linux/arch/mips/loongson/lemote-2f/clock.c
Aaro Koskinen 8e8acb3296 MIPS/loongson2_cpufreq: Fix CPU clock rate setting
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>
2014-05-13 00:29:41 +02:00

147 lines
3.2 KiB
C

/*
* 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/clk.h>
#include <linux/cpufreq.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <asm/clock.h>
#include <asm/mach-loongson/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[] = {
{0, DC_RESV, CPUFREQ_ENTRY_INVALID},
{0, DC_ZERO, CPUFREQ_ENTRY_INVALID},
{0, DC_25PT, 0},
{0, DC_37PT, 0},
{0, DC_50PT, 0},
{0, DC_62PT, 0},
{0, DC_75PT, 0},
{0, DC_87PT, 0},
{0, DC_DISABLE, 0},
{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)
{
unsigned int rate_khz = rate / 1000;
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, 0);
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_khz == loongson2_clockmod_table[i].frequency)
break;
}
if (rate_khz != loongson2_clockmod_table[i].frequency)
return -ENOTSUPP;
clk->rate = rate;
regval = LOONGSON_CHIPCFG0;
regval = (regval & ~0x7) |
(loongson2_clockmod_table[i].driver_data - 1);
LOONGSON_CHIPCFG0 = regval;
return ret;
}
EXPORT_SYMBOL_GPL(clk_set_rate);
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);