blob: 433b60092972d56abba55897158d6c22156cf631 [file] [log] [blame]
/*
* 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/of.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.
*/
static 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;
}
static struct opp_table *_managed_opp(const struct device_node *np)
{
struct opp_table *opp_table;
list_for_each_entry_rcu(opp_table, &opp_tables, node) {
if (opp_table->np == np) {
/*
* Multiple devices can point to the same OPP table and
* so will have same node-pointer, np.
*
* But the OPPs will be considered as shared only if the
* OPP table contains a "opp-shared" property.
*/
return opp_table->shared_opp ? opp_table : NULL;
}
}
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
*
* 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->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);
/**
* 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;
unsigned long latency_ns = 0;
unsigned long min_uV = ~0, max_uV = 0;
int ret;
rcu_read_lock();
opp_table = _find_opp_table(dev);
if (IS_ERR(opp_table)) {
rcu_read_unlock();
return 0;
}
reg = opp_table->regulator;
if (IS_ERR(reg)) {
/* Regulator may not be required for device */
if (reg)
dev_err(dev, "%s: Invalid regulator (%ld)\n", __func__,
PTR_ERR(reg));
rcu_read_unlock();
return 0;
}
list_for_each_entry_rcu(opp, &opp_table->opp_list, node) {
if (!opp->available)
continue;
if (opp->u_volt_min < min_uV)
min_uV = opp->u_volt_min;
if (opp->u_volt_max > max_uV)
max_uV = opp->u_volt_max;
}
rcu_read_unlock();
/*
* The caller needs to ensure that opp_table (and hence the regulator)
* isn't freed, while we are executing this routine.
*/
ret = regulator_set_voltage_time(reg, min_uV, max_uV);
if (ret > 0)
latency_ns = ret * 1000;
return latency_ns;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
/**
* dev_pm_opp_get_max_transition_latency() - Get max transition latency in
* nanoseconds
* @dev: device for which we do this operation
*
* Return: This function returns the max transition latency, in nanoseconds, to
* switch from one OPP to other.
*
* Locking: This function takes rcu_read_lock().
*/
unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
{
return dev_pm_opp_get_max_volt_latency(dev) +
dev_pm_opp_get_max_clock_latency(dev);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
/**
* dev_pm_opp_get_suspend_opp() - Get suspend opp
* @dev: device for which we do this operation
*
* 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);
/**
* 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;
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 && temp_opp->rate >= *freq) {
opp = temp_opp;
*freq = opp->rate;
break;
}
}
return opp;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil);
/**
* dev_pm_opp_find_freq_floor() - Search for a rounded floor freq
* @dev: device for which we do this operation
* @freq: Start frequency
*
* Search for the matching floor *available* OPP from a starting freq
* for a device.
*
* Return: matching *opp and refreshes *freq accordingly, else returns
* ERR_PTR in case of error and should be handled using IS_ERR. Error return
* values can be:
* EINVAL: for bad pointer
* ERANGE: no match found for search
* ENODEV: if device not found in list of registered devices
*
* 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,
unsigned long u_volt, unsigned long u_volt_min,
unsigned long u_volt_max)
{
int ret;
/* Regulator not available for device */
if (IS_ERR(reg)) {
dev_dbg(dev, "%s: regulator not available: %ld\n", __func__,
PTR_ERR(reg));
return 0;
}
dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__, u_volt_min,
u_volt, u_volt_max);
ret = regulator_set_voltage_triplet(reg, u_volt_min, u_volt,
u_volt_max);
if (ret)
dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
__func__, u_volt_min, u_volt, u_volt_max, ret);
return ret;
}
/**
* dev_pm_opp_set_rate() - Configure new OPP based on frequency
* @dev: device for which we do this operation
* @target_freq: frequency to achieve
*
* This configures the power-supplies and clock source to the levels specified
* by the OPP corresponding to the target_freq.
*
* Locking: This function takes rcu_read_lock().
