core.c
/*
* Generic OPP Interface
*
* Copyright (C) 2009-2010 Texas Instruments Incorporated.
* Nishanth Menon
* Romit Dasgupta
* Kevin Hilman
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/regulator/consumer.h>
#include "opp.h"
/*
* The root of the list of all opp-tables. All opp_table structures branch off
* from here, with each opp_table containing the list of opps it supports in
* various states of availability.
*/
LIST_HEAD(opp_tables);
/* Lock to allow exclusive modification to the device and opp lists */
DEFINE_MUTEX(opp_table_lock);
#define opp_rcu_lockdep_assert() \
do { \
RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
!lockdep_is_held(&opp_table_lock), \
"Missing rcu_read_lock() or " \
"opp_table_lock protection"); \
} while (0)
static struct opp_device *_find_opp_dev(const struct device *dev,
struct opp_table *opp_table)
{
struct opp_device *opp_dev;
list_for_each_entry(opp_dev, &opp_table->dev_list, node)
if (opp_dev->dev == dev)
return opp_dev;
return NULL;
}
/**
* _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. Does a RCU reader
* operation to grab the pointer needed.
*
* Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
* -EINVAL based on type of error.
*
* Locking: For readers, this function must be called under rcu_read_lock().
* opp_table is a RCU protected pointer, which means that opp_table is valid
* as long as we are under RCU lock.
*
* For Writers, this function must be called with opp_table_lock held.
*/
struct opp_table *_find_opp_table(struct device *dev)
{
struct opp_table *opp_table;
opp_rcu_lockdep_assert();
if (IS_ERR_OR_NULL(dev)) {
pr_err("%s: Invalid parameters\n", __func__);
return ERR_PTR(-EINVAL);
}
list_for_each_entry_rcu(opp_table, &opp_tables, node)
if (_find_opp_dev(dev, opp_table))
return opp_table;
return ERR_PTR(-ENODEV);
}
/**
* 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.
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. This means that opp which could have been fetched by
* opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
* under RCU lock. The pointer returned by the opp_find_freq family must be
* used in the same section as the usage of this function with the pointer
* prior to unlocking with rcu_read_unlock() to maintain the integrity of the
* pointer.
*/
unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
{
struct dev_pm_opp *tmp_opp;
unsigned long v = 0;
opp_rcu_lockdep_assert();
tmp_opp = rcu_dereference(opp);
if (IS_ERR_OR_NULL(tmp_opp))
pr_err("%s: Invalid parameters\n", __func__);
else
v = tmp_opp->supplies[0].u_volt;
return v;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage);
/**
* dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp
* @opp: opp for which frequency has to be returned for
*
* Return: frequency in hertz corresponding to the opp, else
* return 0
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. This means that opp which could have been fetched by
* opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
* under RCU lock. The pointer returned by the opp_find_freq family must be
* used in the same section as the usage of this function with the pointer
* prior to unlocking with rcu_read_unlock() to maintain the integrity of the
* pointer.
*/
unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
{
struct dev_pm_opp *tmp_opp;
unsigned long f = 0;
opp_rcu_lockdep_assert();
tmp_opp = rcu_dereference(opp);
if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available)
pr_err("%s: Invalid parameters\n", __func__);
else
f = tmp_opp->rate;
return f;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
/**
* dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
* @opp: opp for which turbo mode is being verified
*
* Turbo OPPs are not for normal use, and can be enabled (under certain
* conditions) for short duration of times to finish high throughput work
* quickly. Running on them for longer times may overheat the chip.
*
* Return: true if opp is turbo opp, else false.
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. This means that opp which could have been fetched by
* opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
* under RCU lock. The pointer returned by the opp_find_freq family must be
* used in the same section as the usage of this function with the pointer
* prior to unlocking with rcu_read_unlock() to maintain the integrity of the
* pointer.
*/
bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp)
{
struct dev_pm_opp *tmp_opp;
opp_rcu_lockdep_assert();
tmp_opp = rcu_dereference(opp);
if (IS_ERR_OR_NULL(tmp_opp) || !tmp_opp->available) {
pr_err("%s: Invalid parameters\n", __func__);
return false;
}
return tmp_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.
*
* Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
{
struct opp_table *opp_table;
unsigned long clock_latency_ns;
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
clock_latency_ns = 0;
else
clock_latency_ns = opp_table->clock_latency_ns_max;
rcu_read_unlock();
return clock_latency_ns;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
static int _get_regulator_count(struct device *dev)
{
struct opp_table *opp_table;
int count;
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (!IS_ERR(opp_table))
count = opp_table->regulator_count;
else
count = 0;
rcu_read_unlock();
return count;
}
/**
* dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
* @dev: device for which we do this operation
*
* Return: This function returns the max voltage latency in nanoseconds.
