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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Generic OPP Interface
  *
  * Copyright (C) 2009-2010 Texas Instruments Incorporated.
  *  Nishanth Menon
  *  Romit Dasgupta
  *  Kevin Hilman
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/clk.h>
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/device.h>
 #include <linux/export.h>
 #include <linux/pm_domain.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/xarray.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);
 
 /* OPP tables with uninitialized required OPPs */
 LIST_HEAD(lazy_opp_tables);
 
 /* Lock to allow exclusive modification to the device and opp lists */
 DEFINE_MUTEX(opp_table_lock);
 /* Flag indicating that opp_tables list is being updated at the moment */
 static bool opp_tables_busy;
 
 /* OPP ID allocator */
 static DEFINE_XARRAY_ALLOC1(opp_configs);
 
 static bool _find_opp_dev(const struct device *dev, struct opp_table *opp_table)
 {
     struct opp_device *opp_dev;
     bool found = false;
 
     mutex_lock(&opp_table->lock);
     list_for_each_entry(opp_dev, &opp_table->dev_list, node)
         if (opp_dev->dev == dev) {
             found = true;
             break;
         }
 
     mutex_unlock(&opp_table->lock);
     return found;
 }
 
 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;
 }
 
 /*
  * Returns true if multiple clocks aren't there, else returns false with WARN.
  *
  * We don't force clk_count == 1 here as there are users who don't have a clock
  * representation in the OPP table and manage the clock configuration themselves
  * in an platform specific way.
  */
 static bool assert_single_clk(struct opp_table *opp_table)
 {
     return !WARN_ON(opp_table->clk_count > 1);
 }
 
 /**
  * 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_supplies() - Gets the supply information corresponding to an opp
  * @opp:    opp for which voltage has to be returned for
  * @supplies:   Placeholder for copying the supply information.
  *
  * Return: negative error number on failure, 0 otherwise on success after
  * setting @supplies.
  *
  * This can be used for devices with any number of power supplies. The caller
  * must ensure the @supplies array must contain space for each regulator.
  */
 int dev_pm_opp_get_supplies(struct dev_pm_opp *opp,
                 struct dev_pm_opp_supply *supplies)
 {
     if (IS_ERR_OR_NULL(opp) || !supplies) {
         pr_err("%s: Invalid parameters\n", __func__);
         return -EINVAL;
     }
 
     memcpy(supplies, opp->supplies,
            sizeof(*supplies) * opp->opp_table->regulator_count);
     return 0;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_supplies);
 
 /**
  * dev_pm_opp_get_power() - Gets the power corresponding to an opp
  * @opp:    opp for which power has to be returned for
  *
  * Return: power in micro watt corresponding to the opp, else
  * return 0
  *
  * This is useful only for devices with single power supply.
  */
 unsigned long dev_pm_opp_get_power(struct dev_pm_opp *opp)
 {
     unsigned long opp_power = 0;
     int i;
 
     if (IS_ERR_OR_NULL(opp)) {
         pr_err("%s: Invalid parameters\n", __func__);
         return 0;
     }
     for (i = 0; i < opp->opp_table->regulator_count; i++)
         opp_power += opp->supplies[i].u_watt;
 
     return opp_power;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_power);
 
 /**
  * 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)) {
         pr_err("%s: Invalid parameters\n", __func__);
         return 0;
     }
 
     if (!assert_single_clk(opp->opp_table))
         return 0;
 
     return opp->rates[0];
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
 
 /**
  * dev_pm_opp_get_level() - Gets the level corresponding to an available opp
  * @opp:    opp for which level value has to be returned for
  *
  * Return: level read from device tree corresponding to the opp, else
  * return 0.
  */
 unsigned int dev_pm_opp_get_level(struct dev_pm_opp *opp)
 {
     if (IS_ERR_OR_NULL(opp) || !opp->available) {
         pr_err("%s: Invalid parameters\n", __func__);
         return 0;
     }
 
     return opp->level;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_level);
 
 /**
  * dev_pm_opp_get_required_pstate() - Gets the required performance state
  *                                    corresponding to an available opp
  * @opp:    opp for which performance state has to be returned for
  * @index:  index of the required opp
  *
  * Return: performance state read from device tree corresponding to the
  * required opp, else return 0.
  */
 unsigned int dev_pm_opp_get_required_pstate(struct dev_pm_opp *opp,
                         unsigned int index)
 {
     if (IS_ERR_OR_NULL(opp) || !opp->available ||
         index >= opp->opp_table->required_opp_count) {
         pr_err("%s: Invalid parameters\n", __func__);
         return 0;
     }
 
     /* required-opps not fully initialized yet */
     if (lazy_linking_pending(opp->opp_table))
         return 0;
 
     return opp->required_opps[index]->pstate;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_required_pstate);
 
 /**
  * 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);
 
 /* Helpers to read keys */
 static unsigned long _read_freq(struct dev_pm_opp *opp, int index)
 {
     return opp->rates[0];
 }
 
 static unsigned long _read_level(struct dev_pm_opp *opp, int index)
 {
     return opp->level;
 }
 
 static unsigned long _read_bw(struct dev_pm_opp *opp, int index)
 {
     return opp->bandwidth[index].peak;
 }
 
 /* Generic comparison helpers */
 static bool _compare_exact(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
                unsigned long opp_key, unsigned long key)
 {
     if (opp_key == key) {
         *opp = temp_opp;
         return true;
     }
 
     return false;
 }
 
 static bool _compare_ceil(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
               unsigned long opp_key, unsigned long key)
 {
     if (opp_key >= key) {
         *opp = temp_opp;
         return true;
     }
 
     return false;
 }
 
 static bool _compare_floor(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
                unsigned long opp_key, unsigned long key)
 {
     if (opp_key > key)
         return true;
 
     *opp = temp_opp;
     return false;
 }
 
 /* Generic key finding helpers */
 static struct dev_pm_opp *_opp_table_find_key(struct opp_table *opp_table,
         unsigned long *key, int index, bool available,
         unsigned long (*read)(struct dev_pm_opp *opp, int index),
         bool (*compare)(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
                 unsigned long opp_key, unsigned long key),
         bool (*assert)(struct opp_table *opp_table))
 {
     struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
 
     /* Assert that the requirement is met */
     if (assert && !assert(opp_table))
         return ERR_PTR(-EINVAL);
 
     mutex_lock(&opp_table->lock);
 
     list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
         if (temp_opp->available == available) {
             if (compare(&opp, temp_opp, read(temp_opp, index), *key))
                 break;
         }
     }
 
     /* Increment the reference count of OPP */
     if (!IS_ERR(opp)) {
         *key = read(opp, index);
         dev_pm_opp_get(opp);
     }
 
     mutex_unlock(&opp_table->lock);
 
     return opp;
 }
 
 static struct dev_pm_opp *
 _find_key(struct device *dev, unsigned long *key, int index, bool available,
       unsigned long (*read)(struct dev_pm_opp *opp, int index),
       bool (*compare)(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
               unsigned long opp_key, unsigned long key),
       bool (*assert)(struct opp_table *opp_table))
 {
     struct opp_table *opp_table;
     struct dev_pm_opp *opp;
 
     opp_table = _find_opp_table(dev);
     if (IS_ERR(opp_table)) {
         dev_err(dev, "%s: OPP table not found (%ld)\n", __func__,
             PTR_ERR(opp_table));
         return ERR_CAST(opp_table);
     }
 
     opp = _opp_table_find_key(opp_table, key, index, available, read,
                   compare, assert);
 
     dev_pm_opp_put_opp_table(opp_table);
 
     return opp;
 }
 
 static struct dev_pm_opp *_find_key_exact(struct device *dev,
         unsigned long key, int index, bool available,
         unsigned long (*read)(struct dev_pm_opp *opp, int index),
         bool (*assert)(struct opp_table *opp_table))
 {
     /*
      * The value of key will be updated here, but will be ignored as the
      * caller doesn't need it.
      */
     return _find_key(dev, &key, index, available, read, _compare_exact,
              assert);
 }
 
 static struct dev_pm_opp *_opp_table_find_key_ceil(struct opp_table *opp_table,
         unsigned long *key, int index, bool available,
         unsigned long (*read)(struct dev_pm_opp *opp, int index),
         bool (*assert)(struct opp_table *opp_table))
 {
     return _opp_table_find_key(opp_table, key, index, available, read,
                    _compare_ceil, assert);
 }
 
 static struct dev_pm_opp *_find_key_ceil(struct device *dev, unsigned long *key,
         int index, bool available,
         unsigned long (*read)(struct dev_pm_opp *opp, int index),
         bool (*assert)(struct opp_table *opp_table))
 {
     return _find_key(dev, key, index, available, read, _compare_ceil,
              assert);
 }
 
 static struct dev_pm_opp *_find_key_floor(struct device *dev,
         unsigned long *key, int index, bool available,
         unsigned long (*read)(struct dev_pm_opp *opp, int index),
         bool (*assert)(struct opp_table *opp_table))
 {
     return _find_key(dev, key, index, available, read, _compare_floor,
              assert);
 }
 
