linux/drivers/cpufreq/dbx500-cpufreq.c
Viresh Kumar 4d753aa7b6 thermal: cpu_cooling: use cpufreq_policy to register cooling device
The CPU cooling driver uses the cpufreq policy, to get clip_cpus, the
frequency table, etc. Most of the callers of CPU cooling driver's
registration routines have the cpufreq policy with them, but they only
pass the policy->related_cpus cpumask. The __cpufreq_cooling_register()
routine then gets the policy by itself and uses it.

It would be much better if the callers can pass the policy instead
directly. This also fixes a basic design flaw, where the policy can be
freed while the CPU cooling driver is still active.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-05-27 17:32:24 -07:00

104 lines
2.7 KiB
C

/*
* Copyright (C) STMicroelectronics 2009
* Copyright (C) ST-Ericsson SA 2010-2012
*
* License Terms: GNU General Public License v2
* Author: Sundar Iyer <sundar.iyer@stericsson.com>
* Author: Martin Persson <martin.persson@stericsson.com>
* Author: Jonas Aaberg <jonas.aberg@stericsson.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/cpufreq.h>
#include <linux/cpu_cooling.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
static struct cpufreq_frequency_table *freq_table;
static struct clk *armss_clk;
static struct thermal_cooling_device *cdev;
static int dbx500_cpufreq_target(struct cpufreq_policy *policy,
unsigned int index)
{
/* update armss clk frequency */
return clk_set_rate(armss_clk, freq_table[index].frequency * 1000);
}
static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
{
policy->clk = armss_clk;
return cpufreq_generic_init(policy, freq_table, 20 * 1000);
}
static int dbx500_cpufreq_exit(struct cpufreq_policy *policy)
{
if (!IS_ERR(cdev))
cpufreq_cooling_unregister(cdev);
return 0;
}
static void dbx500_cpufreq_ready(struct cpufreq_policy *policy)
{
cdev = cpufreq_cooling_register(policy);
if (IS_ERR(cdev))
pr_err("Failed to register cooling device %ld\n", PTR_ERR(cdev));
else
pr_info("Cooling device registered: %s\n", cdev->type);
}
static struct cpufreq_driver dbx500_cpufreq_driver = {
.flags = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS |
CPUFREQ_NEED_INITIAL_FREQ_CHECK,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = dbx500_cpufreq_target,
.get = cpufreq_generic_get,
.init = dbx500_cpufreq_init,
.exit = dbx500_cpufreq_exit,
.ready = dbx500_cpufreq_ready,
.name = "DBX500",
.attr = cpufreq_generic_attr,
};
static int dbx500_cpufreq_probe(struct platform_device *pdev)
{
struct cpufreq_frequency_table *pos;
freq_table = dev_get_platdata(&pdev->dev);
if (!freq_table) {
pr_err("dbx500-cpufreq: Failed to fetch cpufreq table\n");
return -ENODEV;
}
armss_clk = clk_get(&pdev->dev, "armss");
if (IS_ERR(armss_clk)) {
pr_err("dbx500-cpufreq: Failed to get armss clk\n");
return PTR_ERR(armss_clk);
}
pr_info("dbx500-cpufreq: Available frequencies:\n");
cpufreq_for_each_entry(pos, freq_table)
pr_info(" %d Mhz\n", pos->frequency / 1000);
return cpufreq_register_driver(&dbx500_cpufreq_driver);
}
static struct platform_driver dbx500_cpufreq_plat_driver = {
.driver = {
.name = "cpufreq-ux500",
},
.probe = dbx500_cpufreq_probe,
};
static int __init dbx500_cpufreq_register(void)
{
return platform_driver_register(&dbx500_cpufreq_plat_driver);
}
device_initcall(dbx500_cpufreq_register);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("cpufreq driver for DBX500");