Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: 69973b830859bc6529a7a0468ba0d80ee5117826 authored by Linus Torvalds on 11 December 2016, 19:17:54 UTC
Linux 4.9
Linux 4.9
Tip revision: 69973b8
pwm-samsung.txt
* Samsung PWM timers
Samsung SoCs contain PWM timer blocks which can be used for system clock source
and clock event timers, as well as to drive SoC outputs with PWM signal. Each
PWM timer block provides 5 PWM channels (not all of them can drive physical
outputs - see SoC and board manual).
Be aware that the clocksource driver supports only uniprocessor systems.
Required properties:
- compatible : should be one of following:
samsung,s3c2410-pwm - for 16-bit timers present on S3C24xx SoCs
samsung,s3c6400-pwm - for 32-bit timers present on S3C64xx SoCs
samsung,s5p6440-pwm - for 32-bit timers present on S5P64x0 SoCs
samsung,s5pc100-pwm - for 32-bit timers present on S5PC100, S5PV210,
Exynos4210 rev0 SoCs
samsung,exynos4210-pwm - for 32-bit timers present on Exynos4210,
Exynos4x12, Exynos5250 and Exynos5420 SoCs
- reg: base address and size of register area
- interrupts: list of timer interrupts (one interrupt per timer, starting at
timer 0)
- clock-names: should contain all following required clock names:
- "timers" - PWM base clock used to generate PWM signals,
and any subset of following optional clock names:
- "pwm-tclk0" - first external PWM clock source,
- "pwm-tclk1" - second external PWM clock source.
Note that not all IP variants allow using all external clock sources.
Refer to SoC documentation to learn which clock source configurations
are available.
- clocks: should contain clock specifiers of all clocks, which input names
have been specified in clock-names property, in same order.
- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
the cells format. The only third cell flag supported by this binding is
PWM_POLARITY_INVERTED.
Optional properties:
- samsung,pwm-outputs: list of PWM channels used as PWM outputs on particular
platform - an array of up to 5 elements being indices of PWM channels
(from 0 to 4), the order does not matter.
Example:
pwm@7f006000 {
compatible = "samsung,s3c6400-pwm";
reg = <0x7f006000 0x1000>;
interrupt-parent = <&vic0>;
interrupts = <23>, <24>, <25>, <27>, <28>;
clocks = <&clock 67>;
clock-names = "timers";
samsung,pwm-outputs = <0>, <1>;
#pwm-cells = <3>;
}