 /**
  * 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)
 {
     return _find_key_exact(dev, freq, 0, available, _read_freq,
                    assert_single_clk);
 }
 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)
 {
     return _opp_table_find_key_ceil(opp_table, freq, 0, true, _read_freq,
                     assert_single_clk);
 }
 
 /**
  * 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)
 {
     return _find_key_ceil(dev, freq, 0, true, _read_freq, assert_single_clk);
 }
 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)
 {
     return _find_key_floor(dev, freq, 0, true, _read_freq, assert_single_clk);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
 
 /**
  * dev_pm_opp_find_level_exact() - search for an exact level
  * @dev:        device for which we do this operation
  * @level:      level to search for
  *
  * 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
  *
  * The callers are required to call dev_pm_opp_put() for the returned OPP after
  * use.
  */
 struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
                            unsigned int level)
 {
     return _find_key_exact(dev, level, 0, true, _read_level, NULL);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact);
 
 /**
  * dev_pm_opp_find_level_ceil() - search for an rounded up level
  * @dev:        device for which we do this operation
  * @level:      level to search for
  *
  * Return: Searches for rounded up 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
  *
  * The callers are required to call dev_pm_opp_put() for the returned OPP after
  * use.
  */
 struct dev_pm_opp *dev_pm_opp_find_level_ceil(struct device *dev,
                           unsigned int *level)
 {
     unsigned long temp = *level;
     struct dev_pm_opp *opp;
 
     opp = _find_key_ceil(dev, &temp, 0, true, _read_level, NULL);
     *level = temp;
     return opp;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_ceil);
 
 /**
  * dev_pm_opp_find_bw_ceil() - Search for a rounded ceil bandwidth
  * @dev:    device for which we do this operation
  * @bw: start bandwidth
  * @index:  which bandwidth to compare, in case of OPPs with several values
  *
  * Search for the matching floor *available* OPP from a starting bandwidth
  * for a device.
  *
  * Return: matching *opp and refreshes *bw 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_bw_ceil(struct device *dev, unsigned int *bw,
                        int index)
 {
     unsigned long temp = *bw;
     struct dev_pm_opp *opp;
 
     opp = _find_key_ceil(dev, &temp, index, true, _read_bw, NULL);
     *bw = temp;
     return opp;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_bw_ceil);
 
 /**
  * dev_pm_opp_find_bw_floor() - Search for a rounded floor bandwidth
  * @dev:    device for which we do this operation
  * @bw: start bandwidth
  * @index:  which bandwidth to compare, in case of OPPs with several values
  *
  * Search for the matching floor *available* OPP from a starting bandwidth
  * for a device.
  *
  * Return: matching *opp and refreshes *bw 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_bw_floor(struct device *dev,
                         unsigned int *bw, int index)
 {
     unsigned long temp = *bw;
     struct dev_pm_opp *opp;
 
     opp = _find_key_floor(dev, &temp, index, true, _read_bw, NULL);
     *bw = temp;
     return opp;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_bw_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 int
 _opp_config_clk_single(struct device *dev, struct opp_table *opp_table,
                struct dev_pm_opp *opp, void *data, bool scaling_down)
 {
     unsigned long *target = data;
     unsigned long freq;
     int ret;
 
     /* One of target and opp must be available */
     if (target) {
         freq = *target;
     } else if (opp) {
         freq = opp->rates[0];
     } else {
         WARN_ON(1);
         return -EINVAL;
     }
 
     ret = clk_set_rate(opp_table->clk, freq);
     if (ret) {
         dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
             ret);
     } else {
         opp_table->rate_clk_single = freq;
     }
 
     return ret;
 }
 
 /*
  * Simple implementation for configuring multiple clocks. Configure clocks in
  * the order in which they are present in the array while scaling up.
  */
 int dev_pm_opp_config_clks_simple(struct device *dev,
         struct opp_table *opp_table, struct dev_pm_opp *opp, void *data,
         bool scaling_down)
 {
     int ret, i;
 
     if (scaling_down) {
         for (i = opp_table->clk_count - 1; i >= 0; i--) {
             ret = clk_set_rate(opp_table->clks[i], opp->rates[i]);
             if (ret) {
                 dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
                     ret);
                 return ret;
             }
         }
     } else {
         for (i = 0; i < opp_table->clk_count; i++) {
             ret = clk_set_rate(opp_table->clks[i], opp->rates[i]);
             if (ret) {
                 dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
                     ret);
                 return ret;
             }
         }
     }
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_config_clks_simple);
 
 static int _opp_config_regulator_single(struct device *dev,
             struct dev_pm_opp *old_opp, struct dev_pm_opp *new_opp,
             struct regulator **regulators, unsigned int count)
 {
     struct regulator *reg = regulators[0];
     int ret;
 
     /* This function only supports single regulator per device */
     if (WARN_ON(count > 1)) {
         dev_err(dev, "multiple regulators are not supported\n");
         return -EINVAL;
     }
 
     ret = _set_opp_voltage(dev, reg, new_opp->supplies);
     if (ret)
         return ret;
 
     /*
      * Enable the regulator after setting its voltages, otherwise it breaks
      * some boot-enabled regulators.
      */
     if (unlikely(!new_opp->opp_table->enabled)) {
         ret = regulator_enable(reg);
         if (ret < 0)
             dev_warn(dev, "Failed to enable regulator: %d", ret);
     }
 
     return 0;
 }
 
 static int _set_opp_bw(const struct opp_table *opp_table,
                struct dev_pm_opp *opp, struct device *dev)
 {
     u32 avg, peak;
     int i, ret;
 
     if (!opp_table->paths)
         return 0;
 
     for (i = 0; i < opp_table->path_count; i++) {
         if (!opp) {
             avg = 0;
             peak = 0;
         } else {
             avg = opp->bandwidth[i].avg;
             peak = opp->bandwidth[i].peak;
         }
         ret = icc_set_bw(opp_table->paths[i], avg, peak);
         if (ret) {
             dev_err(dev, "Failed to %s bandwidth[%d]: %d\n",
                 opp ? "set" : "remove", i, ret);
             return ret;
         }
     }
 
     return 0;
 }
 
 static int _set_required_opp(struct device *dev, struct device *pd_dev,
                  struct dev_pm_opp *opp, int i)
 {
     unsigned int pstate = likely(opp) ? opp->required_opps[i]->pstate : 0;
     int ret;
 
     if (!pd_dev)
         return 0;
 
     ret = dev_pm_genpd_set_performance_state(pd_dev, pstate);
     if (ret) {
         dev_err(dev, "Failed to set performance state of %s: %d (%d)\n",
             dev_name(pd_dev), pstate, ret);
     }
 
     return ret;
 }
 
 /* This is only called for PM domain for now */
 static int _set_required_opps(struct device *dev,
                   struct opp_table *opp_table,
                   struct dev_pm_opp *opp, bool up)
 {
     struct opp_table **required_opp_tables = opp_table->required_opp_tables;
     struct device **genpd_virt_devs = opp_table->genpd_virt_devs;
     int i, ret = 0;
 
     if (!required_opp_tables)
         return 0;
 
     /* required-opps not fully initialized yet */
     if (lazy_linking_pending(opp_table))
         return -EBUSY;
 
     /*
      * We only support genpd's OPPs in the "required-opps" for now, as we
      * don't know much about other use cases. Error out if the required OPP
      * doesn't belong to a genpd.
      */
     if (unlikely(!required_opp_tables[0]->is_genpd)) {
         dev_err(dev, "required-opps don't belong to a genpd\n");
         return -ENOENT;
     }
 
