Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1780 insertions, 0 deletions

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
new file mode 100644
index 000000000..34515f432
--- /dev/null
+++ b/drivers/opp/core.c
@@ -0,0 +1,1780 @@
+/*
+ * Generic OPP Interface
+ *
+ * Copyright (C) 2009-2010 Texas Instruments Incorporated.
+ *	Nishanth Menon
+ *	Romit Dasgupta
+ *	Kevin Hilman
+ *
+ * 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/clk.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/pm_domain.h>
+#include <linux/regulator/consumer.h>
+
+#include "opp.h"
+
+/*
+ * The root of the list of all opp-tables. All opp_table structures branch off
+ * from here, with each opp_table containing the list of opps it supports in
+ * various states of availability.
+ */
+LIST_HEAD(opp_tables);
+/* Lock to allow exclusive modification to the device and opp lists */
+DEFINE_MUTEX(opp_table_lock);
+
+static struct opp_device *_find_opp_dev(const struct device *dev,
+					struct opp_table *opp_table)
+{
+	struct opp_device *opp_dev;
+
+	list_for_each_entry(opp_dev, &opp_table->dev_list, node)
+		if (opp_dev->dev == dev)
+			return opp_dev;
+
+	return NULL;
+}
+
+static struct opp_table *_find_opp_table_unlocked(struct device *dev)
+{
+	struct opp_table *opp_table;
+
+	list_for_each_entry(opp_table, &opp_tables, node) {
+		if (_find_opp_dev(dev, opp_table)) {
+			_get_opp_table_kref(opp_table);
+
+			return opp_table;
+		}
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+/**
+ * _find_opp_table() - find opp_table struct using device pointer
+ * @dev:	device pointer used to lookup OPP table
+ *
+ * Search OPP table for one containing matching device.
+ *
+ * Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
+ * -EINVAL based on type of error.
+ *
+ * The callers must call dev_pm_opp_put_opp_table() after the table is used.
+ */
+struct opp_table *_find_opp_table(struct device *dev)
+{
+	struct opp_table *opp_table;
+
+	if (IS_ERR_OR_NULL(dev)) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	mutex_lock(&opp_table_lock);
+	opp_table = _find_opp_table_unlocked(dev);
+	mutex_unlock(&opp_table_lock);
+
+	return opp_table;
+}
+
+/**
+ * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
+ * @opp:	opp for which voltage has to be returned for
+ *
+ * Return: voltage in micro volt corresponding to the opp, else
+ * return 0
+ *
+ * This is useful only for devices with single power supply.
+ */
+unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
+{
+	if (IS_ERR_OR_NULL(opp)) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return 0;
+	}
+
+	return opp->supplies[0].u_volt;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
+
+/**
+ * dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp
+ * @opp:	opp for which frequency has to be returned for
+ *
+ * Return: frequency in hertz corresponding to the opp, else
+ * return 0
+ */
+unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
+{
+	if (IS_ERR_OR_NULL(opp) || !opp->available) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return 0;
+	}
+
+	return opp->rate;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
+
+/**
+ * dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
+ * @opp: opp for which turbo mode is being verified
+ *
+ * Turbo OPPs are not for normal use, and can be enabled (under certain
+ * conditions) for short duration of times to finish high throughput work
+ * quickly. Running on them for longer times may overheat the chip.
+ *
+ * Return: true if opp is turbo opp, else false.
+ */
+bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
+{
+	if (IS_ERR_OR_NULL(opp) || !opp->available) {
+		pr_err("%s: Invalid parameters\n", __func__);
+		return false;
+	}
+
+	return opp->turbo;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo);
+
+/**
+ * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds
+ * @dev:	device for which we do this operation
+ *
+ * Return: This function returns the max clock latency in nanoseconds.
+ */
+unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
+{
+	struct opp_table *opp_table;
+	unsigned long clock_latency_ns;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return 0;
+
+	clock_latency_ns = opp_table->clock_latency_ns_max;
+
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return clock_latency_ns;
+}
+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.
+ */
+unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *opp;
+	struct regulator *reg;
+	unsigned long latency_ns = 0;
+	int ret, i, count;
+	struct {
+		unsigned long min;
+		unsigned long max;
+	} *uV;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return 0;
+
+	/* Regulator may not be required for the device */
+	if (!opp_table->regulators)
+		goto put_opp_table;
+
+	count = opp_table->regulator_count;
+
+	uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
+	if (!uV)
+		goto put_opp_table;
+
+	mutex_lock(&opp_table->lock);
+
+	for (i = 0; i < count; i++) {
+		uV[i].min = ~0;
+		uV[i].max = 0;
+
+		list_for_each_entry(opp, &opp_table->opp_list, node) {
+			if (!opp->available)
+				continue;
+
+			if (opp->supplies[i].u_volt_min < uV[i].min)
+				uV[i].min = opp->supplies[i].u_volt_min;
+			if (opp->supplies[i].u_volt_max > uV[i].max)
+				uV[i].max = opp->supplies[i].u_volt_max;
+		}
+	}
+
+	mutex_unlock(&opp_table->lock);
+
+	/*
+	 * The caller needs to ensure that opp_table (and hence the regulator)
+	 * isn't freed, while we are executing this routine.
+	 */
+	for (i = 0; i < count; i++) {
+		reg = opp_table->regulators[i];
+		ret = regulator_set_voltage_time(reg, uV[i].min, uV[i].max);
+		if (ret > 0)
+			latency_ns += ret * 1000;
+	}
+
+	kfree(uV);
+put_opp_table:
+	dev_pm_opp_put_opp_table(opp_table);
+
+	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.
