Merge branch 'pm-opp' into pm-cpufreq

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 */
 		};
 	};
 };

arch/arm/boot/dts/exynos4412.dtsi

@@ -64,73 +64,73 @@ cpu0_opp_table: opp_table0 {
 		compatible = "operating-points-v2";
 		opp-shared;
 
-		opp00 {
+		opp@200000000 {
 			opp-hz = /bits/ 64 <200000000>;
 			opp-microvolt = <900000>;
 			clock-latency-ns = <200000>;
 		};
-		opp01 {
+		opp@300000000 {
 			opp-hz = /bits/ 64 <300000000>;
 			opp-microvolt = <900000>;
 			clock-latency-ns = <200000>;
 		};
-		opp02 {
+		opp@400000000 {
 			opp-hz = /bits/ 64 <400000000>;
 			opp-microvolt = <925000>;
 			clock-latency-ns = <200000>;
 		};
-		opp03 {
+		opp@500000000 {
 			opp-hz = /bits/ 64 <500000000>;
 			opp-microvolt = <950000>;
 			clock-latency-ns = <200000>;
 		};
-		opp04 {
+		opp@600000000 {
 			opp-hz = /bits/ 64 <600000000>;
 			opp-microvolt = <975000>;
 			clock-latency-ns = <200000>;
 		};
-		opp05 {
+		opp@700000000 {
 			opp-hz = /bits/ 64 <700000000>;
 			opp-microvolt = <987500>;
 			clock-latency-ns = <200000>;
 		};
-		opp06 {
+		opp@800000000 {
 			opp-hz = /bits/ 64 <800000000>;
 			opp-microvolt = <1000000>;
 			clock-latency-ns = <200000>;
 			opp-suspend;
 		};
-		opp07 {
+		opp@900000000 {
 			opp-hz = /bits/ 64 <900000000>;
 			opp-microvolt = <1037500>;
 			clock-latency-ns = <200000>;
 		};
-		opp08 {
+		opp@1000000000 {
 			opp-hz = /bits/ 64 <1000000000>;
 			opp-microvolt = <1087500>;
 			clock-latency-ns = <200000>;
 		};
-		opp09 {
+		opp@1100000000 {
 			opp-hz = /bits/ 64 <1100000000>;
 			opp-microvolt = <1137500>;
 			clock-latency-ns = <200000>;
 		};
-		opp10 {
+		opp@1200000000 {
 			opp-hz = /bits/ 64 <1200000000>;
 			opp-microvolt = <1187500>;
 			clock-latency-ns = <200000>;
 		};
-		opp11 {
+		opp@1300000000 {
 			opp-hz = /bits/ 64 <1300000000>;
 			opp-microvolt = <1250000>;
 			clock-latency-ns = <200000>;
 		};
-		opp12 {
+		opp@1400000000 {
 			opp-hz = /bits/ 64 <1400000000>;
 			opp-microvolt = <1287500>;
 			clock-latency-ns = <200000>;
 		};
-		opp13 {
+		opp@1500000000 {
 			opp-hz = /bits/ 64 <1500000000>;
 			opp-microvolt = <1350000>;
 			clock-latency-ns = <200000>;

drivers/base/power/opp/Makefile

 ccflags-$(CONFIG_DEBUG_DRIVER)	:= -DDEBUG
 obj-y				+= core.o cpu.o
+obj-$(CONFIG_DEBUG_FS)		+= debugfs.o

drivers/base/power/opp/core.c

@@ -463,6 +463,7 @@ static void _kfree_list_dev_rcu(struct rcu_head *head)
 static void _remove_list_dev(struct device_list_opp *list_dev,
 			     struct device_opp *dev_opp)
 {
+	opp_debug_unregister(list_dev, dev_opp);
 	list_del(&list_dev->node);
 	call_srcu(&dev_opp->srcu_head.srcu, &list_dev->rcu_head,
 		  _kfree_list_dev_rcu);
@@ -472,6 +473,7 @@ struct device_list_opp *_add_list_dev(const struct device *dev,
 				      struct device_opp *dev_opp)
 {
 	struct device_list_opp *list_dev;
+	int ret;
 
 	list_dev = kzalloc(sizeof(*list_dev), GFP_KERNEL);
 	if (!list_dev)
@@ -481,6 +483,12 @@ struct device_list_opp *_add_list_dev(const struct device *dev,
 	list_dev->dev = dev;
 	list_add_rcu(&list_dev->node, &dev_opp->dev_list);
 
