Re: [PATCH 3/3] ARM: dts: add property for maximum ADC clock frequencies

[Jonathan Cameron <jic23@kernel.org>]

On 20/01/15 16:02, Stefan Agner wrote:
> The ADC clock frequency is limited depending on modes used. Add
> device tree property which allow to set the mode used and the
> maximum frequency ratings for the instance. These allows to
> set the ADC clock to a frequency which is within specification
> according to the actual mode used.
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
This should have been sent to the devicetree list and maintainers
in the first place.  Now cc'd.
> ---
>  Documentation/devicetree/bindings/iio/adc/vf610-adc.txt | 9 +++++++++
>  arch/arm/boot/dts/vfxxx.dtsi                            | 4 ++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt
> index 1a4a43d..3eb40e2 100644
> --- a/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt
> +++ b/Documentation/devicetree/bindings/iio/adc/vf610-adc.txt
> @@ -11,6 +11,13 @@ Required properties:
>  - clock-names: Must contain "adc", matching entry in the clocks property.
>  - vref-supply: The regulator supply ADC reference voltage.
>  
> +Recommended properties:
> +- fsl,adck-max-frequency: Maximum frequencies according to datasheets operating
> +  requirements. Three values are required, depending on conversion mode:
> +  - Frequency in normal mode (ADLPC=0, ADHSC=0)
> +  - Frequency in high-speed mode (ADLPC=0, ADHSC=1)
> +  - Frequency in low-power mode (ADLPC=1, ADHSC=0)
> +
>  Example:
>  adc0: adc@4003b000 {
>  	compatible = "fsl,vf610-adc";
> @@ -18,5 +25,7 @@ adc0: adc@4003b000 {
>  	interrupts = <0 53 0x04>;
>  	clocks = <&clks VF610_CLK_ADC0>;
>  	clock-names = "adc";
> +	fsl,adck-max-frequency = <30000000>, <40000000>,
> +				<20000000>;
>  	vref-supply = <&reg_vcc_3v3_mcu>;
>  };
> diff --git a/arch/arm/boot/dts/vfxxx.dtsi b/arch/arm/boot/dts/vfxxx.dtsi
> index 505969a..7584e0a 100644
> --- a/arch/arm/boot/dts/vfxxx.dtsi
> +++ b/arch/arm/boot/dts/vfxxx.dtsi
> @@ -182,6 +182,8 @@
>  				clocks = <&clks VF610_CLK_ADC0>;
>  				clock-names = "adc";
>  				status = "disabled";
> +				fsl,adck-max-frequency = <30000000>, <40000000>,
> +							<20000000>;
>  			};
>  
>  			wdog@4003e000 {
> @@ -361,6 +363,8 @@
>  				clocks = <&clks VF610_CLK_ADC1>;
>  				clock-names = "adc";
>  				status = "disabled";
> +				fsl,adck-max-frequency = <30000000>, <40000000>,
> +							<20000000>;
>  			};
>  
>  			esdhc1: esdhc@400b2000 {
>