+ */
+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_freq() - Get frequency of suspend opp in Hz
+ * @dev:	device for which we do this operation
+ *
+ * Return: This function returns the frequency of the OPP marked as suspend_opp
+ * if one is available, else returns 0;
+ */
+unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev)
+{
+	struct opp_table *opp_table;
+	unsigned long freq = 0;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return 0;
+
+	if (opp_table->suspend_opp && opp_table->suspend_opp->available)
+		freq = dev_pm_opp_get_freq(opp_table->suspend_opp);
+
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return freq;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp_freq);
+
+int _get_opp_count(struct opp_table *opp_table)
+{
+	struct dev_pm_opp *opp;
+	int count = 0;
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(opp, &opp_table->opp_list, node) {
+		if (opp->available)
+			count++;
+	}
+
+	mutex_unlock(&opp_table->lock);
+
+	return count;
+}
+
+/**
+ * dev_pm_opp_get_opp_count() - Get number of opps available in the opp table
+ * @dev:	device for which we do this operation
+ *
+ * Return: This function returns the number of available opps if there are any,
+ * else returns 0 if none or the corresponding error value.
+ */
+int dev_pm_opp_get_opp_count(struct device *dev)
+{
+	struct opp_table *opp_table;
+	int count;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		count = PTR_ERR(opp_table);
+		dev_dbg(dev, "%s: OPP table not found (%d)\n",
+			__func__, count);
+		return count;
+	}
+
+	count = _get_opp_count(opp_table);
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return count;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
+
+/**
+ * dev_pm_opp_find_freq_exact() - search for an exact frequency
+ * @dev:		device for which we do this operation
+ * @freq:		frequency to search for
+ * @available:		true/false - match for available opp
+ *
+ * Return: Searches for exact match in the opp table and returns pointer to the
+ * matching opp if found, else returns ERR_PTR in case of error and should
+ * be handled using IS_ERR. Error return values can be:
+ * EINVAL:	for bad pointer
+ * ERANGE:	no match found for search
+ * ENODEV:	if device not found in list of registered devices
+ *
+ * Note: available is a modifier for the search. if available=true, then the
+ * match is for exact matching frequency and is available in the stored OPP
+ * table. if false, the match is for exact frequency which is not available.
+ *
+ * This provides a mechanism to enable an opp which is not available currently
+ * or the opposite as well.
+ *
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
+ */
+struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
+					      unsigned long freq,
+					      bool available)
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		int r = PTR_ERR(opp_table);
+
+		dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r);
+		return ERR_PTR(r);
+	}
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
+		if (temp_opp->available == available &&
+				temp_opp->rate == freq) {
+			opp = temp_opp;
+
+			/* Increment the reference count of OPP */
+			dev_pm_opp_get(opp);
+			break;
+		}
+	}
+
+	mutex_unlock(&opp_table->lock);
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
+
+static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
+						   unsigned long *freq)
+{
+	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
+		if (temp_opp->available && temp_opp->rate >= *freq) {
+			opp = temp_opp;
+			*freq = opp->rate;
+
+			/* Increment the reference count of OPP */
+			dev_pm_opp_get(opp);
+			break;
+		}
+	}
+
+	mutex_unlock(&opp_table->lock);
+
+	return opp;
+}
+
+/**
+ * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq
+ * @dev:	device for which we do this operation
+ * @freq:	Start frequency
+ *
+ * Search for the matching ceil *available* OPP from a starting freq
+ * for a device.
+ *
+ * Return: matching *opp and refreshes *freq accordingly, else returns
+ * ERR_PTR in case of error and should be handled using IS_ERR. Error return
+ * values can be:
+ * EINVAL:	for bad pointer
+ * ERANGE:	no match found for search
+ * ENODEV:	if device not found in list of registered devices
+ *
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
+ */
+struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
+					     unsigned long *freq)
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *opp;
+
+	if (!dev || !freq) {
+		dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
+		return ERR_PTR(-EINVAL);
+	}
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return ERR_CAST(opp_table);
+
+	opp = _find_freq_ceil(opp_table, freq);
+
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
+
+/**
+ * dev_pm_opp_find_freq_floor() - Search for a rounded floor freq
+ * @dev:	device for which we do this operation
+ * @freq:	Start frequency
+ *
+ * Search for the matching floor *available* OPP from a starting freq
+ * for a device.
