PM / OPP: Fix incorrect comments
[firefly-linux-kernel-4.4.55.git] / drivers / base / power / opp / core.c
index b8e76f75073b47a945b695506bb68176c586a161..bdae09c1d8eb8361c79f87abb83ba1b8df242fd4 100644 (file)
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/clk.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/of.h>
 #include <linux/export.h>
+#include <linux/regulator/consumer.h>
 
 #include "opp.h"
 
@@ -229,6 +231,82 @@ unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
 
+/**
+ * dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the max voltage latency in nanoseconds.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
+{
+       struct device_opp *dev_opp;
+       struct dev_pm_opp *opp;
+       struct regulator *reg;
+       unsigned long latency_ns = 0;
+       unsigned long min_uV = ~0, max_uV = 0;
+       int ret;
+
+       rcu_read_lock();
+
+       dev_opp = _find_device_opp(dev);
+       if (IS_ERR(dev_opp)) {
+               rcu_read_unlock();
+               return 0;
+       }
+
+       reg = dev_opp->regulator;
+       if (IS_ERR(reg)) {
+               /* Regulator may not be required for device */
+               if (reg)
+                       dev_err(dev, "%s: Invalid regulator (%ld)\n", __func__,
+                               PTR_ERR(reg));
+               rcu_read_unlock();
+               return 0;
+       }
+
+       list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
+               if (!opp->available)
+                       continue;
+
+               if (opp->u_volt_min < min_uV)
+                       min_uV = opp->u_volt_min;
+               if (opp->u_volt_max > max_uV)
+                       max_uV = opp->u_volt_max;
+       }
+
+       rcu_read_unlock();
+
+       /*
+        * The caller needs to ensure that dev_opp (and hence the regulator)
+        * isn't freed, while we are executing this routine.
+        */
+       ret = regulator_set_voltage_time(reg, min_uV, max_uV);
+       if (ret > 0)
+               latency_ns = ret * 1000;
+
+       return latency_ns;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
+
+/**
+ * dev_pm_opp_get_max_transition_latency() - Get max transition latency in
+ *                                          nanoseconds
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the max transition latency, in nanoseconds, to
+ * switch from one OPP to other.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
+{
+       return dev_pm_opp_get_max_volt_latency(dev) +
+               dev_pm_opp_get_max_clock_latency(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
+
 /**
  * dev_pm_opp_get_suspend_opp() - Get suspend opp
  * @dev:       device for which we do this operation
@@ -451,6 +529,182 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
+/*
+ * The caller needs to ensure that device_opp (and hence the clk) isn't freed,
+ * while clk returned here is used.
+ */
+static struct clk *_get_opp_clk(struct device *dev)
+{
+       struct device_opp *dev_opp;
+       struct clk *clk;
+
+       rcu_read_lock();
+
+       dev_opp = _find_device_opp(dev);
+       if (IS_ERR(dev_opp)) {
+               dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+               clk = ERR_CAST(dev_opp);
+               goto unlock;
+       }
+
+       clk = dev_opp->clk;
+       if (IS_ERR(clk))
+               dev_err(dev, "%s: No clock available for the device\n",
+                       __func__);
+
+unlock:
+       rcu_read_unlock();
+       return clk;
+}
+
+static int _set_opp_voltage(struct device *dev, struct regulator *reg,
+                           unsigned long u_volt, unsigned long u_volt_min,
+                           unsigned long u_volt_max)
+{
+       int ret;
+
+       /* Regulator not available for device */
+       if (IS_ERR(reg)) {
+               dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
+                       PTR_ERR(reg));
+               return 0;
+       }
+
+       dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__, u_volt_min,
+               u_volt, u_volt_max);
+
+       ret = regulator_set_voltage_triplet(reg, u_volt_min, u_volt,
+                                           u_volt_max);
+       if (ret)
+               dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
+                       __func__, u_volt_min, u_volt, u_volt_max, ret);
+
+       return ret;
+}
+
+/**
+ * dev_pm_opp_set_rate() - Configure new OPP based on frequency
+ * @dev:        device for which we do this operation
+ * @target_freq: frequency to achieve
+ *
+ * This configures the power-supplies and clock source to the levels specified
+ * by the OPP corresponding to the target_freq.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
+{
+       struct device_opp *dev_opp;
+       struct dev_pm_opp *old_opp, *opp;
+       struct regulator *reg;
+       struct clk *clk;
+       unsigned long freq, old_freq;
+       unsigned long u_volt, u_volt_min, u_volt_max;
+       unsigned long ou_volt, ou_volt_min, ou_volt_max;
+       int ret;
+
+       if (unlikely(!target_freq)) {
+               dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
+                       target_freq);
+               return -EINVAL;
+       }
+
+       clk = _get_opp_clk(dev);
+       if (IS_ERR(clk))
+               return PTR_ERR(clk);
+
+       freq = clk_round_rate(clk, target_freq);
+       if ((long)freq <= 0)
+               freq = target_freq;
+
+       old_freq = clk_get_rate(clk);
+
+       /* Return early if nothing to do */
+       if (old_freq == freq) {
+               dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
+                       __func__, freq);
+               return 0;
+       }
+
+       rcu_read_lock();
+
+       dev_opp = _find_device_opp(dev);
+       if (IS_ERR(dev_opp)) {
+               dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+               rcu_read_unlock();
+               return PTR_ERR(dev_opp);
+       }
+
+       old_opp = dev_pm_opp_find_freq_ceil(dev, &old_freq);
+       if (!IS_ERR(old_opp)) {
+               ou_volt = old_opp->u_volt;
+               ou_volt_min = old_opp->u_volt_min;
+               ou_volt_max = old_opp->u_volt_max;
+       } else {
+               dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
+                       __func__, old_freq, PTR_ERR(old_opp));
+       }
+
+       opp = dev_pm_opp_find_freq_ceil(dev, &freq);
+       if (IS_ERR(opp)) {
+               ret = PTR_ERR(opp);
+               dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
+                       __func__, freq, ret);
+               rcu_read_unlock();
+               return ret;
+       }
+
+       u_volt = opp->u_volt;
+       u_volt_min = opp->u_volt_min;
+       u_volt_max = opp->u_volt_max;
+
+       reg = dev_opp->regulator;
+
+       rcu_read_unlock();
+
+       /* Scaling up? Scale voltage before frequency */
+       if (freq > old_freq) {
+               ret = _set_opp_voltage(dev, reg, u_volt, u_volt_min,
+                                      u_volt_max);
+               if (ret)
+                       goto restore_voltage;
+       }
+
+       /* Change frequency */
+
+       dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
+               __func__, old_freq, freq);
+
+       ret = clk_set_rate(clk, freq);
+       if (ret) {
+               dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
+                       ret);
+               goto restore_voltage;
+       }
+
+       /* Scaling down? Scale voltage after frequency */
+       if (freq < old_freq) {
+               ret = _set_opp_voltage(dev, reg, u_volt, u_volt_min,
+                                      u_volt_max);
+               if (ret)
+                       goto restore_freq;
+       }
+
+       return 0;
+
+restore_freq:
+       if (clk_set_rate(clk, old_freq))
+               dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
+                       __func__, old_freq);
+restore_voltage:
+       /* This shouldn't harm even if the voltages weren't updated earlier */
+       if (!IS_ERR(old_opp))
+               _set_opp_voltage(dev, reg, ou_volt, ou_volt_min, ou_volt_max);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
+
 /* List-dev Helpers */
 static void _kfree_list_dev_rcu(struct rcu_head *head)
 {
@@ -463,6 +717,7 @@ 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 +727,7 @@ 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 +737,12 @@ 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;
 }
 
