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linux-next/arch/arm/mach-shmobile/cpuidle.c
Magnus Damm 0af4817b80 ARM: mach-shmobile: CPUIdle support
This patch adds a shared SH-Mobile ARM specific CPUIdle
implementation supporting WFI only at this point. It
serves as a common point for late registration of the
arch-specific CPUIdle code, and supports adding extra
sleep modes using the callback shmobile_cpuidle_setup()
together with shmobile_cpuidle_modes[].

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-05-25 11:19:23 +09:00

93 lines
2.1 KiB
C

/*
* CPUIdle support code for SH-Mobile ARM
*
* Copyright (C) 2011 Magnus Damm
*
* 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/pm.h>
#include <linux/cpuidle.h>
#include <linux/suspend.h>
#include <linux/module.h>
#include <linux/err.h>
#include <asm/system.h>
#include <asm/io.h>
static void shmobile_enter_wfi(void)
{
cpu_do_idle();
}
void (*shmobile_cpuidle_modes[CPUIDLE_STATE_MAX])(void) = {
shmobile_enter_wfi, /* regular sleep mode */
};
static int shmobile_cpuidle_enter(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
ktime_t before, after;
int requested_state = state - &dev->states[0];
dev->last_state = &dev->states[requested_state];
before = ktime_get();
local_irq_disable();
local_fiq_disable();
shmobile_cpuidle_modes[requested_state]();
local_irq_enable();
local_fiq_enable();
after = ktime_get();
return ktime_to_ns(ktime_sub(after, before)) >> 10;
}
static struct cpuidle_device shmobile_cpuidle_dev;
static struct cpuidle_driver shmobile_cpuidle_driver = {
.name = "shmobile_cpuidle",
.owner = THIS_MODULE,
};
void (*shmobile_cpuidle_setup)(struct cpuidle_device *dev);
static int shmobile_cpuidle_init(void)
{
struct cpuidle_device *dev = &shmobile_cpuidle_dev;
struct cpuidle_state *state;
int i;
cpuidle_register_driver(&shmobile_cpuidle_driver);
for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
dev->states[i].name[0] = '\0';
dev->states[i].desc[0] = '\0';
dev->states[i].enter = shmobile_cpuidle_enter;
}
i = CPUIDLE_DRIVER_STATE_START;
state = &dev->states[i++];
snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
strncpy(state->desc, "WFI", CPUIDLE_DESC_LEN);
state->exit_latency = 1;
state->target_residency = 1 * 2;
state->power_usage = 3;
state->flags = 0;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
dev->safe_state = state;
dev->state_count = i;
if (shmobile_cpuidle_setup)
shmobile_cpuidle_setup(dev);
cpuidle_register_device(dev);
return 0;
}
late_initcall(shmobile_cpuidle_init);