Re: [RFC][PATCHv5 4/4] Documentation: Add device tree bindings for Freescale FTM PWM.

[Kumar Gala <galak@codeaurora.org>]

On Oct 28, 2013, at 4:05 AM, Xiubo Li wrote:

> The RFC patch only added "See ../clock/clock-bindings.txt for details of
> the property values."
> 
> 
> 
> This adds the Document for Freescale FTM PWM driver under
> Documentation/devicetree/bindings/pwm/.
> 
> Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
> ---
> .../devicetree/bindings/pwm/pwm-fsl-ftm.txt        | 34 ++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt
> 
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt b/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt
> new file mode 100644
> index 0000000..175b762
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/pwm-fsl-ftm.txt
> @@ -0,0 +1,34 @@
> +Freescale FTM PWM controller

What does FTM stand for, and can we spell out PWM at least once early on.

> +
> +Required properties:
> +- compatible: Should be "fsl,vf610-ftm-pwm"
> +- reg: Physical base address and length of the controller's registers
> +- #pwm-cells: Should be 3. See pwm.txt in this directory for a description of
> +  the cells format.
> +- clock-names : Includes the following module clock source entries:
> +    "ftm0" (system clock),
> +    "ftm0_fix_sel" (fixed frequency clock),
> +    "ftm0_ext_sel" (external clock)
> +- clocks : Must contain a clock specifier for each entry in clock-names,
> +  See ../clock/clock-bindings.txt for details of the property values.
> +- fsl,pwm-counter-clk: The FTM PWM counter clock source, should be one of the
> +  entries in clock-names.

Why do we need this, why not just have only the clock-names/clocks reference the clk that is actually used?

> +- pinctrl-names: must contain a "default" entry.
> +- pinctrl-NNN: One property must exist for each entry in pinctrl-names.
> +  See ../pinctrl/pinctrl-bindings.txt for details of the property values.

let's drop the .. when making directory references.

> +
> +
> +Example:
> +
> +pwm0: pwm@40038000 {
> +		compatible = "fsl,vf610-ftm-pwm";
> +		reg = <0x40038000 0x1000>;
> +		#pwm-cells = <3>;
> +		clock-names = "ftm0", "ftm0_fix_sel", "ftm0_ext_sel";
> +		clocks = <&clks VF610_CLK_FTM0>,
> +			<&clks VF610_CLK_FTM0_FIX_SEL>,
> +			<&clks VF610_CLK_FTM0_EXT_SEL>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&pinctrl_pwm0_1>;
> +		fsl,pwm-counter-clk = "ftm0_ext_sel";
> +};
> -- 
> 1.8.4

- k

-- 
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