Commit bf6fc9fd authored by Dave Jones's avatar Dave Jones

[CPUFREQ] AMD Elan SC520 cpufreq driver.

From: Sean Young <sean@mess.org>
Signed-off-by: default avatarDave Jones <davej@redhat.com>
parent 33100108
......@@ -23,7 +23,7 @@ config X86_ACPI_CPUFREQ
If in doubt, say N.
config ELAN_CPUFREQ
tristate "AMD Elan"
tristate "AMD Elan SC400 and SC410"
select CPU_FREQ_TABLE
depends on X86_ELAN
---help---
......@@ -38,6 +38,18 @@ config ELAN_CPUFREQ
If in doubt, say N.
config SC520_CPUFREQ
tristate "AMD Elan SC520"
select CPU_FREQ_TABLE
depends on X86_ELAN
---help---
This adds the CPUFreq driver for AMD Elan SC520 processor.
For details, take a look at <file:Documentation/cpu-freq/>.
If in doubt, say N.
config X86_POWERNOW_K6
tristate "AMD Mobile K6-2/K6-3 PowerNow!"
select CPU_FREQ_TABLE
......
......@@ -3,6 +3,7 @@ obj-$(CONFIG_X86_POWERNOW_K7) += powernow-k7.o
obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o
obj-$(CONFIG_X86_LONGHAUL) += longhaul.o
obj-$(CONFIG_ELAN_CPUFREQ) += elanfreq.o
obj-$(CONFIG_SC520_CPUFREQ) += sc520_freq.o
obj-$(CONFIG_X86_LONGRUN) += longrun.o
obj-$(CONFIG_X86_GX_SUSPMOD) += gx-suspmod.o
obj-$(CONFIG_X86_SPEEDSTEP_ICH) += speedstep-ich.o
......
/*
* sc520_freq.c: cpufreq driver for the AMD Elan sc520
*
* Copyright (C) 2005 Sean Young <sean@mess.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.
*
* Based on elanfreq.c
*
* 2005-03-30: - initial revision
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/cpufreq.h>
#include <asm/msr.h>
#include <asm/timex.h>
#include <asm/io.h>
#define MMCR_BASE 0xfffef000 /* The default base address */
#define OFFS_CPUCTL 0x2 /* CPU Control Register */
static __u8 __iomem *cpuctl;
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "sc520_freq", msg)
static struct cpufreq_frequency_table sc520_freq_table[] = {
{0x01, 100000},
{0x02, 133000},
{0, CPUFREQ_TABLE_END},
};
static unsigned int sc520_freq_get_cpu_frequency(unsigned int cpu)
{
u8 clockspeed_reg = *cpuctl;
switch (clockspeed_reg & 0x03) {
default:
printk(KERN_ERR "sc520_freq: error: cpuctl register has unexpected value %02x\n", clockspeed_reg);
case 0x01:
return 100000;
case 0x02:
return 133000;
}
}
static void sc520_freq_set_cpu_state (unsigned int state)
{
struct cpufreq_freqs freqs;
u8 clockspeed_reg;
freqs.old = sc520_freq_get_cpu_frequency(0);
freqs.new = sc520_freq_table[state].frequency;
freqs.cpu = 0; /* AMD Elan is UP */
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
dprintk("attempting to set frequency to %i kHz\n",
sc520_freq_table[state].frequency);
local_irq_disable();
clockspeed_reg = *cpuctl & ~0x03;
*cpuctl = clockspeed_reg | sc520_freq_table[state].index;
local_irq_enable();
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
};
static int sc520_freq_verify (struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, &sc520_freq_table[0]);
}
static int sc520_freq_target (struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int newstate = 0;
if (cpufreq_frequency_table_target(policy, sc520_freq_table, target_freq, relation, &newstate))
return -EINVAL;
sc520_freq_set_cpu_state(newstate);
return 0;
}
/*
* Module init and exit code
*/
static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
{
struct cpuinfo_x86 *c = cpu_data;
int result;
/* capability check */
if (c->x86_vendor != X86_VENDOR_AMD ||
c->x86 != 4 || c->x86_model != 9)
return -ENODEV;
/* cpuinfo and default policy values */
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
policy->cpuinfo.transition_latency = 1000000; /* 1ms */
policy->cur = sc520_freq_get_cpu_frequency(0);
result = cpufreq_frequency_table_cpuinfo(policy, sc520_freq_table);
if (result)
return (result);
cpufreq_frequency_table_get_attr(sc520_freq_table, policy->cpu);
return 0;
}
static int sc520_freq_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}
static struct freq_attr* sc520_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver sc520_freq_driver = {
.get = sc520_freq_get_cpu_frequency,
.verify = sc520_freq_verify,
.target = sc520_freq_target,
.init = sc520_freq_cpu_init,
.exit = sc520_freq_cpu_exit,
.name = "sc520_freq",
.owner = THIS_MODULE,
.attr = sc520_freq_attr,
};
static int __init sc520_freq_init(void)
{
struct cpuinfo_x86 *c = cpu_data;
/* Test if we have the right hardware */
if(c->x86_vendor != X86_VENDOR_AMD ||
c->x86 != 4 || c->x86_model != 9) {
dprintk("no Elan SC520 processor found!\n");
return -ENODEV;
}
cpuctl = ioremap((unsigned long)(MMCR_BASE + OFFS_CPUCTL), 1);
if(!cpuctl) {
printk(KERN_ERR "sc520_freq: error: failed to remap memory\n");
return -ENOMEM;
}
return cpufreq_register_driver(&sc520_freq_driver);
}
static void __exit sc520_freq_exit(void)
{
cpufreq_unregister_driver(&sc520_freq_driver);
iounmap(cpuctl);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sean Young <sean@mess.org>");
MODULE_DESCRIPTION("cpufreq driver for AMD's Elan sc520 CPU");
module_init(sc520_freq_init);
module_exit(sc520_freq_exit);
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