     /* Single genpd case */
     if (!genpd_virt_devs)
         return _set_required_opp(dev, dev, opp, 0);
 
     /* Multiple genpd case */
 
     /*
      * Acquire genpd_virt_dev_lock to make sure we don't use a genpd_dev
      * after it is freed from another thread.
      */
     mutex_lock(&opp_table->genpd_virt_dev_lock);
 
     /* Scaling up? Set required OPPs in normal order, else reverse */
     if (up) {
         for (i = 0; i < opp_table->required_opp_count; i++) {
             ret = _set_required_opp(dev, genpd_virt_devs[i], opp, i);
             if (ret)
                 break;
         }
     } else {
         for (i = opp_table->required_opp_count - 1; i >= 0; i--) {
             ret = _set_required_opp(dev, genpd_virt_devs[i], opp, i);
             if (ret)
                 break;
         }
     }
 
     mutex_unlock(&opp_table->genpd_virt_dev_lock);
 
     return ret;
 }
 
 static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
 {
     struct dev_pm_opp *opp = ERR_PTR(-ENODEV);
     unsigned long freq;
 
     if (!IS_ERR(opp_table->clk)) {
         freq = clk_get_rate(opp_table->clk);
         opp = _find_freq_ceil(opp_table, &freq);
     }
 
     /*
      * Unable to find the current OPP ? Pick the first from the list since
      * it is in ascending order, otherwise rest of the code will need to
      * make special checks to validate current_opp.
      */
     if (IS_ERR(opp)) {
         mutex_lock(&opp_table->lock);
         opp = list_first_entry(&opp_table->opp_list, struct dev_pm_opp, node);
         dev_pm_opp_get(opp);
         mutex_unlock(&opp_table->lock);
     }
 
     opp_table->current_opp = opp;
 }
 
 static int _disable_opp_table(struct device *dev, struct opp_table *opp_table)
 {
     int ret;
 
     if (!opp_table->enabled)
         return 0;
 
     /*
      * Some drivers need to support cases where some platforms may
      * have OPP table for the device, while others don't and
      * opp_set_rate() just needs to behave like clk_set_rate().
      */
     if (!_get_opp_count(opp_table))
         return 0;
 
     ret = _set_opp_bw(opp_table, NULL, dev);
     if (ret)
         return ret;
 
     if (opp_table->regulators)
         regulator_disable(opp_table->regulators[0]);
 
     ret = _set_required_opps(dev, opp_table, NULL, false);
 
     opp_table->enabled = false;
     return ret;
 }
 
 static int _set_opp(struct device *dev, struct opp_table *opp_table,
             struct dev_pm_opp *opp, void *clk_data, bool forced)
 {
     struct dev_pm_opp *old_opp;
     int scaling_down, ret;
 
     if (unlikely(!opp))
         return _disable_opp_table(dev, opp_table);
 
     /* Find the currently set OPP if we don't know already */
     if (unlikely(!opp_table->current_opp))
         _find_current_opp(dev, opp_table);
 
     old_opp = opp_table->current_opp;
 
     /* Return early if nothing to do */
     if (!forced && old_opp == opp && opp_table->enabled) {
         dev_dbg(dev, "%s: OPPs are same, nothing to do\n", __func__);
         return 0;
     }
 
     dev_dbg(dev, "%s: switching OPP: Freq %lu -> %lu Hz, Level %u -> %u, Bw %u -> %u\n",
         __func__, old_opp->rates[0], opp->rates[0], old_opp->level,
         opp->level, old_opp->bandwidth ? old_opp->bandwidth[0].peak : 0,
         opp->bandwidth ? opp->bandwidth[0].peak : 0);
 
     scaling_down = _opp_compare_key(opp_table, old_opp, opp);
     if (scaling_down == -1)
         scaling_down = 0;
 
     /* Scaling up? Configure required OPPs before frequency */
     if (!scaling_down) {
         ret = _set_required_opps(dev, opp_table, opp, true);
         if (ret) {
             dev_err(dev, "Failed to set required opps: %d\n", ret);
             return ret;
         }
 
         ret = _set_opp_bw(opp_table, opp, dev);
         if (ret) {
             dev_err(dev, "Failed to set bw: %d\n", ret);
             return ret;
         }
 
         if (opp_table->config_regulators) {
             ret = opp_table->config_regulators(dev, old_opp, opp,
                                opp_table->regulators,
                                opp_table->regulator_count);
             if (ret) {
                 dev_err(dev, "Failed to set regulator voltages: %d\n",
                     ret);
                 return ret;
             }
         }
     }
 
     if (opp_table->config_clks) {
         ret = opp_table->config_clks(dev, opp_table, opp, clk_data, scaling_down);
         if (ret)
             return ret;
     }
 
     /* Scaling down? Configure required OPPs after frequency */
     if (scaling_down) {
         if (opp_table->config_regulators) {
             ret = opp_table->config_regulators(dev, old_opp, opp,
                                opp_table->regulators,
                                opp_table->regulator_count);
             if (ret) {
                 dev_err(dev, "Failed to set regulator voltages: %d\n",
                     ret);
                 return ret;
             }
         }
 
         ret = _set_opp_bw(opp_table, opp, dev);
         if (ret) {
             dev_err(dev, "Failed to set bw: %d\n", ret);
             return ret;
         }
 
         ret = _set_required_opps(dev, opp_table, opp, false);
         if (ret) {
             dev_err(dev, "Failed to set required opps: %d\n", ret);
             return ret;
         }
     }
 
     opp_table->enabled = true;
     dev_pm_opp_put(old_opp);
 
     /* Make sure current_opp doesn't get freed */
     dev_pm_opp_get(opp);
     opp_table->current_opp = opp;
 
     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 to the levels specified by the OPP
  * corresponding to the target_freq, and programs the clock to a value <=
  * target_freq, as rounded by clk_round_rate(). Device wanting to run at fmax
  * provided by the opp, should have already rounded to the target OPP's
  * frequency.
  */
 int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
 {
     struct opp_table *opp_table;
     unsigned long freq = 0, temp_freq;
     struct dev_pm_opp *opp = NULL;
     bool forced = false;
     int ret;
 
     opp_table = _find_opp_table(dev);
     if (IS_ERR(opp_table)) {
         dev_err(dev, "%s: device's opp table doesn't exist\n", __func__);
         return PTR_ERR(opp_table);
     }
 
     if (target_freq) {
         /*
          * For IO devices which require an OPP on some platforms/SoCs
          * while just needing to scale the clock on some others
          * we look for empty OPP tables with just a clock handle and
          * scale only the clk. This makes dev_pm_opp_set_rate()
          * equivalent to a clk_set_rate()
          */
         if (!_get_opp_count(opp_table)) {
             ret = opp_table->config_clks(dev, opp_table, NULL,
                              &target_freq, false);
             goto put_opp_table;
         }
 
         freq = clk_round_rate(opp_table->clk, target_freq);
         if ((long)freq <= 0)
             freq = target_freq;
 
         /*
          * The clock driver may support finer resolution of the
          * frequencies than the OPP table, don't update the frequency we
          * pass to clk_set_rate() here.
          */
         temp_freq = freq;
         opp = _find_freq_ceil(opp_table, &temp_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_opp_table;
         }
 
         /*
          * An OPP entry specifies the highest frequency at which other
          * properties of the OPP entry apply. Even if the new OPP is
          * same as the old one, we may still reach here for a different
          * value of the frequency. In such a case, do not abort but
          * configure the hardware to the desired frequency forcefully.
          */
         forced = opp_table->rate_clk_single != target_freq;
     }
 
     ret = _set_opp(dev, opp_table, opp, &target_freq, forced);
 
     if (target_freq)
         dev_pm_opp_put(opp);
 
 put_opp_table:
     dev_pm_opp_put_opp_table(opp_table);
     return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
 
 /**
  * dev_pm_opp_set_opp() - Configure device for OPP
  * @dev: device for which we do this operation
  * @opp: OPP to set to
  *
  * This configures the device based on the properties of the OPP passed to this
  * routine.
  *
  * Return: 0 on success, a negative error number otherwise.
  */
 int dev_pm_opp_set_opp(struct device *dev, struct dev_pm_opp *opp)
 {
     struct opp_table *opp_table;
     int ret;
 