*/
int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
{
struct opp_table *opp_table;
struct dev_pm_opp *old_opp, *opp;
struct regulator *reg;
struct clk *clk;
unsigned long freq, old_freq;
unsigned long u_volt, u_volt_min, u_volt_max;
unsigned long ou_volt, ou_volt_min, ou_volt_max;
int ret;
if (unlikely(!target_freq)) {
dev_err(dev, "%s: Invalid target frequency %lu\n", __func__,
target_freq);
return -EINVAL;
}
clk = _get_opp_clk(dev);
if (IS_ERR(clk))
return PTR_ERR(clk);
freq = clk_round_rate(clk, target_freq);
if ((long)freq <= 0)
freq = target_freq;
old_freq = clk_get_rate(clk);
/* Return early if nothing to do */
if (old_freq == freq) {
dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
__func__, freq);
return 0;
}
rcu_read_lock();
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 = dev_pm_opp_find_freq_ceil(dev, &old_freq);
if (!IS_ERR(old_opp)) {
ou_volt = old_opp->u_volt;
ou_volt_min = old_opp->u_volt_min;
ou_volt_max = old_opp->u_volt_max;
} else {
dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n",
__func__, old_freq, PTR_ERR(old_opp));
}
opp = dev_pm_opp_find_freq_ceil(dev, &freq);
if (IS_ERR(opp)) {
ret = PTR_ERR(opp);
dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",
__func__, freq, ret);
rcu_read_unlock();
return ret;
}
u_volt = opp->u_volt;
u_volt_min = opp->u_volt_min;
u_volt_max = opp->u_volt_max;
reg = opp_table->regulator;
rcu_read_unlock();
/* Scaling up? Scale voltage before frequency */
if (freq > old_freq) {
ret = _set_opp_voltage(dev, reg, u_volt, u_volt_min,
u_volt_max);
if (ret)
goto restore_voltage;
}
/* Change frequency */
dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
__func__, old_freq, freq);
ret = clk_set_rate(clk, freq);
if (ret) {
dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
ret);
goto restore_voltage;
}
/* Scaling down? Scale voltage after frequency */
if (freq < old_freq) {
ret = _set_opp_voltage(dev, reg, u_volt, u_volt_min,
u_volt_max);
if (ret)
goto restore_freq;
}
return 0;
restore_freq:
if (clk_set_rate(clk, old_freq))
dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
__func__, old_freq);
restore_voltage:
/* This shouldn't harm even if the voltages weren't updated earlier */
if (!IS_ERR(old_opp))
_set_opp_voltage(dev, reg, ou_volt, ou_volt_min, ou_volt_max);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate);
/* 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;
struct device_node *np;
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;
}
/*
* Only required for backward compatibility with v1 bindings, but isn't
* harmful for other cases. And so we do it unconditionally.
*/
np = of_node_get(dev->of_node);
if (np) {
u32 val;
if (!of_property_read_u32(np, "clock-latency", &val))
opp_table->clock_latency_ns_max = val;
of_property_read_u32(np, "voltage-tolerance",
&opp_table->voltage_tolerance_v1);
of_node_put(np);
}
/* Set regulator to a non-NULL error value */
opp_table->regulator = ERR_PTR(-ENXIO);
/* 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 (!IS_ERR(opp_table->regulator))
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.
*/
static 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);
static struct dev_pm_opp *_allocate_opp(struct device *dev,
struct opp_table **opp_table)
{
struct dev_pm_opp *opp;
/* allocate new OPP node */
opp = kzalloc(sizeof(*opp), GFP_KERNEL);
if (!opp)
return NULL;
INIT_LIST_HEAD(&opp->node);
*opp_table = _add_opp_table(dev);
if (!*opp_table) {
kfree(opp);
return NULL;
}
return opp;
}
static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
struct opp_table *opp_table)
{
struct regulator *reg = opp_table->regulator;
if (!IS_ERR(reg) &&
!regulator_is_supported_voltage(reg, opp->u_volt_min,
opp->u_volt_max)) {
pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
__func__, opp->u_volt_min, opp->u_volt_max);
return false;
}
return true;
}
static int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
struct 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->u_volt, opp->available,
new_opp->rate, new_opp->u_volt, new_opp->available);
return opp->available && new_opp->u_volt == opp->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
*/
static 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->u_volt = u_volt;
new_opp->u_volt_min = u_volt - tol;
new_opp->u_volt_max = u_volt + tol;
new_opp->available = true;
new_opp->dynamic = dynamic;
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;
}
/* TODO: Support multiple regulators */
static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
struct opp_table *opp_table)
{
u32 microvolt[3] = {0};
u32 val;
int count, ret;
struct property *prop = NULL;
char name[NAME_MAX];
/* Search for "opp-microvolt-<name>" */
if (opp_table->prop_name) {
snprintf(name, sizeof(name), "opp-microvolt-%s",
opp_table->prop_name);
prop = of_find_property(opp->np, name, NULL);
}
if (!prop) {
/* Search for "opp-microvolt" */
sprintf(name, "opp-microvolt");
prop = of_find_property(opp->np, name, NULL);
/* Missing property isn't a problem, but an invalid entry is */
if (!prop)
return 0;
}
count = of_property_count_u32_elems(opp->np, name);
if (count < 0) {
dev_err(dev, "%s: Invalid %s property (%d)\n",
__func__, name, count);
return count;
}
/* There can be one or three elements here */
if (count != 1 && count != 3) {
dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n",
__func__, name, count);
return -EINVAL;
}
ret = of_property_read_u32_array(opp->np, name, microvolt, count);
if (ret) {
dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
return -EINVAL;
}
opp->u_volt = microvolt[0];
if (count == 1) {
opp->u_volt_min = opp->u_volt;
opp->u_volt_max = opp->u_volt;
} else {
opp->u_volt_min = microvolt[1];
opp->u_volt_max = microvolt[2];
}
/* Search for "opp-microamp-<name>" */
prop = NULL;
if (opp_table->prop_name) {
snprintf(name, sizeof(name), "opp-microamp-%s",
opp_table->prop_name);
prop = of_find_property(opp->np, name, NULL);
}
if (!prop) {
/* Search for "opp-microamp" */
sprintf(name, "opp-microamp");
prop = of_find_property(opp->np, name, NULL);
}
if (prop && !of_property_read_u32(opp->np, name, &val))
opp->u_amp = val;
return 0;
}
/**
* dev_pm_opp_set_supported_hw() - Set supported platforms
* @dev: Device for which supported-hw has to be set.
