Merge branch 'v4.4/topic/mm-kaslr' into linux-linaro-lsk-v4.4
[firefly-linux-kernel-4.4.55.git] / Documentation / devicetree / bindings / opp / opp.txt
index 0cb44dc21f97ca7cfde5056ce7d44941d3439546..601256fe8c0dd99d2df3ff5a77b2cee23a852e5d 100644 (file)
@@ -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 */
                };
        };
 };