@@ -497,6 +759,8 @@ static struct device_opp *_add_device_opp(struct device *dev)
 {
        struct device_opp *dev_opp;
        struct device_list_opp *list_dev;
+       struct device_node *np;
+       int ret;
 
        /* Check for existing list for 'dev' first */
        dev_opp = _find_device_opp(dev);
@@ -519,6 +783,33 @@ static struct device_opp *_add_device_opp(struct device *dev)
                return NULL;
        }
 
+       /*
+        * Only required for backward compatibility with v1 bindings, but isn't
+        * harmful for other cases. And so we do it unconditionally.
+        */
+       np = of_node_get(dev->of_node);
+       if (np) {
+               u32 val;
+
+               if (!of_property_read_u32(np, "clock-latency", &val))
+                       dev_opp->clock_latency_ns_max = val;
+               of_property_read_u32(np, "voltage-tolerance",
+                                    &dev_opp->voltage_tolerance_v1);
+               of_node_put(np);
+       }
+
+       /* Set regulator to a non-NULL error value */
+       dev_opp->regulator = ERR_PTR(-ENXIO);
+
+       /* Find clk for the device */
+       dev_opp->clk = clk_get(dev, NULL);
+       if (IS_ERR(dev_opp->clk)) {
+               ret = PTR_ERR(dev_opp->clk);
+               if (ret != -EPROBE_DEFER)
+                       dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__,
+                               ret);
+       }
+
        srcu_init_notifier_head(&dev_opp->srcu_head);
        INIT_LIST_HEAD(&dev_opp->opp_list);
 
@@ -551,6 +842,19 @@ 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;
+
+       if (!IS_ERR(dev_opp->regulator))
+               return;
+
+       /* Release clk */
+       if (!IS_ERR(dev_opp->clk))
+               clk_put(dev_opp->clk);
+
        list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
                                    node);
 
@@ -596,6 +900,7 @@ 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);
 
@@ -668,11 +973,28 @@ static struct dev_pm_opp *_allocate_opp(struct device *dev,
        return opp;
 }
 
