[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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