*
* Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
{
struct opp_table *opp_table;
struct dev_pm_opp *opp;
struct regulator *reg, **regulators;
unsigned long latency_ns = 0;
int ret, i, count;
struct {
unsigned long min;
unsigned long max;
} *uV;
count = _get_regulator_count(dev);
/* Regulator may not be required for the device */
if (!count)
return 0;
regulators = kmalloc_array(count, sizeof(*regulators), GFP_KERNEL);
if (!regulators)
return 0;
uV = kmalloc_array(count, sizeof(*uV), GFP_KERNEL);
if (!uV)
goto free_regulators;
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
rcu_read_unlock();
goto free_uV;
}
memcpy(regulators, opp_table->regulators, count * sizeof(*regulators));
for (i = 0; i < count; i++) {
uV[i].min = ~0;
uV[i].max = 0;
list_for_each_entry_rcu(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;
}
}
rcu_read_unlock();
/*
* The caller needs to ensure that opp_table (and hence the regulator)
* isn't freed, while we are executing this routine.
*/
for (i = 0; reg = regulators[i], i < count; i++) {
ret = regulator_set_voltage_time(reg, uV[i].min, uV[i].max);
if (ret > 0)
latency_ns += ret * 1000;
}
free_uV:
kfree(uV);
free_regulators:
kfree(regulators);
return latency_ns;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
/**
* dev_pm_opp_get_max_transition_latency() - Get max transition latency in
* nanoseconds
* @dev: device for which we do this operation
*
* Return: This function returns the max transition latency, in nanoseconds, to
* switch from one OPP to other.
*
* Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
{
return dev_pm_opp_get_max_volt_latency(dev) +
dev_pm_opp_get_max_clock_latency(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
/**
* dev_pm_opp_get_suspend_opp() - Get suspend opp
* @dev: device for which we do this operation
*
* Return: This function returns pointer to the suspend opp if it is
* defined and available, otherwise it returns NULL.
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. The reason for the same is that the opp pointer which is
* returned will remain valid for use with opp_get_{voltage, freq} only while
* under the locked area. The pointer returned must be used prior to unlocking
* with rcu_read_unlock() to maintain the integrity of the pointer.
*/
struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
{
struct opp_table *opp_table;
opp_rcu_lockdep_assert();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table) || !opp_table->suspend_opp ||
!opp_table->suspend_opp->available)
return NULL;
return opp_table->suspend_opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp);
/**
* 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.
*
* Locking: This function takes rcu_read_lock().
*/
int dev_pm_opp_get_opp_count(struct device *dev)
{
struct opp_table *opp_table;
struct dev_pm_opp *temp_opp;
int count = 0;
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
count = PTR_ERR(opp_table);
dev_err(dev, "%s: OPP table not found (%d)\n",
__func__, count);
goto out_unlock;
}
list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available)
count++;
}
out_unlock:
rcu_read_unlock();
return count;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
/**
* dev_pm_opp_find_freq_exact() - search for an exact frequency
* @dev: device for which we do this operation
* @freq: frequency to search for
* @available: true/false - match for available opp
*
* Return: Searches for exact match in the opp table and returns pointer to the
* matching opp if found, else returns ERR_PTR in case of error and should
* be handled using IS_ERR. Error return values can be:
* EINVAL: for bad pointer
* ERANGE: no match found for search
* ENODEV: if device not found in list of registered devices
*
* Note: available is a modifier for the search. if available=true, then the
* match is for exact matching frequency and is available in the stored OPP
* table. if false, the match is for exact frequency which is not available.
*
* This provides a mechanism to enable an opp which is not available currently
* or the opposite as well.
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. The reason for the same is that the opp pointer which is
* returned will remain valid for use with opp_get_{voltage, freq} only while
* under the locked area. The pointer returned must be used prior to unlocking
* with rcu_read_unlock() to maintain the integrity of the pointer.
*/
struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
unsigned long freq,
bool available)
{
struct opp_table *opp_table;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
opp_rcu_lockdep_assert();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
int r = PTR_ERR(opp_table);
dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r);
return ERR_PTR(r);
}
list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available == available &&
temp_opp->rate == freq) {
opp = temp_opp;
break;
}
}
return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
unsigned long *freq)
{
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available && temp_opp->rate >= *freq) {
opp = temp_opp;
*freq = opp->rate;
break;
}
}
return opp;
}
/**
* dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq
* @dev: device for which we do this operation
* @freq: Start frequency
*
* Search for the matching ceil *available* OPP from a starting freq
* for a device.
*
* Return: matching *opp and refreshes *freq accordingly, else returns
* ERR_PTR in case of error and should be handled using IS_ERR. Error return
* values can be:
* EINVAL: for bad pointer
* ERANGE: no match found for search
* ENODEV: if device not found in list of registered devices
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. The reason for the same is that the opp pointer which is
* returned will remain valid for use with opp_get_{voltage, freq} only while
* under the locked area. The pointer returned must be used prior to unlocking
* with rcu_read_unlock() to maintain the integrity of the pointer.