+	/* Create debugfs entries for the dev_opp */
+	ret = opp_debug_register(list_dev, dev_opp);
+	if (ret)
+		dev_err(dev, "%s: Failed to register opp debugfs (%d)\n",
+			__func__, ret);
+
 	return list_dev;
 }
 
@@ -551,6 +559,12 @@ static void _remove_device_opp(struct device_opp *dev_opp)
 	if (!list_empty(&dev_opp->opp_list))
 		return;
 
+	if (dev_opp->supported_hw)
+		return;
+
+	if (dev_opp->prop_name)
+		return;
+
 	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
 				    node);
 
@@ -596,6 +610,7 @@ static void _opp_remove(struct device_opp *dev_opp,
 	 */
 	if (notify)
 		srcu_notifier_call_chain(&dev_opp->srcu_head, OPP_EVENT_REMOVE, opp);
+	opp_debug_remove_one(opp);
 	list_del_rcu(&opp->node);
 	call_srcu(&dev_opp->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
 
@@ -673,6 +688,7 @@ static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 {
 	struct dev_pm_opp *opp;
 	struct list_head *head = &dev_opp->opp_list;
+	int ret;
 
 	/*
 	 * Insert new OPP in order of increasing frequency and discard if
@@ -703,6 +719,11 @@ static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 	new_opp->dev_opp = dev_opp;
 	list_add_rcu(&new_opp->node, head);
 
+	ret = opp_debug_create_one(new_opp, dev_opp);
+	if (ret)
+		dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n",
+			__func__, ret);
+
 	return 0;
 }
 
@@ -776,35 +797,48 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 }
 
 /* TODO: Support multiple regulators */
-static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
+static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
+			      struct device_opp *dev_opp)
 {
 	u32 microvolt[3] = {0};
 	u32 val;
 	int count, ret;
+	struct property *prop = NULL;
+	char name[NAME_MAX];
+
+	/* Search for "opp-microvolt-<name>" */
+	if (dev_opp->prop_name) {
+		sprintf(name, "opp-microvolt-%s", dev_opp->prop_name);
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (!prop) {
+		/* Search for "opp-microvolt" */
+		name[13] = '\0';
+		prop = of_find_property(opp->np, name, NULL);
 
-	/* Missing property isn't a problem, but an invalid entry is */
-	if (!of_find_property(opp->np, "opp-microvolt", NULL))
-		return 0;
+		/* Missing property isn't a problem, but an invalid entry is */
+		if (!prop)
+			return 0;
+	}
 
-	count = of_property_count_u32_elems(opp->np, "opp-microvolt");
+	count = of_property_count_u32_elems(opp->np, name);
 	if (count < 0) {
-		dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",
-			__func__, count);
+		dev_err(dev, "%s: Invalid %s property (%d)\n",
+			__func__, name, count);
 		return count;
 	}
 
 	/* There can be one or three elements here */
 	if (count != 1 && count != 3) {
-		dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",
-			__func__, count);
+		dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n",
+			__func__, name, count);
 		return -EINVAL;
 	}
 
-	ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt,
-					 count);
+	ret = of_property_read_u32_array(opp->np, name, microvolt, count);
 	if (ret) {
-		dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__,
-			ret);
+		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 		return -EINVAL;
 	}
 
@@ -812,12 +846,270 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
 	opp->u_volt_min = microvolt[1];
 	opp->u_volt_max = microvolt[2];
 
-	if (!of_property_read_u32(opp->np, "opp-microamp", &val))
+	/* Search for "opp-microamp-<name>" */
+	prop = NULL;
+	if (dev_opp->prop_name) {
+		sprintf(name, "opp-microamp-%s", dev_opp->prop_name);
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (!prop) {
+		/* Search for "opp-microamp" */
+		name[12] = '\0';
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (prop && !of_property_read_u32(opp->np, name, &val))
 		opp->u_amp = val;
 
