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| author | Alper Nebi Yasak <alpernebiyasak@gmail.com> | 2020-10-22 23:49:27 +0300 |
|---|---|---|
| committer | Anatolij Gustschin <agust@denx.de> | 2021-04-10 17:08:39 +0300 |
| commit | 1b9ee2882e6bd1c17ab2ec86249aa0347af68242 (patch) | |
| tree | 97c0a555eae842b114c8fbbc22e2b1acd48c8773 /drivers/pwm/Kconfig | |
| parent | fefa713b1843cf13d3132bfe0cf27710938c5d92 (diff) | |
| download | u-boot-1b9ee2882e6bd1c17ab2ec86249aa0347af68242.tar.xz | |
pwm: Add a driver for Chrome OS EC PWM
This PWM is used in rk3399-gru-bob and rk3399-gru-kevin to control
the display brightness. We can only change the duty cycle, so on
set_config() we just try to match the duty cycle that dividing duty_ns
by period_ns gives us. To disable, we set the duty cycle to zero while
keeping the old value for when we want to re-enable it.
The cros_ec_set_pwm_duty() function is taken from Depthcharge's
cros_ec_set_bl_pwm_duty() but modified to use the generic pwm type.
The driver itself is very loosely based on rk_pwm.c for the general pwm
driver structure.
The devicetree binding file is from Linux, before it was converted to
YAML at 5df5a577a6b4 ("dt-bindings: pwm: Convert google,cros-ec-pwm.txt
to YAML format") in their repo.
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'drivers/pwm/Kconfig')
| -rw-r--r-- | drivers/pwm/Kconfig | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index ccf81abbe9..cf7f4c6840 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -9,6 +9,15 @@ config DM_PWM frequency/period can be controlled along with the proportion of that time that the signal is high. +config PWM_CROS_EC + bool "Enable support for the Chrome OS EC PWM" + depends on DM_PWM + help + This PWM is found on several Chrome OS devices and controlled by + the Chrome OS embedded controller. It may be used to control the + screen brightness and/or the keyboard backlight depending on the + device. + config PWM_EXYNOS bool "Enable support for the Exynos PWM" depends on DM_PWM |