155 lines
3.9 KiB
C
155 lines
3.9 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/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 int dbx500_cpufreq_target(struct cpufreq_policy *policy,
|
|
unsigned int target_freq,
|
|
unsigned int relation)
|
|
{
|
|
struct cpufreq_freqs freqs;
|
|
unsigned int idx;
|
|
int ret;
|
|
|
|
/* Lookup the next frequency */
|
|
if (cpufreq_frequency_table_target(policy, freq_table, target_freq,
|
|
relation, &idx))
|
|
return -EINVAL;
|
|
|
|
freqs.old = policy->cur;
|
|
freqs.new = freq_table[idx].frequency;
|
|
|
|
if (freqs.old == freqs.new)
|
|
return 0;
|
|
|
|
/* pre-change notification */
|
|
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
|
|
|
|
/* update armss clk frequency */
|
|
ret = clk_set_rate(armss_clk, freqs.new * 1000);
|
|
|
|
if (ret) {
|
|
pr_err("dbx500-cpufreq: Failed to set armss_clk to %d Hz: error %d\n",
|
|
freqs.new * 1000, ret);
|
|
freqs.new = freqs.old;
|
|
}
|
|
|
|
/* post change notification */
|
|
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static unsigned int dbx500_cpufreq_getspeed(unsigned int cpu)
|
|
{
|
|
int i = 0;
|
|
unsigned long freq = clk_get_rate(armss_clk) / 1000;
|
|
|
|
/* The value is rounded to closest frequency in the defined table. */
|
|
while (freq_table[i + 1].frequency != CPUFREQ_TABLE_END) {
|
|
if (freq < freq_table[i].frequency +
|
|
(freq_table[i + 1].frequency - freq_table[i].frequency) / 2)
|
|
return freq_table[i].frequency;
|
|
i++;
|
|
}
|
|
|
|
return freq_table[i].frequency;
|
|
}
|
|
|
|
static int dbx500_cpufreq_init(struct cpufreq_policy *policy)
|
|
{
|
|
int res;
|
|
|
|
/* get policy fields based on the table */
|
|
res = cpufreq_table_validate_and_show(policy, freq_table);
|
|
if (res) {
|
|
pr_err("dbx500-cpufreq: Failed to read policy table\n");
|
|
return res;
|
|
}
|
|
|
|
policy->min = policy->cpuinfo.min_freq;
|
|
policy->max = policy->cpuinfo.max_freq;
|
|
policy->cur = dbx500_cpufreq_getspeed(policy->cpu);
|
|
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
|
|
|
|
/*
|
|
* FIXME : Need to take time measurement across the target()
|
|
* function with no/some/all drivers in the notification
|
|
* list.
|
|
*/
|
|
policy->cpuinfo.transition_latency = 20 * 1000; /* in ns */
|
|
|
|
/* policy sharing between dual CPUs */
|
|
cpumask_setall(policy->cpus);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct cpufreq_driver dbx500_cpufreq_driver = {
|
|
.flags = CPUFREQ_STICKY | CPUFREQ_CONST_LOOPS,
|
|
.verify = cpufreq_generic_frequency_table_verify,
|
|
.target = dbx500_cpufreq_target,
|
|
.get = dbx500_cpufreq_getspeed,
|
|
.init = dbx500_cpufreq_init,
|
|
.name = "DBX500",
|
|
.attr = cpufreq_generic_attr,
|
|
};
|
|
|
|
static int dbx500_cpufreq_probe(struct platform_device *pdev)
|
|
{
|
|
int i = 0;
|
|
|
|
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");
|
|
while (freq_table[i].frequency != CPUFREQ_TABLE_END) {
|
|
pr_info(" %d Mhz\n", freq_table[i].frequency/1000);
|
|
i++;
|
|
}
|
|
|
|
return cpufreq_register_driver(&dbx500_cpufreq_driver);
|
|
}
|
|
|
|
static struct platform_driver dbx500_cpufreq_plat_driver = {
|
|
.driver = {
|
|
.name = "cpufreq-ux500",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.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");
|