pwm: Add MediaTek display PWM driver support

Add display PWM driver support to modify backlight for MT8173 and
MT6595. The PWM has one channel to control the brightness of the
display. When the (high_width / period) is closer to 1, the screen
is brighter; otherwise, it is darker.

Signed-off-by: YH Huang <yh.huang@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 49ef5156b418..0cfaf6b3aa03 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -249,6 +249,17 @@ config PWM_LPSS_PLATFORM
           To compile this driver as a module, choose M here: the module
           will be called pwm-lpss-platform.
 
+config PWM_MTK_DISP
+        tristate "MediaTek display PWM driver"
+        depends on ARCH_MEDIATEK || COMPILE_TEST
+        depends on HAS_IOMEM
+        help
+          Generic PWM framework driver for MediaTek disp-pwm device.
+          The PWM is used to control the backlight brightness for display.
+
+          To compile this driver as a module, choose M here: the module
+          will be called pwm-mtk-disp.
+
 config PWM_MXS
         tristate "Freescale MXS PWM support"
         depends on ARCH_MXS && OF