 	return 0;
 }
 
+/**
+ * dev_pm_opp_set_supported_hw() - Set supported platforms
+ * @dev: Device for which supported-hw has to be set.
+ * @versions: Array of hierarchy of versions to match.
+ * @count: Number of elements in the array.
+ *
+ * This is required only for the V2 bindings, and it enables a platform to
+ * specify the hierarchy of versions it supports. OPP layer will then enable
+ * OPPs, which are available for those versions, based on its 'opp-supported-hw'
+ * property.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
+				unsigned int count)
+{
+	struct device_opp *dev_opp;
+	int ret = 0;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	/* Do we already have a version hierarchy associated with dev_opp? */
+	if (dev_opp->supported_hw) {
+		dev_err(dev, "%s: Already have supported hardware list\n",
+			__func__);
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dev_opp->supported_hw = kmemdup(versions, count * sizeof(*versions),
+					GFP_KERNEL);
+	if (!dev_opp->supported_hw) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dev_opp->supported_hw_count = count;
+	mutex_unlock(&dev_opp_list_lock);
+	return 0;
+
+err:
+	_remove_device_opp(dev_opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
+
+/**
+ * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
+ * @dev: Device for which supported-hw has to be set.
+ *
+ * This is required only for the V2 bindings, and is called for a matching
+ * dev_pm_opp_set_supported_hw(). Until this is called, the device_opp structure
+ * will not be freed.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_put_supported_hw(struct device *dev)
+{
+	struct device_opp *dev_opp;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	if (!dev_opp->supported_hw) {
+		dev_err(dev, "%s: Doesn't have supported hardware list\n",
+			__func__);
+		goto unlock;
+	}
+
+	kfree(dev_opp->supported_hw);
+	dev_opp->supported_hw = NULL;
+	dev_opp->supported_hw_count = 0;
+
+	/* Try freeing device_opp if this was the last blocking resource */
+	_remove_device_opp(dev_opp);
+
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
+
+/**
+ * dev_pm_opp_set_prop_name() - Set prop-extn name
+ * @dev: Device for which the regulator has to be set.
+ * @name: name to postfix to properties.
+ *
+ * This is required only for the V2 bindings, and it enables a platform to
+ * specify the extn to be used for certain property names. The properties to
+ * which the extension will apply are opp-microvolt and opp-microamp. OPP core
+ * should postfix the property name with -<name> while looking for them.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	struct device_opp *dev_opp;
+	int ret = 0;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	/* Do we already have a prop-name associated with dev_opp? */
+	if (dev_opp->prop_name) {
+		dev_err(dev, "%s: Already have prop-name %s\n", __func__,
+			dev_opp->prop_name);
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dev_opp->prop_name = kstrdup(name, GFP_KERNEL);
+	if (!dev_opp->prop_name) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_unlock(&dev_opp_list_lock);
+	return 0;
+
+err:
+	_remove_device_opp(dev_opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
+
+/**
+ * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
+ * @dev: Device for which the regulator has to be set.
+ *
+ * This is required only for the V2 bindings, and is called for a matching
+ * dev_pm_opp_set_prop_name(). Until this is called, the device_opp structure
+ * will not be freed.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_put_prop_name(struct device *dev)
+{
+	struct device_opp *dev_opp;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	if (!dev_opp->prop_name) {
+		dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);
+		goto unlock;
+	}
+
+	kfree(dev_opp->prop_name);
+	dev_opp->prop_name = NULL;
+
+	/* Try freeing device_opp if this was the last blocking resource */
+	_remove_device_opp(dev_opp);
+
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
+
+static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
+			      struct device_node *np)
+{
+	unsigned int count = dev_opp->supported_hw_count;
+	u32 version;
+	int ret;
+
+	if (!dev_opp->supported_hw)
+		return true;
+
+	while (count--) {
+		ret = of_property_read_u32_index(np, "opp-supported-hw", count,
+						 &version);
+		if (ret) {
+			dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
+				 __func__, count, ret);
+			return false;
+		}
+
+		/* Both of these are bitwise masks of the versions */
+		if (!(version & dev_opp->supported_hw[count]))
+			return false;
+	}
+
+	return true;
+}
+
 /**
  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
  * @dev:	device for which we do this operation
@@ -864,6 +1156,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 		goto free_opp;
 	}
 