+ *
+ * Return: matching *opp and refreshes *freq accordingly, else returns
+ * ERR_PTR in case of error and should be handled using IS_ERR. Error return
+ * values can be:
+ * EINVAL:	for bad pointer
+ * ERANGE:	no match found for search
+ * ENODEV:	if device not found in list of registered devices
+ *
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
+ */
+struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
+					      unsigned long *freq)
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+	if (!dev || !freq) {
+		dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
+		return ERR_PTR(-EINVAL);
+	}
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return ERR_CAST(opp_table);
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
+		if (temp_opp->available) {
+			/* go to the next node, before choosing prev */
+			if (temp_opp->rate > *freq)
+				break;
+			else
+				opp = temp_opp;
+		}
+	}
+
+	/* Increment the reference count of OPP */
+	if (!IS_ERR(opp))
+		dev_pm_opp_get(opp);
+	mutex_unlock(&opp_table->lock);
+	dev_pm_opp_put_opp_table(opp_table);
+
+	if (!IS_ERR(opp))
+		*freq = opp->rate;
+
+	return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
+
+static int _set_opp_voltage(struct device *dev, struct regulator *reg,
+			    struct dev_pm_opp_supply *supply)
+{
+	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__,
+		supply->u_volt_min, supply->u_volt, supply->u_volt_max);
+
+	ret = regulator_set_voltage_triplet(reg, supply->u_volt_min,
+					    supply->u_volt, supply->u_volt_max);
+	if (ret)
+		dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
+			__func__, supply->u_volt_min, supply->u_volt,
+			supply->u_volt_max, ret);
+
+	return ret;
+}
+
+static inline int
+_generic_set_opp_clk_only(struct device *dev, struct clk *clk,
+			  unsigned long old_freq, unsigned long freq)
+{
+	int ret;
+
+	ret = clk_set_rate(clk, freq);
+	if (ret) {
+		dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
+			ret);
+	}
+
+	return ret;
+}
+
+static inline int
+_generic_set_opp_domain(struct device *dev, struct clk *clk,
+			unsigned long old_freq, unsigned long freq,
+			unsigned int old_pstate, unsigned int new_pstate)
+{
+	int ret;
+
+	/* Scaling up? Scale domain performance state before frequency */
+	if (freq > old_freq) {
+		ret = dev_pm_genpd_set_performance_state(dev, new_pstate);
+		if (ret)
+			return ret;
+	}
+
+	ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
+	if (ret)
+		goto restore_domain_state;
+
+	/* Scaling down? Scale domain performance state after frequency */
+	if (freq < old_freq) {
+		ret = dev_pm_genpd_set_performance_state(dev, new_pstate);
+		if (ret)
+			goto restore_freq;
+	}
+
+	return 0;
+
+restore_freq:
+	if (_generic_set_opp_clk_only(dev, clk, freq, old_freq))
+		dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
+			__func__, old_freq);
+restore_domain_state:
+	if (freq > old_freq)
+		dev_pm_genpd_set_performance_state(dev, old_pstate);
+
+	return ret;
+}
+
+static int _generic_set_opp_regulator(const struct opp_table *opp_table,
+				      struct device *dev,
+				      unsigned long old_freq,
+				      unsigned long freq,
+				      struct dev_pm_opp_supply *old_supply,
+				      struct dev_pm_opp_supply *new_supply)
+{
+	struct regulator *reg = opp_table->regulators[0];
+	int ret;
+
+	/* This function only supports single regulator per device */
+	if (WARN_ON(opp_table->regulator_count > 1)) {
+		dev_err(dev, "multiple regulators are not supported\n");
+		return -EINVAL;
+	}
+
+	/* Scaling up? Scale voltage before frequency */
+	if (freq >= old_freq) {
+		ret = _set_opp_voltage(dev, reg, new_supply);
+		if (ret)
+			goto restore_voltage;
+	}
+
+	/* Change frequency */
+	ret = _generic_set_opp_clk_only(dev, opp_table->clk, old_freq, freq);
+	if (ret)
+		goto restore_voltage;
+
+	/* Scaling down? Scale voltage after frequency */
+	if (freq < old_freq) {
+		ret = _set_opp_voltage(dev, reg, new_supply);
+		if (ret)
+			goto restore_freq;
+	}
+
+	return 0;
+
+restore_freq:
+	if (_generic_set_opp_clk_only(dev, opp_table->clk, freq, 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 (old_supply)
+		_set_opp_voltage(dev, reg, old_supply);
+
+	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.
+ */
+int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
+{
+	struct opp_table *opp_table;
+	unsigned long freq, old_freq;
+	struct dev_pm_opp *old_opp, *opp;
+	struct clk *clk;
+	int ret, size;
+
+	if (unlikely(!target_freq)) {
+		dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
+			target_freq);
+		return -EINVAL;
+	}
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+		return PTR_ERR(opp_table);
+	}
+
+	clk = opp_table->clk;
+	if (IS_ERR(clk)) {
+		dev_err(dev, "%s: No clock available for the device\n",
+			__func__);
+		ret = PTR_ERR(clk);
+		goto put_opp_table;
+	}
+
+	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);
+		ret = 0;
+		goto put_opp_table;
+	}
+
+	old_opp = _find_freq_ceil(opp_table, &old_freq);
+	if (IS_ERR(old_opp)) {
+		dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
+			__func__, old_freq, PTR_ERR(old_opp));
+	}
+
+	opp = _find_freq_ceil(opp_table, &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);
+		goto put_old_opp;
+	}
+
+	dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
+		old_freq, freq);
+
+	/* Only frequency scaling */
+	if (!opp_table->regulators) {
+		/*
+		 * We don't support devices with both regulator and
+		 * domain performance-state for now.
+		 */
+		if (opp_table->genpd_performance_state)
+			ret = _generic_set_opp_domain(dev, clk, old_freq, freq,
+						      IS_ERR(old_opp) ? 0 : old_opp->pstate,
+						      opp->pstate);
+		else
+			ret = _generic_set_opp_clk_only(dev, clk, old_freq, freq);
+	} else if (!opp_table->set_opp) {
+		ret = _generic_set_opp_regulator(opp_table, dev, old_freq, freq,
+						 IS_ERR(old_opp) ? NULL : old_opp->supplies,
+						 opp->supplies);
+	} else {
+		struct dev_pm_set_opp_data *data;
+
+		data = opp_table->set_opp_data;
+		data->regulators = opp_table->regulators;
+		data->regulator_count = opp_table->regulator_count;
+		data->clk = clk;
+		data->dev = dev;
+
+		data->old_opp.rate = old_freq;
+		size = sizeof(*opp->supplies) * opp_table->regulator_count;
+		if (IS_ERR(old_opp))
+			memset(data->old_opp.supplies, 0, size);
+		else
+			memcpy(data->old_opp.supplies, old_opp->supplies, size);
+
+		data->new_opp.rate = freq;
+		memcpy(data->new_opp.supplies, opp->supplies, size);
+
+		ret = opp_table->set_opp(data);
+	}
+
+	dev_pm_opp_put(opp);
+put_old_opp:
+	if (!IS_ERR(old_opp))
+		dev_pm_opp_put(old_opp);
+put_opp_table:
+	dev_pm_opp_put_opp_table(opp_table);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
+
+/* OPP-dev Helpers */
+static void _remove_opp_dev(struct opp_device *opp_dev,
+			    struct opp_table *opp_table)
+{
+	opp_debug_unregister(opp_dev, opp_table);
+	list_del(&opp_dev->node);
+	kfree(opp_dev);
+}
+
+struct opp_device *_add_opp_dev(const struct device *dev,
+				struct opp_table *opp_table)
+{
+	struct opp_device *opp_dev;
+	int ret;
+
+	opp_dev = kzalloc(sizeof(*opp_dev), GFP_KERNEL);
+	if (!opp_dev)
+		return NULL;
+
+	/* Initialize opp-dev */
+	opp_dev->dev = dev;
+	list_add(&opp_dev->node, &opp_table->dev_list);
+
+	/* Create debugfs entries for the opp_table */
+	ret = opp_debug_register(opp_dev, opp_table);
+	if (ret)
+		dev_err(dev, "%s: Failed to register opp debugfs (%d)\n",
+			__func__, ret);
+
+	return opp_dev;
+}
+
+static struct opp_table *_allocate_opp_table(struct device *dev)
+{
+	struct opp_table *opp_table;
+	struct opp_device *opp_dev;
+	int ret;
+
+	/*
+	 * Allocate a new OPP table. In the infrequent case where a new
+	 * device is needed to be added, we pay this penalty.