+static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
+                                        struct device_opp *dev_opp)
+{
+       struct regulator *reg = dev_opp->regulator;
+
+       if (!IS_ERR(reg) &&
+           !regulator_is_supported_voltage(reg, opp->u_volt_min,
+                                           opp->u_volt_max)) {
+               pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
+                       __func__, opp->u_volt_min, opp->u_volt_max);
+               return false;
+       }
+
+       return true;
+}
+
 static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
                    struct device_opp *dev_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 +1025,17 @@ 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);
+
+       if (!_opp_supported_by_regulators(new_opp, dev_opp)) {
+               new_opp->available = false;
+               dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
+                        __func__, new_opp->rate);
+       }
+
        return 0;
 }
 
@@ -738,6 +1071,7 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 {
        struct device_opp *dev_opp;
        struct dev_pm_opp *new_opp;
+       unsigned long tol;
        int ret;
 
        /* Hold our list modification lock here */
@@ -751,7 +1085,10 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 
        /* populate the opp table */
        new_opp->rate = freq;
+       tol = u_volt * dev_opp->voltage_tolerance_v1 / 100;
        new_opp->u_volt = u_volt;
+       new_opp->u_volt_min = u_volt - tol;
+       new_opp->u_volt_max = u_volt + tol;
        new_opp->available = true;
        new_opp->dynamic = dynamic;
 
@@ -776,48 +1113,434 @@ unlock:
 }
 
 /* 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) {
+               snprintf(name, sizeof(name), "opp-microvolt-%s",
+                        dev_opp->prop_name);
+               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;
+       if (!prop) {
+               /* Search for "opp-microvolt" */
+               sprintf(name, "opp-microvolt");
+               prop = of_find_property(opp->np, name, NULL);
+
+               /* 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;
        }
 
        opp->u_volt = microvolt[0];
-       opp->u_volt_min = microvolt[1];
-       opp->u_volt_max = microvolt[2];
 
-       if (!of_property_read_u32(opp->np, "opp-microamp", &val))
+       if (count == 1) {
+               opp->u_volt_min = opp->u_volt;
+               opp->u_volt_max = opp->u_volt;
+       } else {
+               opp->u_volt_min = microvolt[1];
+               opp->u_volt_max = microvolt[2];
+       }
+
+       /* Search for "opp-microamp-<name>" */
+       prop = NULL;
+       if (dev_opp->prop_name) {
+               snprintf(name, sizeof(name), "opp-microamp-%s",
+                        dev_opp->prop_name);
+               prop = of_find_property(opp->np, name, NULL);
+       }
+
+       if (!prop) {
+               /* Search for "opp-microamp" */
+               sprintf(name, "opp-microamp");
+               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 put.
+ *
+ * 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 prop-name 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 prop-name has to be put.
+ *
+ * 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);
+
+/**
+ * dev_pm_opp_set_regulator() - Set regulator name for the device
+ * @dev: Device for which regulator name is being set.
+ * @name: Name of the regulator.
+ *
+ * In order to support OPP switching, OPP layer needs to know the name of the
+ * device's regulator, as the core would be required to switch voltages as well.
+ *
+ * This must be called before any OPPs are initialized for the device.
+ *
+ * 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_regulator(struct device *dev, const char *name)
+{
+       struct device_opp *dev_opp;
+       struct regulator *reg;
+       int ret;
+
+       mutex_lock(&dev_opp_list_lock);
+
+       dev_opp = _add_device_opp(dev);
+       if (!dev_opp) {
+               ret = -ENOMEM;
+               goto unlock;
+       }
+
+       /* This should be called before OPPs are initialized */
+       if (WARN_ON(!list_empty(&dev_opp->opp_list))) {
+               ret = -EBUSY;
+               goto err;
+       }
+
+       /* Already have a regulator set */
+       if (WARN_ON(!IS_ERR(dev_opp->regulator))) {
+               ret = -EBUSY;
+               goto err;
+       }
+       /* Allocate the regulator */
+       reg = regulator_get_optional(dev, name);
+       if (IS_ERR(reg)) {
+               ret = PTR_ERR(reg);
+               if (ret != -EPROBE_DEFER)
+                       dev_err(dev, "%s: no regulator (%s) found: %d\n",
+                               __func__, name, ret);
+               goto err;
+       }
+
+       dev_opp->regulator = reg;
+
+       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_regulator);
+
+/**
+ * dev_pm_opp_put_regulator() - Releases resources blocked for regulator
+ * @dev: Device for which regulator was set.
+ *
+ * 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_regulator(struct device *dev)
+{
+       struct device_opp *dev_opp;
+
+       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;
+       }
+
+       if (IS_ERR(dev_opp->regulator)) {
+               dev_err(dev, "%s: Doesn't have regulator set\n", __func__);
+               goto unlock;
+       }
+
+       /* Make sure there are no concurrent readers while updating dev_opp */
+       WARN_ON(!list_empty(&dev_opp->opp_list));
+
+       regulator_put(dev_opp->regulator);
+       dev_opp->regulator = ERR_PTR(-ENXIO);
+
+       /* 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_regulator);
+
+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 +1587,12 @@ 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 +1608,7 @@ 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 +1618,14 @@ 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)