+	/* Check if the OPP supports hardware's hierarchy of versions or not */
+	if (!_opp_is_supported(dev, dev_opp, np)) {
+		dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
+		goto free_opp;
+	}
+
 	/*
 	 * Rate is defined as an unsigned long in clk API, and so casting
 	 * explicitly to its type. Must be fixed once rate is 64 bit
@@ -879,7 +1177,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 	if (!of_property_read_u32(np, "clock-latency-ns", &val))
 		new_opp->clock_latency_ns = val;
 
-	ret = opp_parse_supplies(new_opp, dev);
+	ret = opp_parse_supplies(new_opp, dev, dev_opp);
 	if (ret)
 		goto free_opp;
 
@@ -889,12 +1187,14 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 
 	/* OPP to select on device suspend */
 	if (of_property_read_bool(np, "opp-suspend")) {
-		if (dev_opp->suspend_opp)
+		if (dev_opp->suspend_opp) {
 			dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
 				 __func__, dev_opp->suspend_opp->rate,
 				 new_opp->rate);
-		else
+		} else {
+			new_opp->suspend = true;
 			dev_opp->suspend_opp = new_opp;
+		}
 	}
 
 	if (new_opp->clock_latency_ns > dev_opp->clock_latency_ns_max)

drivers/base/power/opp/debugfs.c

+/*
+ * Generic OPP debugfs interface
+ *
+ * Copyright (C) 2015-2016 Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/limits.h>
+
+#include "opp.h"
+
+static struct dentry *rootdir;
+
+static void opp_set_dev_name(const struct device *dev, char *name)
+{
+	if (dev->parent)
+		snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent),
+			 dev_name(dev));
+	else
+		snprintf(name, NAME_MAX, "%s", dev_name(dev));
+}
+
+void opp_debug_remove_one(struct dev_pm_opp *opp)
+{
+	debugfs_remove_recursive(opp->dentry);
+}
+
+int opp_debug_create_one(struct dev_pm_opp *opp, struct device_opp *dev_opp)
+{
+	struct dentry *pdentry = dev_opp->dentry;
+	struct dentry *d;
+	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */
+
+	/* Rate is unique to each OPP, use it to give opp-name */
+	snprintf(name, sizeof(name), "opp:%lu", opp->rate);
+
+	/* Create per-opp directory */
+	d = debugfs_create_dir(name, pdentry);
+	if (!d)
+		return -ENOMEM;
+
+	if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
+		return -ENOMEM;
+
+	if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
+		return -ENOMEM;
+
+	if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
+		return -ENOMEM;
+
+	if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
+		return -ENOMEM;
+
+	if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
+		return -ENOMEM;
+
+	if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d, &opp->u_volt))
+		return -ENOMEM;
+
+	if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d, &opp->u_volt_min))
+		return -ENOMEM;
+
+	if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d, &opp->u_volt_max))
+		return -ENOMEM;
+
+	if (!debugfs_create_ulong("u_amp", S_IRUGO, d, &opp->u_amp))
+		return -ENOMEM;
+
+	if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
+				  &opp->clock_latency_ns))
+		return -ENOMEM;
+
+	opp->dentry = d;
+	return 0;
+}
+
+static int device_opp_debug_create_dir(struct device_list_opp *list_dev,
+				       struct device_opp *dev_opp)
+{
+	const struct device *dev = list_dev->dev;
+	struct dentry *d;
+
+	opp_set_dev_name(dev, dev_opp->dentry_name);
+
+	/* Create device specific directory */
+	d = debugfs_create_dir(dev_opp->dentry_name, rootdir);
+	if (!d) {
+		dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
+		return -ENOMEM;
+	}
+
+	list_dev->dentry = d;
+	dev_opp->dentry = d;
+
+	return 0;
+}
+
+static int device_opp_debug_create_link(struct device_list_opp *list_dev,
+					struct device_opp *dev_opp)
+{
+	const struct device *dev = list_dev->dev;
+	char name[NAME_MAX];
+	struct dentry *d;
+
+	opp_set_dev_name(list_dev->dev, name);
+
+	/* Create device specific directory link */
+	d = debugfs_create_symlink(name, rootdir, dev_opp->dentry_name);
+	if (!d) {
+		dev_err(dev, "%s: Failed to create link\n", __func__);
+		return -ENOMEM;
+	}
+
+	list_dev->dentry = d;
+
+	return 0;
+}
+
+/**
+ * opp_debug_register - add a device opp node to the debugfs 'opp' directory
+ * @list_dev: list-dev pointer for device
+ * @dev_opp: the device-opp being added
+ *
+ * Dynamically adds device specific directory in debugfs 'opp' directory. If the
+ * device-opp is shared with other devices, then links will be created for all
+ * devices except the first.
+ *
+ * Return: 0 on success, otherwise negative error.
+ */
+int opp_debug_register(struct device_list_opp *list_dev,
+		       struct device_opp *dev_opp)
+{
+	if (!rootdir) {
+		pr_debug("%s: Uninitialized rootdir\n", __func__);
+		return -EINVAL;
+	}
+
+	if (dev_opp->dentry)
+		return device_opp_debug_create_link(list_dev, dev_opp);
+
+	return device_opp_debug_create_dir(list_dev, dev_opp);
+}
+
+static void opp_migrate_dentry(struct device_list_opp *list_dev,
+			       struct device_opp *dev_opp)
+{
+	struct device_list_opp *new_dev;
+	const struct device *dev;
+	struct dentry *dentry;
+
+	/* Look for next list-dev */
+	list_for_each_entry(new_dev, &dev_opp->dev_list, node)
+		if (new_dev != list_dev)
+			break;
+
+	/* new_dev is guaranteed to be valid here */
+	dev = new_dev->dev;
+	debugfs_remove_recursive(new_dev->dentry);
+
+	opp_set_dev_name(dev, dev_opp->dentry_name);
+
+	dentry = debugfs_rename(rootdir, list_dev->dentry, rootdir,
+				dev_opp->dentry_name);
+	if (!dentry) {
+		dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
+			__func__, dev_name(list_dev->dev), dev_name(dev));
+		return;
+	}
+
+	new_dev->dentry = dentry;
+	dev_opp->dentry = dentry;
+}
+
+/**
+ * opp_debug_unregister - remove a device opp node from debugfs opp directory
+ * @list_dev: list-dev pointer for device
+ * @dev_opp: the device-opp being removed
+ *
+ * Dynamically removes device specific directory from debugfs 'opp' directory.
+ */
+void opp_debug_unregister(struct device_list_opp *list_dev,
+			  struct device_opp *dev_opp)
+{
+	if (list_dev->dentry == dev_opp->dentry) {
+		/* Move the real dentry object under another device */
+		if (!list_is_singular(&dev_opp->dev_list)) {
+			opp_migrate_dentry(list_dev, dev_opp);
+			goto out;
+		}
+		dev_opp->dentry = NULL;
+	}
+
+	debugfs_remove_recursive(list_dev->dentry);
+
+out:
+	list_dev->dentry = NULL;
+}
+
+static int __init opp_debug_init(void)
+{
+	/* Create /sys/kernel/debug/opp directory */
+	rootdir = debugfs_create_dir("opp", NULL);
+	if (!rootdir) {
+		pr_err("%s: Failed to create root directory\n", __func__);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+core_initcall(opp_debug_init);

