linux/arch/arm/mach-omap2/cpuidle34xx.c
Tero Kristo cf22854cee OMAP3: PM: Added resched check into idle calls
Fixes a bug where scheduling is delayed until next wakeup due to race
condition (e.g. interrupt requests scheduling just before omap_sram_idle
is entered.)

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2009-11-11 14:42:50 -08:00

319 lines
9.5 KiB
C

/*
* linux/arch/arm/mach-omap2/cpuidle34xx.c
*
* OMAP3 CPU IDLE Routines
*
* Copyright (C) 2008 Texas Instruments, Inc.
* Rajendra Nayak <rnayak@ti.com>
*
* Copyright (C) 2007 Texas Instruments, Inc.
* Karthik Dasu <karthik-dp@ti.com>
*
* Copyright (C) 2006 Nokia Corporation
* Tony Lindgren <tony@atomide.com>
*
* Copyright (C) 2005 Texas Instruments, Inc.
* Richard Woodruff <r-woodruff2@ti.com>
*
* Based on pm.c for omap2
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/sched.h>
#include <linux/cpuidle.h>
#include <plat/prcm.h>
#include <plat/irqs.h>
#include <plat/powerdomain.h>
#include <plat/clockdomain.h>
#include <plat/control.h>
#include <plat/serial.h>
#include "pm.h"
#ifdef CONFIG_CPU_IDLE
#define OMAP3_MAX_STATES 7
#define OMAP3_STATE_C1 0 /* C1 - MPU WFI + Core active */
#define OMAP3_STATE_C2 1 /* C2 - MPU WFI + Core inactive */
#define OMAP3_STATE_C3 2 /* C3 - MPU CSWR + Core inactive */
#define OMAP3_STATE_C4 3 /* C4 - MPU OFF + Core iactive */
#define OMAP3_STATE_C5 4 /* C5 - MPU RET + Core RET */
#define OMAP3_STATE_C6 5 /* C6 - MPU OFF + Core RET */
#define OMAP3_STATE_C7 6 /* C7 - MPU OFF + Core OFF */
struct omap3_processor_cx {
u8 valid;
u8 type;
u32 sleep_latency;
u32 wakeup_latency;
u32 mpu_state;
u32 core_state;
u32 threshold;
u32 flags;
};
struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
struct omap3_processor_cx current_cx_state;
struct powerdomain *mpu_pd, *core_pd;
static int omap3_idle_bm_check(void)
{
if (!omap3_can_sleep())
return 1;
return 0;
}
static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
omap2_clkdm_allow_idle(clkdm);
return 0;
}
static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
omap2_clkdm_deny_idle(clkdm);
return 0;
}
/**
* omap3_enter_idle - Programs OMAP3 to enter the specified state
* @dev: cpuidle device
* @state: The target state to be programmed
*
* Called from the CPUidle framework to program the device to the
* specified target state selected by the governor.
*/
static int omap3_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
struct timespec ts_preidle, ts_postidle, ts_idle;
u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
current_cx_state = *cx;
/* Used to keep track of the total time in idle */
getnstimeofday(&ts_preidle);
local_irq_disable();
local_fiq_disable();
if (!enable_off_mode) {
if (mpu_state < PWRDM_POWER_RET)
mpu_state = PWRDM_POWER_RET;
if (core_state < PWRDM_POWER_RET)
core_state = PWRDM_POWER_RET;
}
pwrdm_set_next_pwrst(mpu_pd, mpu_state);
pwrdm_set_next_pwrst(core_pd, core_state);
if (omap_irq_pending() || need_resched())
goto return_sleep_time;
if (cx->type == OMAP3_STATE_C1) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
}
/* Execute ARM wfi */
omap_sram_idle();
if (cx->type == OMAP3_STATE_C1) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
}
return_sleep_time:
getnstimeofday(&ts_postidle);
ts_idle = timespec_sub(ts_postidle, ts_preidle);
local_irq_enable();
local_fiq_enable();
return (u32)timespec_to_ns(&ts_idle)/1000;
}
/**
* omap3_enter_idle_bm - Checks for any bus activity
* @dev: cpuidle device
* @state: The target state to be programmed
*
* Used for C states with CPUIDLE_FLAG_CHECK_BM flag set. This
* function checks for any pending activity and then programs the
* device to the specified or a safer state.
*/
static int omap3_enter_idle_bm(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct cpuidle_state *new_state = state;
if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && omap3_idle_bm_check()) {
BUG_ON(!dev->safe_state);
new_state = dev->safe_state;
}
dev->last_state = new_state;
return omap3_enter_idle(dev, new_state);
}
DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
/* omap3_init_power_states - Initialises the OMAP3 specific C states.
*
* Below is the desciption of each C state.
* C1 . MPU WFI + Core active
