187 lines
4.7 KiB
C
187 lines
4.7 KiB
C
/*
|
|
* cpufreq driver for the SuperH processors.
|
|
*
|
|
* Copyright (C) 2002 - 2012 Paul Mundt
|
|
* Copyright (C) 2002 M. R. Brown
|
|
*
|
|
* Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c
|
|
*
|
|
* Copyright (C) 2004-2007 Atmel Corporation
|
|
*
|
|
* 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.
|
|
*/
|
|
#define pr_fmt(fmt) "cpufreq: " fmt
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/cpufreq.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/err.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/sh_clk.h>
|
|
|
|
static DEFINE_PER_CPU(struct clk, sh_cpuclk);
|
|
|
|
struct cpufreq_target {
|
|
struct cpufreq_policy *policy;
|
|
unsigned int freq;
|
|
};
|
|
|
|
static unsigned int sh_cpufreq_get(unsigned int cpu)
|
|
{
|
|
return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000;
|
|
}
|
|
|
|
static long __sh_cpufreq_target(void *arg)
|
|
{
|
|
struct cpufreq_target *target = arg;
|
|
struct cpufreq_policy *policy = target->policy;
|
|
int cpu = policy->cpu;
|
|
struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
|
|
struct cpufreq_freqs freqs;
|
|
struct device *dev;
|
|
long freq;
|
|
|
|
if (smp_processor_id() != cpu)
|
|
return -ENODEV;
|
|
|
|
dev = get_cpu_device(cpu);
|
|
|
|
/* Convert target_freq from kHz to Hz */
|
|
freq = clk_round_rate(cpuclk, target->freq * 1000);
|
|
|
|
if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
|
|
return -EINVAL;
|
|
|
|
dev_dbg(dev, "requested frequency %u Hz\n", target->freq * 1000);
|
|
|
|
freqs.old = sh_cpufreq_get(cpu);
|
|
freqs.new = (freq + 500) / 1000;
|
|
freqs.flags = 0;
|
|
|
|
cpufreq_freq_transition_begin(target->policy, &freqs);
|
|
clk_set_rate(cpuclk, freq);
|
|
cpufreq_freq_transition_end(target->policy, &freqs, 0);
|
|
|
|
dev_dbg(dev, "set frequency %lu Hz\n", freq);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Here we notify other drivers of the proposed change and the final change.
|
|
*/
|
|
static int sh_cpufreq_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
struct cpufreq_target data = { .policy = policy, .freq = target_freq };
|
|
|
|
return work_on_cpu(policy->cpu, __sh_cpufreq_target, &data);
|
|
}
|
|
|
|
static int sh_cpufreq_verify(struct cpufreq_policy_data *policy)
|
|
{
|
|
struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu);
|
|
struct cpufreq_frequency_table *freq_table;
|
|
|
|
freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
|
|
if (freq_table)
|
|
return cpufreq_frequency_table_verify(policy, freq_table);
|
|
|
|
cpufreq_verify_within_cpu_limits(policy);
|
|
|
|
policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000;
|
|
policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
|
|
|
|
cpufreq_verify_within_cpu_limits(policy);
|
|
return 0;
|
|
}
|
|
|
|
static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int cpu = policy->cpu;
|
|
struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
|
|
struct cpufreq_frequency_table *freq_table;
|
|
struct device *dev;
|
|
|
|
dev = get_cpu_device(cpu);
|
|
|
|
cpuclk = clk_get(dev, "cpu_clk");
|
|
if (IS_ERR(cpuclk)) {
|
|
dev_err(dev, "couldn't get CPU clk\n");
|
|
return PTR_ERR(cpuclk);
|
|
}
|
|
|
|
freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
|
|
if (freq_table) {
|
|
policy->freq_table = freq_table;
|
|
} else {
|
|
dev_notice(dev, "no frequency table found, falling back "
|
|
"to rate rounding.\n");
|
|
|
|
policy->min = policy->cpuinfo.min_freq =
|
|
(clk_round_rate(cpuclk, 1) + 500) / 1000;
|
|
policy->max = policy->cpuinfo.max_freq =
|
|
(clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int cpu = policy->cpu;
|
|
struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
|
|
|
|
clk_put(cpuclk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void sh_cpufreq_cpu_ready(struct cpufreq_policy *policy)
|
|
{
|
|
struct device *dev = get_cpu_device(policy->cpu);
|
|
|
|
dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, "
|
|
"Maximum %u.%03u MHz.\n",
|
|
policy->min / 1000, policy->min % 1000,
|
|
policy->max / 1000, policy->max % 1000);
|
|
}
|
|
|
|
static struct cpufreq_driver sh_cpufreq_driver = {
|
|
.name = "sh",
|
|
.flags = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
|
|
.get = sh_cpufreq_get,
|
|
.target = sh_cpufreq_target,
|
|
.verify = sh_cpufreq_verify,
|
|
.init = sh_cpufreq_cpu_init,
|
|
.exit = sh_cpufreq_cpu_exit,
|
|
.ready = sh_cpufreq_cpu_ready,
|
|
.attr = cpufreq_generic_attr,
|
|
};
|
|
|
|
static int __init sh_cpufreq_module_init(void)
|
|
{
|
|
pr_notice("SuperH CPU frequency driver.\n");
|
|
return cpufreq_register_driver(&sh_cpufreq_driver);
|
|
}
|
|
|
|
static void __exit sh_cpufreq_module_exit(void)
|
|
{
|
|
cpufreq_unregister_driver(&sh_cpufreq_driver);
|
|
}
|
|
|
|
module_init(sh_cpufreq_module_init);
|
|
module_exit(sh_cpufreq_module_exit);
|
|
|
|
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
|
|
MODULE_DESCRIPTION("cpufreq driver for SuperH");
|
|
MODULE_LICENSE("GPL");
|