/*
* File: arch/blackfin/mach-bf548/cpu.c
* Based on:
* Author:
*
* Created:
* Description: clock scaling for the bf54x
*
* Modified:
* Copyright 2004-2007 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <asm/dpmc.h>
#include <linux/fs.h>
#include <asm/bfin-global.h>
/* CONFIG_CLKIN_HZ=25000000 */
#define VCO5 (CONFIG_CLKIN_HZ*45)
#define VCO4 (CONFIG_CLKIN_HZ*36)
#define VCO3 (CONFIG_CLKIN_HZ*27)
#define VCO2 (CONFIG_CLKIN_HZ*18)
#define VCO1 (CONFIG_CLKIN_HZ*9)
#define VCO(x) VCO##x
#define MFREQ(x) {VCO(x),VCO(x)/4},{VCO(x),VCO(x)/2},{VCO(x),VCO(x)}
/* frequency */
static struct cpufreq_frequency_table bf548_freq_table[] = {
MFREQ(1),
MFREQ(3),
{VCO4, VCO4 / 2}, {VCO4, VCO4},
MFREQ(5),
{0, CPUFREQ_TABLE_END},
};
/*
* dpmc_fops->ioctl()
* static int dpmc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
*/
static int bf548_getfreq(unsigned int cpu)
{
unsigned long cclk_mhz;
/* The driver only support single cpu */
if (cpu == 0)
dpmc_fops.ioctl(NULL, NULL, IOCTL_GET_CORECLOCK, &cclk_mhz);
else
cclk_mhz = -1;
return cclk_mhz;
}
static int bf548_target(struct cpufreq_policy *policy,
unsigned int target_freq, unsigned int relation)
{
unsigned long cclk_mhz;
unsigned long vco_mhz;
unsigned long flags;
unsigned int index;
struct cpufreq_freqs freqs;
if (cpufreq_frequency_table_target(policy, bf548_freq_table, target_freq, relation, &index))
return -EINVAL;
cclk_mhz = bf548_freq_table[index].frequency;
vco_mhz = bf548_freq_table[index].index;
dpmc_fops.ioctl(NULL, NULL, IOCTL_CHANGE_FREQUENCY, &vco_mhz);
freqs.old = bf548_getfreq(0);
freqs.new = cclk_mhz;
freqs.cpu = 0;
pr_debug("cclk begin change to cclk %d,vco=%d,index=%d,target=%d,oldfreq=%d\n",
cclk_mhz, vco_mhz, index, target_freq, freqs.old);
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
local_irq_save(flags);
dpmc_fops.ioctl(NULL, NULL, IOCTL_SET_CCLK, &cclk_mhz);
local_irq_restore(flags);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
vco_mhz = get_vco();
cclk_mhz = get_cclk();
return 0;
}
/* make sure that only the "userspace" governor is run -- anything else wouldn't make sense on
* this platform, anyway.
*/
static int bf548_verify_speed(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, &bf548_freq_table);
}
static int __init __bf548_cpu_init(struct cpufreq_policy *policy)
{
if (policy->cpu != 0)
return -EINVAL;
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
/*Now ,only support one cpu */
policy->cur = bf548_getfreq(0);
cpufreq_frequency_table_get_attr(bf548_freq_table, policy->cpu);
return cpufreq_frequency_table_cpuinfo(policy, bf548_freq_table);
}
static struct freq_attr *bf548_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver bf548_driver = {
.verify = bf548_verify_speed,
.target = bf548_target,
.get = bf548_getfreq,
.init = __bf548_cpu_init,
.name = "bf548",
.owner = THIS_MODULE,
.attr = bf548_freq_attr,
};
static int __init bf548_cpu_init(void)
{
return cpufreq_register_driver(&bf548_driver);
}
static void __exit bf548_cpu_exit(void)
{
cpufreq_unregister_driver(&bf548_driver);
}
MODULE_AUTHOR("Mickael Kang");
MODULE_DESCRIPTION("cpufreq driver for BF548 CPU");
MODULE_LICENSE("GPL");
module_init(bf548_cpu_init);
module_exit(bf548_cpu_exit);