*/
struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev,
unsigned long *freq)
{
struct opp_table *opp_table;
opp_rcu_lockdep_assert();
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
}
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
return ERR_CAST(opp_table);
return _find_freq_ceil(opp_table, freq);
}
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
*
* Locking: This function must be called under rcu_read_lock(). opp is a rcu
* protected pointer. The reason for the same is that the opp pointer which is
* returned will remain valid for use with opp_get_{voltage, freq} only while
* under the locked area. The pointer returned must be used prior to unlocking
* with rcu_read_unlock() to maintain the integrity of the pointer.
*/
struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
unsigned long *freq)
{
struct opp_table *opp_table;
struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
opp_rcu_lockdep_assert();
if (!dev || !freq) {
dev_err(dev, "%s: Invalid argument freq=%p\n", __func__, freq);
return ERR_PTR(-EINVAL);
}
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
return ERR_CAST(opp_table);
list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) {
if (temp_opp->available) {
/* go to the next node, before choosing prev */
if (temp_opp->rate > *freq)
break;
else
opp = temp_opp;
}
}
if (!IS_ERR(opp))
*freq = opp->rate;
return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);
/*
* The caller needs to ensure that opp_table (and hence the clk) isn't freed,
* while clk returned here is used.
*/
static struct clk *_get_opp_clk(struct device *dev)
{
struct opp_table *opp_table;
struct clk *clk;
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
dev_err(dev, "%s: device opp doesn't exist\n", __func__);
clk = ERR_CAST(opp_table);
goto unlock;
}
clk = opp_table->clk;
if (IS_ERR(clk))
dev_err(dev, "%s: No clock available for the device\n",
__func__);
unlock:
rcu_read_unlock();
return clk;
}
static int _set_opp_voltage(struct device *dev, struct regulator *reg,
struct dev_pm_opp_supply *supply)
{
int ret;
/* Regulator not available for device */
if (IS_ERR(reg)) {
dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
PTR_ERR(reg));
return 0;
}
dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__,
supply->u_volt_min, supply->u_volt, supply->u_volt_max);
ret = regulator_set_voltage_triplet(reg, supply->u_volt_min,
supply->u_volt, supply->u_volt_max);
if (ret)
dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
__func__, supply->u_volt_min, supply->u_volt,
supply->u_volt_max, ret);
return ret;
}
static inline int
_generic_set_opp_clk_only(struct device *dev, struct clk *clk,
unsigned long old_freq, unsigned long freq)
{
int ret;
ret = clk_set_rate(clk, freq);
if (ret) {
dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
ret);
}
return ret;
}
static int _generic_set_opp(struct dev_pm_set_opp_data *data)
{
struct dev_pm_opp_supply *old_supply = data->old_opp.supplies;
struct dev_pm_opp_supply *new_supply = data->new_opp.supplies;
unsigned long old_freq = data->old_opp.rate, freq = data->new_opp.rate;
struct regulator *reg = data->regulators[0];
struct device *dev= data->dev;
int ret;
/* This function only supports single regulator per device */
if (WARN_ON(data->regulator_count > 1)) {
dev_err(dev, "multiple regulators are not supported\n");
return -EINVAL;
}
/* Scaling up? Scale voltage before frequency */
if (freq > old_freq) {
ret = _set_opp_voltage(dev, reg, new_supply);
if (ret)
goto restore_voltage;
}
/* Change frequency */
ret = _generic_set_opp_clk_only(dev, data->clk, old_freq, freq);
if (ret)
goto restore_voltage;
/* Scaling down? Scale voltage after frequency */
if (freq < old_freq) {
ret = _set_opp_voltage(dev, reg, new_supply);
if (ret)
goto restore_freq;
}
return 0;
restore_freq:
if (_generic_set_opp_clk_only(dev, data->clk, freq, old_freq))
dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
__func__, old_freq);
restore_voltage:
/* This shouldn't harm even if the voltages weren't updated earlier */
if (old_supply->u_volt)
_set_opp_voltage(dev, reg, old_supply);
return ret;
}
/**
* dev_pm_opp_set_rate() - Configure new OPP based on frequency
* @dev: device for which we do this operation
* @target_freq: frequency to achieve
*
* This configures the power-supplies and clock source to the levels specified
* by the OPP corresponding to the target_freq.
*
* Locking: This function takes rcu_read_lock().