+	 */
+	opp_table = kzalloc(sizeof(*opp_table), GFP_KERNEL);
+	if (!opp_table)
+		return NULL;
+
+	INIT_LIST_HEAD(&opp_table->dev_list);
+
+	/* Mark regulator count uninitialized */
+	opp_table->regulator_count = -1;
+
+	opp_dev = _add_opp_dev(dev, opp_table);
+	if (!opp_dev) {
+		kfree(opp_table);
+		return NULL;
+	}
+
+	_of_init_opp_table(opp_table, dev);
+
+	/* Find clk for the device */
+	opp_table->clk = clk_get(dev, NULL);
+	if (IS_ERR(opp_table->clk)) {
+		ret = PTR_ERR(opp_table->clk);
+		if (ret != -EPROBE_DEFER)
+			dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__,
+				ret);
+	}
+
+	BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
+	INIT_LIST_HEAD(&opp_table->opp_list);
+	mutex_init(&opp_table->lock);
+	kref_init(&opp_table->kref);
+
+	/* Secure the device table modification */
+	list_add(&opp_table->node, &opp_tables);
+	return opp_table;
+}
+
+void _get_opp_table_kref(struct opp_table *opp_table)
+{
+	kref_get(&opp_table->kref);
+}
+
+struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
+{
+	struct opp_table *opp_table;
+
+	/* Hold our table modification lock here */
+	mutex_lock(&opp_table_lock);
+
+	opp_table = _find_opp_table_unlocked(dev);
+	if (!IS_ERR(opp_table))
+		goto unlock;
+
+	opp_table = _allocate_opp_table(dev);
+
+unlock:
+	mutex_unlock(&opp_table_lock);
+
+	return opp_table;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_table);
+
+static void _opp_table_kref_release(struct kref *kref)
+{
+	struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
+	struct opp_device *opp_dev;
+
+	/* Release clk */
+	if (!IS_ERR(opp_table->clk))
+		clk_put(opp_table->clk);
+
+	opp_dev = list_first_entry(&opp_table->dev_list, struct opp_device,
+				   node);
+
+	_remove_opp_dev(opp_dev, opp_table);
+
+	/* dev_list must be empty now */
+	WARN_ON(!list_empty(&opp_table->dev_list));
+
+	mutex_destroy(&opp_table->lock);
+	list_del(&opp_table->node);
+	kfree(opp_table);
+
+	mutex_unlock(&opp_table_lock);
+}
+
+void dev_pm_opp_put_opp_table(struct opp_table *opp_table)
+{
+	kref_put_mutex(&opp_table->kref, _opp_table_kref_release,
+		       &opp_table_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_opp_table);
+
+void _opp_free(struct dev_pm_opp *opp)
+{
+	kfree(opp);
+}
+
+static void _opp_kref_release(struct kref *kref)
+{
+	struct dev_pm_opp *opp = container_of(kref, struct dev_pm_opp, kref);
+	struct opp_table *opp_table = opp->opp_table;
+
+	/*
+	 * Notify the changes in the availability of the operable
+	 * frequency/voltage list.
+	 */
+	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
+	opp_debug_remove_one(opp);
+	list_del(&opp->node);
+	kfree(opp);
+
+	mutex_unlock(&opp_table->lock);
+	dev_pm_opp_put_opp_table(opp_table);
+}
+
+void dev_pm_opp_get(struct dev_pm_opp *opp)
+{
+	kref_get(&opp->kref);
+}
+
+void dev_pm_opp_put(struct dev_pm_opp *opp)
+{
+	kref_put_mutex(&opp->kref, _opp_kref_release, &opp->opp_table->lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put);
+
+/**
+ * dev_pm_opp_remove()  - Remove an OPP from OPP table
+ * @dev:	device for which we do this operation
+ * @freq:	OPP to remove with matching 'freq'
+ *
+ * This function removes an opp from the opp table.
