[PATCH 3/3] ARM: dts: add property for maximum ADC clock frequencies
Jonathan Cameron
jic23 at kernel.org
Wed Jan 28 10:19:51 PST 2015
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 at 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 at 4003b000 {
> compatible = "fsl,vf610-adc";
> @@ -18,5 +25,7 @@ adc0: adc at 4003b000 {
> interrupts = <0 53 0x04>;
> clocks = <&clks VF610_CLK_ADC0>;
> clock-names = "adc";
> + fsl,adck-max-frequency = <30000000>, <40000000>,
> + <20000000>;
> vref-supply = <®_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 at 4003e000 {
> @@ -361,6 +363,8 @@
> clocks = <&clks VF610_CLK_ADC1>;
> clock-names = "adc";
> status = "disabled";
> + fsl,adck-max-frequency = <30000000>, <40000000>,
> + <20000000>;
> };
>
> esdhc1: esdhc at 400b2000 {
>
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