Re: [PATCH v10 1/2] dt-bindings: cpufreq: Introduce QCOM CPUFREQ Firmware bindings

[Rob Herring <robh@kernel.org>]

On Wed, Nov 21, 2018 at 10:02:36AM -0800, Matthias Kaehlcke wrote:
> On Wed, Nov 21, 2018 at 04:12:46PM +0530, Taniya Das wrote:
> > Add QCOM cpufreq firmware device bindings for Qualcomm Technology Inc's
> > SoCs. This is required for managing the cpu frequency transitions which are
> > controlled by the hardware engine.
> > 
> > Signed-off-by: Taniya Das <tdas@codeaurora.org>
> > ---
> >  .../bindings/cpufreq/cpufreq-qcom-hw.txt           | 172 +++++++++++++++++++++
> >  1 file changed, 172 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
> > new file mode 100644
> > index 0000000..90e396b
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
> > @@ -0,0 +1,172 @@
> > +Qualcomm Technologies, Inc. CPUFREQ Bindings
> > +
> > +CPUFREQ HW is a hardware engine used by some Qualcomm Technologies, Inc. (QTI)
> > +SoCs to manage frequency in hardware. It is capable of controlling frequency
> > +for multiple clusters.
> > +
> > +Properties:
> > +- compatible
> > +	Usage:		required
> > +	Value type:	<string>
> > +	Definition:	must be "qcom,cpufreq-hw".
> > +
> > +- clocks
> > +	Usage:		required
> > +	Value type:	<phandle> From common clock binding.
> > +	Definition:	clock handle for XO clock and GPLL0 clock.
> > +
> > +- clock-names
> > +	Usage:		required
> > +	Value type:	<string> From common clock binding.
> > +	Definition:	must be "xo", "cpu_clk".
> > +
> > +- reg
> > +	Usage:		required
> > +	Value type:	<prop-encoded-array>
> > +	Definition:	Addresses and sizes for the memory of the HW bases in
> > +			each frequency domain.
> > +- reg-names
> > +	Usage:		Optional
> > +	Value type:	<string>
> > +	Definition:	Frequency domain name i.e.
> > +			"freq-domain0", "freq-domain1".
> > +
> > +- freq-domain-cells:
> > +	Usage:		required.
> > +	Definition:	Number of cells in a freqency domain specifier.
> > +
> > +* Property qcom,freq-domain
> > +Devices supporting freq-domain must set their "qcom,freq-domain" property with
> > +phandle to a cpufreq_hw followed by the Domain ID(0/1) in the CPU DT node.
> > +
> > +
> > +Example:
> > +
> > +Example 1: Dual-cluster, Quad-core per cluster. CPUs within a cluster switch
> > +DCVS state together.
> > +
> > +/ {
> > +	cpus {
> > +		#address-cells = <2>;
> > +		#size-cells = <0>;
> > +
> > +		CPU0: cpu@0 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x0>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_0>;
> > +			qcom,freq-domain = <&cpufreq_hw 0>;
> > +			L2_0: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +				L3_0: l3-cache {
> > +				      compatible = "cache";
> > +				};
> > +			};
> > +		};
> > +
> > +		CPU1: cpu@100 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x100>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_100>;
> > +			qcom,freq-domain = <&cpufreq_hw 0>;
> > +			L2_100: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +
> > +		CPU2: cpu@200 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x200>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_200>;
> > +			qcom,freq-domain = <&cpufreq_hw 0>;
> > +			L2_200: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +
> > +		CPU3: cpu@300 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x300>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_300>;
> > +			qcom,freq-domain = <&cpufreq_hw 0>;
> > +			L2_300: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +
> > +		CPU4: cpu@400 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x400>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_400>;
> > +			qcom,freq-domain = <&cpufreq_hw 1>;
> > +			L2_400: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +
> > +		CPU5: cpu@500 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x500>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_500>;
> > +			qcom,freq-domain = <&cpufreq_hw 1>;
> > +			L2_500: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +
> > +		CPU6: cpu@600 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x600>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_600>;
> > +			qcom,freq-domain = <&cpufreq_hw 1>;
> > +			L2_600: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +
> > +		CPU7: cpu@700 {
> > +			device_type = "cpu";
> > +			compatible = "qcom,kryo385";
> > +			reg = <0x0 0x700>;
> > +			enable-method = "psci";
> > +			next-level-cache = <&L2_700>;
> > +			qcom,freq-domain = <&cpufreq_hw 1>;
> > +			L2_700: l2-cache {
> > +				compatible = "cache";
> > +				next-level-cache = <&L3_0>;
> > +			};
> > +		};
> > +	};
> > +
> > + soc {
> > +	cpufreq_hw: cpufreq@17d43000 {
> > +		compatible = "qcom,cpufreq-hw";
> > +		reg = <0x17d43000 0x1400>, <0x17d45800 0x1400>;
> > +		reg-names = "freq-domain0", "freq-domain1";
> > +
> > +		clocks = <&rpmhcc RPMH_CXO_CLK>, <&gcc GPLL0>;
> > +		clock-names = "xo", "gcc_cpuss_gpll0_clk_src";
> 
> I don't have/find the document with the clock configuration of this
> IP block, but the 'clock-names' sound more like aliases for the actual
> clocks specified in the 'clocks' property (especially
> 'gcc_cpuss_gpll0_clk_src') than input signals from the IP POV, which
> I'd expect to have more generic names.

Also, this doesn't match the documented value above.

Rob