platform/x86: nvidia-wmi-ec-backlight: Use acpi_video_get_backlight_type()

Add an acpi_video_get_backlight_type() == acpi_backlight_nvidia_wmi_ec
check. This will make nvidia-wmi-ec-backlight properly honor the user
selecting a different backlight driver through the acpi_backlight=...
kernel commandline option.

Since the auto-detect code check for nvidia-wmi-ec-backlight in
drivers/acpi/video_detect.c already checks that the WMI advertised
brightness-source is the embedded controller, this new check makes it
unnecessary for nvidia_wmi_ec_backlight_probe() to check this itself.

Suggested-by: Daniel Dadap <ddadap@nvidia.com>
Reviewed-by: Daniel Dadap <ddadap@nvidia.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index f2f98e942cf295e1b6d0769abe6500695f42b005..0cc5ac35fc570b1b61df133357e3d21056b30452 100644 (file)
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -93,6 +93,7 @@ config PEAQ_WMI
 
 config NVIDIA_WMI_EC_BACKLIGHT
        tristate "EC Backlight Driver for Hybrid Graphics Notebook Systems"
+       depends on ACPI_VIDEO
        depends on ACPI_WMI
        depends on BACKLIGHT_CLASS_DEVICE
        help

diff --git a/drivers/platform/x86/nvidia-wmi-ec-backlight.c b/drivers/platform/x86/nvidia-wmi-ec-backlight.c
index be803e47eac0d4a5de56f8101cd45f2979d08b94..baccdf6585382d06559252ded2a18c57a2108f85 100644 (file)
--- a/drivers/platform/x86/nvidia-wmi-ec-backlight.c
+++ b/drivers/platform/x86/nvidia-wmi-ec-backlight.c
@@ -10,6 +10,7 @@
 #include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
 #include <linux/types.h>
 #include <linux/wmi.h>
+#include <acpi/video.h>
 
 /**
  * wmi_brightness_notify() - helper function for calling WMI-wrapped ACPI method
@@ -87,19 +88,10 @@ static int nvidia_wmi_ec_backlight_probe(struct wmi_device *wdev, const void *ct
 {
        struct backlight_properties props = {};
        struct backlight_device *bdev;
-       u32 source;
        int ret;
 
-       ret = wmi_brightness_notify(wdev, WMI_BRIGHTNESS_METHOD_SOURCE,
-                                  WMI_BRIGHTNESS_MODE_GET, &source);
-       if (ret)
-               return ret;
-
-       /*
-        * This driver is only to be used when brightness control is handled
-        * by the EC; otherwise, the GPU driver(s) should control brightness.
-        */
-       if (source != WMI_BRIGHTNESS_SOURCE_EC)
+       /* drivers/acpi/video_detect.c also checks that SOURCE == EC */
+       if (acpi_video_get_backlight_type() != acpi_backlight_nvidia_wmi_ec)
                return -ENODEV;
 
        /*