From c9ecd920324a647bf1f2b47f771c8f599cc7b551 Mon Sep 17 00:00:00 2001
From: Ansuel Smith <ansuelsmth@gmail.com>
Date: Sat, 22 Feb 2020 18:02:17 +0100
Subject: [PATCH 2/8] Documentation: cpufreq: add qcom,krait-cache bindings
Document dedicated cpufreq for Krait CPUs.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
.../bindings/cpufreq/qcom-cpufreq-krait.yaml | 221 ++++++++++++++++++
1 file changed, 221 insertions(+)
create mode 100644 Documentation/devicetree/bindings/cpufreq/qcom-cpufreq-krait.yaml
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/qcom-cpufreq-krait.yaml
@@ -0,0 +1,221 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cpufreq/qcom-cpufreq-krait.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: CPU Frequency scaling driver for Krait SoCs
+
+maintainers:
+ - Ansuel Smith <ansuelsmth@gmail.com>
+
+description: |
+ The krait cpufreq driver is a dedicated frequency scaling driver
+ based on cpufreq-dt generic driver that scale L2 cache and the
+ cores. TEST
+
+ The L2 cache is scaled based on the max clk across all cores and
+ the clock is decided based on the opp-level set in the device tree.
+
+ Different core freq can be linked to a specific l2 freq and the driver
+ on frequency change will scale the core and the l2 clk based of the
+ linked freq.
+
+ On Krait SoC is present a bug and on every L2 clk change the driver
+ needs to set the clk to the idle freq before changing it to the new value.
+
+ This requires the qcom cpufreq nvmem driver to parse the different opp
+ core clk and an additional opp table for the l2 scaling.
+
+ If the driver detect broken config (for example missing opp-level) the
+ cpufreq driver skips the l2 scaling
+
+ Referring to this example opp-level can be used to link a range of cpu freq
+ to a specific l2 freq:
+ cpu opp freq 384000000 has opp-level 0
+ l2 opp freq 384000000 has opp-level 0
+ The driver will scale l2 to 384000000
+
+ cpu opp freq 600000000-1000000000 has opp-level 1
+ l2 opp freq 1000000000 has opp-level 1
+ The driver will scale l2 to 1000000000
+
+allOf:
+ - $ref: /schemas/cache-controller.yaml#
+
+select:
+ properties:
+ compatible:
+ items:
+ - enum:
+ - qcom,krait-cache
+
+ required:
+ - compatible
+
+properties:
+ compatible:
+ items:
+ - const: qcom,krait-cache
+ - const: cache
+
+ cache-level:
+ const: 2
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ const: l2
+
+ l2-supply: true
+
+ operating-points-v2: true
+
+required:
+ - compatible
+ - cache-level
+ - clocks
+ - clock-names
+ - l2-supply
+ - operating-points-v2
+
+additionalProperties: false
+
+examples:
+ - |
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu0: cpu@0 {
+ compatible = "qcom,krait";
+ enable-method = "qcom,kpss-acc-v1";
+ device_type = "cpu";
+ reg = <0>;
+ next-level-cache = <&L2>;
+ qcom,acc = <&acc0>;
+ qcom,saw = <&saw0>;
+ clocks = <&kraitcc 0>, <&kraitcc 4>;
+ clock-names = "cpu", "l2";
+ clock-latency = <100000>;
+ cpu-supply = <&smb208_s2a>;
+ operating-points-v2 = <&opp_table0>;
+ voltage-tolerance = <5>;
+ cooling-min-state = <0>;
+ cooling-max-state = <10>;
+ #cooling-cells = <2>;
+ cpu-idle-states = <&CPU_SPC>;
+ };
+
+ /* ... */
+
+ };
+
+ opp_table0: opp_table0 {
+ compatible = "operating-points-v2-kryo-cpu";
+ nvmem-cells = <&speedbin_efuse>;
+
+ opp-384000000 {
+ opp-hz = /bits/ 64 <384000000>;
+ opp-microvolt-speed0-pvs0-v0 = <1000000>;
+ opp-microvolt-speed0-pvs1-v0 = <925000>;
+ opp-microvolt-speed0-pvs2-v0 = <875000>;
+ opp-microvolt-speed0-pvs3-v0 = <800000>;
+ opp-supported-hw = <0x1>;
+ clock-latency-ns = <100000>;
+ opp-level = <0>;
+ };
+
+ opp-600000000 {
+ opp-hz = /bits/ 64 <600000000>;
+ opp-microvolt-speed0-pvs0-v0 = <1050000>;
+ opp-microvolt-speed0-pvs1-v0 = <975000>;
+ opp-microvolt-speed0-pvs2-v0 = <925000>;
+ opp-microvolt-speed0-pvs3-v0 = <850000>;
+ opp-supported-hw = <0x1>;
+ clock-latency-ns = <100000>;
+ opp-level = <1>;
+ };
+
+ opp-800000000 {
+ opp-hz = /bits/ 64 <800000000>;
+ opp-microvolt-speed0-pvs0-v0 = <1100000>;
+ opp-microvolt-speed0-pvs1-v0 = <1025000>;
+ opp-microvolt-speed0-pvs2-v0 = <995000>;
+ opp-microvolt-speed0-pvs3-v0 = <900000>;
+ opp-supported-hw = <0x1>;
+ clock-latency-ns = <100000>;
+ opp-level = <1>;
+ };
+
+ opp-1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt-speed0-pvs0-v0 = <1150000>;
+ opp-microvolt-speed0-pvs1-v0 = <1075000>;
+ opp-microvolt-speed0-pvs2-v0 = <1025000>;
+ opp-microvolt-speed0-pvs3-v0 = <950000>;
+ opp-supported-hw = <0x1>;
+ clock-latency-ns = <100000>;
+ opp-level = <1>;
+ };
+
+ opp-1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt-speed0-pvs0-v0 = <1200000>;
+ opp-microvolt-speed0-pvs1-v0 = <1125000>;
+ opp-microvolt-speed0-pvs2-v0 = <1075000>;
+ opp-microvolt-speed0-pvs3-v0 = <1000000>;
+ opp-supported-hw = <0x1>;
+ clock-latency-ns = <100000>;
+ opp-level = <2>;
+ };
+
+ opp-1400000000 {
+ opp-hz = /bits/ 64 <1400000000>;
+ opp-microvolt-speed0-pvs0-v0 = <1250000>;
+ opp-microvolt-speed0-pvs1-v0 = <1175000>;
+ opp-microvolt-speed0-pvs2-v0 = <1125000>;
+ opp-microvolt-speed0-pvs3-v0 = <1050000>;
+ opp-supported-hw = <0x1>;
+ clock-latency-ns = <100000>;
+ opp-level = <2>;
+ };
+ };
+
+ opp_table_l2: opp_table_l2 {
+ compatible = "operating-points-v2";
+
+ opp-384000000 {
+ opp-hz = /bits/ 64 <384000000>;
+ opp-microvolt = <1100000>;
+ clock-latency-ns = <100000>;
+ opp-level = <0>;
+ };
+ opp-1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <1100000>;
+ clock-latency-ns = <100000>;
+ opp-level = <1>;
+ };
+ opp-1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt = <1150000>;
+ clock-latency-ns = <100000>;
+ opp-level = <2>;
+ };
+ };
+
+ soc {
+ L2: l2-cache {
+ compatible = "qcom,krait-cache", "cache";
+ cache-level = <2>;
+
+ clocks = <&kraitcc 4>;
+ clock-names = "l2";
+ l2-supply = <&smb208_s1a>;
+ operating-points-v2 = <&opp_table_l2>;
+ };
+ };
+
+...