* C2 . MPU WFI + Core inactive
* C3 . MPU CSWR + Core inactive
* C4 . MPU OFF + Core inactive
* C5 . MPU CSWR + Core CSWR
* C6 . MPU OFF + Core CSWR
* C7 . MPU OFF + Core OFF
*/
void omap_init_power_states(void)
{
/* C1 . MPU WFI + Core active */
omap3_power_states[OMAP3_STATE_C1].valid = 1;
omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
omap3_power_states[OMAP3_STATE_C1].sleep_latency = 2;
omap3_power_states[OMAP3_STATE_C1].wakeup_latency = 2;
omap3_power_states[OMAP3_STATE_C1].threshold = 5;
omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
/* C2 . MPU WFI + Core inactive */
omap3_power_states[OMAP3_STATE_C2].valid = 1;
omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
omap3_power_states[OMAP3_STATE_C2].sleep_latency = 10;
omap3_power_states[OMAP3_STATE_C2].wakeup_latency = 10;
omap3_power_states[OMAP3_STATE_C2].threshold = 30;
omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID;
/* C3 . MPU CSWR + Core inactive */
omap3_power_states[OMAP3_STATE_C3].valid = 1;
omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
omap3_power_states[OMAP3_STATE_C3].sleep_latency = 50;
omap3_power_states[OMAP3_STATE_C3].wakeup_latency = 50;
omap3_power_states[OMAP3_STATE_C3].threshold = 300;
omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C4 . MPU OFF + Core inactive */
omap3_power_states[OMAP3_STATE_C4].valid = 1;
omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
omap3_power_states[OMAP3_STATE_C4].sleep_latency = 1500;
omap3_power_states[OMAP3_STATE_C4].wakeup_latency = 1800;
omap3_power_states[OMAP3_STATE_C4].threshold = 4000;
omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C5 . MPU CSWR + Core CSWR*/
omap3_power_states[OMAP3_STATE_C5].valid = 1;
omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
omap3_power_states[OMAP3_STATE_C5].sleep_latency = 2500;
omap3_power_states[OMAP3_STATE_C5].wakeup_latency = 7500;
omap3_power_states[OMAP3_STATE_C5].threshold = 12000;
omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C6 . MPU OFF + Core CSWR */
omap3_power_states[OMAP3_STATE_C6].valid = 1;
omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
omap3_power_states[OMAP3_STATE_C6].sleep_latency = 3000;
omap3_power_states[OMAP3_STATE_C6].wakeup_latency = 8500;
omap3_power_states[OMAP3_STATE_C6].threshold = 15000;
omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C7 . MPU OFF + Core OFF */
omap3_power_states[OMAP3_STATE_C7].valid = 1;
omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
omap3_power_states[OMAP3_STATE_C7].sleep_latency = 10000;
omap3_power_states[OMAP3_STATE_C7].wakeup_latency = 30000;
omap3_power_states[OMAP3_STATE_C7].threshold = 300000;
omap3_power_states[OMAP3_STATE_C7].mpu_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C7].core_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C7].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
}
struct cpuidle_driver omap3_idle_driver = {
.name = "omap3_idle",
.owner = THIS_MODULE,
};
/**
* omap3_idle_init - Init routine for OMAP3 idle
*
* Registers the OMAP3 specific cpuidle driver with the cpuidle
* framework with the valid set of states.
*/
int __init omap3_idle_init(void)
{
int i, count = 0;
struct omap3_processor_cx *cx;
struct cpuidle_state *state;
struct cpuidle_device *dev;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
omap_init_power_states();
cpuidle_register_driver(&omap3_idle_driver);
dev = &per_cpu(omap3_idle_dev, smp_processor_id());
for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
cx = &omap3_power_states[i];
state = &dev->states[count];
if (!cx->valid)
continue;
cpuidle_set_statedata(state, cx);
state->exit_latency = cx->sleep_latency + cx->wakeup_latency;
state->target_residency = cx->threshold;
state->flags = cx->flags;
state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
omap3_enter_idle_bm : omap3_enter_idle;
if (cx->type == OMAP3_STATE_C1)
dev->safe_state = state;
sprintf(state->name, "C%d", count+1);
count++;
}
if (!count)
return -EINVAL;
dev->state_count = count;
if (cpuidle_register_device(dev)) {
printk(KERN_ERR "%s: CPUidle register device failed\n",
__func__);
return -EIO;
}
return 0;
}
#else
int __init omap3_idle_init(void)
{
return 0;
}
#endif /* CONFIG_CPU_IDLE */