| Simon Glass | fc760cb | 2016-01-21 19:44:54 -0700 | [diff] [blame] | 1 | config DM_PWM |
| 2 | bool "Enable support for pulse-width modulation devices (PWM)" |
| 3 | depends on DM |
| 4 | help |
| 5 | A pulse-width modulator emits a pulse of varying width and provides |
| 6 | control over the duty cycle (high and low time) of the signal. This |
| 7 | is often used to control a voltage level. The more time the PWM |
| 8 | spends in the 'high' state, the higher the voltage. The PWM's |
| 9 | frequency/period can be controlled along with the proportion of that |
| 10 | time that the signal is high. |
| Simon Glass | 0e23fd8 | 2016-01-21 19:44:55 -0700 | [diff] [blame] | 11 | |
| 12 | config PWM_ROCKCHIP |
| 13 | bool "Enable support for the Rockchip PWM" |
| 14 | depends on DM_PWM |
| 15 | help |
| 16 | This PWM is found on RK3288 and other Rockchip SoCs. It supports a |
| 17 | programmable period and duty cycle. A 32-bit counter is used. |
| 18 | Various options provided in the hardware (such as capture mode and |
| 19 | continuous/single-shot) are not supported by the driver. |
| Simon Glass | 41fa035 | 2016-01-30 16:38:00 -0700 | [diff] [blame] | 20 | |
| 21 | config PWM_TEGRA |
| 22 | bool "Enable support for the Tegra PWM" |
| Simon Glass | 91c08af | 2016-01-30 16:38:01 -0700 | [diff] [blame] | 23 | depends on DM_PWM |
| Simon Glass | 41fa035 | 2016-01-30 16:38:00 -0700 | [diff] [blame] | 24 | help |
| 25 | This PWM is found on Tegra 20 and other Nvidia SoCs. It supports |
| 26 | four channels with a programmable period and duty cycle. Only a |
| 27 | 32KHz clock is supported by the driver but the duty cycle is |
| 28 | configurable. |