* @versions: Array of hierarchy of versions to match.
* @count: Number of elements in the array.
*
* This is required only for the V2 bindings, and it enables a platform to
* specify the hierarchy of versions it supports. OPP layer will then enable
* OPPs, which are available for those versions, based on its 'opp-supported-hw'
* property.
*
* Locking: The internal 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);
/**
* dev_pm_opp_set_regulator() - Set regulator name for the device
* @dev: Device for which regulator name is being set.
* @name: Name of the regulator.
*
* In order to support OPP switching, OPP layer needs to know the name of the
* device's regulator, as the core would be required to switch voltages as well.
*
* This must be called before any OPPs are initialized for the device.
*
* Locking: The internal 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_regulator(struct device *dev, const char *name)
{
struct opp_table *opp_table;
struct regulator *reg;
int ret;
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 a regulator set */
if (WARN_ON(!IS_ERR(opp_table->regulator))) {
ret = -EBUSY;
goto err;
}
/* Allocate the regulator */
reg = regulator_get_optional(dev, name);
if (IS_ERR(reg)) {
ret = PTR_ERR(reg);
if (ret != -EPROBE_DEFER)
dev_err(dev, "%s: no regulator (%s) found: %d\n",
__func__, name, ret);
goto err;
}
opp_table->regulator = reg;
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_regulator);
/**
* dev_pm_opp_put_regulator() - Releases resources blocked for regulator
* @dev: Device for which regulator was set.
*
* 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_regulator(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 (IS_ERR(opp_table->regulator)) {
dev_err(dev, "%s: Doesn't have regulator set\n", __func__);
goto unlock;
}
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
regulator_put(opp_table->regulator);
opp_table->regulator = ERR_PTR(-ENXIO);
/* 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_regulator);
static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table,
struct device_node *np)
{
unsigned int count = opp_table->supported_hw_count;
u32 version;
int ret;
if (!opp_table->supported_hw)
return true;
while (count--) {
ret = of_property_read_u32_index(np, "opp-supported-hw", count,
&version);
if (ret) {
dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
__func__, count, ret);
return false;
}
/* Both of these are bitwise masks of the versions */
if (!(version & opp_table->supported_hw[count]))
return false;
}
return true;
}
/**
* _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
* @dev: device for which we do this operation
* @np: device node
*
* This function adds an opp definition to the opp table and returns status. The
* opp can be controlled using dev_pm_opp_enable/disable functions and may be
* removed by dev_pm_opp_remove.
*
* 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
* -EINVAL Failed parsing the OPP node
*/
static int _opp_add_static_v2(struct device *dev, struct device_node *np)
{
struct opp_table *opp_table;
struct dev_pm_opp *new_opp;
u64 rate;
u32 val;
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;
}
ret = of_property_read_u64(np, "opp-hz", &rate);
if (ret < 0) {
dev_err(dev, "%s: opp-hz not found\n", __func__);
goto free_opp;
}
/* Check if the OPP supports hardware's hierarchy of versions or not */
if (!_opp_is_supported(dev, opp_table, np)) {
dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
goto free_opp;
}
/*
* Rate is defined as an unsigned long in clk API, and so casting
* explicitly to its type. Must be fixed once rate is 64 bit
* guaranteed in clk API.
