[PATCH 8/8] dt: cpufreq: st: Provide bindings for ST's CPUFreq implementation
Lee Jones
lee.jones at linaro.org
Mon Jun 22 08:43:57 PDT 2015
Cc: devicetree at vger.kernel.org
Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
.../devicetree/bindings/cpufreq/cpufreq-st.txt | 48 ++++++++++++++++++++++
1 file changed, 48 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..cfa8952
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
@@ -0,0 +1,48 @@
+Binding for ST's CPUFreq driver
+===============================
+
+Required properties:
+-------------------
+- compatible : Supported values are:
+ "st,stih407-cpufreq"
+
+Required properties [for working voltage scaling]:
+-------------------------------------------------
+
+Located in CPUFreq's node:
+
+- st,syscfg : Phandle to Major number register
+ First cell: offset to major number
+- st,syscfg-eng : Phandle to Minor number and Pcode registers
+ First cell: offset to process code
+ Second cell: offset to minor number
+
+Located in CPU's node:
+
+- st,opp-list : Bootloader provided node containing one or more 'opp at X' sub-nodes
+ - opp@{1..X} : Each 'opp at X' subnode will contain the following properties:
+ - st,avs : List of available voltages [uV] indexed by process code
+ - st,freq : CPU frequency [Hz] for this OPP
+ - st,cuts : Cut version this OPP is suitable for [0xFF means ALL]
+ - st,substrate : Substrate version this OPP is suitable for [0xFF means ALL]
+
+WARNING: The st,opp-list will be provided by the bootloader. Do not attempt to
+ artificially synthesise the st,opp-list node or any of its descendants.
+ They are very platform specific and may damage the hardware if created
+ incorrectly.
+
+Required properties [if the voltage scaling properties are missing]:
+-------------------------------------------------------------------
+
+Located in CPU's node:
+
+- operating-points : [See: ../power/opp.txt]
+
+Example:
+-------
+
+cpufreq {
+ compatible = "st,stih407-cpufreq";
+ st,syscfg = <&syscfg [major_offset]>;
+ st,syscfg-eng = <&syscfg_eng [pcode_offset] [minor_offset]>;
+};
--
1.9.1
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