+ */
+void dev_pm_opp_remove(struct device *dev, unsigned long freq)
+{
+	struct dev_pm_opp *opp;
+	struct opp_table *opp_table;
+	bool found = false;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return;
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(opp, &opp_table->opp_list, node) {
+		if (opp->rate == freq) {
+			found = true;
+			break;
+		}
+	}
+
+	mutex_unlock(&opp_table->lock);
+
+	if (found) {
+		dev_pm_opp_put(opp);
+	} else {
+		dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
+			 __func__, freq);
+	}
+
+	dev_pm_opp_put_opp_table(opp_table);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
+
+struct dev_pm_opp *_opp_allocate(struct opp_table *table)
+{
+	struct dev_pm_opp *opp;
+	int count, supply_size;
+
+	/* Allocate space for at least one supply */
+	count = table->regulator_count > 0 ? table->regulator_count : 1;
+	supply_size = sizeof(*opp->supplies) * count;
+
+	/* allocate new OPP node and supplies structures */
+	opp = kzalloc(sizeof(*opp) + supply_size, GFP_KERNEL);
+	if (!opp)
+		return NULL;
+
+	/* Put the supplies at the end of the OPP structure as an empty array */
+	opp->supplies = (struct dev_pm_opp_supply *)(opp + 1);
+	INIT_LIST_HEAD(&opp->node);
+
+	return opp;
+}
+
+static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
+					 struct opp_table *opp_table)
+{
+	struct regulator *reg;
+	int i;
+
+	if (!opp_table->regulators)
+		return true;
+
+	for (i = 0; i < opp_table->regulator_count; i++) {
+		reg = opp_table->regulators[i];
+
+		if (!regulator_is_supported_voltage(reg,
+					opp->supplies[i].u_volt_min,
+					opp->supplies[i].u_volt_max)) {
+			pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
+				__func__, opp->supplies[i].u_volt_min,
+				opp->supplies[i].u_volt_max);
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int _opp_is_duplicate(struct device *dev, struct dev_pm_opp *new_opp,
+			     struct opp_table *opp_table,
+			     struct list_head **head)
+{
+	struct dev_pm_opp *opp;
+
+	/*
+	 * Insert new OPP in order of increasing frequency and discard if
+	 * already present.
+	 *
+	 * Need to use &opp_table->opp_list in the condition part of the 'for'
+	 * loop, don't replace it with head otherwise it will become an infinite
+	 * loop.
+	 */
+	list_for_each_entry(opp, &opp_table->opp_list, node) {
+		if (new_opp->rate > opp->rate) {
+			*head = &opp->node;
+			continue;
+		}
+
+		if (new_opp->rate < opp->rate)
+			return 0;
+
+		/* Duplicate OPPs */
+		dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
+			 __func__, opp->rate, opp->supplies[0].u_volt,
+			 opp->available, new_opp->rate,
+			 new_opp->supplies[0].u_volt, new_opp->available);
+
+		/* Should we compare voltages for all regulators here ? */
+		return opp->available &&
+		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;
+	}
+
+	return 0;
+}
+
+/*
+ * Returns:
+ * 0: On success. And appropriate error message for duplicate OPPs.
+ * -EBUSY: For OPP with same freq/volt and is available. The callers of
+ *  _opp_add() must return 0 if they receive -EBUSY from it. This is to make
+ *  sure we don't print error messages unnecessarily if different parts of
+ *  kernel try to initialize the OPP table.
+ * -EEXIST: For OPP with same freq but different volt or is unavailable. This
+ *  should be considered an error by the callers of _opp_add().
+ */
+int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
+	     struct opp_table *opp_table, bool rate_not_available)
+{
+	struct list_head *head;
+	int ret;
+
+	mutex_lock(&opp_table->lock);
+	head = &opp_table->opp_list;
+
+	if (likely(!rate_not_available)) {
+		ret = _opp_is_duplicate(dev, new_opp, opp_table, &head);
+		if (ret) {
+			mutex_unlock(&opp_table->lock);
+			return ret;
+		}
+	}
+
+	list_add(&new_opp->node, head);
+	mutex_unlock(&opp_table->lock);
+
+	new_opp->opp_table = opp_table;
+	kref_init(&new_opp->kref);
+
+	/* Get a reference to the OPP table */
+	_get_opp_table_kref(opp_table);
+
+	ret = opp_debug_create_one(new_opp, opp_table);
+	if (ret)
+		dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n",
+			__func__, ret);
+
+	if (!_opp_supported_by_regulators(new_opp, opp_table)) {
+		new_opp->available = false;
+		dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
+			 __func__, new_opp->rate);
+	}
+
+	return 0;
+}
+
+/**
+ * _opp_add_v1() - Allocate a OPP based on v1 bindings.
+ * @opp_table:	OPP table
+ * @dev:	device for which we do this operation
+ * @freq:	Frequency in Hz for this OPP
+ * @u_volt:	Voltage in uVolts for this OPP
+ * @dynamic:	Dynamically added OPPs.
+ *
+ * This function adds an opp definition to the opp table and returns status.
+ * The opp is made available by default and it can be controlled using
+ * dev_pm_opp_enable/disable functions and may be removed by dev_pm_opp_remove.
+ *
+ * NOTE: "dynamic" parameter impacts OPPs added by the dev_pm_opp_of_add_table
+ * and freed by dev_pm_opp_of_remove_table.
+ *
+ * Return:
+ * 0		On success OR
+ *		Duplicate OPPs (both freq and volt are same) and opp->available
+ * -EEXIST	Freq are same and volt are different OR
+ *		Duplicate OPPs (both freq and volt are same) and !opp->available
+ * -ENOMEM	Memory allocation failure
+ */
+int _opp_add_v1(struct opp_table *opp_table, struct device *dev,
+		unsigned long freq, long u_volt, bool dynamic)
+{
+	struct dev_pm_opp *new_opp;
+	unsigned long tol;
+	int ret;
+
+	new_opp = _opp_allocate(opp_table);
+	if (!new_opp)
+		return -ENOMEM;
+
+	/* populate the opp table */
+	new_opp->rate = freq;
+	tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
+	new_opp->supplies[0].u_volt = u_volt;
+	new_opp->supplies[0].u_volt_min = u_volt - tol;
+	new_opp->supplies[0].u_volt_max = u_volt + tol;
+	new_opp->available = true;
+	new_opp->dynamic = dynamic;
+
+	ret = _opp_add(dev, new_opp, opp_table, false);
+	if (ret) {
+		/* Don't return error for duplicate OPPs */
+		if (ret == -EBUSY)
+			ret = 0;
+		goto free_opp;
+	}
+
+	/*
+	 * Notify the changes in the availability of the operable
+	 * frequency/voltage list.
