linux/drivers/cpufreq/freq_table.c
Viresh Kumar 44139ed494 cpufreq: Allow drivers to enable boost support after registering driver
In some cases it wouldn't be known at time of driver registration, if
the driver needs to support boost frequencies.

For example, while getting boost information from DT with opp-v2
bindings, we need to parse the bindings for all the CPUs to know if
turbo/boost OPPs are supported or not.

One way out to do that efficiently is to delay supporting boost mode
(i.e. creating /sys/devices/system/cpu/cpufreq/boost file), until the
time OPP bindings are parsed.

At that point, the driver can enable boost support. This can be done at
->init(), where the frequency table is created.

To do that, the driver requires few APIs from cpufreq core that let him
do this. This patch provides these APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-08-07 03:25:23 +02:00

318 lines
7.8 KiB
C

/*
* linux/drivers/cpufreq/freq_table.c
*
* Copyright (C) 2002 - 2003 Dominik Brodowski
*
* 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/cpufreq.h>
#include <linux/module.h>
/*********************************************************************
* FREQUENCY TABLE HELPERS *
*********************************************************************/
bool policy_has_boost_freq(struct cpufreq_policy *policy)
{
struct cpufreq_frequency_table *pos, *table = policy->freq_table;
if (!table)
return false;
cpufreq_for_each_valid_entry(pos, table)
if (pos->flags & CPUFREQ_BOOST_FREQ)
return true;
return false;
}
EXPORT_SYMBOL_GPL(policy_has_boost_freq);
int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
struct cpufreq_frequency_table *pos;
unsigned int min_freq = ~0;
unsigned int max_freq = 0;
unsigned int freq;
cpufreq_for_each_valid_entry(pos, table) {
freq = pos->frequency;
if (!cpufreq_boost_enabled()
&& (pos->flags & CPUFREQ_BOOST_FREQ))
continue;
pr_debug("table entry %u: %u kHz\n", (int)(pos - table), freq);
if (freq < min_freq)
min_freq = freq;
if (freq > max_freq)
max_freq = freq;
}
policy->min = policy->cpuinfo.min_freq = min_freq;
policy->max = policy->cpuinfo.max_freq = max_freq;
if (policy->min == ~0)
return -EINVAL;
else
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
struct cpufreq_frequency_table *pos;
unsigned int freq, next_larger = ~0;
bool found = false;
pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
policy->min, policy->max, policy->cpu);
cpufreq_verify_within_cpu_limits(policy);
cpufreq_for_each_valid_entry(pos, table) {
freq = pos->frequency;
if ((freq >= policy->min) && (freq <= policy->max)) {
found = true;
break;
}
if ((next_larger > freq) && (freq > policy->max))
next_larger = freq;
}
if (!found) {
policy->max = next_larger;
cpufreq_verify_within_cpu_limits(policy);
}
pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
policy->min, policy->max, policy->cpu);
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
/*
* Generic routine to verify policy & frequency table, requires driver to set
* policy->freq_table prior to it.
*/
int cpufreq_generic_frequency_table_verify(struct cpufreq_policy *policy)
{
struct cpufreq_frequency_table *table =
cpufreq_frequency_get_table(policy->cpu);
if (!table)
return -ENODEV;
return cpufreq_frequency_table_verify(policy, table);
}
EXPORT_SYMBOL_GPL(cpufreq_generic_frequency_table_verify);
int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table,
unsigned int target_freq,
unsigned int relation,
unsigned int *index)
{
struct cpufreq_frequency_table optimal = {
.driver_data = ~0,
.frequency = 0,
};
struct cpufreq_frequency_table suboptimal = {
.driver_data = ~0,
.frequency = 0,
};
struct cpufreq_frequency_table *pos;
unsigned int freq, diff, i = 0;
pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
target_freq, relation, policy->cpu);
switch (relation) {
case CPUFREQ_RELATION_H:
suboptimal.frequency = ~0;
break;
case CPUFREQ_RELATION_L:
case CPUFREQ_RELATION_C:
