/*
* Generic OPP helper interface for CPU device
*
* Copyright (C) 2009-2014 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/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/slab.h>
#include "opp.h"
#ifdef CONFIG_CPU_FREQ
/**
* dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device
* @dev: device for which we do this operation
* @table: Cpufreq table returned back to caller
*
* Generate a cpufreq table for a provided device- this assumes that the
* opp table is already initialized and ready for usage.
*
* This function allocates required memory for the cpufreq table. It is
* expected that the caller does the required maintenance such as freeing
* the table as required.
*
* Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM
* if no memory available for the operation (table is not populated), returns 0
* if successful and table is populated.
*
* WARNING: It is important for the callers to ensure refreshing their copy of
* the table if any of the mentioned functions have been invoked in the interim.
*/
int dev_pm_opp_init_cpufreq_table(struct device *dev,
struct cpufreq_frequency_table **table)
{
struct dev_pm_opp *opp;
struct cpufreq_frequency_table *freq_table = NULL;
int i, max_opps, ret = 0;
unsigned long rate;
max_opps = dev_pm_opp_get_opp_count(dev);
if (max_opps <= 0)
return max_opps ? max_opps : -ENODATA;
freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_KERNEL);
if (!freq_table)
return -ENOMEM;
for (i = 0, rate = 0; i < max_opps; i++, rate++) {
/* find next rate */
opp = dev_pm_opp_find_freq_ceil(dev, &rate);
if (IS_ERR(opp)) {
ret = PTR_ERR(opp);
goto out;
}
freq_table[i].driver_data = i;
freq_table[i].frequency = rate / 1000;
/* Is Boost/turbo opp ? */
if (dev_pm_opp_is_turbo(opp))
freq_table[i].flags = CPUFREQ_BOOST_FREQ;
dev_pm_opp_put(opp);
}
freq_table[i].driver_data = i;
freq_table[i].frequency = CPUFREQ_TABLE_END;
*table = &freq_table[0];
out:
if (ret)
kfree(freq_table);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table);
/**
* dev_pm_opp_free_cpufreq_table() - free the cpufreq table
* @dev: device for which we do this operation
* @table: table to free
*
* Free up the table allocated by dev_pm_opp_init_cpufreq_table
*/
void dev_pm_opp_free_cpufreq_table(struct device *dev,
struct cpufreq_frequency_table **table)
{
if (!table)
return;
kfree(*table);
*table = NULL;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table);
#endif /* CONFIG_CPU_FREQ */
void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask,
int last_cpu)
{
struct device *cpu_dev;
int cpu;
WARN_ON(cpumask_empty(cpumask));
for_each_cpu(cpu, cpumask) {
if (cpu == last_cpu)
break;
cpu_dev = get_cpu_device(cpu);
if (!cpu_dev) {
pr_err("%s: failed to get cpu%d device\n", __func__,
cpu);
continue;
}
_dev_pm_opp_find_and_remove_table(cpu_dev);
}
}
/**
* dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask
* @cpumask: cpumask for which OPP table needs to be removed
*
* This removes the OPP tables for CPUs present in the @cpumask.
* This should be used to remove all the OPPs entries associated with
* the cpus in @cpumask.
*/
void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask)
{
_dev_pm_opp_cpumask_remove_table(cpumask, -1);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table);
/**
* dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs
* @cpu_dev: CPU device for which we do this operation
* @cpumask: cpumask of the CPUs which share the OPP table with @cpu_dev
*
* This marks OPP table of the @cpu_dev as shared by the CPUs present in
* @cpumask.
*
* Returns -ENODEV if OPP table isn't already present.
*/
int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev,
const struct cpumask *cpumask)
{
struct opp_device *opp_dev;
struct opp_table *opp_table;
struct device *dev;
int cpu, ret = 0;
opp_table = _find_opp_table(cpu_dev);
if (IS_ERR(opp_table))
return PTR_ERR(opp_table);
for_each_cpu(cpu, cpumask) {
if (cpu == cpu_dev->id)
continue;
dev = get_cpu_device(cpu);
if (!dev) {
dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
__func__, cpu);
continue;
}
opp_dev = _add_opp_dev(dev, opp_table);
if (!opp_dev) {
dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n",
__func__, cpu);
continue;
}
/* Mark opp-table as multiple CPUs are sharing it now */
opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED;
}
dev_pm_opp_put_opp_table(opp_table);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
/**
* dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev
* @cpu_dev: CPU device for which we do this operation
* @cpumask: cpumask to update with information of sharing CPUs
*
* This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev.
*
* Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP
* table's status is access-unknown.
*/
int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
{
struct opp_device *opp_dev;
struct opp_table *opp_table;
int ret = 0;
opp_table = _find_opp_table(cpu_dev);
if (IS_ERR(opp_table))
return PTR_ERR(opp_table);
if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN) {
ret = -EINVAL;
goto put_opp_table;
}
cpumask_clear(cpumask);
if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) {
mutex_lock(&opp_table->lock);
list_for_each_entry(opp_dev, &opp_table->dev_list, node)
cpumask_set_cpu(opp_dev->dev->id, cpumask);
mutex_unlock(&opp_table->lock);
} else {
cpumask_set_cpu(cpu_dev->id, cpumask);
}
put_opp_table:
dev_pm_opp_put_opp_table(opp_table);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus);