     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);
     }
 
     ret = _set_opp(dev, opp_table, opp, NULL, false);
     dev_pm_opp_put_opp_table(opp_table);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_set_opp);
 
 /* 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;
 
     opp_dev = kzalloc(sizeof(*opp_dev), GFP_KERNEL);
     if (!opp_dev)
         return NULL;
 
     /* Initialize opp-dev */
     opp_dev->dev = dev;
 
     mutex_lock(&opp_table->lock);
     list_add(&opp_dev->node, &opp_table->dev_list);
     mutex_unlock(&opp_table->lock);
 
     /* Create debugfs entries for the opp_table */
     opp_debug_register(opp_dev, opp_table);
 
     return opp_dev;
 }
 
 static struct opp_table *_allocate_opp_table(struct device *dev, int index)
 {
     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 ERR_PTR(-ENOMEM);
 
     mutex_init(&opp_table->lock);
     mutex_init(&opp_table->genpd_virt_dev_lock);
     INIT_LIST_HEAD(&opp_table->dev_list);
     INIT_LIST_HEAD(&opp_table->lazy);
 
     opp_table->clk = ERR_PTR(-ENODEV);
 
     /* Mark regulator count uninitialized */
     opp_table->regulator_count = -1;
 
     opp_dev = _add_opp_dev(dev, opp_table);
     if (!opp_dev) {
         ret = -ENOMEM;
         goto err;
     }
 
     _of_init_opp_table(opp_table, dev, index);
 
     /* Find interconnect path(s) for the device */
     ret = dev_pm_opp_of_find_icc_paths(dev, opp_table);
     if (ret) {
         if (ret == -EPROBE_DEFER)
             goto remove_opp_dev;
 
         dev_warn(dev, "%s: Error finding interconnect paths: %d\n",
              __func__, ret);
     }
 
     BLOCKING_INIT_NOTIFIER_HEAD(&opp_table->head);
     INIT_LIST_HEAD(&opp_table->opp_list);
     kref_init(&opp_table->kref);
 
     return opp_table;
 
 remove_opp_dev:
     _remove_opp_dev(opp_dev, opp_table);
 err:
     kfree(opp_table);
     return ERR_PTR(ret);
 }
 
 void _get_opp_table_kref(struct opp_table *opp_table)
 {
     kref_get(&opp_table->kref);
 }
 
 static struct opp_table *_update_opp_table_clk(struct device *dev,
                            struct opp_table *opp_table,
                            bool getclk)
 {
     int ret;
 
     /*
      * Return early if we don't need to get clk or we have already done it
      * earlier.
      */
     if (!getclk || IS_ERR(opp_table) || !IS_ERR(opp_table->clk) ||
         opp_table->clks)
         return opp_table;
 
     /* Find clk for the device */
     opp_table->clk = clk_get(dev, NULL);
 
     ret = PTR_ERR_OR_ZERO(opp_table->clk);
     if (!ret) {
         opp_table->config_clks = _opp_config_clk_single;
         opp_table->clk_count = 1;
         return opp_table;
     }
 
     if (ret == -ENOENT) {
         /*
          * There are few platforms which don't want the OPP core to
          * manage device's clock settings. In such cases neither the
          * platform provides the clks explicitly to us, nor the DT
          * contains a valid clk entry. The OPP nodes in DT may still
          * contain "opp-hz" property though, which we need to parse and
          * allow the platform to find an OPP based on freq later on.
          *
          * This is a simple solution to take care of such corner cases,
          * i.e. make the clk_count 1, which lets us allocate space for
          * frequency in opp->rates and also parse the entries in DT.
          */
         opp_table->clk_count = 1;
 
         dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__, ret);
         return opp_table;
     }
 
     dev_pm_opp_put_opp_table(opp_table);
     dev_err_probe(dev, ret, "Couldn't find clock\n");
 
     return ERR_PTR(ret);
 }
 
 /*
  * We need to make sure that the OPP table for a device doesn't get added twice,
  * if this routine gets called in parallel with the same device pointer.
  *
  * The simplest way to enforce that is to perform everything (find existing
  * table and if not found, create a new one) under the opp_table_lock, so only
  * one creator gets access to the same. But that expands the critical section
  * under the lock and may end up causing circular dependencies with frameworks
  * like debugfs, interconnect or clock framework as they may be direct or
  * indirect users of OPP core.
  *
  * And for that reason we have to go for a bit tricky implementation here, which
  * uses the opp_tables_busy flag to indicate if another creator is in the middle
  * of adding an OPP table and others should wait for it to finish.
  */
 struct opp_table *_add_opp_table_indexed(struct device *dev, int index,
                      bool getclk)
 {
     struct opp_table *opp_table;
 
 again:
     mutex_lock(&opp_table_lock);
 
     opp_table = _find_opp_table_unlocked(dev);
     if (!IS_ERR(opp_table))
         goto unlock;
 
     /*
      * The opp_tables list or an OPP table's dev_list is getting updated by
      * another user, wait for it to finish.
      */
     if (unlikely(opp_tables_busy)) {
         mutex_unlock(&opp_table_lock);
         cpu_relax();
         goto again;
     }
 
     opp_tables_busy = true;
     opp_table = _managed_opp(dev, index);
 
     /* Drop the lock to reduce the size of critical section */
     mutex_unlock(&opp_table_lock);
 
     if (opp_table) {
         if (!_add_opp_dev(dev, opp_table)) {
             dev_pm_opp_put_opp_table(opp_table);
             opp_table = ERR_PTR(-ENOMEM);
         }
 
         mutex_lock(&opp_table_lock);
     } else {
         opp_table = _allocate_opp_table(dev, index);
 
         mutex_lock(&opp_table_lock);
         if (!IS_ERR(opp_table))
             list_add(&opp_table->node, &opp_tables);
     }
 
     opp_tables_busy = false;
 
 unlock:
     mutex_unlock(&opp_table_lock);
 
     return _update_opp_table_clk(dev, opp_table, getclk);
 }
 
 static struct opp_table *_add_opp_table(struct device *dev, bool getclk)
 {
     return _add_opp_table_indexed(dev, 0, getclk);
 }
 
 struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
 {
     return _find_opp_table(dev);
 }
 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, *temp;
     int i;
 
     /* Drop the lock as soon as we can */
     list_del(&opp_table->node);
     mutex_unlock(&opp_table_lock);
 
     if (opp_table->current_opp)
         dev_pm_opp_put(opp_table->current_opp);
 
     _of_clear_opp_table(opp_table);
 
     /* Release automatically acquired single clk */
     if (!IS_ERR(opp_table->clk))
         clk_put(opp_table->clk);
 
     if (opp_table->paths) {
         for (i = 0; i < opp_table->path_count; i++)
             icc_put(opp_table->paths[i]);
         kfree(opp_table->paths);
     }
 
     WARN_ON(!list_empty(&opp_table->opp_list));
 
     list_for_each_entry_safe(opp_dev, temp, &opp_table->dev_list, node) {
         /*
          * The OPP table is getting removed, drop the performance state
          * constraints.
          */
         if (opp_table->genpd_performance_state)
             dev_pm_genpd_set_performance_state((struct device *)(opp_dev->dev), 0);
 
         _remove_opp_dev(opp_dev, opp_table);
     }
 
     mutex_destroy(&opp_table->genpd_virt_dev_lock);
     mutex_destroy(&opp_table->lock);
     kfree(opp_table);
 }
 
 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;
 
     list_del(&opp->node);
     mutex_unlock(&opp_table->lock);
 
     /*
      * Notify the changes in the availability of the operable
      * frequency/voltage list.
      */
     blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_REMOVE, opp);
     _of_clear_opp(opp_table, opp);
     opp_debug_remove_one(opp);
     kfree(opp);
 }
 
 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 = NULL, *iter;
     struct opp_table *opp_table;
 
     opp_table = _find_opp_table(dev);
     if (IS_ERR(opp_table))
         return;
 
     if (!assert_single_clk(opp_table))
         goto put_table;
 
     mutex_lock(&opp_table->lock);
 
     list_for_each_entry(iter, &opp_table->opp_list, node) {
         if (iter->rates[0] == freq) {
             opp = iter;
             break;
         }
     }
 
     mutex_unlock(&opp_table->lock);
 
     if (opp) {
         dev_pm_opp_put(opp);
 