+	 */
+	blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADD, new_opp);
+	return 0;
+
+free_opp:
+	_opp_free(new_opp);
+
+	return ret;
+}
+
+/**
+ * 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.
+ */
+struct opp_table *dev_pm_opp_set_supported_hw(struct device *dev,
+			const u32 *versions, unsigned int count)
+{
+	struct opp_table *opp_table;
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return ERR_PTR(-ENOMEM);
+
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	/* Another CPU that shares the OPP table has set the property ? */
+	if (opp_table->supported_hw)
+		return opp_table;
+
+	opp_table->supported_hw = kmemdup(versions, count * sizeof(*versions),
+					GFP_KERNEL);
+	if (!opp_table->supported_hw) {
+		dev_pm_opp_put_opp_table(opp_table);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	opp_table->supported_hw_count = count;
+
+	return opp_table;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
+
+/**
+ * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
+ * @opp_table: OPP table returned by dev_pm_opp_set_supported_hw().
+ *
+ * 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 opp_table structure
+ * will not be freed.
+ */
+void dev_pm_opp_put_supported_hw(struct opp_table *opp_table)
+{
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	kfree(opp_table->supported_hw);
+	opp_table->supported_hw = NULL;
+	opp_table->supported_hw_count = 0;
+
+	dev_pm_opp_put_opp_table(opp_table);
+}
+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.
+ */
+struct opp_table *dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	struct opp_table *opp_table;
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return ERR_PTR(-ENOMEM);
+
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	/* Another CPU that shares the OPP table has set the property ? */
+	if (opp_table->prop_name)
+		return opp_table;
+
+	opp_table->prop_name = kstrdup(name, GFP_KERNEL);
+	if (!opp_table->prop_name) {
+		dev_pm_opp_put_opp_table(opp_table);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return opp_table;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
+
+/**
+ * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
+ * @opp_table: OPP table returned by dev_pm_opp_set_prop_name().
+ *
+ * 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 opp_table structure
+ * will not be freed.
+ */
+void dev_pm_opp_put_prop_name(struct opp_table *opp_table)
+{
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	kfree(opp_table->prop_name);
+	opp_table->prop_name = NULL;
+
+	dev_pm_opp_put_opp_table(opp_table);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
+
+static int _allocate_set_opp_data(struct opp_table *opp_table)
+{
+	struct dev_pm_set_opp_data *data;
+	int len, count = opp_table->regulator_count;
+
+	if (WARN_ON(!opp_table->regulators))
+		return -EINVAL;
+
+	/* space for set_opp_data */
+	len = sizeof(*data);
+
+	/* space for old_opp.supplies and new_opp.supplies */
+	len += 2 * sizeof(struct dev_pm_opp_supply) * count;
+
+	data = kzalloc(len, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->old_opp.supplies = (void *)(data + 1);
+	data->new_opp.supplies = data->old_opp.supplies + count;
+
+	opp_table->set_opp_data = data;
+
+	return 0;
+}
+
+static void _free_set_opp_data(struct opp_table *opp_table)
+{
+	kfree(opp_table->set_opp_data);
+	opp_table->set_opp_data = NULL;
+}
+
+/**
+ * dev_pm_opp_set_regulators() - Set regulator names for the device
+ * @dev: Device for which regulator name is being set.
+ * @names: Array of pointers to the names of the regulator.
+ * @count: Number of regulators.
+ *
+ * In order to support OPP switching, OPP layer needs to know the name of the
+ * device's regulators, as the core would be required to switch voltages as
+ * well.
+ *
+ * This must be called before any OPPs are initialized for the device.
+ */
+struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
+					    const char * const names[],
+					    unsigned int count)
+{
+	struct opp_table *opp_table;
+	struct regulator *reg;
+	int ret, i;
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return ERR_PTR(-ENOMEM);
+
+	/* This should be called before OPPs are initialized */
+	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	/* Another CPU that shares the OPP table has set the regulators ? */
+	if (opp_table->regulators)
+		return opp_table;
+
+	opp_table->regulators = kmalloc_array(count,
+					      sizeof(*opp_table->regulators),
+					      GFP_KERNEL);
+	if (!opp_table->regulators) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	for (i = 0; i < count; i++) {
+		reg = regulator_get_optional(dev, names[i]);
+		if (IS_ERR(reg)) {
+			ret = PTR_ERR(reg);
+			if (ret != -EPROBE_DEFER)
+				dev_err(dev, "%s: no regulator (%s) found: %d\n",
+					__func__, names[i], ret);
+			goto free_regulators;
+		}
+
+		opp_table->regulators[i] = reg;
+	}
+
+	opp_table->regulator_count = count;
+
+	/* Allocate block only once to pass to set_opp() routines */
+	ret = _allocate_set_opp_data(opp_table);
+	if (ret)
+		goto free_regulators;
+
+	return opp_table;
+
+free_regulators:
+	while (i != 0)
+		regulator_put(opp_table->regulators[--i]);
+
+	kfree(opp_table->regulators);
+	opp_table->regulators = NULL;
+	opp_table->regulator_count = -1;
+err:
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulators);
+
+/**
+ * dev_pm_opp_put_regulators() - Releases resources blocked for regulator
+ * @opp_table: OPP table returned from dev_pm_opp_set_regulators().