drivers/base/power/opp/opp.h

@@ -17,6 +17,7 @@
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
+#include <linux/limits.h>
 #include <linux/pm_opp.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
@@ -50,9 +51,10 @@ extern struct mutex dev_opp_list_lock;
  *		are protected by the dev_opp_list_lock for integrity.
  *		IMPORTANT: the opp nodes should be maintained in increasing
  *		order.
- * @dynamic:	not-created from static DT entries.
  * @available:	true/false - marks if this OPP as available or not
+ * @dynamic:	not-created from static DT entries.
  * @turbo:	true if turbo (boost) OPP
+ * @suspend:	true if suspend OPP
  * @rate:	Frequency in hertz
  * @u_volt:	Target voltage in microvolts corresponding to this OPP
  * @u_volt_min:	Minimum voltage in microvolts corresponding to this OPP
@@ -63,6 +65,7 @@ extern struct mutex dev_opp_list_lock;
  * @dev_opp:	points back to the device_opp struct this opp belongs to
  * @rcu_head:	RCU callback head used for deferred freeing
  * @np:		OPP's device node.
+ * @dentry:	debugfs dentry pointer (per opp)
  *
  * This structure stores the OPP information for a given device.
  */
@@ -72,6 +75,7 @@ struct dev_pm_opp {
 	bool available;
 	bool dynamic;
 	bool turbo;
+	bool suspend;
 	unsigned long rate;
 
 	unsigned long u_volt;
@@ -84,6 +88,10 @@ struct dev_pm_opp {
 	struct rcu_head rcu_head;
 
 	struct device_node *np;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *dentry;
+#endif
 };
 