*/
int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
{
struct opp_table *opp_table;
unsigned long freq, old_freq;
int (*set_opp)(struct dev_pm_set_opp_data *data);
struct dev_pm_opp *old_opp, *opp;
struct regulator **regulators;
struct dev_pm_set_opp_data *data;
struct clk *clk;
int ret, size;
if (unlikely(!target_freq)) {
dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
target_freq);
return -EINVAL;
}
clk = _get_opp_clk(dev);
if (IS_ERR(clk))
return PTR_ERR(clk);
freq = clk_round_rate(clk, target_freq);
if ((long)freq <= 0)
freq = target_freq;
old_freq = clk_get_rate(clk);
/* Return early if nothing to do */
if (old_freq == freq) {
dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
__func__, freq);
return 0;
}
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
dev_err(dev, "%s: device opp doesn't exist\n", __func__);
rcu_read_unlock();
return PTR_ERR(opp_table);
}
old_opp = _find_freq_ceil(opp_table, &old_freq);
if (IS_ERR(old_opp)) {
dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
__func__, old_freq, PTR_ERR(old_opp));
}
opp = _find_freq_ceil(opp_table, &freq);
if (IS_ERR(opp)) {
ret = PTR_ERR(opp);
dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
__func__, freq, ret);
rcu_read_unlock();
return ret;
}
dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n", __func__,
old_freq, freq);
regulators = opp_table->regulators;
/* Only frequency scaling */
if (!regulators) {
rcu_read_unlock();
return _generic_set_opp_clk_only(dev, clk, old_freq, freq);
}
if (opp_table->set_opp)
set_opp = opp_table->set_opp;
else
set_opp = _generic_set_opp;
data = opp_table->set_opp_data;
data->regulators = regulators;
data->regulator_count = opp_table->regulator_count;
data->clk = clk;
data->dev = dev;
data->old_opp.rate = old_freq;
size = sizeof(*opp->supplies) * opp_table->regulator_count;
if (IS_ERR(old_opp))
memset(data->old_opp.supplies, 0, size);
else
memcpy(data->old_opp.supplies, old_opp->supplies, size);
data->new_opp.rate = freq;
memcpy(data->new_opp.supplies, opp->supplies, size);
rcu_read_unlock();
return set_opp(data);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
/* OPP-dev Helpers */
static void _kfree_opp_dev_rcu(struct rcu_head *head)
{
struct opp_device *opp_dev;
opp_dev = container_of(head, struct opp_device, rcu_head);
kfree_rcu(opp_dev, rcu_head);
}
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);
call_srcu(&opp_table->srcu_head.srcu, &opp_dev->rcu_head,
_kfree_opp_dev_rcu);
}
struct opp_device *_add_opp_dev(const struct device *dev,
struct opp_table *opp_table)
{
struct opp_device *opp_dev;
int ret;
opp_dev = kzalloc(sizeof(*opp_dev), GFP_KERNEL);
if (!opp_dev)
return NULL;
/* Initialize opp-dev */
opp_dev->dev = dev;
list_add_rcu(&opp_dev->node, &opp_table->dev_list);
/* Create debugfs entries for the opp_table */
ret = opp_debug_register(opp_dev, opp_table);
if (ret)
dev_err(dev, "%s: Failed to register opp debugfs (%d)\n",
__func__, ret);
return opp_dev;
}
/**
* _add_opp_table() - Find OPP table or allocate a new one
* @dev: device for which we do this operation
*
* It tries to find an existing table first, if it couldn't find one, it
* allocates a new OPP table and returns that.
*
* Return: valid opp_table pointer if success, else NULL.
*/
static struct opp_table *_add_opp_table(struct device *dev)
{
struct opp_table *opp_table;
struct opp_device *opp_dev;
int ret;
/* Check for existing table for 'dev' first */
opp_table = _find_opp_table(dev);
if (!IS_ERR(opp_table))
return opp_table;
/*
* Allocate a new OPP table. In the infrequent case where a new
* device is needed to be added, we pay this penalty.
*/
opp_table = kzalloc(sizeof(*opp_table), GFP_KERNEL);
if (!opp_table)
return NULL;
INIT_LIST_HEAD(&opp_table->dev_list);
opp_dev = _add_opp_dev(dev, opp_table);
if (!opp_dev) {
kfree(opp_table);
return NULL;
}
_of_init_opp_table(opp_table, dev);
/* Find clk for the device */
opp_table->clk = clk_get(dev, NULL);
if (IS_ERR(opp_table->clk)) {
ret = PTR_ERR(opp_table->clk);
if (ret != -EPROBE_DEFER)
dev_dbg(dev, "%s: Couldn't find clock: %d\n", __func__,
ret);
}
srcu_init_notifier_head(&opp_table->srcu_head);
INIT_LIST_HEAD(&opp_table->opp_list);
/* Secure the device table modification */
list_add_rcu(&opp_table->node, &opp_tables);
return opp_table;
}
/**
* _kfree_device_rcu() - Free opp_table RCU handler
* @head: RCU head
*/
static void _kfree_device_rcu(struct rcu_head *head)
{
struct opp_table *opp_table = container_of(head, struct opp_table,
rcu_head);
kfree_rcu(opp_table, rcu_head);
}
/**
* _remove_opp_table() - Removes a OPP table
* @opp_table: OPP table to be removed.
*
* Removes/frees OPP table if it doesn't contain any OPPs.
