linux/drivers/cpufreq/cpufreq-dt.c

385 lines
9.3 KiB
C

/*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
*
* Copyright (C) 2014 Linaro.
* Viresh Kumar <viresh.kumar@linaro.org>
*
* 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/cpu.h>
#include <linux/cpu_cooling.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#include "cpufreq-dt.h"
struct private_data {
struct opp_table *opp_table;
struct device *cpu_dev;
struct thermal_cooling_device *cdev;
const char *reg_name;
};
static struct freq_attr *cpufreq_dt_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL, /* Extra space for boost-attr if required */
NULL,
};
static int set_target(struct cpufreq_policy *policy, unsigned int index)
{
struct private_data *priv = policy->driver_data;
unsigned long freq = policy->freq_table[index].frequency;
int ret;
ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
if (!ret) {
arch_set_freq_scale(policy->related_cpus, freq,
policy->cpuinfo.max_freq);
}
return ret;
}
/*
* An earlier version of opp-v1 bindings used to name the regulator
* "cpu0-supply", we still need to handle that for backwards compatibility.
*/
static const char *find_supply_name(struct device *dev)
{
struct device_node *np;
struct property *pp;
int cpu = dev->id;
const char *name = NULL;
np = of_node_get(dev->of_node);
/* This must be valid for sure */
if (WARN_ON(!np))
return NULL;
/* Try "cpu0" for older DTs */
if (!cpu) {
pp = of_find_property(np, "cpu0-supply", NULL);
if (pp) {
name = "cpu0";
goto node_put;
}
}
pp = of_find_property(np, "cpu-supply", NULL);
if (pp) {
name = "cpu";
goto node_put;
}
dev_dbg(dev, "no regulator for cpu%d\n", cpu);
node_put:
of_node_put(np);
return name;
}
static int resources_available(void)
{
struct device *cpu_dev;
struct regulator *cpu_reg;
struct clk *cpu_clk;
int ret = 0;
const char *name;
cpu_dev = get_cpu_device(0);
if (!cpu_dev) {
pr_err("failed to get cpu0 device\n");
return -ENODEV;
}
cpu_clk = clk_get(cpu_dev, NULL);
ret = PTR_ERR_OR_ZERO(cpu_clk);
if (ret) {
/*
* If cpu's clk node is present, but clock is not yet
* registered, we should try defering probe.
*/
if (ret == -EPROBE_DEFER)
dev_dbg(cpu_dev, "clock not ready, retry\n");
else
dev_err(cpu_dev, "failed to get clock: %d\n", ret);
return ret;
}
clk_put(cpu_clk);
name = find_supply_name(cpu_dev);
/* Platform doesn't require regulator */
if (!name)
return 0;
cpu_reg = regulator_get_optional(cpu_dev, name);
ret = PTR_ERR_OR_ZERO(cpu_reg);
if (ret) {
/*
* If cpu's regulator supply node is present, but regulator is
* not yet registered, we should try defering probe.
*/
if (ret == -EPROBE_DEFER)
dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n");
else
dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret);
return ret;
}
regulator_put(cpu_reg);
return 0;
}
static int cpufreq_init(struct cpufreq_policy *policy)
{
struct cpufreq_frequency_table *freq_table;
struct opp_table *opp_table = NULL;
struct private_data *priv;
struct device *cpu_dev;
struct clk *cpu_clk;
unsigned int transition_latency;
bool fallback = false;
const char *name;
int ret;
cpu_dev = get_cpu_device(policy->cpu);
if (!cpu_dev) {
pr_err("failed to get cpu%d device\n", policy->cpu);
return -ENODEV;
}
cpu_clk = clk_get(cpu_dev, NULL);
if (IS_ERR(cpu_clk)) {
ret = PTR_ERR(cpu_clk);
dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret);
return ret;
}
/* Get OPP-sharing information from "operating-points-v2" bindings */
ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus);
if (ret) {
if (ret != -ENOENT)
goto out_put_clk;
/*
* operating-points-v2 not supported, fallback to old method of
* finding shared-OPPs for backward compatibility if the
* platform hasn't set sharing CPUs.
*/
if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus))
fallback = true;
}
/*
* OPP layer will be taking care of regulators now, but it needs to know
* the name of the regulator first.