         /* Drop the reference taken by dev_pm_opp_add() */
         dev_pm_opp_put_opp_table(opp_table);
     } else {
         dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
              __func__, freq);
     }
 
 put_table:
     /* Drop the reference taken by _find_opp_table() */
     dev_pm_opp_put_opp_table(opp_table);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
 
 static struct dev_pm_opp *_opp_get_next(struct opp_table *opp_table,
                     bool dynamic)
 {
     struct dev_pm_opp *opp = NULL, *temp;
 
     mutex_lock(&opp_table->lock);
     list_for_each_entry(temp, &opp_table->opp_list, node) {
         /*
          * Refcount must be dropped only once for each OPP by OPP core,
          * do that with help of "removed" flag.
          */
         if (!temp->removed && dynamic == temp->dynamic) {
             opp = temp;
             break;
         }
     }
 
     mutex_unlock(&opp_table->lock);
     return opp;
 }
 
 /*
  * Can't call dev_pm_opp_put() from under the lock as debugfs removal needs to
  * happen lock less to avoid circular dependency issues. This routine must be
  * called without the opp_table->lock held.
  */
 static void _opp_remove_all(struct opp_table *opp_table, bool dynamic)
 {
     struct dev_pm_opp *opp;
 
     while ((opp = _opp_get_next(opp_table, dynamic))) {
         opp->removed = true;
         dev_pm_opp_put(opp);
 
         /* Drop the references taken by dev_pm_opp_add() */
         if (dynamic)
             dev_pm_opp_put_opp_table(opp_table);
     }
 }
 
 bool _opp_remove_all_static(struct opp_table *opp_table)
 {
     mutex_lock(&opp_table->lock);
 
     if (!opp_table->parsed_static_opps) {
         mutex_unlock(&opp_table->lock);
         return false;
     }
 
     if (--opp_table->parsed_static_opps) {
         mutex_unlock(&opp_table->lock);
         return true;
     }
 
     mutex_unlock(&opp_table->lock);
 
     _opp_remove_all(opp_table, false);
     return true;
 }
 
 /**
  * dev_pm_opp_remove_all_dynamic() - Remove all dynamically created OPPs
  * @dev:    device for which we do this operation
  *
  * This function removes all dynamically created OPPs from the opp table.
  */
 void dev_pm_opp_remove_all_dynamic(struct device *dev)
 {
     struct opp_table *opp_table;
 
     opp_table = _find_opp_table(dev);
     if (IS_ERR(opp_table))
         return;
 
     _opp_remove_all(opp_table, true);
 
     /* Drop the reference taken by _find_opp_table() */
     dev_pm_opp_put_opp_table(opp_table);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove_all_dynamic);
 
 struct dev_pm_opp *_opp_allocate(struct opp_table *opp_table)
 {
     struct dev_pm_opp *opp;
     int supply_count, supply_size, icc_size, clk_size;
 
     /* Allocate space for at least one supply */
     supply_count = opp_table->regulator_count > 0 ?
             opp_table->regulator_count : 1;
     supply_size = sizeof(*opp->supplies) * supply_count;
     clk_size = sizeof(*opp->rates) * opp_table->clk_count;
     icc_size = sizeof(*opp->bandwidth) * opp_table->path_count;
 
     /* allocate new OPP node and supplies structures */
     opp = kzalloc(sizeof(*opp) + supply_size + clk_size + icc_size, GFP_KERNEL);
     if (!opp)
         return NULL;
 
     /* Put the supplies, bw and clock at the end of the OPP structure */
     opp->supplies = (struct dev_pm_opp_supply *)(opp + 1);
 
     opp->rates = (unsigned long *)(opp->supplies + supply_count);
 
     if (icc_size)
         opp->bandwidth = (struct dev_pm_opp_icc_bw *)(opp->rates + opp_table->clk_count);
 
     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_compare_rate(struct opp_table *opp_table,
                  struct dev_pm_opp *opp1, struct dev_pm_opp *opp2)
 {
     int i;
 
     for (i = 0; i < opp_table->clk_count; i++) {
         if (opp1->rates[i] != opp2->rates[i])
             return opp1->rates[i] < opp2->rates[i] ? -1 : 1;
     }
 
     /* Same rates for both OPPs */
     return 0;
 }
 
 static int _opp_compare_bw(struct opp_table *opp_table, struct dev_pm_opp *opp1,
                struct dev_pm_opp *opp2)
 {
     int i;
 
     for (i = 0; i < opp_table->path_count; i++) {
         if (opp1->bandwidth[i].peak != opp2->bandwidth[i].peak)
             return opp1->bandwidth[i].peak < opp2->bandwidth[i].peak ? -1 : 1;
     }
 
     /* Same bw for both OPPs */
     return 0;
 }
 
 /*
  * Returns
  * 0: opp1 == opp2
  * 1: opp1 > opp2
  * -1: opp1 < opp2
  */
 int _opp_compare_key(struct opp_table *opp_table, struct dev_pm_opp *opp1,
              struct dev_pm_opp *opp2)
 {
     int ret;
 
     ret = _opp_compare_rate(opp_table, opp1, opp2);
     if (ret)
         return ret;
 
     ret = _opp_compare_bw(opp_table, opp1, opp2);
     if (ret)
         return ret;
 
     if (opp1->level != opp2->level)
         return opp1->level < opp2->level ? -1 : 1;
 
     /* Duplicate OPPs */
     return 0;
 }
 
 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;
     int opp_cmp;
 
     /*
      * 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) {
         opp_cmp = _opp_compare_key(opp_table, new_opp, opp);
         if (opp_cmp > 0) {
             *head = &opp->node;
             continue;
         }
 
         if (opp_cmp < 0)
             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->rates[0], opp->supplies[0].u_volt,
              opp->available, new_opp->rates[0],
              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;
 }
 
 void _required_opps_available(struct dev_pm_opp *opp, int count)
 {
     int i;
 
     for (i = 0; i < count; i++) {
         if (opp->required_opps[i]->available)
             continue;
 
         opp->available = false;
         pr_warn("%s: OPP not supported by required OPP %pOF (%lu)\n",
              __func__, opp->required_opps[i]->np, opp->rates[0]);
         return;
     }
 }
 
 /*
  * 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)
 {
     struct list_head *head;
     int ret;
 
     mutex_lock(&opp_table->lock);
     head = &opp_table->opp_list;
 
     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);
 
     opp_debug_create_one(new_opp, opp_table);
 
     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->rates[0]);
     }
 
     /* required-opps not fully initialized yet */
     if (lazy_linking_pending(opp_table))
         return 0;
 
     _required_opps_available(new_opp, opp_table->required_opp_count);
 
     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;
 
     if (!assert_single_clk(opp_table))
         return -EINVAL;
 
     new_opp = _opp_allocate(opp_table);
     if (!new_opp)
         return -ENOMEM;
 
     /* populate the opp table */
     new_opp->rates[0] = 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);
     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;
 }
 
 /**
  * _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.
  */
 static int _opp_set_supported_hw(struct opp_table *opp_table,
                  const u32 *versions, unsigned int count)
 {
     /* Another CPU that shares the OPP table has set the property ? */
     if (opp_table->supported_hw)
         return 0;
 
     opp_table->supported_hw = kmemdup(versions, count * sizeof(*versions),
                     GFP_KERNEL);
     if (!opp_table->supported_hw)
         return -ENOMEM;
 
     opp_table->supported_hw_count = count;
 
     return 0;
 }
 
 /**
  * _opp_put_supported_hw() - Releases resources blocked for supported hw
  * @opp_table: OPP table returned by _opp_set_supported_hw().
  *
  * This is required only for the V2 bindings, and is called for a matching
  * _opp_set_supported_hw(). Until this is called, the opp_table structure
  * will not be freed.
  */
 static void _opp_put_supported_hw(struct opp_table *opp_table)
 {
     if (opp_table->supported_hw) {
         kfree(opp_table->supported_hw);
         opp_table->supported_hw = NULL;
         opp_table->supported_hw_count = 0;
     }
 }
 
