linux/arch/sh/kernel/cpu/shmobile/cpuidle.c
Magnus Damm 63cd91dfd4 sh: SuperH Mobile Software Standby support for cpuidle
This patch adds "SuperH Mobile Standby Mode [SF]" to the list
of cpuidle sleep modes. If the software latency requirements
from cpuidle are met together with fulfilled hardware
requirements then deep sleep modes can be entered.

Tested on sh7722 and sh7724 with "Sleep Mode", "Sleep Mode + SF"
and "Software Standby Mode + SF" together with a multimedia
work load and flood ping without packet drop.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-08-18 10:17:32 +09:00

114 lines
3.1 KiB
C

/*
* arch/sh/kernel/cpu/shmobile/cpuidle.c
*
* Cpuidle support code for SuperH Mobile
*
* Copyright (C) 2009 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/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/suspend.h>
#include <linux/cpuidle.h>
#include <asm/suspend.h>
#include <asm/uaccess.h>
#include <asm/hwblk.h>
static unsigned long cpuidle_mode[] = {
SUSP_SH_SLEEP, /* regular sleep mode */
SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
};
static int cpuidle_sleep_enter(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
unsigned long allowed_mode = arch_hwblk_sleep_mode();
ktime_t before, after;
int requested_state = state - &dev->states[0];
int allowed_state;
int k;
/* convert allowed mode to allowed state */
for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
if (cpuidle_mode[k] == allowed_mode)
break;
allowed_state = k;
/* take the following into account for sleep mode selection:
* - allowed_state: best mode allowed by hardware (clock deps)
* - requested_state: best mode allowed by software (latencies)
*/
k = min_t(int, allowed_state, requested_state);
dev->last_state = &dev->states[k];
before = ktime_get();
sh_mobile_call_standby(cpuidle_mode[k]);
after = ktime_get();
return ktime_to_ns(ktime_sub(after, before)) >> 10;
}
static struct cpuidle_device cpuidle_dev;
static struct cpuidle_driver cpuidle_driver = {
.name = "sh_idle",
.owner = THIS_MODULE,
};
void sh_mobile_setup_cpuidle(void)
{
struct cpuidle_device *dev = &cpuidle_dev;
struct cpuidle_state *state;
int i;
cpuidle_register_driver(&cpuidle_driver);
for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
dev->states[i].name[0] = '\0';
dev->states[i].desc[0] = '\0';
}
i = CPUIDLE_DRIVER_STATE_START;
state = &dev->states[i++];
snprintf(state->name, CPUIDLE_NAME_LEN, "C0");
strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
state->exit_latency = 1;
state->target_residency = 1 * 2;
state->power_usage = 3;
state->flags = 0;
state->flags |= CPUIDLE_FLAG_SHALLOW;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->enter = cpuidle_sleep_enter;
dev->safe_state = state;
state = &dev->states[i++];
snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
strncpy(state->desc, "SuperH Sleep Mode [SF]", CPUIDLE_DESC_LEN);
state->exit_latency = 100;
state->target_residency = 1 * 2;
state->power_usage = 1;
state->flags = 0;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->enter = cpuidle_sleep_enter;
state = &dev->states[i++];
snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
strncpy(state->desc, "SuperH Mobile Standby Mode [SF]", CPUIDLE_DESC_LEN);
state->exit_latency = 2300;
state->target_residency = 1 * 2;
state->power_usage = 1;
state->flags = 0;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->enter = cpuidle_sleep_enter;
dev->state_count = i;
cpuidle_register_device(dev);
}