backlight: add backlight type

There may be multiple ways of controlling the backlight on a given
machine.  Allow drivers to expose the type of interface they are
providing, making it possible for userspace to make appropriate policy
decisions.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c
index ad3d099..c978470 100644
--- a/drivers/platform/x86/acer-wmi.c
+++ b/drivers/platform/x86/acer-wmi.c
@@ -1031,6 +1031,7 @@
 	struct backlight_device *bd;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = max_brightness;
 	bd = backlight_device_register("acer-wmi", dev, NULL, &acer_bl_ops,
 				       &props);
diff --git a/drivers/platform/x86/asus-laptop.c b/drivers/platform/x86/asus-laptop.c
index f3aa6a7..5a6f7d7 100644
--- a/drivers/platform/x86/asus-laptop.c
+++ b/drivers/platform/x86/asus-laptop.c
@@ -667,6 +667,7 @@
 
 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.max_brightness = 15;
+	props.type = BACKLIGHT_PLATFORM;
 
 	bd = backlight_device_register(ASUS_LAPTOP_FILE,
 				       &asus->platform_device->dev, asus,
diff --git a/drivers/platform/x86/asus_acpi.c b/drivers/platform/x86/asus_acpi.c
index fe49593..f503607 100644
--- a/drivers/platform/x86/asus_acpi.c
+++ b/drivers/platform/x86/asus_acpi.c
@@ -1507,6 +1507,7 @@
 	}
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = 15;
 	asus_backlight_device = backlight_device_register("asus", NULL, NULL,
 							  &asus_backlight_data,
diff --git a/drivers/platform/x86/classmate-laptop.c b/drivers/platform/x86/classmate-laptop.c
index 9111354..94f93b6 100644
--- a/drivers/platform/x86/classmate-laptop.c
+++ b/drivers/platform/x86/classmate-laptop.c
@@ -564,6 +564,7 @@
 		return -ENOMEM;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = 7;
 	ipml->bd = backlight_device_register("cmpc_bl", &acpi->dev,
 					     acpi->handle, &cmpc_bl_ops,
diff --git a/drivers/platform/x86/compal-laptop.c b/drivers/platform/x86/compal-laptop.c
index 034572b..eb95878 100644
--- a/drivers/platform/x86/compal-laptop.c
+++ b/drivers/platform/x86/compal-laptop.c
@@ -970,6 +970,7 @@
 	if (!acpi_video_backlight_support()) {
 		struct backlight_properties props;
 		memset(&props, 0, sizeof(struct backlight_properties));
+		props.type = BACKLIGHT_PLATFORM;
 		props.max_brightness = BACKLIGHT_LEVEL_MAX;
 		compalbl_device = backlight_device_register(DRIVER_NAME,
 							    NULL, NULL,
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index ad24ef3..de301aa8 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -671,6 +671,7 @@
 	if (max_intensity) {
 		struct backlight_properties props;
 		memset(&props, 0, sizeof(struct backlight_properties));
+		props.type = BACKLIGHT_PLATFORM;
 		props.max_brightness = max_intensity;
 		dell_backlight_device = backlight_device_register("dell_backlight",
 								  &platform_device->dev,
diff --git a/drivers/platform/x86/eeepc-laptop.c b/drivers/platform/x86/eeepc-laptop.c
index 49d9ad7..6605bea 100644
--- a/drivers/platform/x86/eeepc-laptop.c
+++ b/drivers/platform/x86/eeepc-laptop.c
@@ -1147,6 +1147,7 @@
 	struct backlight_device *bd;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = 15;
 	bd = backlight_device_register(EEEPC_LAPTOP_FILE,
 				       &eeepc->platform_device->dev, eeepc,
diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
index 95e3b09..493054c 100644
--- a/drivers/platform/x86/fujitsu-laptop.c
+++ b/drivers/platform/x86/fujitsu-laptop.c
@@ -1128,6 +1128,7 @@
 
 		memset(&props, 0, sizeof(struct backlight_properties));
 		max_brightness = fujitsu->max_brightness;
+		props.type = BACKLIGHT_PLATFORM;
 		props.max_brightness = max_brightness - 1;
 		fujitsu->bl_device = backlight_device_register("fujitsu-laptop",
 							       NULL, NULL,
diff --git a/drivers/platform/x86/msi-laptop.c b/drivers/platform/x86/msi-laptop.c
index 7e9bb6d..142d385 100644
--- a/drivers/platform/x86/msi-laptop.c
+++ b/drivers/platform/x86/msi-laptop.c
@@ -804,6 +804,7 @@
 	} else {
 		struct backlight_properties props;
 		memset(&props, 0, sizeof(struct backlight_properties));
+		props.type = BACKLIGHT_PLATFORM;
 		props.max_brightness = MSI_LCD_LEVEL_MAX - 1;
 		msibl_device = backlight_device_register("msi-laptop-bl", NULL,
 							 NULL, &msibl_ops,
diff --git a/drivers/platform/x86/msi-wmi.c b/drivers/platform/x86/msi-wmi.c
index 35278ad..d5419c9 100644
--- a/drivers/platform/x86/msi-wmi.c
+++ b/drivers/platform/x86/msi-wmi.c
@@ -254,6 +254,7 @@
 	if (!acpi_video_backlight_support()) {
 		struct backlight_properties props;
 		memset(&props, 0, sizeof(struct backlight_properties));
+		props.type = BACKLIGHT_PLATFORM;
 		props.max_brightness = ARRAY_SIZE(backlight_map) - 1;
 		backlight = backlight_device_register(DRV_NAME, NULL, NULL,
 						      &msi_backlight_ops,
diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
index cc1e0ba..05be30e 100644
--- a/drivers/platform/x86/panasonic-laptop.c
+++ b/drivers/platform/x86/panasonic-laptop.c
@@ -602,6 +602,7 @@
 	}
 	/* initialize backlight */
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = pcc->sinf[SINF_AC_MAX_BRIGHT];
 	pcc->backlight = backlight_device_register("panasonic", NULL, pcc,
 						   &pcc_backlight_ops, &props);
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 5e83370..13d8d63 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1305,8 +1305,9 @@
 		       "controlled by ACPI video driver\n");
 	} else if (ACPI_SUCCESS(acpi_get_handle(sony_nc_acpi_handle, "GBRT",
 						&handle))) {
-							struct backlight_properties props;
+		struct backlight_properties props;
 		memset(&props, 0, sizeof(struct backlight_properties));
+		props.type = BACKLIGHT_PLATFORM;
 		props.max_brightness = SONY_MAX_BRIGHTNESS - 1;
 		sony_backlight_device = backlight_device_register("sony", NULL,
 								  NULL,
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index eb99223..947bdca 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6307,6 +6307,7 @@
 		return 1;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = bright_maxlvl;
 	props.brightness = b & TP_EC_BACKLIGHT_LVLMSK;
 	ibm_backlight_device = backlight_device_register(TPACPI_BACKLIGHT_DEV_NAME,
diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index 209cced..63f42a2 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -1018,6 +1018,7 @@
 		create_toshiba_proc_entries();
 	}
 
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS - 1;
 	toshiba_backlight_device = backlight_device_register("toshiba",
 							     &toshiba_acpi.p_dev->dev,