- 根目录:
- arch
- arm
- mach-omap2
- cpuidle34xx.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 <linux/export.h>
#include <linux/cpu_pm.h>
#include <plat/prcm.h>
#include <plat/irqs.h>
#include "powerdomain.h"
#include "clockdomain.h"
#include "pm.h"
#include "control.h"
#include "common.h"
#ifdef CONFIG_CPU_IDLE
/*
* The latencies/thresholds for various C states have
* to be configured from the respective board files.
* These are some default values (which might not provide
* the best power savings) used on boards which do not
* pass these details from the board file.
*/
static struct cpuidle_params cpuidle_params_table[] = {
/* C1 */
{2 + 2, 5, 1},
/* C2 */
{10 + 10, 30, 1},
/* C3 */
{50 + 50, 300, 1},
/* C4 */
{1500 + 1800, 4000, 1},
/* C5 */
{2500 + 7500, 12000, 1},
/* C6 */
{3000 + 8500, 15000, 1},
/* C7 */
{10000 + 30000, 300000, 1},
};
#define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
/* Mach specific information to be recorded in the C-state driver_data */
struct omap3_idle_statedata {
u32 mpu_state;
u32 core_state;
u8 valid;
};
struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES];
struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
clkdm_allow_idle(clkdm);
return 0;
}
static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
clkdm_deny_idle(clkdm);
return 0;
}
static int __omap3_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct omap3_idle_statedata *cx =
cpuidle_get_statedata(&dev->states_usage[index]);
u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
local_fiq_disable();
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;
/* Deny idle for C1 */
if (index == 0) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
}
/*
* Call idle CPU PM enter notifier chain so that
* VFP context is saved.
*/
if (mpu_state == PWRDM_POWER_OFF)
cpu_pm_enter();
/* Execute ARM wfi */
omap_sram_idle();
/*
* Call idle CPU PM enter notifier chain to restore
* VFP context.
*/
if (pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
cpu_pm_exit();
/* Re-allow idle for C1 */
if (index == 0) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
}
return_sleep_time:
local_fiq_enable();
return index;
}
/**
* omap3_enter_idle - Programs OMAP3 to enter the specified state
* @dev: cpuidle device
* @drv: cpuidle driver
* @index: the index of state to be entered
*
* Called from the CPUidle framework to program the device to the
* specified target state selected by the governor.
*/
static inline int omap3_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
return cpuidle_wrap_enter(dev, drv, index, __omap3_enter_idle);
}
/**
* next_valid_state - Find next valid C-state
* @dev: cpuidle device
* @drv: cpuidle driver
* @index: Index of currently selected c-state
*
* If the state corresponding to index is valid, index is returned back
* to the caller. Else, this function searches for a lower c-state which is
* still valid (as defined in omap3_power_states[]) and returns its index.
*
* A state is valid if the 'valid' field is enabled and
* if it satisfies the enable_off_mode condition.
*/
static int next_valid_state(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct cpuidle_state_usage *curr_usage = &dev->states_usage[index];
struct cpuidle_state *curr = &drv->states[index];
struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr_usage);
u32 mpu_deepest_state = PWRDM_POWER_RET;
u32 core_deepest_state = PWRDM_POWER_RET;
int next_index = -1;
if (enable_off_mode) {
mpu_deepest_state = PWRDM_POWER_OFF;
/*
* Erratum i583: valable for ES rev < Es1.2 on 3630.
* CORE OFF mode is not supported in a stable form, restrict
* instead the CORE state to RET.
*/
if (!IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583))
core_deepest_state = PWRDM_POWER_OFF;
}
/* Check if current state is valid */
if ((cx->valid) &&
(cx->mpu_state >= mpu_deepest_state) &&
(cx->core_state >= core_deepest_state)) {
return index;
} else {
int idx = OMAP3_NUM_STATES - 1;
/* Reach the current state starting at highest C-state */
for (; idx >= 0; idx--) {
if (&drv->states[idx] == curr) {
next_index = idx;
break;
}
}
/* Should never hit this condition */
WARN_ON(next_index == -1);
/*
* Drop to next valid state.
* Start search from the next (lower) state.
*/
idx--;
for (; idx >= 0; idx--) {
cx = cpuidle_get_statedata(&dev->states_usage[idx]);
if ((cx->valid) &&
(cx->mpu_state >= mpu_deepest_state) &&
(cx->core_state >= core_deepest_state)) {
next_index = idx;
break;
}
}
/*
* C1 is always valid.
* So, no need to check for 'next_index == -1' outside
* this loop.
*/
}
return next_index;
}
/**
* omap3_enter_idle_bm - Checks for any bus activity
* @dev: cpuidle device
* @drv: cpuidle driver
* @index: array index of target state to be programmed
*
* 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_driver *drv,
int index)
{
int new_state_idx;
u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state;
struct omap3_idle_statedata *cx;
int ret;
/*
* Prevent idle completely if CAM is active.
* CAM does not have wakeup capability in OMAP3.
*/
cam_state = pwrdm_read_pwrst(cam_pd);
if (cam_state == PWRDM_POWER_ON) {
new_state_idx = drv->safe_state_index;
goto select_state;
}
/*
* FIXME: we currently manage device-specific idle states
* for PER and CORE in combination with CPU-specific
* idle states. This is wrong, and device-specific
* idle management needs to be separated out into
* its own code.
