[PATCH v5 10/11] dt: cpufreq: st: Provide bindings for ST's CPUFreq implementation

Rob Herring robh at kernel.org
Tue Dec 8 19:52:40 PST 2015


On Tue, Dec 08, 2015 at 02:32:03PM +0000, Lee Jones wrote:
> Cc: devicetree at vger.kernel.org
> Signed-off-by: Lee Jones <lee.jones at linaro.org>

Acked-by: Rob Herring <robh at kernel.org>

> ---
>  .../devicetree/bindings/cpufreq/cpufreq-st.txt     | 91 ++++++++++++++++++++++
>  1 file changed, 91 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
> 
> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
> new file mode 100644
> index 0000000..d91a02a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
> @@ -0,0 +1,91 @@
> +Binding for ST's CPUFreq driver
> +===============================
> +
> +ST's CPUFreq driver attempts to read 'process' and 'version' attributes
> +from the SoC, then supplies the OPP framework with 'prop' and 'supported
> +hardware' information respectively.  The framework is then able to read
> +the DT and operate in the usual way.
> +
> +For more information about the expected DT format [See: ../opp/opp.txt].
> +
> +Frequency Scaling only
> +----------------------
> +
> +No vendor specific driver required for this.
> +
> +Located in CPU's node:
> +
> +- operating-points		: [See: ../power/opp.txt]
> +
> +Example [safe]
> +--------------
> +
> +cpus {
> +	cpu at 0 {
> +				 /* kHz     uV   */
> +		operating-points = <1500000 0
> +				    1200000 0
> +				    800000  0
> +				    500000  0>;
> +	};
> +};
> +
> +Dynamic Voltage and Frequency Scaling (DVFS)
> +--------------------------------------------
> +
> +This requires the ST CPUFreq driver to supply 'process' and 'version' info.
> +
> +Located in CPU's node:
> +
> +- operating-points-v2		: [See ../power/opp.txt]
> +
> +Example [unsafe]
> +----------------
> +
> +cpus {
> +	cpu at 0 {
> +		operating-points-v2	= <&cpu0_opp_table>;
> +	};
> +};
> +
> +cpu0_opp_table: opp_table {
> +	compatible = "operating-points-v2";
> +
> +	/* ############################################################### */
> +	/* # WARNING: Do not attempt to copy/replicate these nodes,      # */
> +	/* #          they are only to be supplied by the bootloader !!! # */
> +	/* ############################################################### */
> +	opp0 {
> +		/*			   Major       Minor       Substrate */
> +		/*			   2           all         all       */
> +		opp-supported-hw	= <0x00000004  0xffffffff  0xffffffff>;
> +		opp-hz			= /bits/ 64 <1500000000>;
> +		clock-latency-ns	= <10000000>;
> +
> +		opp-microvolt-pcode0	= <1200000>;
> +		opp-microvolt-pcode1	= <1200000>;
> +		opp-microvolt-pcode2	= <1200000>;
> +		opp-microvolt-pcode3	= <1200000>;
> +		opp-microvolt-pcode4	= <1170000>;
> +		opp-microvolt-pcode5	= <1140000>;
> +		opp-microvolt-pcode6	= <1100000>;
> +		opp-microvolt-pcode7	= <1070000>;
> +	};
> +
> +	opp1 {
> +		/*			   Major       Minor       Substrate */
> +		/*			   all         all         all       */
> +		opp-supported-hw	= <0xffffffff  0xffffffff  0xffffffff>;
> +		opp-hz			= /bits/ 64 <1200000000>;
> +		clock-latency-ns	= <10000000>;
> +
> +		opp-microvolt-pcode0	= <1110000>;
> +		opp-microvolt-pcode1	= <1150000>;
> +		opp-microvolt-pcode2	= <1100000>;
> +		opp-microvolt-pcode3	= <1080000>;
> +		opp-microvolt-pcode4	= <1040000>;
> +		opp-microvolt-pcode5	= <1020000>;
> +		opp-microvolt-pcode6	= <980000>;
> +		opp-microvolt-pcode7	= <930000>;
> +	};
> +};
> -- 
> 1.9.1
> 
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