u-boot-brain/drivers/pwm/Makefile
Alper Nebi Yasak 1b9ee2882e 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>
2021-04-10 16:08:39 +02:00

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Makefile

# SPDX-License-Identifier: GPL-2.0+
#
# (C) Copyright 2006
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# (C) Copyright 2001
# Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
#ccflags-y += -DDEBUG
obj-$(CONFIG_DM_PWM) += pwm-uclass.o
obj-$(CONFIG_PWM_CROS_EC) += cros_ec_pwm.o
obj-$(CONFIG_PWM_EXYNOS) += exynos_pwm.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o pwm-imx-util.o
obj-$(CONFIG_PWM_MESON) += pwm-meson.o
obj-$(CONFIG_PWM_MTK) += pwm-mtk.o
obj-$(CONFIG_PWM_ROCKCHIP) += rk_pwm.o
obj-$(CONFIG_PWM_SANDBOX) += sandbox_pwm.o
obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o
obj-$(CONFIG_PWM_TEGRA) += tegra_pwm.o
obj-$(CONFIG_PWM_SUNXI) += sunxi_pwm.o
obj-$(CONFIG_PWM_TI_EHRPWM) += pwm-ti-ehrpwm.o