*/
/*
* Prevent PER off if CORE is not in retention or off as this
* would disable PER wakeups completely.
*/
cx = cpuidle_get_statedata(&dev->states_usage[index]);
core_next_state = cx->core_state;
per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
if ((per_next_state == PWRDM_POWER_OFF) &&
(core_next_state > PWRDM_POWER_RET))
per_next_state = PWRDM_POWER_RET;
/* Are we changing PER target state? */
if (per_next_state != per_saved_state)
pwrdm_set_next_pwrst(per_pd, per_next_state);
new_state_idx = next_valid_state(dev, drv, index);
select_state:
ret = omap3_enter_idle(dev, drv, new_state_idx);
/* Restore original PER state if it was modified */
if (per_next_state != per_saved_state)
pwrdm_set_next_pwrst(per_pd, per_saved_state);
return ret;
}
DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
{
int i;
if (!cpuidle_board_params)
return;
for (i = 0; i < OMAP3_NUM_STATES; i++) {
cpuidle_params_table[i].valid = cpuidle_board_params[i].valid;
cpuidle_params_table[i].exit_latency =
cpuidle_board_params[i].exit_latency;
cpuidle_params_table[i].target_residency =
cpuidle_board_params[i].target_residency;
}
return;
}
struct cpuidle_driver omap3_idle_driver = {
.name = "omap3_idle",
.owner = THIS_MODULE,
};
/* Helper to fill the C-state common data*/
static inline void _fill_cstate(struct cpuidle_driver *drv,
int idx, const char *descr)
{
struct cpuidle_state *state = &drv->states[idx];
state->exit_latency = cpuidle_params_table[idx].exit_latency;
state->target_residency = cpuidle_params_table[idx].target_residency;
state->flags = CPUIDLE_FLAG_TIME_VALID;
state->enter = omap3_enter_idle_bm;
sprintf(state->name, "C%d", idx + 1);
strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
}
/* Helper to register the driver_data */
static inline struct omap3_idle_statedata *_fill_cstate_usage(
struct cpuidle_device *dev,
int idx)
{
struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
struct cpuidle_state_usage *state_usage = &dev->states_usage[idx];
cx->valid = cpuidle_params_table[idx].valid;
cpuidle_set_statedata(state_usage, cx);
return cx;
}
/**
* omap3_idle_init - Init routine for OMAP3 idle
*
* Registers the OMAP3 specific cpuidle driver to the cpuidle
* framework with the valid set of states.
*/
int __init omap3_idle_init(void)
{
struct cpuidle_device *dev;
struct cpuidle_driver *drv = &omap3_idle_driver;
struct omap3_idle_statedata *cx;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
per_pd = pwrdm_lookup("per_pwrdm");
cam_pd = pwrdm_lookup("cam_pwrdm");
drv->safe_state_index = -1;
dev = &per_cpu(omap3_idle_dev, smp_processor_id());
/* C1 . MPU WFI + Core active */
_fill_cstate(drv, 0, "MPU ON + CORE ON");
(&drv->states[0])->enter = omap3_enter_idle;
drv->safe_state_index = 0;
cx = _fill_cstate_usage(dev, 0);
cx->valid = 1; /* C1 is always valid */
cx->mpu_state = PWRDM_POWER_ON;
cx->core_state = PWRDM_POWER_ON;
/* C2 . MPU WFI + Core inactive */
_fill_cstate(drv, 1, "MPU ON + CORE ON");
cx = _fill_cstate_usage(dev, 1);
cx->mpu_state = PWRDM_POWER_ON;
cx->core_state = PWRDM_POWER_ON;
/* C3 . MPU CSWR + Core inactive */
_fill_cstate(drv, 2, "MPU RET + CORE ON");
cx = _fill_cstate_usage(dev, 2);
cx->mpu_state = PWRDM_POWER_RET;
cx->core_state = PWRDM_POWER_ON;
/* C4 . MPU OFF + Core inactive */
_fill_cstate(drv, 3, "MPU OFF + CORE ON");
cx = _fill_cstate_usage(dev, 3);
cx->mpu_state = PWRDM_POWER_OFF;
cx->core_state = PWRDM_POWER_ON;
/* C5 . MPU RET + Core RET */
_fill_cstate(drv, 4, "MPU RET + CORE RET");
cx = _fill_cstate_usage(dev, 4);
cx->mpu_state = PWRDM_POWER_RET;
cx->core_state = PWRDM_POWER_RET;
/* C6 . MPU OFF + Core RET */
_fill_cstate(drv, 5, "MPU OFF + CORE RET");
cx = _fill_cstate_usage(dev, 5);
cx->mpu_state = PWRDM_POWER_OFF;
cx->core_state = PWRDM_POWER_RET;
/* C7 . MPU OFF + Core OFF */
_fill_cstate(drv, 6, "MPU OFF + CORE OFF");
cx = _fill_cstate_usage(dev, 6);
/*
* Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
* enable OFF mode in a stable form for previous revisions.
* We disable C7 state as a result.
*/
if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
cx->valid = 0;
pr_warn("%s: core off state C7 disabled due to i583\n",
__func__);
}
cx->mpu_state = PWRDM_POWER_OFF;
cx->core_state = PWRDM_POWER_OFF;
drv->state_count = OMAP3_NUM_STATES;
cpuidle_register_driver(&omap3_idle_driver);
dev->state_count = OMAP3_NUM_STATES;
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 */