 /**
  * _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.
  */
 static int _opp_set_prop_name(struct opp_table *opp_table, const char *name)
 {
     /* Another CPU that shares the OPP table has set the property ? */
     if (!opp_table->prop_name) {
         opp_table->prop_name = kstrdup(name, GFP_KERNEL);
         if (!opp_table->prop_name)
             return -ENOMEM;
     }
 
     return 0;
 }
 
 /**
  * _opp_put_prop_name() - Releases resources blocked for prop-name
  * @opp_table: OPP table returned by _opp_set_prop_name().
  *
  * This is required only for the V2 bindings, and is called for a matching
  * _opp_set_prop_name(). Until this is called, the opp_table structure
  * will not be freed.
  */
 static void _opp_put_prop_name(struct opp_table *opp_table)
 {
     if (opp_table->prop_name) {
         kfree(opp_table->prop_name);
         opp_table->prop_name = NULL;
     }
 }
 
 /**
  * _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.
  */
 static int _opp_set_regulators(struct opp_table *opp_table, struct device *dev,
                    const char * const names[])
 {
     const char * const *temp = names;
     struct regulator *reg;
     int count = 0, ret, i;
 
     /* Count number of regulators */
     while (*temp++)
         count++;
 
     if (!count)
         return -EINVAL;
 
     /* Another CPU that shares the OPP table has set the regulators ? */
     if (opp_table->regulators)
         return 0;
 
     opp_table->regulators = kmalloc_array(count,
                           sizeof(*opp_table->regulators),
                           GFP_KERNEL);
     if (!opp_table->regulators)
         return -ENOMEM;
 
     for (i = 0; i < count; i++) {
         reg = regulator_get_optional(dev, names[i]);
         if (IS_ERR(reg)) {
             ret = dev_err_probe(dev, PTR_ERR(reg),
                         "%s: no regulator (%s) found\n",
                         __func__, names[i]);
             goto free_regulators;
         }
 
         opp_table->regulators[i] = reg;
     }
 
     opp_table->regulator_count = count;
 
     /* Set generic config_regulators() for single regulators here */
     if (count == 1)
         opp_table->config_regulators = _opp_config_regulator_single;
 
     return 0;
 
 free_regulators:
     while (i != 0)
         regulator_put(opp_table->regulators[--i]);
 
     kfree(opp_table->regulators);
     opp_table->regulators = NULL;
     opp_table->regulator_count = -1;
 
     return ret;
 }
 
 /**
  * _opp_put_regulators() - Releases resources blocked for regulator
  * @opp_table: OPP table returned from _opp_set_regulators().
  */
 static void _opp_put_regulators(struct opp_table *opp_table)
 {
     int i;
 
     if (!opp_table->regulators)
         return;
 
     if (opp_table->enabled) {
         for (i = opp_table->regulator_count - 1; i >= 0; i--)
             regulator_disable(opp_table->regulators[i]);
     }
 
     for (i = opp_table->regulator_count - 1; i >= 0; i--)
         regulator_put(opp_table->regulators[i]);
 
     kfree(opp_table->regulators);
     opp_table->regulators = NULL;
     opp_table->regulator_count = -1;
 }
 
 static void _put_clks(struct opp_table *opp_table, int count)
 {
     int i;
 
     for (i = count - 1; i >= 0; i--)
         clk_put(opp_table->clks[i]);
 
     kfree(opp_table->clks);
     opp_table->clks = NULL;
 }
 
 /**
  * _opp_set_clknames() - Set clk names for the device
  * @dev: Device for which clk names is being set.
  * @names: Clk names.
  *
  * In order to support OPP switching, OPP layer needs to get pointers to the
  * clocks 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 names of the clks to
  * use.
  *
  * This must be called before any OPPs are initialized for the device.
  */
 static int _opp_set_clknames(struct opp_table *opp_table, struct device *dev,
                  const char * const names[],
                  config_clks_t config_clks)
 {
     const char * const *temp = names;
     int count = 0, ret, i;
     struct clk *clk;
 
     /* Count number of clks */
     while (*temp++)
         count++;
 
     /*
      * This is a special case where we have a single clock, whose connection
      * id name is NULL, i.e. first two entries are NULL in the array.
      */
     if (!count && !names[1])
         count = 1;
 
     /* Fail early for invalid configurations */
     if (!count || (!config_clks && count > 1))
         return -EINVAL;
 
     /* Another CPU that shares the OPP table has set the clkname ? */
     if (opp_table->clks)
         return 0;
 
     opp_table->clks = kmalloc_array(count, sizeof(*opp_table->clks),
                     GFP_KERNEL);
     if (!opp_table->clks)
         return -ENOMEM;
 
     /* Find clks for the device */
     for (i = 0; i < count; i++) {
         clk = clk_get(dev, names[i]);
         if (IS_ERR(clk)) {
             ret = dev_err_probe(dev, PTR_ERR(clk),
                         "%s: Couldn't find clock with name: %s\n",
                         __func__, names[i]);
             goto free_clks;
         }
 
         opp_table->clks[i] = clk;
     }
 
     opp_table->clk_count = count;
     opp_table->config_clks = config_clks;
 
     /* Set generic single clk set here */
     if (count == 1) {
         if (!opp_table->config_clks)
             opp_table->config_clks = _opp_config_clk_single;
 
         /*
          * We could have just dropped the "clk" field and used "clks"
          * everywhere. Instead we kept the "clk" field around for
          * following reasons:
          *
          * - avoiding clks[0] everywhere else.
          * - not running single clk helpers for multiple clk usecase by
          *   mistake.
          *
          * Since this is single-clk case, just update the clk pointer
          * too.
          */
         opp_table->clk = opp_table->clks[0];
     }
 
     return 0;
 
 free_clks:
     _put_clks(opp_table, i);
     return ret;
 }
 
 /**
  * _opp_put_clknames() - Releases resources blocked for clks.
  * @opp_table: OPP table returned from _opp_set_clknames().
  */
 static void _opp_put_clknames(struct opp_table *opp_table)
 {
     if (!opp_table->clks)
         return;
 
     opp_table->config_clks = NULL;
     opp_table->clk = ERR_PTR(-ENODEV);
 
     _put_clks(opp_table, opp_table->clk_count);
 }
 
 /**
  * _opp_set_config_regulators_helper() - Register custom set regulator helper.
  * @dev: Device for which the helper is getting registered.
  * @config_regulators: Custom set regulator helper.
  *
  * This is useful to support platforms with multiple regulators per device.
  *
  * This must be called before any OPPs are initialized for the device.
  */
 static int _opp_set_config_regulators_helper(struct opp_table *opp_table,
         struct device *dev, config_regulators_t config_regulators)
 {
     /* Another CPU that shares the OPP table has set the helper ? */
     if (!opp_table->config_regulators)
         opp_table->config_regulators = config_regulators;
 
     return 0;
 }
 
 /**
  * _opp_put_config_regulators_helper() - Releases resources blocked for
  *                   config_regulators helper.
  * @opp_table: OPP table returned from _opp_set_config_regulators_helper().
  *
  * Release resources blocked for platform specific config_regulators helper.
  */
 static void _opp_put_config_regulators_helper(struct opp_table *opp_table)
 {
     if (opp_table->config_regulators)
         opp_table->config_regulators = NULL;
 }
 
 static void _detach_genpd(struct opp_table *opp_table)
 {
     int index;
 
     if (!opp_table->genpd_virt_devs)
         return;
 
     for (index = 0; index < opp_table->required_opp_count; index++) {
         if (!opp_table->genpd_virt_devs[index])
             continue;
 
         dev_pm_domain_detach(opp_table->genpd_virt_devs[index], false);
         opp_table->genpd_virt_devs[index] = NULL;
     }
 
     kfree(opp_table->genpd_virt_devs);
     opp_table->genpd_virt_devs = NULL;
 }
 
 /**
  * _opp_attach_genpd - Attach genpd(s) for the device and save virtual device pointer
  * @dev: Consumer device for which the genpd is getting attached.
  * @names: Null terminated array of pointers containing names of genpd to attach.
  * @virt_devs: Pointer to return the array of virtual devices.
  *
  * Multiple generic power domains for a device are supported with the help of
  * virtual genpd devices, which are created for each consumer device - genpd
  * pair. These are the device structures which are attached to the power domain
  * and are required by the OPP core to set the performance state of the genpd.
  * The same API also works for the case where single genpd is available and so
  * we don't need to support that separately.
  *
  * This helper will normally be called by the consumer driver of the device
  * "dev", as only that has details of the genpd names.
  *
  * This helper needs to be called once with a list of all genpd to attach.
  * Otherwise the original device structure will be used instead by the OPP core.
  *
  * The order of entries in the names array must match the order in which
  * "required-opps" are added in DT.
  */
 static int _opp_attach_genpd(struct opp_table *opp_table, struct device *dev,
             const char * const *names, struct device ***virt_devs)
 {
     struct device *virt_dev;
     int index = 0, ret = -EINVAL;
     const char * const *name = names;
 
     if (opp_table->genpd_virt_devs)
         return 0;
 
