mirror of
https://github.com/torvalds/linux.git
synced 2024-12-26 12:52:30 +00:00
d4019f0a92
Most of the drivers do following in their ->target_index() routines: struct cpufreq_freqs freqs; freqs.old = old freq... freqs.new = new freq... cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); /* Change rate here */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); This is replicated over all cpufreq drivers today and there doesn't exists a good enough reason why this shouldn't be moved to cpufreq core instead. There are few special cases though, like exynos5440, which doesn't do everything on the call to ->target_index() routine and call some kind of bottom halves for doing this work, work/tasklet/etc.. They may continue doing notification from their own code as flag: CPUFREQ_ASYNC_NOTIFICATION is already set for them. All drivers are also modified in this patch to avoid breaking 'git bisect', as double notification would happen otherwise. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org> Reviewed-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
142 lines
3.0 KiB
C
142 lines
3.0 KiB
C
/*
|
|
* 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 <linux/timex.h>
|
|
#include <linux/io.h>
|
|
|
|
#include <asm/cpu_device_id.h>
|
|
#include <asm/msr.h>
|
|
|
|
#define MMCR_BASE 0xfffef000 /* The default base address */
|
|
#define OFFS_CPUCTL 0x2 /* CPU Control Register */
|
|
|
|
static __u8 __iomem *cpuctl;
|
|
|
|
#define PFX "sc520_freq: "
|
|
|
|
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 PFX "error: cpuctl register has unexpected "
|
|
"value %02x\n", clockspeed_reg);
|
|
case 0x01:
|
|
return 100000;
|
|
case 0x02:
|
|
return 133000;
|
|
}
|
|
}
|
|
|
|
static int sc520_freq_target(struct cpufreq_policy *policy, unsigned int state)
|
|
{
|
|
|
|
u8 clockspeed_reg;
|
|
|
|
local_irq_disable();
|
|
|
|
clockspeed_reg = *cpuctl & ~0x03;
|
|
*cpuctl = clockspeed_reg | sc520_freq_table[state].driver_data;
|
|
|
|
local_irq_enable();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Module init and exit code
|
|
*/
|
|
|
|
static int sc520_freq_cpu_init(struct cpufreq_policy *policy)
|
|
{
|
|
struct cpuinfo_x86 *c = &cpu_data(0);
|
|
|
|
/* capability check */
|
|
if (c->x86_vendor != X86_VENDOR_AMD ||
|
|
c->x86 != 4 || c->x86_model != 9)
|
|
return -ENODEV;
|
|
|
|
/* cpuinfo and default policy values */
|
|
policy->cpuinfo.transition_latency = 1000000; /* 1ms */
|
|
|
|
return cpufreq_table_validate_and_show(policy, sc520_freq_table);
|
|
}
|
|
|
|
|
|
static struct cpufreq_driver sc520_freq_driver = {
|
|
.get = sc520_freq_get_cpu_frequency,
|
|
.verify = cpufreq_generic_frequency_table_verify,
|
|
.target_index = sc520_freq_target,
|
|
.init = sc520_freq_cpu_init,
|
|
.exit = cpufreq_generic_exit,
|
|
.name = "sc520_freq",
|
|
.attr = cpufreq_generic_attr,
|
|
};
|
|
|
|
static const struct x86_cpu_id sc520_ids[] = {
|
|
{ X86_VENDOR_AMD, 4, 9 },
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(x86cpu, sc520_ids);
|
|
|
|
static int __init sc520_freq_init(void)
|
|
{
|
|
int err;
|
|
|
|
if (!x86_match_cpu(sc520_ids))
|
|
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;
|
|
}
|
|
|
|
err = cpufreq_register_driver(&sc520_freq_driver);
|
|
if (err)
|
|
iounmap(cpuctl);
|
|
|
|
return err;
|
|
}
|
|
|
|
|
|
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);
|
|
|