// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
*
* Copyright (C) 2014 Linaro.
* Viresh Kumar <[email protected]>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/list.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 list_head node;
cpumask_var_t cpus;
struct device *cpu_dev;
struct cpufreq_frequency_table *freq_table;
bool have_static_opps;
int opp_token;
};
static LIST_HEAD(priv_list);
static struct freq_attr *cpufreq_dt_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL, /* Extra space for boost-attr if required */
NULL,
};
static struct private_data *cpufreq_dt_find_data(int cpu)
{
struct private_data *priv;
list_for_each_entry(priv, &priv_list, node) {
if (cpumask_test_cpu(cpu, priv->cpus))
return priv;
}
return 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;
return dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
}
/*
* 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 __free(device_node) = of_node_get(dev->of_node);
int cpu = dev->id;
/* This must be valid for sure */
if (WARN_ON(!np))
return NULL;
/* Try "cpu0" for older DTs */
if (!cpu && of_property_present(np, "cpu0-supply"))
return "cpu0";
if (of_property_present(np, "cpu-supply"))
return "cpu";
dev_dbg(dev, "no regulator for cpu%d\n", cpu);
return NULL;
}
static int cpufreq_init(struct cpufreq_policy *policy)
{
struct private_data *priv;
struct device *cpu_dev;
struct clk *cpu_clk;
unsigned int transition_latency;
int ret;
priv = cpufreq_dt_find_data(policy->cpu);
if (!priv) {
pr_err("failed to find data for cpu%d\n", policy->cpu);
return -ENODEV;
}
cpu_dev = priv->cpu_dev;
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;
}
transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev);
if (!transition_latency)
transition_latency = CPUFREQ_ETERNAL;
cpumask_copy(policy->cpus, priv->cpus);
policy->driver_data = priv;
policy->clk = cpu_clk;
policy->freq_table = priv->freq_table;
policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000;
policy->cpuinfo.transition_latency = transition_latency;
policy->dvfs_possible_from_any_cpu = true;
/* 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_clk_put;
cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs;
}
return 0;
out_clk_put:
clk_put(cpu_clk);
return ret;
}
static int cpufreq_online(struct cpufreq_policy *policy)
{
/* We did light-weight tear down earlier, nothing to do here */
return 0;
}
static int cpufreq_offline(struct cpufreq_policy *policy)
{
/*
* Preserve policy->driver_data and don't free resources on light-weight
* tear down.
*/
return 0;
}
static void cpufreq_exit(struct cpufreq_policy *policy)
{
clk_put(policy->clk);
}
static struct cpufreq_driver dt_cpufreq_driver = {
.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
CPUFREQ_IS_COOLING_DEV,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = set_target,
.get = cpufreq_generic_get,
.init = cpufreq_init,
.exit = cpufreq_exit,
.online = cpufreq_online,
.offline = cpufreq_offline,
.register_em = cpufreq_register_em_with_opp,
.name = "cpufreq-dt",
.attr = cpufreq_dt_attr,
.suspend = cpufreq_generic_suspend,
};
static int dt_cpufreq_early_init(struct device *dev, int cpu)
{
struct private_data *priv;
struct device *cpu_dev;
bool fallback = false;
const char *reg_name[] = { NULL, NULL };
int ret;
/* Check if this CPU is already covered by some other policy */
if (cpufreq_dt_find_data(cpu))
return 0;
cpu_dev = get_cpu_device(cpu);
if (!cpu_dev)
return -EPROBE_DEFER;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
if (!zalloc_cpumask_var(&priv->cpus, GFP_KERNEL))
return -ENOMEM;
cpumask_set_cpu(cpu, priv->cpus);
priv->cpu_dev = cpu_dev;
/*
* OPP layer will be taking care of regulators now, but it needs to know
* the name of the regulator first.