+ */
+void dev_pm_opp_put_regulators(struct opp_table *opp_table)
+{
+	int i;
+
+	if (!opp_table->regulators)
+		goto put_opp_table;
+
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	for (i = opp_table->regulator_count - 1; i >= 0; i--)
+		regulator_put(opp_table->regulators[i]);
+
+	_free_set_opp_data(opp_table);
+
+	kfree(opp_table->regulators);
+	opp_table->regulators = NULL;
+	opp_table->regulator_count = -1;
+
+put_opp_table:
+	dev_pm_opp_put_opp_table(opp_table);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators);
+
+/**
+ * dev_pm_opp_set_clkname() - Set clk name for the device
+ * @dev: Device for which clk name is being set.
+ * @name: Clk name.
+ *
+ * In order to support OPP switching, OPP layer needs to get pointer to the
+ * clock for the device. Simple cases work fine without using this routine (i.e.
+ * by passing connection-id as NULL), but for a device with multiple clocks
+ * available, the OPP core needs to know the exact name of the clk to use.
+ *
+ * This must be called before any OPPs are initialized for the device.
+ */
+struct opp_table *dev_pm_opp_set_clkname(struct device *dev, const char *name)
+{
+	struct opp_table *opp_table;
+	int ret;
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return ERR_PTR(-ENOMEM);
+
+	/* This should be called before OPPs are initialized */
+	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
+		ret = -EBUSY;
+		goto err;
+	}
+
+	/* Already have default clk set, free it */
+	if (!IS_ERR(opp_table->clk))
+		clk_put(opp_table->clk);
+
+	/* Find clk for the device */
+	opp_table->clk = clk_get(dev, name);
+	if (IS_ERR(opp_table->clk)) {
+		ret = PTR_ERR(opp_table->clk);
+		if (ret != -EPROBE_DEFER) {
+			dev_err(dev, "%s: Couldn't find clock: %d\n", __func__,
+				ret);
+		}
+		goto err;
+	}
+
+	return opp_table;
+
+err:
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_clkname);
+
+/**
+ * dev_pm_opp_put_clkname() - Releases resources blocked for clk.
+ * @opp_table: OPP table returned from dev_pm_opp_set_clkname().
+ */
+void dev_pm_opp_put_clkname(struct opp_table *opp_table)
+{
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	clk_put(opp_table->clk);
+	opp_table->clk = ERR_PTR(-EINVAL);
+
+	dev_pm_opp_put_opp_table(opp_table);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_clkname);
+
+/**
+ * dev_pm_opp_register_set_opp_helper() - Register custom set OPP helper
+ * @dev: Device for which the helper is getting registered.
+ * @set_opp: Custom set OPP helper.
+ *
+ * This is useful to support complex platforms (like platforms with multiple
+ * regulators per device), instead of the generic OPP set rate helper.
+ *
+ * This must be called before any OPPs are initialized for the device.
+ */
+struct opp_table *dev_pm_opp_register_set_opp_helper(struct device *dev,
+			int (*set_opp)(struct dev_pm_set_opp_data *data))
+{
+	struct opp_table *opp_table;
+
+	if (!set_opp)
+		return ERR_PTR(-EINVAL);
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return ERR_PTR(-ENOMEM);
+
+	/* This should be called before OPPs are initialized */
+	if (WARN_ON(!list_empty(&opp_table->opp_list))) {
+		dev_pm_opp_put_opp_table(opp_table);
+		return ERR_PTR(-EBUSY);
+	}
+
+	/* Another CPU that shares the OPP table has set the helper ? */
+	if (!opp_table->set_opp)
+		opp_table->set_opp = set_opp;
+
+	return opp_table;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_register_set_opp_helper);
+
+/**
+ * dev_pm_opp_unregister_set_opp_helper() - Releases resources blocked for
+ *					   set_opp helper
+ * @opp_table: OPP table returned from dev_pm_opp_register_set_opp_helper().
+ *
+ * Release resources blocked for platform specific set_opp helper.
+ */
+void dev_pm_opp_unregister_set_opp_helper(struct opp_table *opp_table)
+{
+	/* Make sure there are no concurrent readers while updating opp_table */
+	WARN_ON(!list_empty(&opp_table->opp_list));
+
+	opp_table->set_opp = NULL;
+	dev_pm_opp_put_opp_table(opp_table);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_unregister_set_opp_helper);
+
+/**
+ * dev_pm_opp_add()  - Add an OPP table from a table definitions
+ * @dev:	device for which we do this operation
+ * @freq:	Frequency in Hz for this OPP
+ * @u_volt:	Voltage in uVolts for this OPP
+ *
+ * This function adds an opp definition to the opp table and returns status.
+ * The opp is made available by default and it can be controlled using
+ * dev_pm_opp_enable/disable functions.
+ *
+ * Return:
+ * 0		On success OR
+ *		Duplicate OPPs (both freq and volt are same) and opp->available
+ * -EEXIST	Freq are same and volt are different OR
+ *		Duplicate OPPs (both freq and volt are same) and !opp->available
+ * -ENOMEM	Memory allocation failure
+ */
+int dev_pm_opp_add(struct device *dev, unsigned long freq, unsigned long u_volt)
+{
+	struct opp_table *opp_table;
+	int ret;
+
+	opp_table = dev_pm_opp_get_opp_table(dev);
+	if (!opp_table)
+		return -ENOMEM;
+
+	/* Fix regulator count for dynamic OPPs */
+	opp_table->regulator_count = 1;
+
+	ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
+
+	dev_pm_opp_put_opp_table(opp_table);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_add);
+
+/**
+ * _opp_set_availability() - helper to set the availability of an opp
+ * @dev:		device for which we do this operation
+ * @freq:		OPP frequency to modify availability
+ * @availability_req:	availability status requested for this opp
+ *
+ * Set the availability of an OPP, opp_{enable,disable} share a common logic
+ * which is isolated here.