     /*
      * If the genpd's OPP table isn't already initialized, parsing of the
      * required-opps fail for dev. We should retry this after genpd's OPP
      * table is added.
      */
     if (!opp_table->required_opp_count)
         return -EPROBE_DEFER;
 
     mutex_lock(&opp_table->genpd_virt_dev_lock);
 
     opp_table->genpd_virt_devs = kcalloc(opp_table->required_opp_count,
                          sizeof(*opp_table->genpd_virt_devs),
                          GFP_KERNEL);
     if (!opp_table->genpd_virt_devs)
         goto unlock;
 
     while (*name) {
         if (index >= opp_table->required_opp_count) {
             dev_err(dev, "Index can't be greater than required-opp-count - 1, %s (%d : %d)\n",
                 *name, opp_table->required_opp_count, index);
             goto err;
         }
 
         virt_dev = dev_pm_domain_attach_by_name(dev, *name);
         if (IS_ERR_OR_NULL(virt_dev)) {
             ret = PTR_ERR(virt_dev) ? : -ENODEV;
             dev_err(dev, "Couldn't attach to pm_domain: %d\n", ret);
             goto err;
         }
 
         opp_table->genpd_virt_devs[index] = virt_dev;
         index++;
         name++;
     }
 
     if (virt_devs)
         *virt_devs = opp_table->genpd_virt_devs;
     mutex_unlock(&opp_table->genpd_virt_dev_lock);
 
     return 0;
 
 err:
     _detach_genpd(opp_table);
 unlock:
     mutex_unlock(&opp_table->genpd_virt_dev_lock);
     return ret;
 
 }
 
 /**
  * _opp_detach_genpd() - Detach genpd(s) from the device.
  * @opp_table: OPP table returned by _opp_attach_genpd().
  *
  * This detaches the genpd(s), resets the virtual device pointers, and puts the
  * OPP table.
  */
 static void _opp_detach_genpd(struct opp_table *opp_table)
 {
     /*
      * Acquire genpd_virt_dev_lock to make sure virt_dev isn't getting
      * used in parallel.
      */
     mutex_lock(&opp_table->genpd_virt_dev_lock);
     _detach_genpd(opp_table);
     mutex_unlock(&opp_table->genpd_virt_dev_lock);
 }
 
 static void _opp_clear_config(struct opp_config_data *data)
 {
     if (data->flags & OPP_CONFIG_GENPD)
         _opp_detach_genpd(data->opp_table);
     if (data->flags & OPP_CONFIG_REGULATOR)
         _opp_put_regulators(data->opp_table);
     if (data->flags & OPP_CONFIG_SUPPORTED_HW)
         _opp_put_supported_hw(data->opp_table);
     if (data->flags & OPP_CONFIG_REGULATOR_HELPER)
         _opp_put_config_regulators_helper(data->opp_table);
     if (data->flags & OPP_CONFIG_PROP_NAME)
         _opp_put_prop_name(data->opp_table);
     if (data->flags & OPP_CONFIG_CLK)
         _opp_put_clknames(data->opp_table);
 
     dev_pm_opp_put_opp_table(data->opp_table);
     kfree(data);
 }
 
 /**
  * dev_pm_opp_set_config() - Set OPP configuration for the device.
  * @dev: Device for which configuration is being set.
  * @config: OPP configuration.
  *
  * This allows all device OPP configurations to be performed at once.
  *
  * This must be called before any OPPs are initialized for the device. This may
  * be called multiple times for the same OPP table, for example once for each
  * CPU that share the same table. This must be balanced by the same number of
  * calls to dev_pm_opp_clear_config() in order to free the OPP table properly.
  *
  * This returns a token to the caller, which must be passed to
  * dev_pm_opp_clear_config() to free the resources later. The value of the
  * returned token will be >= 1 for success and negative for errors. The minimum
  * value of 1 is chosen here to make it easy for callers to manage the resource.
  */
 int dev_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
 {
     struct opp_table *opp_table;
     struct opp_config_data *data;
     unsigned int id;
     int ret;
 
     data = kmalloc(sizeof(*data), GFP_KERNEL);
     if (!data)
         return -ENOMEM;
 
     opp_table = _add_opp_table(dev, false);
     if (IS_ERR(opp_table)) {
         kfree(data);
         return PTR_ERR(opp_table);
     }
 
     data->opp_table = opp_table;
     data->flags = 0;
 
     /* This should be called before OPPs are initialized */
     if (WARN_ON(!list_empty(&opp_table->opp_list))) {
         ret = -EBUSY;
         goto err;
     }
 
     /* Configure clocks */
     if (config->clk_names) {
         ret = _opp_set_clknames(opp_table, dev, config->clk_names,
                     config->config_clks);
         if (ret)
             goto err;
 
         data->flags |= OPP_CONFIG_CLK;
     } else if (config->config_clks) {
         /* Don't allow config callback without clocks */
         ret = -EINVAL;
         goto err;
     }
 
     /* Configure property names */
     if (config->prop_name) {
         ret = _opp_set_prop_name(opp_table, config->prop_name);
         if (ret)
             goto err;
 
         data->flags |= OPP_CONFIG_PROP_NAME;
     }
 
     /* Configure config_regulators helper */
     if (config->config_regulators) {
         ret = _opp_set_config_regulators_helper(opp_table, dev,
                         config->config_regulators);
         if (ret)
             goto err;
 
         data->flags |= OPP_CONFIG_REGULATOR_HELPER;
     }
 
     /* Configure supported hardware */
     if (config->supported_hw) {
         ret = _opp_set_supported_hw(opp_table, config->supported_hw,
                         config->supported_hw_count);
         if (ret)
             goto err;
 
         data->flags |= OPP_CONFIG_SUPPORTED_HW;
     }
 
     /* Configure supplies */
     if (config->regulator_names) {
         ret = _opp_set_regulators(opp_table, dev,
                       config->regulator_names);
         if (ret)
             goto err;
 
         data->flags |= OPP_CONFIG_REGULATOR;
     }
 
     /* Attach genpds */
     if (config->genpd_names) {
         ret = _opp_attach_genpd(opp_table, dev, config->genpd_names,
                     config->virt_devs);
         if (ret)
             goto err;
 
         data->flags |= OPP_CONFIG_GENPD;
     }
 
     ret = xa_alloc(&opp_configs, &id, data, XA_LIMIT(1, INT_MAX),
                GFP_KERNEL);
     if (ret)
         goto err;
 
     return id;
 
 err:
     _opp_clear_config(data);
     return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_set_config);
 
 /**
  * dev_pm_opp_clear_config() - Releases resources blocked for OPP configuration.
  * @opp_table: OPP table returned from dev_pm_opp_set_config().
  *
  * This allows all device OPP configurations to be cleared at once. This must be
  * called once for each call made to dev_pm_opp_set_config(), in order to free
  * the OPPs properly.
  *
  * Currently the first call itself ends up freeing all the OPP configurations,
  * while the later ones only drop the OPP table reference. This works well for
  * now as we would never want to use an half initialized OPP table and want to
  * remove the configurations together.
  */
 void dev_pm_opp_clear_config(int token)
 {
     struct opp_config_data *data;
 
     /*
      * This lets the callers call this unconditionally and keep their code
      * simple.
      */
     if (unlikely(token <= 0))
         return;
 
     data = xa_erase(&opp_configs, token);
     if (WARN_ON(!data))
         return;
 
     _opp_clear_config(data);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_clear_config);
 
 static void devm_pm_opp_config_release(void *token)
 {
     dev_pm_opp_clear_config((unsigned long)token);
 }
 
