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

From: Taniya Das
Date: Sat Dec 01 2018 - 22:44:07 EST


Hello Rob,

On 11/27/2018 12:28 AM, Rob Herring wrote:
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@xxxxxxxxxxxxxx>
---
.../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


Thanks, updated it in the latest patch.

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