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Message-Id: <1438010430-5802-2-git-send-email-lee.jones@linaro.org>
Date: Mon, 27 Jul 2015 16:20:30 +0100
From: Lee Jones <lee.jones@...aro.org>
To: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: kernel@...inux.com, rjw@...ysocki.net, viresh.kumar@...aro.org,
linux-pm@...r.kernel.org, devicetree@...r.kernel.org,
ajitpal.singh@...com, sre@...nel.org, dbaryshkov@...il.com,
Lee Jones <lee.jones@...aro.org>
Subject: [PATCH v4 2/2] dt: power: st: Provide bindings for ST's OPPs
These OPPs are used in ST's CPUFreq implementation.
Signed-off-by: Lee Jones <lee.jones@...aro.org>
---
Changelog:
- None, new patch
Documentation/devicetree/bindings/power/opp-st.txt | 76 ++++++++++++++++++++++
1 file changed, 76 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/opp-st.txt
diff --git a/Documentation/devicetree/bindings/power/opp-st.txt b/Documentation/devicetree/bindings/power/opp-st.txt
new file mode 100644
index 0000000..6eb2a91
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/opp-st.txt
@@ -0,0 +1,76 @@
+STMicroelectronics OPP (Operating Performance Points) Bindings
+--------------------------------------------------------------
+
+Frequency Scaling only
+----------------------
+
+Located in CPU's node:
+
+- operating-points : [See: ./opp.txt]
+
+Example [safe]
+--------------
+
+cpus {
+ cpu@0 {
+ /* kHz uV */
+ operating-points = <1500000 0
+ 1200000 0
+ 800000 0
+ 500000 0>;
+ };
+};
+
+Dynamic Voltage and Frequency Scaling (DVFS)
+--------------------------------------------
+
+Located in 'cpu0-opp-list' node [to be provided ONLY by the bootloader]:
+
+- compatible : Should be "operating-points-v2-sti"
+- opp{1..N} : Each 'oppX' subnode will contain the following properties:
+ - opp-hz : CPU frequency [Hz] for this OPP [See: ./opp.txt]
+ - 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]
+- 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
+
+WARNING: The opp{1..N} nodes will be provided by the bootloader. Do not attempt to
+ artificially synthesise the opp{1..N} nodes or any of their descendants.
+ They are very platform specific and may damage the hardware if created
+ incorrectly.
+
+Example [unsafe]
+----------------
+
+cpus {
+ cpu@0 {
+ 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";
+ st,syscfg = <&syscfg [major_offset]>;
+ st,syscfg-eng = <&syscfg_eng [pcode_offset] [minor_offset]>;
+
+ 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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