+ *
+ * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
+ * copy operation, returns 0 if no modification was done OR modification was
+ * successful.
+ */
+static int _opp_set_availability(struct device *dev, unsigned long freq,
+				 bool availability_req)
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
+	int r = 0;
+
+	/* Find the opp_table */
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		r = PTR_ERR(opp_table);
+		dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r);
+		return r;
+	}
+
+	mutex_lock(&opp_table->lock);
+
+	/* Do we have the frequency? */
+	list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
+		if (tmp_opp->rate == freq) {
+			opp = tmp_opp;
+			break;
+		}
+	}
+
+	if (IS_ERR(opp)) {
+		r = PTR_ERR(opp);
+		goto unlock;
+	}
+
+	/* Is update really needed? */
+	if (opp->available == availability_req)
+		goto unlock;
+
+	opp->available = availability_req;
+
+	dev_pm_opp_get(opp);
+	mutex_unlock(&opp_table->lock);
+
+	/* Notify the change of the OPP availability */
+	if (availability_req)
+		blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ENABLE,
+					     opp);
+	else
+		blocking_notifier_call_chain(&opp_table->head,
+					     OPP_EVENT_DISABLE, opp);
+
+	dev_pm_opp_put(opp);
+	goto put_table;
+
+unlock:
+	mutex_unlock(&opp_table->lock);
+put_table:
+	dev_pm_opp_put_opp_table(opp_table);
+	return r;
+}
+
+/**
+ * dev_pm_opp_enable() - Enable a specific OPP
+ * @dev:	device for which we do this operation
+ * @freq:	OPP frequency to enable
+ *
+ * Enables a provided opp. If the operation is valid, this returns 0, else the
+ * corresponding error value. It is meant to be used for users an OPP available
+ * after being temporarily made unavailable with dev_pm_opp_disable.
+ *
+ * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
+ * copy operation, returns 0 if no modification was done OR modification was
+ * successful.
+ */
+int dev_pm_opp_enable(struct device *dev, unsigned long freq)
+{
+	return _opp_set_availability(dev, freq, true);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_enable);
+
+/**
+ * dev_pm_opp_disable() - Disable a specific OPP
+ * @dev:	device for which we do this operation
+ * @freq:	OPP frequency to disable
+ *
+ * Disables a provided opp. If the operation is valid, this returns
+ * 0, else the corresponding error value. It is meant to be a temporary
+ * control by users to make this OPP not available until the circumstances are
+ * right to make it available again (with a call to dev_pm_opp_enable).
+ *
+ * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
+ * copy operation, returns 0 if no modification was done OR modification was
+ * successful.
+ */
+int dev_pm_opp_disable(struct device *dev, unsigned long freq)
+{
+	return _opp_set_availability(dev, freq, false);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_disable);
+
+/**
+ * dev_pm_opp_register_notifier() - Register OPP notifier for the device
+ * @dev:	Device for which notifier needs to be registered
+ * @nb:		Notifier block to be registered
+ *
+ * Return: 0 on success or a negative error value.
+ */
+int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)
+{
+	struct opp_table *opp_table;
+	int ret;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return PTR_ERR(opp_table);
+
+	ret = blocking_notifier_chain_register(&opp_table->head, nb);
+
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ret;
+}
+EXPORT_SYMBOL(dev_pm_opp_register_notifier);
+
+/**
+ * dev_pm_opp_unregister_notifier() - Unregister OPP notifier for the device
+ * @dev:	Device for which notifier needs to be unregistered
+ * @nb:		Notifier block to be unregistered
+ *
+ * Return: 0 on success or a negative error value.
+ */
+int dev_pm_opp_unregister_notifier(struct device *dev,
+				   struct notifier_block *nb)
+{
+	struct opp_table *opp_table;
+	int ret;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table))
+		return PTR_ERR(opp_table);
+
+	ret = blocking_notifier_chain_unregister(&opp_table->head, nb);
+
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return ret;
+}
+EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);
+
+/*
+ * Free OPPs either created using static entries present in DT or even the
+ * dynamically added entries based on remove_all param.
+ */
+void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev,
+			      bool remove_all)
+{
+	struct dev_pm_opp *opp, *tmp;
+
+	/* Find if opp_table manages a single device */
+	if (list_is_singular(&opp_table->dev_list)) {
+		/* Free static OPPs */
+		list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
+			if (remove_all || !opp->dynamic)
+				dev_pm_opp_put(opp);
+		}
+
+		/*
+		 * The OPP table is getting removed, drop the performance state
+		 * constraints.
+		 */
+		if (opp_table->genpd_performance_state)
+			dev_pm_genpd_set_performance_state(dev, 0);
+	} else {
+		_remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
+	}
+}
+
+void _dev_pm_opp_find_and_remove_table(struct device *dev, bool remove_all)
+{
+	struct opp_table *opp_table;
+
+	/* Check for existing table for 'dev' */
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		int error = PTR_ERR(opp_table);
+
+		if (error != -ENODEV)
+			WARN(1, "%s: opp_table: %d\n",
+			     IS_ERR_OR_NULL(dev) ?
+					"Invalid device" : dev_name(dev),
+			     error);
+		return;
+	}
+
+	_dev_pm_opp_remove_table(opp_table, dev, remove_all);
+
+	dev_pm_opp_put_opp_table(opp_table);
+}
+
+/**
+ * dev_pm_opp_remove_table() - Free all OPPs associated with the device
+ * @dev:	device pointer used to lookup OPP table.
+ *
+ * Free both OPPs created using static entries present in DT and the
+ * dynamically added entries.
+ */
+void dev_pm_opp_remove_table(struct device *dev)
+{
+	_dev_pm_opp_find_and_remove_table(dev, true);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);