*/
new_opp->rate = (unsigned long)rate;
new_opp->turbo = of_property_read_bool(np, "turbo-mode");
new_opp->np = np;
new_opp->dynamic = false;
new_opp->available = true;
if (!of_property_read_u32(np, "clock-latency-ns", &val))
new_opp->clock_latency_ns = val;
ret = opp_parse_supplies(new_opp, dev, opp_table);
if (ret)
goto free_opp;
ret = _opp_add(dev, new_opp, opp_table);
if (ret)
goto free_opp;
/* OPP to select on device suspend */
if (of_property_read_bool(np, "opp-suspend")) {
if (opp_table->suspend_opp) {
dev_warn(dev, "%s: Multiple suspend OPPs found (%lu %lu)\n",
__func__, opp_table->suspend_opp->rate,
new_opp->rate);
} else {
new_opp->suspend = true;
opp_table->suspend_opp = new_opp;
}
}
if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;
mutex_unlock(&opp_table_lock);
pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n",
__func__, new_opp->turbo, new_opp->rate, new_opp->u_volt,
new_opp->u_volt_min, new_opp->u_volt_max,
new_opp->clock_latency_ns);
/*
* 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_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);
#ifdef CONFIG_OF
/**
* dev_pm_opp_of_remove_table() - Free OPP table entries created from static DT
* entries
* @dev: device pointer used to lookup OPP table.
*
* Free OPPs created using static entries present in DT.
*
* 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_of_remove_table(struct device *dev)
{
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 (!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);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_remove_table);
/* Returns opp descriptor node for a device, caller must do of_node_put() */
struct device_node *_of_get_opp_desc_node(struct device *dev)
{
/*
* TODO: Support for multiple OPP tables.
*
* There should be only ONE phandle present in "operating-points-v2"
* property.
*/
return of_parse_phandle(dev->of_node, "operating-points-v2", 0);
}
/* Initializes OPP tables based on new bindings */
static int _of_add_opp_table_v2(struct device *dev, struct device_node *opp_np)
{
struct device_node *np;
struct opp_table *opp_table;
int ret = 0, count = 0;
mutex_lock(&opp_table_lock);
opp_table = _managed_opp(opp_np);
if (opp_table) {
/* OPPs are already managed */
if (!_add_opp_dev(dev, opp_table))
ret = -ENOMEM;
mutex_unlock(&opp_table_lock);
return ret;
}
mutex_unlock(&opp_table_lock);
/* We have opp-table node now, iterate over it and add OPPs */
for_each_available_child_of_node(opp_np, np) {
count++;
ret = _opp_add_static_v2(dev, np);
if (ret) {
dev_err(dev, "%s: Failed to add OPP, %d\n", __func__,
ret);
goto free_table;
}
}
/* There should be one of more OPP defined */
if (WARN_ON(!count))
return -ENOENT;
mutex_lock(&opp_table_lock);
opp_table = _find_opp_table(dev);
if (WARN_ON(IS_ERR(opp_table))) {
ret = PTR_ERR(opp_table);
mutex_unlock(&opp_table_lock);
goto free_table;
}
opp_table->np = opp_np;
opp_table->shared_opp = of_property_read_bool(opp_np, "opp-shared");
mutex_unlock(&opp_table_lock);
return 0;
free_table:
dev_pm_opp_of_remove_table(dev);
return ret;
}
/* Initializes OPP tables based on old-deprecated bindings */
static int _of_add_opp_table_v1(struct device *dev)
{
const struct property *prop;
const __be32 *val;
int nr;
prop = of_find_property(dev->of_node, "operating-points", NULL);
if (!prop)
return -ENODEV;
if (!prop->value)
return -ENODATA;
/*
* Each OPP is a set of tuples consisting of frequency and
* voltage like <freq-kHz vol-uV>.
*/
nr = prop->length / sizeof(u32);
if (nr % 2) {
dev_err(dev, "%s: Invalid OPP table\n", __func__);
return -EINVAL;
}
val = prop->value;
while (nr) {
unsigned long freq = be32_to_cpup(val++) * 1000;
unsigned long volt = be32_to_cpup(val++);
if (_opp_add_v1(dev, freq, volt, false))
dev_warn(dev, "%s: Failed to add OPP %ld\n",
__func__, freq);
nr -= 2;
}
return 0;
}
/**
* dev_pm_opp_of_add_table() - Initialize opp table from device tree
* @dev: device pointer used to lookup OPP table.
*
* Register the initial OPP table with the OPP library for given device.
*
* 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.
*
* 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
* -ENODEV when 'operating-points' property is not found or is invalid data
* in device node.
* -ENODATA when empty 'operating-points' property is found
* -EINVAL when invalid entries are found in opp-v2 table
*/
int dev_pm_opp_of_add_table(struct device *dev)
{
struct device_node *opp_np;
int ret;
/*
* OPPs have two version of bindings now. The older one is deprecated,
* try for the new binding first.
*/
opp_np = _of_get_opp_desc_node(dev);
if (!opp_np) {
/*
* Try old-deprecated bindings for backward compatibility with
* older dtbs.
*/
return _of_add_opp_table_v1(dev);
}
ret = _of_add_opp_table_v2(dev, opp_np);
of_node_put(opp_np);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_add_table);
#endif