*/
reg_name[0] = find_supply_name(cpu_dev);
if (reg_name[0]) {
priv->opp_token = dev_pm_opp_set_regulators(cpu_dev, reg_name);
if (priv->opp_token < 0) {
ret = dev_err_probe(cpu_dev, priv->opp_token,
"failed to set regulators\n");
goto free_cpumask;
}
}
/* Get OPP-sharing information from "operating-points-v2" bindings */
ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->cpus);
if (ret) {
if (ret != -ENOENT)
goto out;
/*
* operating-points-v2 not supported, fallback to all CPUs share
* OPP for backward compatibility if the platform hasn't set
* sharing CPUs.
*/
if (dev_pm_opp_get_sharing_cpus(cpu_dev, priv->cpus))
fallback = true;
}
/*
* Initialize OPP tables for all priv->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 priv->cpus. Otherwise, we will end up creating
* duplicate OPPs for the CPUs.
*
* OPPs might be populated at runtime, don't fail for error here unless
* it is -EPROBE_DEFER.
*/
ret = dev_pm_opp_of_cpumask_add_table(priv->cpus);
if (!ret) {
priv->have_static_opps = true;
} else if (ret == -EPROBE_DEFER) {
goto out;
}
/*
* The OPP table must be initialized, statically or dynamically, by this
* point.
*/
ret = dev_pm_opp_get_opp_count(cpu_dev);
if (ret <= 0) {
dev_err(cpu_dev, "OPP table can't be empty\n");
ret = -ENODEV;
goto out;
}
if (fallback) {
cpumask_setall(priv->cpus);
ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->cpus);
if (ret)
dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n",
__func__, ret);
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &priv->freq_table);
if (ret) {
dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
goto out;
}
list_add(&priv->node, &priv_list);
return 0;
out:
if (priv->have_static_opps)
dev_pm_opp_of_cpumask_remove_table(priv->cpus);
dev_pm_opp_put_regulators(priv->opp_token);
free_cpumask:
free_cpumask_var(priv->cpus);
return ret;
}
static void dt_cpufreq_release(void)
{
struct private_data *priv, *tmp;
list_for_each_entry_safe(priv, tmp, &priv_list, node) {
dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &priv->freq_table);
if (priv->have_static_opps)
dev_pm_opp_of_cpumask_remove_table(priv->cpus);
dev_pm_opp_put_regulators(priv->opp_token);
free_cpumask_var(priv->cpus);
list_del(&priv->node);
}
}
static int dt_cpufreq_probe(struct platform_device *pdev)
{
struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev);
int ret, cpu;
/* Request resources early so we can return in case of -EPROBE_DEFER */
for_each_possible_cpu(cpu) {
ret = dt_cpufreq_early_init(&pdev->dev, cpu);
if (ret)
goto err;
}
if (data) {
if (data->have_governor_per_policy)
dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY;
dt_cpufreq_driver.resume = data->resume;
if (data->suspend)
dt_cpufreq_driver.suspend = data->suspend;
if (data->get_intermediate) {
dt_cpufreq_driver.target_intermediate = data->target_intermediate;
dt_cpufreq_driver.get_intermediate = data->get_intermediate;
}
}
ret = cpufreq_register_driver(&dt_cpufreq_driver);
if (ret) {
dev_err(&pdev->dev, "failed register driver: %d\n", ret);
goto err;
}
return 0;
err:
dt_cpufreq_release();
return ret;
}
static void dt_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_unregister_driver(&dt_cpufreq_driver);
dt_cpufreq_release();
}
static struct platform_driver dt_cpufreq_platdrv = {
.driver = {
.name = "cpufreq-dt",
},
.probe = dt_cpufreq_probe,
.remove_new = dt_cpufreq_remove,
};
module_platform_driver(dt_cpufreq_platdrv);
MODULE_ALIAS("platform:cpufreq-dt");
MODULE_AUTHOR("Viresh Kumar <[email protected]>");
MODULE_AUTHOR("Shawn Guo <[email protected]>");
MODULE_DESCRIPTION("Generic cpufreq driver");
MODULE_LICENSE("GPL");
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