optimal.frequency = ~0;
break;
}
cpufreq_for_each_valid_entry(pos, table) {
freq = pos->frequency;
i = pos - table;
if ((freq < policy->min) || (freq > policy->max))
continue;
if (freq == target_freq) {
optimal.driver_data = i;
break;
}
switch (relation) {
case CPUFREQ_RELATION_H:
if (freq < target_freq) {
if (freq >= optimal.frequency) {
optimal.frequency = freq;
optimal.driver_data = i;
}
} else {
if (freq <= suboptimal.frequency) {
suboptimal.frequency = freq;
suboptimal.driver_data = i;
}
}
break;
case CPUFREQ_RELATION_L:
if (freq > target_freq) {
if (freq <= optimal.frequency) {
optimal.frequency = freq;
optimal.driver_data = i;
}
} else {
if (freq >= suboptimal.frequency) {
suboptimal.frequency = freq;
suboptimal.driver_data = i;
}
}
break;
case CPUFREQ_RELATION_C:
diff = abs(freq - target_freq);
if (diff < optimal.frequency ||
(diff == optimal.frequency &&
freq > table[optimal.driver_data].frequency)) {
optimal.frequency = diff;
optimal.driver_data = i;
}
break;
}
}
if (optimal.driver_data > i) {
if (suboptimal.driver_data > i)
return -EINVAL;
*index = suboptimal.driver_data;
} else
*index = optimal.driver_data;
pr_debug("target index is %u, freq is:%u kHz\n", *index,
table[*index].frequency);
return 0;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
int cpufreq_frequency_table_get_index(struct cpufreq_policy *policy,
unsigned int freq)
{
struct cpufreq_frequency_table *pos, *table;
table = cpufreq_frequency_get_table(policy->cpu);
if (unlikely(!table)) {
pr_debug("%s: Unable to find frequency table\n", __func__);
return -ENOENT;
}
cpufreq_for_each_valid_entry(pos, table)
if (pos->frequency == freq)
return pos - table;
return -EINVAL;
}
EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_index);
/**
* show_available_freqs - show available frequencies for the specified CPU
*/
static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf,
bool show_boost)
{
ssize_t count = 0;
struct cpufreq_frequency_table *pos, *table = policy->freq_table;
if (!table)
return -ENODEV;
cpufreq_for_each_valid_entry(pos, table) {
/*
* show_boost = true and driver_data = BOOST freq
* display BOOST freqs
*
* show_boost = false and driver_data = BOOST freq
* show_boost = true and driver_data != BOOST freq
* continue - do not display anything
*
* show_boost = false and driver_data != BOOST freq
* display NON BOOST freqs
*/
if (show_boost ^ (pos->flags & CPUFREQ_BOOST_FREQ))
continue;
count += sprintf(&buf[count], "%d ", pos->frequency);
}
count += sprintf(&buf[count], "\n");
return count;
}
#define cpufreq_attr_available_freq(_name) \
struct freq_attr cpufreq_freq_attr_##_name##_freqs = \
__ATTR_RO(_name##_frequencies)
/**
* show_scaling_available_frequencies - show available normal frequencies for
* the specified CPU
*/
static ssize_t scaling_available_frequencies_show(struct cpufreq_policy *policy,
char *buf)
{
return show_available_freqs(policy, buf, false);
}
cpufreq_attr_available_freq(scaling_available);
EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
/**
* show_available_boost_freqs - show available boost frequencies for
* the specified CPU
*/
static ssize_t scaling_boost_frequencies_show(struct cpufreq_policy *policy,
char *buf)
{
return show_available_freqs(policy, buf, true);
}
cpufreq_attr_available_freq(scaling_boost);
EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_boost_freqs);
struct freq_attr *cpufreq_generic_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
#ifdef CONFIG_CPU_FREQ_BOOST_SW
&cpufreq_freq_attr_scaling_boost_freqs,
#endif
NULL,
};
EXPORT_SYMBOL_GPL(cpufreq_generic_attr);
int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
int ret = cpufreq_frequency_table_cpuinfo(policy, table);
if (!ret)
policy->freq_table = table;
return ret;
}
EXPORT_SYMBOL_GPL(cpufreq_table_validate_and_show);
MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
MODULE_DESCRIPTION("CPUfreq frequency table helpers");
MODULE_LICENSE("GPL");