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>
Enhanced high resolution PWM module (EHRPWM) hardware can be used to
generate PWM output over 2 channels. This commit adds PWM driver support
for EHRPWM device present on AM33XX SOC.
The code is based on the drivers/pwm/pwm-tiehrpwm.c driver of the Linux
kernel version 5.9-rc7.
For DT binding details see:
- Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
Signed-off-by: Dario Binacchi <dariobin@libero.it>
This adds the driver for the PWM controller found in the Amlogic SoCs.
This PWM is only a set of Gates, Dividers and Counters:
PWM output is achieved by calculating a clock that permits calculating
two periods (low and high). The counter then has to be set to switch after
N cycles for the first half period.
The hardware has no "polarity" setting. This driver reverses the period
cycles (the low length is inverted with the high length) for
PWM_POLARITY_INVERSED.
Disabling the PWM stops the output immediately (without waiting for the
current period to complete first).
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Adds a PWM driver for PWM chip present in SiFive's HiFive Unleashed SoC
This driver is simple port of Linux pwm sifive driver from Linux v5.6
commit: 9e37a53eb051 ("pwm: sifive: Add a driver for SiFive SoC PWM")
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
This commit adds basic support for PWM found on Allwinner A64.
It can be used for pwm_backlight driver (e.g. for Pinebook)
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Unfortunately a test for the PWM uclass was not included when it was
submitted. This was noticed when trying to add more functionality:
http://patchwork.ozlabs.org/patch/748172/
Add a simple test to get us started.
Signed-off-by: Simon Glass <sjg@chromium.org>
This driver supports the standard PWM API. There are 5 PWMs. Four are used
normally and the last is normally used as a timer.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
Use the driver-model PWM driver in preference to the old code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Move this option to Kconfig and clean up the header files. Adjust the only
user (the LCD driver) to work with the new driver.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Add a uclass that supports Pulse Width Modulation (PWM) devices. It
provides methods to enable/disable and configure the device.
Signed-off-by: Simon Glass <sjg@chromium.org>
