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>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.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>
Both CONFIG_PWM_TEGRA and CONFIG_PWM_EXYNOS depend on CONFIG_DM_PWM,
i.e. they are already guarded by Kconfig correctly. Remove unneeded
ifdef CONFIG_DM_PWM ... endif.
While we are here, let's tidy up alignment and sort the lines
alphabetically in Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-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>
This PWM supports four channels. The driver always uses the 32KHz clock,
and adjusts the duty cycle accordingly.
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>
add basic support for the pwm modul found on imx6.
Pieces of this code are based on linux code from drivers/pwm/pwm-imx.c
Commit "cd3de83f1476 Linux 3.16-rc4"
Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