*/
static void _remove_opp_table(struct opp_table *opp_table)
{
struct opp_device *opp_dev;
if (!list_empty(&opp_table->opp_list))
return;
if (opp_table->supported_hw)
return;
if (opp_table->prop_name)
return;
if (opp_table->regulators)
return;
if (opp_table->set_opp)
return;
/* Release clk */
if (!IS_ERR(opp_table->clk))
clk_put(opp_table->clk);
opp_dev = list_first_entry(&opp_table->dev_list, struct opp_device,
node);
_remove_opp_dev(opp_dev, opp_table);
/* dev_list must be empty now */
WARN_ON(!list_empty(&opp_table->dev_list));
list_del_rcu(&opp_table->node);
call_srcu(&opp_table->srcu_head.srcu, &opp_table->rcu_head,
_kfree_device_rcu);
}
/**
* _kfree_opp_rcu() - Free OPP RCU handler
* @head: RCU head
*/
static void _kfree_opp_rcu(struct rcu_head *head)
{
struct dev_pm_opp *opp = container_of(head, struct dev_pm_opp, rcu_head);
kfree_rcu(opp, rcu_head);
}
/**
* _opp_remove() - Remove an OPP from a table definition
* @opp_table: points back to the opp_table struct this opp belongs to
* @opp: pointer to the OPP to remove
* @notify: OPP_EVENT_REMOVE notification should be sent or not
*
* This function removes an opp definition from the opp table.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* It is assumed that the caller holds required mutex for an RCU updater
* strategy.
*/
void _opp_remove(struct opp_table *opp_table, struct dev_pm_opp *opp,
bool notify)
{
/*
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
if (notify)
srcu_notifier_call_chain(&opp_table->srcu_head,
OPP_EVENT_REMOVE, opp);
opp_debug_remove_one(opp);
list_del_rcu(&opp->node);
call_srcu(&opp_table->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
_remove_opp_table(opp_table);
}
/**
* 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.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
void dev_pm_opp_remove(struct device *dev, unsigned long freq)
{
struct dev_pm_opp *opp;
struct opp_table *opp_table;
bool found = false;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
goto unlock;
list_for_each_entry(opp, &opp_table->opp_list, node) {
if (opp->rate == freq) {
found = true;
break;
}
}
if (!found) {
dev_warn(dev, "%s: Couldn't find OPP with freq: %lu\n",
__func__, freq);
goto unlock;
}
_opp_remove(opp_table, opp, true);
unlock:
mutex_unlock(&opp_table_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
struct dev_pm_opp *_allocate_opp(struct device *dev,
struct opp_table **opp_table)
{
struct dev_pm_opp *opp;
int count, supply_size;
struct opp_table *table;
table = _add_opp_table(dev);
if (!table)
return NULL;
/* Allocate space for at least one supply */
count = table->regulator_count ? table->regulator_count : 1;
supply_size = sizeof(*opp->supplies) * count;
/* allocate new OPP node and supplies structures */
opp = kzalloc(sizeof(*opp) + supply_size, GFP_KERNEL);
if (!opp) {
kfree(table);
return NULL;
}
/* Put the supplies at the end of the OPP structure as an empty array */
opp->supplies = (struct dev_pm_opp_supply *)(opp + 1);
INIT_LIST_HEAD(&opp->node);
*opp_table = table;
return opp;
}
static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
struct opp_table *opp_table)
{
struct regulator *reg;
int i;
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;
}
int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
struct opp_table *opp_table)
{
struct dev_pm_opp *opp;
struct list_head *head = &opp_table->opp_list;
int ret;
/*
* 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_rcu(opp, &opp_table->opp_list, node) {
if (new_opp->rate > opp->rate) {
head = &opp->node;
continue;
}
if (new_opp->rate < opp->rate)
break;
/* Duplicate OPPs */
dev_warn(dev, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
__func__, opp->rate, opp->supplies[0].u_volt,
opp->available, new_opp->rate,
new_opp->supplies[0].u_volt, new_opp->available);
/* Should we compare voltages for all regulators here ? */
return opp->available &&
new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST;
}
new_opp->opp_table = opp_table;
list_add_rcu(&new_opp->node, head);
ret = opp_debug_create_one(new_opp, opp_table);
if (ret)
dev_err(dev, "%s: Failed to register opp to debugfs (%d)\n",
__func__, ret);
if (!_opp_supported_by_regulators(new_opp, opp_table)) {
new_opp->available = false;
dev_warn(dev, "%s: OPP not supported by regulators (%lu)\n",
__func__, new_opp->rate);
}
return 0;
}
/**
* _opp_add_v1() - Allocate a OPP based on v1 bindings.