 /**
@@ -91,6 +99,7 @@ struct dev_pm_opp {
  * @node:	list node
  * @dev:	device to which the struct object belongs
  * @rcu_head:	RCU callback head used for deferred freeing
+ * @dentry:	debugfs dentry pointer (per device)
  *
  * This is an internal data structure maintaining the list of devices that are
  * managed by 'struct device_opp'.
@@ -99,6 +108,10 @@ struct device_list_opp {
 	struct list_head node;
 	const struct device *dev;
 	struct rcu_head rcu_head;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *dentry;
+#endif
 };
 
 /**
@@ -113,7 +126,14 @@ struct device_list_opp {
  * @dev_list:	list of devices that share these OPPs
  * @opp_list:	list of opps
  * @np:		struct device_node pointer for opp's DT node.
+ * @clock_latency_ns_max: Max clock latency in nanoseconds.
  * @shared_opp: OPP is shared between multiple devices.
+ * @suspend_opp: Pointer to OPP to be used during device suspend.
+ * @supported_hw: Array of version number to support.
+ * @supported_hw_count: Number of elements in supported_hw array.
+ * @prop_name: A name to postfix to many DT properties, while parsing them.
+ * @dentry:	debugfs dentry pointer of the real device directory (not links).
+ * @dentry_name: Name of the real dentry.
  *
  * This is an internal data structure maintaining the link to opps attached to
  * a device. This structure is not meant to be shared to users as it is
@@ -135,6 +155,15 @@ struct device_opp {
 	unsigned long clock_latency_ns_max;
 	bool shared_opp;
 	struct dev_pm_opp *suspend_opp;
+
+	unsigned int *supported_hw;
+	unsigned int supported_hw_count;
+	const char *prop_name;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *dentry;
+	char dentry_name[NAME_MAX];
+#endif
 };
 
 /* Routines internal to opp core */
@@ -143,4 +172,26 @@ struct device_list_opp *_add_list_dev(const struct device *dev,
 				      struct device_opp *dev_opp);
 struct device_node *_of_get_opp_desc_node(struct device *dev);
 
+#ifdef CONFIG_DEBUG_FS
+void opp_debug_remove_one(struct dev_pm_opp *opp);
+int opp_debug_create_one(struct dev_pm_opp *opp, struct device_opp *dev_opp);
+int opp_debug_register(struct device_list_opp *list_dev,
+		       struct device_opp *dev_opp);
+void opp_debug_unregister(struct device_list_opp *list_dev,
+			  struct device_opp *dev_opp);
+#else
+static inline void opp_debug_remove_one(struct dev_pm_opp *opp) {}
+
+static inline int opp_debug_create_one(struct dev_pm_opp *opp,
+				       struct device_opp *dev_opp)
+{ return 0; }
+static inline int opp_debug_register(struct device_list_opp *list_dev,
+				     struct device_opp *dev_opp)
+{ return 0; }
+
+static inline void opp_debug_unregister(struct device_list_opp *list_dev,
+					struct device_opp *dev_opp)
+{ }
+#endif		/* DEBUG_FS */
+
 #endif		/* __DRIVER_OPP_H__ */

include/linux/pm_opp.h

@@ -55,6 +55,11 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq);
 int dev_pm_opp_disable(struct device *dev, unsigned long freq);
 
 struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
+int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
+				unsigned int count);
+void dev_pm_opp_put_supported_hw(struct device *dev);
+int dev_pm_opp_set_prop_name(struct device *dev, const char *name);
+void dev_pm_opp_put_prop_name(struct device *dev);
 #else
 static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
 {
@@ -129,6 +134,23 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(
 {
 	return ERR_PTR(-EINVAL);
 }
+
+static inline int dev_pm_opp_set_supported_hw(struct device *dev,
+					      const u32 *versions,
+					      unsigned int count)
+{
+	return -EINVAL;
+}
+
+static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
+
+static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	return -EINVAL;
+}
+
+static inline void dev_pm_opp_put_prop_name(struct device *dev) {}
+
 #endif		/* CONFIG_PM_OPP */
 
 #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)