 /**
  * devm_pm_opp_set_config() - Set OPP configuration for the device.
  * @dev: Device for which configuration is being set.
  * @config: OPP configuration.
  *
  * This allows all device OPP configurations to be performed at once.
  * This is a resource-managed variant of dev_pm_opp_set_config().
  *
  * Return: 0 on success and errorno otherwise.
  */
 int devm_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
 {
     int token = dev_pm_opp_set_config(dev, config);
 
     if (token < 0)
         return token;
 
     return devm_add_action_or_reset(dev, devm_pm_opp_config_release,
                     (void *) ((unsigned long) token));
 }
 EXPORT_SYMBOL_GPL(devm_pm_opp_set_config);
 
 /**
  * dev_pm_opp_xlate_required_opp() - Find required OPP for @src_table OPP.
  * @src_table: OPP table which has @dst_table as one of its required OPP table.
  * @dst_table: Required OPP table of the @src_table.
  * @src_opp: OPP from the @src_table.
  *
  * This function returns the OPP (present in @dst_table) pointed out by the
  * "required-opps" property of the @src_opp (present in @src_table).
  *
  * The callers are required to call dev_pm_opp_put() for the returned OPP after
  * use.
  *
  * Return: pointer to 'struct dev_pm_opp' on success and errorno otherwise.
  */
 struct dev_pm_opp *dev_pm_opp_xlate_required_opp(struct opp_table *src_table,
                          struct opp_table *dst_table,
                          struct dev_pm_opp *src_opp)
 {
     struct dev_pm_opp *opp, *dest_opp = ERR_PTR(-ENODEV);
     int i;
 
     if (!src_table || !dst_table || !src_opp ||
         !src_table->required_opp_tables)
         return ERR_PTR(-EINVAL);
 
     /* required-opps not fully initialized yet */
     if (lazy_linking_pending(src_table))
         return ERR_PTR(-EBUSY);
 
     for (i = 0; i < src_table->required_opp_count; i++) {
         if (src_table->required_opp_tables[i] == dst_table) {
             mutex_lock(&src_table->lock);
 
             list_for_each_entry(opp, &src_table->opp_list, node) {
                 if (opp == src_opp) {
                     dest_opp = opp->required_opps[i];
                     dev_pm_opp_get(dest_opp);
                     break;
                 }
             }
 
             mutex_unlock(&src_table->lock);
             break;
         }
     }
 
     if (IS_ERR(dest_opp)) {
         pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__,
                src_table, dst_table);
     }
 
     return dest_opp;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_xlate_required_opp);
 
 /**
  * dev_pm_opp_xlate_performance_state() - Find required OPP's pstate for src_table.
  * @src_table: OPP table which has dst_table as one of its required OPP table.
  * @dst_table: Required OPP table of the src_table.
  * @pstate: Current performance state of the src_table.
  *
  * This Returns pstate of the OPP (present in @dst_table) pointed out by the
  * "required-opps" property of the OPP (present in @src_table) which has
  * performance state set to @pstate.
  *
  * Return: Zero or positive performance state on success, otherwise negative
  * value on errors.
  */
 int dev_pm_opp_xlate_performance_state(struct opp_table *src_table,
                        struct opp_table *dst_table,
                        unsigned int pstate)
 {
     struct dev_pm_opp *opp;
     int dest_pstate = -EINVAL;
     int i;
 
     /*
      * Normally the src_table will have the "required_opps" property set to
      * point to one of the OPPs in the dst_table, but in some cases the
      * genpd and its master have one to one mapping of performance states
      * and so none of them have the "required-opps" property set. Return the
      * pstate of the src_table as it is in such cases.
      */
     if (!src_table || !src_table->required_opp_count)
         return pstate;
 
     /* required-opps not fully initialized yet */
     if (lazy_linking_pending(src_table))
         return -EBUSY;
 
     for (i = 0; i < src_table->required_opp_count; i++) {
         if (src_table->required_opp_tables[i]->np == dst_table->np)
             break;
     }
 
     if (unlikely(i == src_table->required_opp_count)) {
         pr_err("%s: Couldn't find matching OPP table (%p: %p)\n",
                __func__, src_table, dst_table);
         return -EINVAL;
     }
 
     mutex_lock(&src_table->lock);
 
     list_for_each_entry(opp, &src_table->opp_list, node) {
         if (opp->pstate == pstate) {
             dest_pstate = opp->required_opps[i]->pstate;
             goto unlock;
         }
     }
 
     pr_err("%s: Couldn't find matching OPP (%p: %p)\n", __func__, src_table,
            dst_table);
 
 unlock:
     mutex_unlock(&src_table->lock);
 
     return dest_pstate;
 }
 
 /**
  * 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 = _add_opp_table(dev, true);
     if (IS_ERR(opp_table))
         return PTR_ERR(opp_table);
 
     /* Fix regulator count for dynamic OPPs */
     opp_table->regulator_count = 1;
 
     ret = _opp_add_v1(opp_table, dev, freq, u_volt, true);
     if (ret)
         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;
     }
 
     if (!assert_single_clk(opp_table)) {
         r = -EINVAL;
         goto put_table;
     }
 
     mutex_lock(&opp_table->lock);
 
     /* Do we have the frequency? */
     list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
         if (tmp_opp->rates[0] == 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_adjust_voltage() - helper to change the voltage of an OPP
  * @dev:        device for which we do this operation
  * @freq:       OPP frequency to adjust voltage of
  * @u_volt:     new OPP target voltage
  * @u_volt_min:     new OPP min voltage
  * @u_volt_max:     new OPP max voltage
  *
  * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
  * copy operation, returns 0 if no modifcation was done OR modification was
  * successful.
  */
 int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
                   unsigned long u_volt, unsigned long u_volt_min,
                   unsigned long u_volt_max)
 
 {
     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;
     }
 
     if (!assert_single_clk(opp_table)) {
         r = -EINVAL;
         goto put_table;
     }
 
     mutex_lock(&opp_table->lock);
 
     /* Do we have the frequency? */
     list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
         if (tmp_opp->rates[0] == freq) {
             opp = tmp_opp;
             break;
         }
     }
 
     if (IS_ERR(opp)) {
         r = PTR_ERR(opp);
         goto adjust_unlock;
     }
 
     /* Is update really needed? */
     if (opp->supplies->u_volt == u_volt)
         goto adjust_unlock;
 
     opp->supplies->u_volt = u_volt;
     opp->supplies->u_volt_min = u_volt_min;
     opp->supplies->u_volt_max = u_volt_max;
 
     dev_pm_opp_get(opp);
     mutex_unlock(&opp_table->lock);
 
     /* Notify the voltage change of the OPP */
     blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE,
                      opp);
 
     dev_pm_opp_put(opp);
     goto put_table;
 
 adjust_unlock:
     mutex_unlock(&opp_table->lock);
 put_table:
     dev_pm_opp_put_opp_table(opp_table);
     return r;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_adjust_voltage);
 
 /**
  * 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);
 
 /**
  * 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)
 {
     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;
     }
 
     /*
      * Drop the extra reference only if the OPP table was successfully added
      * with dev_pm_opp_of_add_table() earlier.
      **/
     if (_opp_remove_all_static(opp_table))
         dev_pm_opp_put_opp_table(opp_table);
 
     /* Drop reference taken by _find_opp_table() */
     dev_pm_opp_put_opp_table(opp_table);
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);
 
 /**
  * dev_pm_opp_sync_regulators() - Sync state of voltage regulators
  * @dev:    device for which we do this operation
  *
  * Sync voltage state of the OPP table regulators.
  *
  * Return: 0 on success or a negative error value.
  */
 int dev_pm_opp_sync_regulators(struct device *dev)
 {
     struct opp_table *opp_table;
     struct regulator *reg;
     int i, ret = 0;
 
     /* Device may not have OPP table */
     opp_table = _find_opp_table(dev);
     if (IS_ERR(opp_table))
         return 0;
 
     /* Regulator may not be required for the device */
     if (unlikely(!opp_table->regulators))
         goto put_table;
 
     /* Nothing to sync if voltage wasn't changed */
     if (!opp_table->enabled)
         goto put_table;
 
     for (i = 0; i < opp_table->regulator_count; i++) {
         reg = opp_table->regulators[i];
         ret = regulator_sync_voltage(reg);
         if (ret)
             break;
     }
 put_table:
     /* Drop reference taken by _find_opp_table() */
     dev_pm_opp_put_opp_table(opp_table);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_sync_regulators);