Cc: [email protected]
Signed-off-by: Lee Jones <[email protected]>
---
Only submitting the binding document as requested by Viresh.
v2 => v3:
- Using OPP v2
- Moved OPPs out of the CPU node into their own one
- Using generic 'opp-hz' property
.../devicetree/bindings/cpufreq/cpufreq-st.txt | 77 ++++++++++++++++++++++
1 file changed, 77 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..a478eec
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
@@ -0,0 +1,77 @@
+Binding for ST's CPUFreq driver
+===============================
+
+Required properties [for working voltage scaling]:
+-------------------------------------------------
+
+Located in CPU'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 'cpu0-opp-list' node [to be provided ONLY by the bootloader]:
+
+ - opp{1..N} : Each 'oppX' subnode will contain the following
properties:
+ - opp-hz : CPU frequency [Hz] for this OPP
+ - st,avs : List of available voltages [uV] indexed by process
code
+ - 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 cpu0-opp-list will be provided by the bootloader. Do not attempt
to
+ artificially synthesise the cpu0-opp-list node or any of its
descendants.
+ They are very platform specific and may damage the hardware if created
+ incorrectly.
+
+Required properties [if voltage scaling properties are missing]:
+-------------------------------------------------------------------
+
+Located in CPU's node:
+
+- operating-points : [See: ../power/opp.txt]
+
+Example [safe]:
+--------------
+
+cpus {
+ cpu@0 {
+ /* kHz uV */
+ operating-points = <1500000 0
+ 1200000 0
+ 800000 0
+ 500000 0>;
+ };
+};
+
+Example [unsafe]:
+----------------
+
+cpus {
+ cpu@0 {
+ st,syscfg = <&syscfg [major_offset]>;
+ st,syscfg-eng = <&syscfg_eng [pcode_offset]
[minor_offset]>;
+ operating-points-v2 = <&cpu0_opp_list>;
+ };
+};
+
+/* ############################################################ */
+/* # WARNING: Do not attempt to copy/replicate this node, # */
+/* # it is only to be supplied by the bootloader !!! # */
+/* ############################################################ */
+cpu0-opp-list {
+ compatible = "operating-points-v2-sti";
+ opp0 {
+ opp-hz = <1200000000>;
+ st,avs = <1110 1150 1100 1080 1040 1020 980 930>;
+ st,substrate = <0xff>;
+ st,cuts = <0xff>;
+ };
+ opp1 {
+ opp-hz = <1500000000>;
+ st,avs = <1200 1200 1200 1200 1170 1140 1100 1070>;
+ st,substrate = <0xff>;
+ st,cuts = <0x2>;
+ };
+};
--
1.9.1
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