*/
name = find_supply_name(cpu_dev);
if (name) {
opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1);
if (IS_ERR(opp_table)) {
ret = PTR_ERR(opp_table);
dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n",
policy->cpu, ret);
goto out_put_clk;
}
}
/*
* Initialize OPP tables for all policy->cpus. They will be shared by
* all CPUs which have marked their CPUs shared with OPP bindings.
*
* For platforms not using operating-points-v2 bindings, we do this
* before updating policy->cpus. Otherwise, we will end up creating
* duplicate OPPs for policy->cpus.
*
* OPPs might be populated at runtime, don't check for error here
*/
dev_pm_opp_of_cpumask_add_table(policy->cpus);
/*
* But we need OPP table to function so if it is not there let's
* give platform code chance to provide it for us.
*/
ret = dev_pm_opp_get_opp_count(cpu_dev);
if (ret <= 0) {
dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n");
ret = -EPROBE_DEFER;
goto out_free_opp;
}
if (fallback) {
cpumask_setall(policy->cpus);
/*
* OPP tables are initialized only for policy->cpu, do it for
* others as well.
*/
ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);
if (ret)
dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
__func__, ret);
}
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv) {
ret = -ENOMEM;
goto out_free_opp;
}
priv->reg_name = name;
priv->opp_table = opp_table;
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto out_free_priv;
}
priv->cpu_dev = cpu_dev;
policy->driver_data = priv;
policy->clk = cpu_clk;
policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
ret = cpufreq_table_validate_and_show(policy, freq_table);
if (ret) {
dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__,
ret);
goto out_free_cpufreq_table;
}
/* Support turbo/boost mode */
if (policy_has_boost_freq(policy)) {
/* This gets disabled by core on driver unregister */
ret = cpufreq_enable_boost_support();
if (ret)
goto out_free_cpufreq_table;
cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
}
transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
if (!transition_latency)
transition_latency = CPUFREQ_ETERNAL;
policy->cpuinfo.transition_latency = transition_latency;
policy->dvfs_possible_from_any_cpu = true;
return 0;
out_free_cpufreq_table:
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_free_priv:
kfree(priv);
out_free_opp:
dev_pm_opp_of_cpumask_remove_table(policy->cpus);
if (name)
dev_pm_opp_put_regulators(opp_table);
out_put_clk:
clk_put(cpu_clk);
return ret;
}
static int cpufreq_exit(struct cpufreq_policy *policy)
{
struct private_data *priv = policy->driver_data;
cpufreq_cooling_unregister(priv->cdev);
dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
if (priv->reg_name)
dev_pm_opp_put_regulators(priv->opp_table);
clk_put(policy->clk);
kfree(priv);
return 0;
}
static void cpufreq_ready(struct cpufreq_policy *policy)
{
struct private_data *priv = policy->driver_data;
priv->cdev = of_cpufreq_cooling_register(policy);
}
static struct cpufreq_driver dt_cpufreq_driver = {
.flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = set_target,
.get = cpufreq_generic_get,
.init = cpufreq_init,
.exit = cpufreq_exit,
.ready = cpufreq_ready,
.name = "cpufreq-dt",
.attr = cpufreq_dt_attr,
.suspend = cpufreq_generic_suspend,
};
static int dt_cpufreq_probe(struct platform_device *pdev)
{
struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
int ret;
/*
* All per-cluster (CPUs sharing clock/voltages) initialization is done
* from ->init(). In probe(), we just need to make sure that clk and
* regulators are available. Else defer probe and retry.
*
* FIXME: Is checking this only for CPU0 sufficient ?
*/
ret = resources_available();
if (ret)
return ret;
if (data && data->have_governor_per_policy)
dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
ret = cpufreq_register_driver(&dt_cpufreq_driver);
if (ret)
dev_err(&pdev->dev, "failed register driver: %d\n", ret);
return ret;
}
static int dt_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&dt_cpufreq_driver);
return 0;
}
static struct platform_driver dt_cpufreq_platdrv = {
.driver = {
.name = "cpufreq-dt",
},
.probe = dt_cpufreq_probe,
.remove = dt_cpufreq_remove,
};
module_platform_driver(dt_cpufreq_platdrv);
MODULE_ALIAS("platform:cpufreq-dt");
MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
MODULE_DESCRIPTION("Generic cpufreq driver");
MODULE_LICENSE("GPL");