* @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.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*
* 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 device *dev, unsigned long freq, long u_volt,
bool dynamic)
{
struct opp_table *opp_table;
struct dev_pm_opp *new_opp;
unsigned long tol;
int ret;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
new_opp = _allocate_opp(dev, &opp_table);
if (!new_opp) {
ret = -ENOMEM;
goto unlock;
}
/* populate the opp table */
new_opp->rate = freq;
tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
new_opp->supplies[0].u_volt = u_volt;
new_opp->supplies[0].u_volt_min = u_volt - tol;
new_opp->supplies[0].u_volt_max = u_volt + tol;
new_opp->available = true;
new_opp->dynamic = dynamic;
ret = _opp_add(dev, new_opp, opp_table);
if (ret)
goto free_opp;
mutex_unlock(&opp_table_lock);
/*
* Notify the changes in the availability of the operable
* frequency/voltage list.
*/
srcu_notifier_call_chain(&opp_table->srcu_head, OPP_EVENT_ADD, new_opp);
return 0;
free_opp:
_opp_remove(opp_table, new_opp, false);
unlock:
mutex_unlock(&opp_table_lock);
return ret;
}
/**
* dev_pm_opp_set_supported_hw() - Set supported platforms
* @dev: Device for which supported-hw has to be set.
* @versions: Array of hierarchy of versions to match.
* @count: Number of elements in the array.
*
* This is required only for the V2 bindings, and it enables a platform to
* specify the hierarchy of versions it supports. OPP layer will then enable
* OPPs, which are available for those versions, based on its 'opp-supported-hw'
* property.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
unsigned int count)
{
struct opp_table *opp_table;
int ret = 0;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
opp_table = _add_opp_table(dev);
if (!opp_table) {
ret = -ENOMEM;
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
/* Do we already have a version hierarchy associated with opp_table? */
if (opp_table->supported_hw) {
dev_err(dev, "%s: Already have supported hardware list\n",
__func__);
ret = -EBUSY;
goto err;
}
opp_table->supported_hw = kmemdup(versions, count * sizeof(*versions),
GFP_KERNEL);
if (!opp_table->supported_hw) {
ret = -ENOMEM;
goto err;
}
opp_table->supported_hw_count = count;
mutex_unlock(&opp_table_lock);
return 0;
err:
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
/**
* dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
* @dev: Device for which supported-hw has to be put.
*
* This is required only for the V2 bindings, and is called for a matching
* dev_pm_opp_set_supported_hw(). Until this is called, the opp_table structure
* will not be freed.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
void dev_pm_opp_put_supported_hw(struct device *dev)
{
struct opp_table *opp_table;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
/* Check for existing table for 'dev' first */
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
dev_err(dev, "Failed to find opp_table: %ld\n",
PTR_ERR(opp_table));
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
if (!opp_table->supported_hw) {
dev_err(dev, "%s: Doesn't have supported hardware list\n",
__func__);
goto unlock;
}
kfree(opp_table->supported_hw);
opp_table->supported_hw = NULL;
opp_table->supported_hw_count = 0;
/* Try freeing opp_table if this was the last blocking resource */
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
/**
* dev_pm_opp_set_prop_name() - Set prop-extn name
* @dev: Device for which the prop-name has to be set.
* @name: name to postfix to properties.
*
* This is required only for the V2 bindings, and it enables a platform to
* specify the extn to be used for certain property names. The properties to
* which the extension will apply are opp-microvolt and opp-microamp. OPP core
* should postfix the property name with -<name> while looking for them.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
{
struct opp_table *opp_table;
int ret = 0;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
opp_table = _add_opp_table(dev);
if (!opp_table) {
ret = -ENOMEM;
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
/* Do we already have a prop-name associated with opp_table? */
if (opp_table->prop_name) {
dev_err(dev, "%s: Already have prop-name %s\n", __func__,
opp_table->prop_name);
ret = -EBUSY;
goto err;
}
opp_table->prop_name = kstrdup(name, GFP_KERNEL);
if (!opp_table->prop_name) {
ret = -ENOMEM;
goto err;
}
mutex_unlock(&opp_table_lock);
return 0;
err:
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
/**
* dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
* @dev: Device for which the prop-name has to be put.
*
* This is required only for the V2 bindings, and is called for a matching
* dev_pm_opp_set_prop_name(). Until this is called, the opp_table structure
* will not be freed.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
void dev_pm_opp_put_prop_name(struct device *dev)
{
struct opp_table *opp_table;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
/* Check for existing table for 'dev' first */
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
dev_err(dev, "Failed to find opp_table: %ld\n",
PTR_ERR(opp_table));
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
if (!opp_table->prop_name) {
dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);
goto unlock;
}
kfree(opp_table->prop_name);
opp_table->prop_name = NULL;
/* Try freeing opp_table if this was the last blocking resource */
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
static int _allocate_set_opp_data(struct opp_table *opp_table)
{
struct dev_pm_set_opp_data *data;
int len, count = opp_table->regulator_count;
if (WARN_ON(!count))
return -EINVAL;
/* space for set_opp_data */
len = sizeof(*data);
/* space for old_opp.supplies and new_opp.supplies */
len += 2 * sizeof(struct dev_pm_opp_supply) * count;
data = kzalloc(len, GFP_KERNEL);
if (!data)
return -ENOMEM;
data->old_opp.supplies = (void *)(data + 1);
data->new_opp.supplies = data->old_opp.supplies + count;
opp_table->set_opp_data = data;
return 0;
}
static void _free_set_opp_data(struct opp_table *opp_table)
{
kfree(opp_table->set_opp_data);
opp_table->set_opp_data = NULL;
}
/**
* dev_pm_opp_set_regulators() - Set regulator names for the device
* @dev: Device for which regulator name is being set.
