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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-12-28 01:34:35 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-12-28 01:34:35 +0100
commit9ad55cd9e600de238e3937705e642f0253f3bc42 (patch)
tree09a32fd285cd16d145ade7ca148def347f4f462d /Documentation/devicetree
parenta7def561c2ad8572c5d016ac96949e5e9999965f (diff)
parent4157c2fc84b21c06d9fdbaf85e8b7e0f944433f2 (diff)
Merge back earlier cpufreq material for v4.5.
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/arm/cpus.txt17
-rw-r--r--Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt91
-rw-r--r--Documentation/devicetree/bindings/opp/opp.txt132
3 files changed, 201 insertions, 39 deletions
diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index 3a07a87fef20..6aca64f289b6 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -242,6 +242,23 @@ nodes to be present and contain the properties described below.
Definition: Specifies the syscon node controlling the cpu core
power domains.
+ - dynamic-power-coefficient
+ Usage: optional
+ Value type: <prop-encoded-array>
+ Definition: A u32 value that represents the running time dynamic
+ power coefficient in units of mW/MHz/uVolt^2. The
+ coefficient can either be calculated from power
+ measurements or derived by analysis.
+
+ The dynamic power consumption of the CPU is
+ proportional to the square of the Voltage (V) and
+ the clock frequency (f). The coefficient is used to
+ calculate the dynamic power as below -
+
+ Pdyn = dynamic-power-coefficient * V^2 * f
+
+ where voltage is in uV, frequency is in MHz.
+
Example 1 (dual-cluster big.LITTLE system 32-bit):
cpus {
diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
new file mode 100644
index 000000000000..d91a02a3b6b0
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-st.txt
@@ -0,0 +1,91 @@
+Binding for ST's CPUFreq driver
+===============================
+
+ST's CPUFreq driver attempts to read 'process' and 'version' attributes
+from the SoC, then supplies the OPP framework with 'prop' and 'supported
+hardware' information respectively. The framework is then able to read
+the DT and operate in the usual way.
+
+For more information about the expected DT format [See: ../opp/opp.txt].
+
+Frequency Scaling only
+----------------------
+
+No vendor specific driver required for this.
+
+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>;
+ };
+};
+
+Dynamic Voltage and Frequency Scaling (DVFS)
+--------------------------------------------
+
+This requires the ST CPUFreq driver to supply 'process' and 'version' info.
+
+Located in CPU's node:
+
+- operating-points-v2 : [See ../power/opp.txt]
+
+Example [unsafe]
+----------------
+
+cpus {
+ cpu@0 {
+ operating-points-v2 = <&cpu0_opp_table>;
+ };
+};
+
+cpu0_opp_table: opp_table {
+ compatible = "operating-points-v2";
+
+ /* ############################################################### */
+ /* # WARNING: Do not attempt to copy/replicate these nodes, # */
+ /* # they are only to be supplied by the bootloader !!! # */
+ /* ############################################################### */
+ opp0 {
+ /* Major Minor Substrate */
+ /* 2 all all */
+ opp-supported-hw = <0x00000004 0xffffffff 0xffffffff>;
+ opp-hz = /bits/ 64 <1500000000>;
+ clock-latency-ns = <10000000>;
+
+ opp-microvolt-pcode0 = <1200000>;
+ opp-microvolt-pcode1 = <1200000>;
+ opp-microvolt-pcode2 = <1200000>;
+ opp-microvolt-pcode3 = <1200000>;
+ opp-microvolt-pcode4 = <1170000>;
+ opp-microvolt-pcode5 = <1140000>;
+ opp-microvolt-pcode6 = <1100000>;
+ opp-microvolt-pcode7 = <1070000>;
+ };
+
+ opp1 {
+ /* Major Minor Substrate */
+ /* all all all */
+ opp-supported-hw = <0xffffffff 0xffffffff 0xffffffff>;
+ opp-hz = /bits/ 64 <1200000000>;
+ clock-latency-ns = <10000000>;
+
+ opp-microvolt-pcode0 = <1110000>;
+ opp-microvolt-pcode1 = <1150000>;
+ opp-microvolt-pcode2 = <1100000>;
+ opp-microvolt-pcode3 = <1080000>;
+ opp-microvolt-pcode4 = <1040000>;
+ opp-microvolt-pcode5 = <1020000>;
+ opp-microvolt-pcode6 = <980000>;
+ opp-microvolt-pcode7 = <930000>;
+ };
+};
diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt
index 0cb44dc21f97..601256fe8c0d 100644
--- a/Documentation/devicetree/bindings/opp/opp.txt
+++ b/Documentation/devicetree/bindings/opp/opp.txt
@@ -45,21 +45,10 @@ Devices supporting OPPs must set their "operating-points-v2" property with
phandle to a OPP table in their DT node. The OPP core will use this phandle to
find the operating points for the device.
