linux/drivers/cpufreq/cpufreq-cpu0.c
Lucas Stach e3beb0ac52 cpufreq: cpu0: drop wrong devm usage
This driver is using devres managed calls incorrectly, giving the cpu0
device as first parameter instead of the cpufreq platform device.
This results in resources not being freed if the cpufreq platform device
is unbound, for example if probing has to be deferred for a missing
regulator.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 3.9+ <stable@vger.kernel.org> # 3.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-20 01:29:20 +02:00

252 lines
6.4 KiB
C

/*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
*
* The OPP code in function cpu0_set_target() is reused from
* drivers/cpufreq/omap-cpufreq.c
*
* 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>
static unsigned int transition_latency;
static unsigned int voltage_tolerance; /* in percentage */
static struct device *cpu_dev;
static struct clk *cpu_clk;
static struct regulator *cpu_reg;
static struct cpufreq_frequency_table *freq_table;
static struct thermal_cooling_device *cdev;
static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
{
struct dev_pm_opp *opp;
unsigned long volt = 0, volt_old = 0, tol = 0;
unsigned int old_freq, new_freq;
long freq_Hz, freq_exact;
int ret;
freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
if (freq_Hz <= 0)
freq_Hz = freq_table[index].frequency * 1000;
freq_exact = freq_Hz;
new_freq = freq_Hz / 1000;
old_freq = clk_get_rate(cpu_clk) / 1000;
if (!IS_ERR(cpu_reg)) {
rcu_read_lock();
opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
if (IS_ERR(opp)) {
rcu_read_unlock();
pr_err("failed to find OPP for %ld\n", freq_Hz);
return PTR_ERR(opp);
}
volt = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
tol = volt * voltage_tolerance / 100;
volt_old = regulator_get_voltage(cpu_reg);
}
pr_debug("%u MHz, %ld mV --> %u MHz, %ld mV\n",
old_freq / 1000, volt_old ? volt_old / 1000 : -1,
new_freq / 1000, volt ? volt / 1000 : -1);
/* scaling up? scale voltage before frequency */
if (!IS_ERR(cpu_reg) && new_freq > old_freq) {
ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
if (ret) {
pr_err("failed to scale voltage up: %d\n", ret);
return ret;
}
}
ret = clk_set_rate(cpu_clk, freq_exact);
if (ret) {
pr_err("failed to set clock rate: %d\n", ret);
if (!IS_ERR(cpu_reg))
regulator_set_voltage_tol(cpu_reg, volt_old, tol);
return ret;
}
/* scaling down? scale voltage after frequency */
if (!IS_ERR(cpu_reg) && new_freq < old_freq) {
ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
if (ret) {
pr_err("failed to scale voltage down: %d\n", ret);
clk_set_rate(cpu_clk, old_freq * 1000);
}
}
return ret;
}
static int cpu0_cpufreq_init(struct cpufreq_policy *policy)
{
policy->clk = cpu_clk;
return cpufreq_generic_init(policy, freq_table, transition_latency);
}
static struct cpufreq_driver cpu0_cpufreq_driver = {
.flags = CPUFREQ_STICKY,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = cpu0_set_target,
.get = cpufreq_generic_get,
.init = cpu0_cpufreq_init,
.name = "generic_cpu0",
.attr = cpufreq_generic_attr,
};
static int cpu0_cpufreq_probe(struct platform_device *pdev)
{
struct device_node *np;
int ret;
cpu_dev = get_cpu_device(0);
if (!cpu_dev) {
pr_err("failed to get cpu0 device\n");
return -ENODEV;
}
np = of_node_get(cpu_dev->of_node);
if (!np) {
pr_err("failed to find cpu0 node\n");
return -ENOENT;
}
cpu_reg = regulator_get_optional(cpu_dev, "cpu0");
if (IS_ERR(cpu_reg)) {
/*
* If cpu0 regulator supply node is present, but regulator is
* not yet registered, we should try defering probe.
*/
if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) {
dev_err(cpu_dev, "cpu0 regulator not ready, retry\n");
ret = -EPROBE_DEFER;
goto out_put_node;
}
pr_warn("failed to get cpu0 regulator: %ld\n",
PTR_ERR(cpu_reg));
}
cpu_clk = clk_get(cpu_dev, NULL);
if (IS_ERR(cpu_clk)) {
ret = PTR_ERR(cpu_clk);
pr_err("failed to get cpu0 clock: %d\n", ret);
goto out_put_reg;
}
ret = of_init_opp_table(cpu_dev);
if (ret) {
pr_err("failed to init OPP table: %d\n", ret);
goto out_put_clk;
}
ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
if (ret) {
pr_err("failed to init cpufreq table: %d\n", ret);
goto out_put_clk;
}
of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance);
if (of_property_read_u32(np, "clock-latency", &transition_latency))
transition_latency = CPUFREQ_ETERNAL;
if (!IS_ERR(cpu_reg)) {
struct dev_pm_opp *opp;
unsigned long min_uV, max_uV;
int i;
/*
* OPP is maintained in order of increasing frequency, and
* freq_table initialised from OPP is therefore sorted in the
* same order.
*/
for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
;
rcu_read_lock();
opp = dev_pm_opp_find_freq_exact(cpu_dev,
freq_table[0].frequency * 1000, true);
min_uV = dev_pm_opp_get_voltage(opp);
opp = dev_pm_opp_find_freq_exact(cpu_dev,
freq_table[i-1].frequency * 1000, true);
max_uV = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
if (ret > 0)
transition_latency += ret * 1000;
}
ret = cpufreq_register_driver(&cpu0_cpufreq_driver);
if (ret) {
pr_err("failed register driver: %d\n", ret);
goto out_free_table;
}
/*
* For now, just loading the cooling device;
* thermal DT code takes care of matching them.
*/
if (of_find_property(np, "#cooling-cells", NULL)) {
cdev = of_cpufreq_cooling_register(np, cpu_present_mask);
if (IS_ERR(cdev))
pr_err("running cpufreq without cooling device: %ld\n",
PTR_ERR(cdev));
}
of_node_put(np);
return 0;
out_free_table:
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
out_put_clk:
if (!IS_ERR(cpu_clk))
clk_put(cpu_clk);
out_put_reg:
if (!IS_ERR(cpu_reg))
regulator_put(cpu_reg);
out_put_node:
of_node_put(np);
return ret;
}
static int cpu0_cpufreq_remove(struct platform_device *pdev)
{
cpufreq_cooling_unregister(cdev);
cpufreq_unregister_driver(&cpu0_cpufreq_driver);
dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
return 0;
}
static struct platform_driver cpu0_cpufreq_platdrv = {
.driver = {
.name = "cpufreq-cpu0",
.owner = THIS_MODULE,
},
.probe = cpu0_cpufreq_probe,
.remove = cpu0_cpufreq_remove,
};
module_platform_driver(cpu0_cpufreq_platdrv);
MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
MODULE_DESCRIPTION("Generic CPU0 cpufreq driver");
MODULE_LICENSE("GPL");