* @names: Array of pointers to the names of the regulator.
* @count: Number of regulators.
*
* In order to support OPP switching, OPP layer needs to know the name of the
* device's regulators, as the core would be required to switch voltages as
* well.
*
* This must be called before any OPPs are initialized for the device.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
const char * const names[],
unsigned int count)
{
struct opp_table *opp_table;
struct regulator *reg;
int ret, i;
mutex_lock(&opp_table_lock);
opp_table = _add_opp_table(dev);
if (!opp_table) {
ret = -ENOMEM;
goto unlock;
}
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
ret = -EBUSY;
goto err;
}
/* Already have regulators set */
if (opp_table->regulators) {
ret = -EBUSY;
goto err;
}
opp_table->regulators = kmalloc_array(count,
sizeof(*opp_table->regulators),
GFP_KERNEL);
if (!opp_table->regulators) {
ret = -ENOMEM;
goto err;
}
for (i = 0; i < count; i++) {
reg = regulator_get_optional(dev, names[i]);
if (IS_ERR(reg)) {
ret = PTR_ERR(reg);
if (ret != -EPROBE_DEFER)
dev_err(dev, "%s: no regulator (%s) found: %d\n",
__func__, names[i], ret);
goto free_regulators;
}
opp_table->regulators[i] = reg;
}
opp_table->regulator_count = count;
/* Allocate block only once to pass to set_opp() routines */
ret = _allocate_set_opp_data(opp_table);
if (ret)
goto free_regulators;
mutex_unlock(&opp_table_lock);
return opp_table;
free_regulators:
while (i != 0)
regulator_put(opp_table->regulators[--i]);
kfree(opp_table->regulators);
opp_table->regulators = NULL;
opp_table->regulator_count = 0;
err:
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulators);
/**
* dev_pm_opp_put_regulators() - Releases resources blocked for regulator
* @opp_table: OPP table returned from dev_pm_opp_set_regulators().
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
void dev_pm_opp_put_regulators(struct opp_table *opp_table)
{
int i;
mutex_lock(&opp_table_lock);
if (!opp_table->regulators) {
pr_err("%s: Doesn't have regulators set\n", __func__);
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
for (i = opp_table->regulator_count - 1; i >= 0; i--)
regulator_put(opp_table->regulators[i]);
_free_set_opp_data(opp_table);
kfree(opp_table->regulators);
opp_table->regulators = NULL;
opp_table->regulator_count = 0;
/* Try freeing opp_table if this was the last blocking resource */
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators);
/**
* dev_pm_opp_register_set_opp_helper() - Register custom set OPP helper
* @dev: Device for which the helper is getting registered.
* @set_opp: Custom set OPP helper.
*
* This is useful to support complex platforms (like platforms with multiple
* regulators per device), instead of the generic OPP set rate helper.
*
* This must be called before any OPPs are initialized for the device.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
int dev_pm_opp_register_set_opp_helper(struct device *dev,
int (*set_opp)(struct dev_pm_set_opp_data *data))
{
struct opp_table *opp_table;
int ret;
if (!set_opp)
return -EINVAL;
mutex_lock(&opp_table_lock);
opp_table = _add_opp_table(dev);
if (!opp_table) {
ret = -ENOMEM;
goto unlock;
}
/* This should be called before OPPs are initialized */
if (WARN_ON(!list_empty(&opp_table->opp_list))) {
ret = -EBUSY;
goto err;
}
/* Already have custom set_opp helper */
if (WARN_ON(opp_table->set_opp)) {
ret = -EBUSY;
goto err;
}
opp_table->set_opp = set_opp;
mutex_unlock(&opp_table_lock);
return 0;
err:
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_register_set_opp_helper);
/**
* dev_pm_opp_register_put_opp_helper() - Releases resources blocked for
* set_opp helper
* @dev: Device for which custom set_opp helper has to be cleared.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
void dev_pm_opp_register_put_opp_helper(struct device *dev)
{
struct opp_table *opp_table;
mutex_lock(&opp_table_lock);
/* Check for existing table for 'dev' first */
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
dev_err(dev, "Failed to find opp_table: %ld\n",
PTR_ERR(opp_table));
goto unlock;
}
if (!opp_table->set_opp) {
dev_err(dev, "%s: Doesn't have custom set_opp helper set\n",
__func__);
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
opp_table->set_opp = NULL;
/* Try freeing opp_table if this was the last blocking resource */
_remove_opp_table(opp_table);
unlock:
mutex_unlock(&opp_table_lock);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_register_put_opp_helper);
/**
* dev_pm_opp_add() - Add an OPP table from a table definitions
* @dev: device for which we do this operation
* @freq: Frequency in Hz for this OPP
* @u_volt: Voltage in uVolts for this OPP
*
* This function adds an opp definition to the opp table and returns status.