-Devices may want to choose OPP tables at runtime and so can provide a list of
-phandles here. But only *one* of them should be chosen at runtime. This must be
-accompanied by a corresponding "operating-points-names" property, to uniquely
-identify the OPP tables.
-
If required, this can be extended for SoC vendor specfic bindings. Such bindings
should be documented as Documentation/devicetree/bindings/power/<vendor>-opp.txt
and should have a compatible description like: "operating-points-v2-<vendor>".
-Optional properties:
-- operating-points-names: Names of OPP tables (required if multiple OPP
- tables are present), to uniquely identify them. The same list must be present
- for all the CPUs which are sharing clock/voltage rails and hence the OPP
- tables.
-
* OPP Table Node
This describes the OPPs belonging to a device. This node can have following
@@ -100,6 +89,14 @@ Optional properties:
Entries for multiple regulators must be present in the same order as
regulators are specified in device's DT node.
+- opp-microvolt-<name>: Named opp-microvolt property. This is exactly similar to
+ the above opp-microvolt property, but allows multiple voltage ranges to be
+ provided for the same OPP. At runtime, the platform can pick a <name> and
+ matching opp-microvolt-<name> property will be enabled for all OPPs. If the
+ platform doesn't pick a specific <name> or the <name> doesn't match with any
+ opp-microvolt-<name> properties, then opp-microvolt property shall be used, if
+ present.
+
- opp-microamp: The maximum current drawn by the device in microamperes
considering system specific parameters (such as transients, process, aging,
maximum operating temperature range etc.) as necessary. This may be used to
@@ -112,6 +109,9 @@ Optional properties:
for few regulators, then this should be marked as zero for them. If it isn't
required for any regulator, then this property need not be present.
+- opp-microamp-<name>: Named opp-microamp property. Similar to
+ opp-microvolt-<name> property, but for microamp instead.
+
- clock-latency-ns: Specifies the maximum possible transition latency (in
nanoseconds) for switching to this OPP from any other OPP.
@@ -123,6 +123,26 @@ Optional properties:
- opp-suspend: Marks the OPP to be used during device suspend. Only one OPP in
the table should have this.
+- opp-supported-hw: This enables us to select only a subset of OPPs from the
+ larger OPP table, based on what version of the hardware we are running on. We
+ still can't have multiple nodes with the same opp-hz value in OPP table.
+
+ It's an user defined array containing a hierarchy of hardware version numbers,
+ supported by the OPP. For example: a platform with hierarchy of three levels
+ of versions (A, B and C), this field should be like <X Y Z>, where X
+ corresponds to Version hierarchy A, Y corresponds to version hierarchy B and Z
+ corresponds to version hierarchy C.
+
+ Each level of hierarchy is represented by a 32 bit value, and so there can be
+ only 32 different supported version per hierarchy. i.e. 1 bit per version. A
+ value of 0xFFFFFFFF will enable the OPP for all versions for that hierarchy
+ level. And a value of 0x00000000 will disable the OPP completely, and so we
+ never want that to happen.
+
+ If 32 values aren't sufficient for a version hierarchy, than that version
+ hierarchy can be contained in multiple 32 bit values. i.e. <X Y Z1 Z2> in the
+ above example, Z1 & Z2 refer to the version hierarchy Z.
+
- status: Marks the node enabled/disabled.
Example 1: Single cluster Dual-core ARM cortex A9, switch DVFS states together.
@@ -157,20 +177,20 @@ Example 1: Single cluster Dual-core ARM cortex A9, switch DVFS states together.
compatible = "operating-points-v2";
opp-shared;
- opp00 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
opp-microvolt = <970000 975000 985000>;
opp-microamp = <70000>;
clock-latency-ns = <300000>;
opp-suspend;
};
- opp01 {
+ opp@1100000000 {
opp-hz = /bits/ 64 <1100000000>;
opp-microvolt = <980000 1000000 1010000>;
opp-microamp = <80000>;
clock-latency-ns = <310000>;
};
- opp02 {
+ opp@1200000000 {
opp-hz = /bits/ 64 <1200000000>;
opp-microvolt = <1025000>;
clock-latency-ns = <290000>;
@@ -236,20 +256,20 @@ independently.
* independently.
