platform/x86: Add driver for Apple gmux device

Apple laptops with hybrid graphics have a device named gmux that
controls the muxing of the LVDS panel between the GPUs as well as screen
brightness. This driver adds support for the gmux device. Only backlight
control is supported initially.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Tested-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index ce10f0313961..c5b4bfed7bb4 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -752,4 +752,14 @@ config SAMSUNG_Q10
           This driver provides support for backlight control on Samsung Q10
           and related laptops, including Dell Latitude X200.
 
+config APPLE_GMUX
+        tristate "Apple Gmux Driver"
+        depends on PNP
+        select BACKLIGHT_CLASS_DEVICE
+        ---help---
+          This driver provides support for the gmux device found on many
+          Apple laptops, which controls the display mux for the hybrid
+          graphics as well as the backlight. Currently only backlight
+          control is supported by the driver.
+
 endif # X86_PLATFORM_DEVICES