forked from Minki/linux
8e8acb3296
Loongson2 has been using (incorrectly) kHz for cpu_clk rate. This has
been unnoticed, as loongson2_cpufreq was the only place where the rate
was set/get. After commit 652ed95d5f
(cpufreq: introduce cpufreq_generic_get() routine) things however broke,
and now loops_per_jiffy adjustments are incorrect (1000 times too long).
The patch fixes this by changing cpu_clk rate to Hz.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: cpufreq@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Patchwork: https://patchwork.linux-mips.org/patch/6678/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
202 lines
4.7 KiB
C
202 lines
4.7 KiB
C
/*
|
|
* Cpufreq driver for the loongson-2 processors
|
|
*
|
|
* The 2E revision of loongson processor not support this feature.
|
|
*
|
|
* Copyright (C) 2006 - 2008 Lemote Inc. & Insititute of Computing Technology
|
|
* Author: Yanhua, yanh@lemote.com
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
#include <linux/cpufreq.h>
|
|
#include <linux/module.h>
|
|
#include <linux/err.h>
|
|
#include <linux/sched.h> /* set_cpus_allowed() */
|
|
#include <linux/delay.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include <asm/clock.h>
|
|
#include <asm/idle.h>
|
|
|
|
#include <asm/mach-loongson/loongson.h>
|
|
|
|
static uint nowait;
|
|
|
|
static void (*saved_cpu_wait) (void);
|
|
|
|
static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
|
|
unsigned long val, void *data);
|
|
|
|
static struct notifier_block loongson2_cpufreq_notifier_block = {
|
|
.notifier_call = loongson2_cpu_freq_notifier
|
|
};
|
|
|
|
static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
|
|
unsigned long val, void *data)
|
|
{
|
|
if (val == CPUFREQ_POSTCHANGE)
|
|
current_cpu_data.udelay_val = loops_per_jiffy;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Here we notify other drivers of the proposed change and the final change.
|
|
*/
|
|
static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
|
|
unsigned int index)
|
|
{
|
|
unsigned int cpu = policy->cpu;
|
|
cpumask_t cpus_allowed;
|
|
unsigned int freq;
|
|
|
|
cpus_allowed = current->cpus_allowed;
|
|
set_cpus_allowed_ptr(current, cpumask_of(cpu));
|
|
|
|
freq =
|
|
((cpu_clock_freq / 1000) *
|
|
loongson2_clockmod_table[index].driver_data) / 8;
|
|
|
|
set_cpus_allowed_ptr(current, &cpus_allowed);
|
|
|
|
/* setting the cpu frequency */
|
|
clk_set_rate(policy->clk, freq * 1000);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
|
|
{
|
|
struct clk *cpuclk;
|
|
int i;
|
|
unsigned long rate;
|
|
int ret;
|
|
|
|
cpuclk = clk_get(NULL, "cpu_clk");
|
|
if (IS_ERR(cpuclk)) {
|
|
printk(KERN_ERR "cpufreq: couldn't get CPU clk\n");
|
|
return PTR_ERR(cpuclk);
|
|
}
|
|
|
|
rate = cpu_clock_freq / 1000;
|
|
if (!rate) {
|
|
clk_put(cpuclk);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* clock table init */
|
|
for (i = 2;
|
|
(loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
|
|
i++)
|
|
loongson2_clockmod_table[i].frequency = (rate * i) / 8;
|
|
|
|
ret = clk_set_rate(cpuclk, rate * 1000);
|
|
if (ret) {
|
|
clk_put(cpuclk);
|
|
return ret;
|
|
}
|
|
|
|
policy->clk = cpuclk;
|
|
return cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0);
|
|
}
|
|
|
|
static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
|
|
{
|
|
clk_put(policy->clk);
|
|
return 0;
|
|
}
|
|
|
|
static struct cpufreq_driver loongson2_cpufreq_driver = {
|
|
.name = "loongson2",
|
|
.init = loongson2_cpufreq_cpu_init,
|
|
.verify = cpufreq_generic_frequency_table_verify,
|
|
.target_index = loongson2_cpufreq_target,
|
|
.get = cpufreq_generic_get,
|
|
.exit = loongson2_cpufreq_exit,
|
|
.attr = cpufreq_generic_attr,
|
|
};
|
|
|
|
static struct platform_device_id platform_device_ids[] = {
|
|
{
|
|
.name = "loongson2_cpufreq",
|
|
},
|
|
{}
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(platform, platform_device_ids);
|
|
|
|
static struct platform_driver platform_driver = {
|
|
.driver = {
|
|
.name = "loongson2_cpufreq",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.id_table = platform_device_ids,
|
|
};
|
|
|
|
/*
|
|
* This is the simple version of Loongson-2 wait, Maybe we need do this in
|
|
* interrupt disabled context.
|
|
*/
|
|
|
|
static DEFINE_SPINLOCK(loongson2_wait_lock);
|
|
|
|
static void loongson2_cpu_wait(void)
|
|
{
|
|
unsigned long flags;
|
|
u32 cpu_freq;
|
|
|
|
spin_lock_irqsave(&loongson2_wait_lock, flags);
|
|
cpu_freq = LOONGSON_CHIPCFG0;
|
|
LOONGSON_CHIPCFG0 &= ~0x7; /* Put CPU into wait mode */
|
|
LOONGSON_CHIPCFG0 = cpu_freq; /* Restore CPU state */
|
|
spin_unlock_irqrestore(&loongson2_wait_lock, flags);
|
|
local_irq_enable();
|
|
}
|
|
|
|
static int __init cpufreq_init(void)
|
|
{
|
|
int ret;
|
|
|
|
/* Register platform stuff */
|
|
ret = platform_driver_register(&platform_driver);
|
|
if (ret)
|
|
return ret;
|
|
|
|
pr_info("cpufreq: Loongson-2F CPU frequency driver.\n");
|
|
|
|
cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
|
|
|
ret = cpufreq_register_driver(&loongson2_cpufreq_driver);
|
|
|
|
if (!ret && !nowait) {
|
|
saved_cpu_wait = cpu_wait;
|
|
cpu_wait = loongson2_cpu_wait;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit cpufreq_exit(void)
|
|
{
|
|
if (!nowait && saved_cpu_wait)
|
|
cpu_wait = saved_cpu_wait;
|
|
cpufreq_unregister_driver(&loongson2_cpufreq_driver);
|
|
cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
|
|
|
platform_driver_unregister(&platform_driver);
|
|
}
|
|
|
|
module_init(cpufreq_init);
|
|
module_exit(cpufreq_exit);
|
|
|
|
module_param(nowait, uint, 0644);
|
|
MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");
|
|
|
|
MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
|
|
MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
|
|
MODULE_LICENSE("GPL");
|