*/
- opp00 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
opp-microvolt = <970000 975000 985000>;
opp-microamp = <70000>;
clock-latency-ns = <300000>;
opp-suspend;
};
- opp01 {
+ opp@1100000000 {
opp-hz = /bits/ 64 <1100000000>;
opp-microvolt = <980000 1000000 1010000>;
opp-microamp = <80000>;
clock-latency-ns = <310000>;
};
- opp02 {
+ opp@1200000000 {
opp-hz = /bits/ 64 <1200000000>;
opp-microvolt = <1025000>;
opp-microamp = <90000;
@@ -312,20 +332,20 @@ DVFS state together.
compatible = "operating-points-v2";
opp-shared;
- opp00 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
opp-microvolt = <970000 975000 985000>;
opp-microamp = <70000>;
clock-latency-ns = <300000>;
opp-suspend;
};
- opp01 {
+ opp@1100000000 {
opp-hz = /bits/ 64 <1100000000>;
opp-microvolt = <980000 1000000 1010000>;
opp-microamp = <80000>;
clock-latency-ns = <310000>;
};
- opp02 {
+ opp@1200000000 {
opp-hz = /bits/ 64 <1200000000>;
opp-microvolt = <1025000>;
opp-microamp = <90000>;
@@ -338,20 +358,20 @@ DVFS state together.
compatible = "operating-points-v2";
opp-shared;
- opp10 {
+ opp@1300000000 {
opp-hz = /bits/ 64 <1300000000>;
opp-microvolt = <1045000 1050000 1055000>;
opp-microamp = <95000>;
clock-latency-ns = <400000>;
opp-suspend;
};
- opp11 {
+ opp@1400000000 {
opp-hz = /bits/ 64 <1400000000>;
opp-microvolt = <1075000>;
opp-microamp = <100000>;
clock-latency-ns = <400000>;
};
- opp12 {
+ opp@1500000000 {
opp-hz = /bits/ 64 <1500000000>;
opp-microvolt = <1010000 1100000 1110000>;
opp-microamp = <95000>;
@@ -378,7 +398,7 @@ Example 4: Handling multiple regulators
compatible = "operating-points-v2";
opp-shared;
- opp00 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
opp-microvolt = <970000>, /* Supply 0 */
<960000>, /* Supply 1 */
@@ -391,7 +411,7 @@ Example 4: Handling multiple regulators
/* OR */
- opp00 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
opp-microvolt = <970000 975000 985000>, /* Supply 0 */
<960000 965000 975000>, /* Supply 1 */
@@ -404,7 +424,7 @@ Example 4: Handling multiple regulators
/* OR */
- opp00 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
opp-microvolt = <970000 975000 985000>, /* Supply 0 */
<960000 965000 975000>, /* Supply 1 */
@@ -417,7 +437,8 @@ Example 4: Handling multiple regulators
};
};
-Example 5: Multiple OPP tables
+Example 5: opp-supported-hw
+(example: three level hierarchy of versions: cuts, substrate and process)
/ {
cpus {
@@ -426,40 +447,73 @@ Example 5: Multiple OPP tables
...
cpu-supply = <&cpu_supply>
- operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>;
- operating-points-names = "slow", "fast";
+ operating-points-v2 = <&cpu0_opp_table_slow>;
};
};
- cpu0_opp_table_slow: opp_table_slow {
+ opp_table {
compatible = "operating-points-v2";
status = "okay";
opp-shared;
- opp00 {
+ opp@600000000 {
+ /*
+ * Supports all substrate and process versions for 0xF
+ * cuts, i.e. only first four cuts.
+ */
+ opp-supported-hw = <0xF 0xFFFFFFFF 0xFFFFFFFF>
opp-hz = /bits/ 64 <600000000>;
+ opp-microvolt = <900000 915000 925000>;
...
};
- opp01 {
+ opp@800000000 {
+ /*
+ * Supports:
+ * - cuts: only one, 6th cut (represented by 6th bit).
+ * - substrate: supports 16 different substrate versions
+ * - process: supports 9 different process versions
+ */
+ opp-supported-hw = <0x20 0xff0000ff 0x0000f4f0>
opp-hz = /bits/ 64 <800000000>;
+ opp-microvolt = <900000 915000 925000>;
...
};
};
+};
+
+Example 6: opp-microvolt-<name>, opp-microamp-<name>:
+(example: device with two possible microvolt ranges: slow and fast)
- cpu0_opp_table_fast: opp_table_fast {
+/ {
+ cpus {
+ cpu@0 {
+ compatible = "arm,cortex-a7";
+ ...
+
+ operating-points-v2 = <&cpu0_opp_table>;
+ };
+ };
+
+ cpu0_opp_table: opp_table0 {
compatible = "operating-points-v2";
- status = "okay";
opp-shared;
- opp10 {
+ opp@1000000000 {
opp-hz = /bits/ 64 <1000000000>;
- ...
+ opp-microvolt-slow = <900000 915000 925000>;
+ opp-microvolt-fast = <970000 975000 985000>;
+ opp-microamp-slow = <70000>;
+ opp-microamp-fast = <71000>;
};
- opp11 {
- opp-hz = /bits/ 64 <1100000000>;
- ...
+ opp@1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt-slow = <900000 915000 925000>, /* Supply vcc0 */
+ <910000 925000 935000>; /* Supply vcc1 */
+ opp-microvolt-fast = <970000 975000 985000>, /* Supply vcc0 */
+ <960000 965000 975000>; /* Supply vcc1 */
+ opp-microamp = <70000>; /* Will be used for both slow/fast */
};
};
};