* The opp is made available by default and it can be controlled using
* dev_pm_opp_enable/disable functions.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*
* 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)
{
return _opp_add_v1(dev, freq, u_volt, true);
}
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 with an RCU operation, 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.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function internally uses RCU updater strategy with mutex locks to
* keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex locking or synchronize_rcu() blocking calls cannot be used.
*/
static int _opp_set_availability(struct device *dev, unsigned long freq,
bool availability_req)
{
struct opp_table *opp_table;
struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV);
int r = 0;
/* keep the node allocated */
new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL);
if (!new_opp)
return -ENOMEM;
mutex_lock(&opp_table_lock);
/* 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);
goto unlock;
}
/* Do we have the frequency? */
list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
if (tmp_opp->rate == freq) {
opp = tmp_opp;
break;
}
}
if (IS_ERR(opp)) {
r = PTR_ERR(opp);
goto unlock;
}
/* Is update really needed? */
if (opp->available == availability_req)
goto unlock;
/* copy the old data over */
*new_opp = *opp;
/* plug in new node */
new_opp->available = availability_req;
list_replace_rcu(&opp->node, &new_opp->node);
mutex_unlock(&opp_table_lock);
call_srcu(&opp_table->srcu_head.srcu, &opp->rcu_head, _kfree_opp_rcu);
/* Notify the change of the OPP availability */
if (availability_req)
srcu_notifier_call_chain(&opp_table->srcu_head,
OPP_EVENT_ENABLE, new_opp);
else
srcu_notifier_call_chain(&opp_table->srcu_head,
OPP_EVENT_DISABLE, new_opp);
return 0;
unlock:
mutex_unlock(&opp_table_lock);
kfree(new_opp);
return r;
}
/**
* dev_pm_opp_enable() - Enable a specific OPP
* @dev: device for which we do this operation
* @freq: OPP frequency to enable
*
* Enables a provided opp. If the operation is valid, this returns 0, else the
* corresponding error value. It is meant to be used for users an OPP available
* after being temporarily made unavailable with dev_pm_opp_disable.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function indirectly uses RCU and mutex locks to keep the
* integrity of the internal data structures. Callers should ensure that
* this function is *NOT* called under RCU protection or in contexts where
* mutex locking or synchronize_rcu() blocking calls cannot be used.
*
* 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).
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function indirectly uses RCU and mutex locks to keep the
* integrity of the internal data structures. Callers should ensure that
* this function is *NOT* called under RCU protection or in contexts where
* mutex locking or synchronize_rcu() blocking calls cannot be used.
*
* 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_get_notifier() - find notifier_head of the device with opp
* @dev: device pointer used to lookup OPP table.
*
* Return: pointer to notifier head if found, otherwise -ENODEV or
* -EINVAL based on type of error casted as pointer. value must be checked
* with IS_ERR to determine valid pointer or error result.
*
* Locking: This function must be called under rcu_read_lock(). opp_table is a
* RCU protected pointer. The reason for the same is that the opp pointer which
* is returned will remain valid for use with opp_get_{voltage, freq} only while
* under the locked area. The pointer returned must be used prior to unlocking
* with rcu_read_unlock() to maintain the integrity of the pointer.
*/
struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev)
{
struct opp_table *opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table))
return ERR_CAST(opp_table); /* matching type */
return &opp_table->srcu_head;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier);
/*
* Free OPPs either created using static entries present in DT or even the
* dynamically added entries based on remove_all param.
*/
void _dev_pm_opp_remove_table(struct device *dev, bool remove_all)
{
struct opp_table *opp_table;
struct dev_pm_opp *opp, *tmp;
/* Hold our table modification lock here */
mutex_lock(&opp_table_lock);
/* 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);
goto unlock;
}
/* Find if opp_table manages a single device */
if (list_is_singular(&opp_table->dev_list)) {
/* Free static OPPs */
list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
if (remove_all || !opp->dynamic)
_opp_remove(opp_table, opp, true);
}
} else {
_remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
}
unlock:
mutex_unlock(&opp_table_lock);
}
/**
* 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.
*
* Locking: The internal opp_table and opp structures are RCU protected.
* Hence this function indirectly uses RCU updater strategy with mutex locks
* to keep the integrity of the internal data structures. Callers should ensure
* that this function is *NOT* called under RCU protection or in contexts where
* mutex cannot be locked.
*/
void dev_pm_opp_remove_table(struct device *dev)
{
_dev_pm_opp_remove_table(dev, true);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table);