
+		driver_data->backlight_ops.get_brightness(mbp_backlight_device);
 	backlight_update_status(mbp_backlight_device);
 
 	return 0;
@@ -103,7 +193,7 @@ static void __exit mbp_exit(void)
 {
 	backlight_device_unregister(mbp_backlight_device);
 
-	release_region(0xb2, 2);
+	release_region(driver_data->iostart, driver_data->iolen);
 }
 
 module_init(mbp_init);