blob: 5426779d9fdb77700d05b897e7af3acff8d753e1 [file] [log] [blame]
/*
* 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/module.h>
#include <linux/cpufreq.h>
#include <linux/platform_device.h>
#include <asm/clock.h>
#include <loongson.h>
static LIST_HEAD(clock_list);
static DEFINE_SPINLOCK(clock_lock);
static DEFINE_MUTEX(clock_list_sem);
/* Minimum CLK support */
enum {
DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
DC_87PT, DC_DISABLE, DC_RESV
};
struct cpufreq_frequency_table loongson2_clockmod_table[] = {
{DC_RESV, CPUFREQ_ENTRY_INVALID},
{DC_ZERO, CPUFREQ_ENTRY_INVALID},
{DC_25PT, 0},
{DC_37PT, 0},
{DC_50PT, 0},
{DC_62PT, 0},
{DC_75PT, 0},
{DC_87PT, 0},
{DC_DISABLE, 0},
{DC_RESV, CPUFREQ_TABLE_END},
};
EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
static struct clk cpu_clk = {
.name = "cpu_clk",
.flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
.rate = 800000000,
};
struct clk *clk_get(struct device *dev, const char *id)
{
return &cpu_clk;
}
EXPORT_SYMBOL(clk_get);
static void propagate_rate(struct clk *clk)
{
struct clk *clkp;
list_for_each_entry(clkp, &clock_list, node) {
if (likely(clkp->parent != clk))
continue;
if (likely(clkp->ops && clkp->ops->recalc))
clkp->ops->recalc(clkp);
if (unlikely(clkp->flags & CLK_RATE_PROPAGATES))
propagate_rate(clkp);
}
}
int clk_enable(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return (unsigned long)clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
return clk_set_rate_ex(clk, rate, 0);
}
EXPORT_SYMBOL_GPL(clk_set_rate);
int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
{
int ret = 0;
int regval;
int i;
if (likely(clk->ops && clk->ops->set_rate)) {
unsigned long flags;
spin_lock_irqsave(&clock_lock, flags);
ret = clk->ops->set_rate(clk, rate, algo_id);
spin_unlock_irqrestore(&clock_lock, flags);
}
if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
propagate_rate(clk);
for (i = 0; loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END;
i++) {
if (loongson2_clockmod_table[i].frequency ==
CPUFREQ_ENTRY_INVALID)
continue;
if (rate == loongson2_clockmod_table[i].frequency)
break;
}
if (rate != loongson2_clockmod_table[i].frequency)
return -ENOTSUPP;
clk->rate = rate;
regval = LOONGSON_CHIPCFG0;
regval = (regval & ~0x7) | (loongson2_clockmod_table[i].index - 1);
LOONGSON_CHIPCFG0 = regval;
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate_ex);
long clk_round_rate(struct clk *clk, unsigned long rate)
{
if (likely(clk->ops && clk->ops->round_rate)) {
unsigned long flags, rounded;
spin_lock_irqsave(&clock_lock, flags);
rounded = clk->ops->round_rate(clk, rate);
spin_unlock_irqrestore(&clock_lock, flags);
return rounded;
}
return rate;
}
EXPORT_SYMBOL_GPL(clk_round_rate);
/*
* This is the simple version of Loongson-2 wait, Maybe we need do this in
* interrupt disabled content
*/
DEFINE_SPINLOCK(loongson2_wait_lock);
void loongson2_cpu_wait(void)
{
u32 cpu_freq;
unsigned long flags;
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);
}
EXPORT_SYMBOL_GPL(loongson2_cpu_wait);
MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
MODULE_DESCRIPTION("cpufreq driver for Loongson 2F");
MODULE_LICENSE("GPL");