Re: [PATCH v2 3/3] ARM: dts: add property for maximum ADC clock frequencies

From: Stefan Agner
Date: Mon Mar 16 2015 - 11:18:24 EST


Forgot to add i.MX/Vybrid maintainers Shawn and Sascha.

On 2015-03-16 16:10, 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.
>
> Acked-by: Fugang Duan <B38611@xxxxxxxxxxxxx>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
> ---
> 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 a29c7ce..c6609bd 100644
> --- a/arch/arm/boot/dts/vfxxx.dtsi
> +++ b/arch/arm/boot/dts/vfxxx.dtsi
> @@ -189,6 +189,8 @@
> clocks = <&clks VF610_CLK_ADC0>;
> clock-names = "adc";
> status = "disabled";
> + fsl,adck-max-frequency = <30000000>, <40000000>,
> + <20000000>;
> };
>
> wdoga5: wdog@4003e000 {
> @@ -387,6 +389,8 @@
> clocks = <&clks VF610_CLK_ADC1>;
> clock-names = "adc";
> status = "disabled";
> + fsl,adck-max-frequency = <30000000>, <40000000>,
> + <20000000>;
> };
>
> esdhc1: esdhc@400b2000 {

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