/*
* 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/of.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 list 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.
*
* Locking: The internal device_opp and opp structures are RCU protected.
* Since we just use the regular accessor functions to access the internal data
* structures, we use RCU read lock inside this function. As a result, users of
* this function DONOT need to use explicit locks for invoking.
*/
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;
rcu_read_lock();
max_opps = dev_pm_opp_get_opp_count(dev);
if (max_opps <= 0) {
ret = max_opps ? max_opps : -ENODATA;
goto out;
}
freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC);
if (!freq_table) {
ret = -ENOMEM;
goto out;
}
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;
}
freq_table[i].driver_data = i;
freq_table[i].frequency = CPUFREQ_TABLE_END;
*table = &freq_table[0];
out:
rcu_read_unlock();
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 */
/* Required only for V1 bindings, as v2 can manage it from DT itself */
int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
{
struct device_list_opp *list_dev;
struct device_opp *dev_opp;
struct device *dev;
int cpu, ret = 0;
mutex_lock(&dev_opp_list_lock);
dev_opp = _find_device_opp(cpu_dev);
if (IS_ERR(dev_opp)) {
ret = -EINVAL;
goto unlock;
}
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;
}
list_dev = _add_list_dev(dev, dev_opp);
if (!list_dev) {
dev_err(dev, "%s: failed to add list-dev for cpu%d device\n",
__func__, cpu);
continue;
}
}
unlock:
mutex_unlock(&dev_opp_list_lock);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus);
#ifdef CONFIG_OF
void dev_pm_opp_of_cpumask_remove_table(cpumask_var_t cpumask)
{
struct device *cpu_dev;
int cpu;
WARN_ON(cpumask_empty(cpumask));
for_each_cpu(cpu, cpumask) {
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_of_remove_table(cpu_dev);
}
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_remove_table);
int dev_pm_opp_of_cpumask_add_table(cpumask_var_t cpumask)
{
struct device *cpu_dev;
int cpu, ret = 0;
WARN_ON(cpumask_empty(cpumask));
for_each_cpu(cpu, cpumask) {
cpu_dev = get_cpu_device(cpu);
if (!cpu_dev) {
pr_err("%s: failed to get cpu%d device\n", __func__,
cpu);
continue;
}
ret = dev_pm_opp_of_add_table(cpu_dev);
if (ret) {
pr_err("%s: couldn't find opp table for cpu:%d, %d\n",
__func__, cpu, ret);
/* Free all other OPPs */
dev_pm_opp_of_cpumask_remove_table(cpumask);
break;
}
}
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_cpumask_add_table);
/*
* Works only for OPP v2 bindings.
*
* cpumask should be already set to mask of cpu_dev->id.
* Returns -ENOENT if operating-points-v2 bindings aren't supported.
*/
int dev_pm_opp_of_get_sharing_cpus(struct device *cpu_dev, cpumask_var_t cpumask)
{
struct device_node *np, *tmp_np;
struct device *tcpu_dev;
int cpu, ret = 0;
/* Get OPP descriptor node */
np = _of_get_opp_desc_node(cpu_dev);
if (!np) {
dev_dbg(cpu_dev, "%s: Couldn't find cpu_dev node.\n", __func__);
return -ENOENT;
}
/* OPPs are shared ? */
if (!of_property_read_bool(np, "opp-shared"))
goto put_cpu_node;
for_each_possible_cpu(cpu) {
if (cpu == cpu_dev->id)
continue;
tcpu_dev = get_cpu_device(cpu);
if (!tcpu_dev) {
dev_err(cpu_dev, "%s: failed to get cpu%d device\n",
__func__, cpu);
ret = -ENODEV;
goto put_cpu_node;
}
/* Get OPP descriptor node */
tmp_np = _of_get_opp_desc_node(tcpu_dev);
if (!tmp_np) {
dev_err(tcpu_dev, "%s: Couldn't find tcpu_dev node.\n",
__func__);
ret = -ENOENT;
goto put_cpu_node;
}
/* CPUs are sharing opp node */
if (np == tmp_np)
cpumask_set_cpu(cpu, cpumask);
of_node_put(tmp_np);
}
put_cpu_node:
of_node_put(np);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_of_get_sharing_cpus);
#endif