spends in the 'high' state, the higher the voltage. The PWM's
frequency/period can be controlled along with the proportion of that
time that the signal is high.
+
+config PWM_EXYNOS
+ bool "Enable support for the Exynos PWM"
+ depends on DM_PWM
+ help
+ This PWM is found on Samsung Exynos 5250 and other Samsung SoCs. It
+ supports a programmable period and duty cycle. A 32-bit counter is
+ used. It provides 5 channels which can be independently
+ programmed. Channel 4 (the last) is normally used as a timer.
+
+config PWM_ROCKCHIP
+ bool "Enable support for the Rockchip PWM"
+ depends on DM_PWM
+ help
+ This PWM is found on RK3288 and other Rockchip SoCs. It supports a
+ programmable period and duty cycle. A 32-bit counter is used.
+ Various options provided in the hardware (such as capture mode and
+ continuous/single-shot) are not supported by the driver.
+
+config PWM_TEGRA
+ bool "Enable support for the Tegra PWM"
+ depends on DM_PWM
+ help
+ This PWM is found on Tegra 20 and other Nvidia SoCs. It supports
+ four channels with a programmable period and duty cycle. Only a
+ 32KHz clock is supported by the driver but the duty cycle is
+ configurable.