Re: [PATCH v8 1/2] dt-bindings: cpufreq: Introduce QCOM CPUFREQ Firmware bindings

From: Taniya Das
Date: Thu Oct 11 2018 - 06:32:22 EST


Hello Rob,

Thanks for your review comments.

On 9/27/2018 9:01 PM, Rob Herring wrote:
On Sun, Sep 23, 2018 at 04:03:12PM +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 | 169 +++++++++++++++++++++
1 file changed, 169 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..c06941c
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt
@@ -0,0 +1,169 @@
+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".
+
+* 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: qcom,cpufreq-hw {

Should have a unit-address and node names should be generic. We don't
really have one for this, but let's go with 'cpufreq', so:

cpufreq@17d43000


Thanks Rob, will update in the next patch.

+ 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", "cpu_clk";
+
+ #freq-domains-cells = <1>

Not documented, but I don't think you need this if it is always 1 and
because this is not a common binding.


I would add it in the next patch just to keep it documented.

Rob


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