[deliverable/linux.git] / Documentation / devicetree / bindings / pwm / 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>;
	}
Commit	Line	Data
5b5ff97d TF	1	* Samsung PWM timers
	2
	3	Samsung SoCs contain PWM timer blocks which can be used for system clock source
	4	and clock event timers, as well as to drive SoC outputs with PWM signal. Each
	5	PWM timer block provides 5 PWM channels (not all of them can drive physical
	6	outputs - see SoC and board manual).
	7
	8	Be aware that the clocksource driver supports only uniprocessor systems.
	9
	10	Required properties:
	11	- compatible : should be one of following:
	12	samsung,s3c2410-pwm - for 16-bit timers present on S3C24xx SoCs
	13	samsung,s3c6400-pwm - for 32-bit timers present on S3C64xx SoCs
	14	samsung,s5p6440-pwm - for 32-bit timers present on S5P64x0 SoCs
	15	samsung,s5pc100-pwm - for 32-bit timers present on S5PC100, S5PV210,
	16	Exynos4210 rev0 SoCs
	17	samsung,exynos4210-pwm - for 32-bit timers present on Exynos4210,
1b3f25ce	18	Exynos4x12, Exynos5250 and Exynos5420 SoCs
5b5ff97d TF	19	- reg: base address and size of register area
	20	- interrupts: list of timer interrupts (one interrupt per timer, starting at
	21	timer 0)
f51a87a9 TF	22	- clock-names: should contain all following required clock names:
	23	- "timers" - PWM base clock used to generate PWM signals,
	24	and any subset of following optional clock names:
	25	- "pwm-tclk0" - first external PWM clock source,
	26	- "pwm-tclk1" - second external PWM clock source.
	27	Note that not all IP variants allow using all external clock sources.
	28	Refer to SoC documentation to learn which clock source configurations
	29	are available.
	30	- clocks: should contain clock specifiers of all clocks, which input names
	31	have been specified in clock-names property, in same order.
ebeec0af LP	32	- #pwm-cells: should be 3. See pwm.txt in this directory for a description of
	33	the cells format. The only third cell flag supported by this binding is
	34	PWM_POLARITY_INVERTED.
5b5ff97d TF	35
	36	Optional properties:
	37	- samsung,pwm-outputs: list of PWM channels used as PWM outputs on particular
	38	platform - an array of up to 5 elements being indices of PWM channels
	39	(from 0 to 4), the order does not matter.
	40
	41	Example:
	42	pwm@7f006000 {
	43	compatible = "samsung,s3c6400-pwm";
	44	reg = <0x7f006000 0x1000>;
	45	interrupt-parent = <&vic0>;
	46	interrupts = <23>, <24>, <25>, <27>, <28>;
f51a87a9 TF	47	clocks = <&clock 67>;
f51a87a9 TF	48	clock-names = "timers";
5b5ff97d TF	49	samsung,pwm-outputs = <0>, <1>;
	50	#pwm-cells = <3>;
	51	}