/*
* 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 <asm/cpuidle.h>
#include "powerdomain.h"
#include "clockdomain.h"
#include "pm.h"
#include "control.h"
#include "common.h"
/* Mach specific information to be recorded in the C-state driver_data */
struct omap3_idle_statedata {
u8 mpu_state;
u8 core_state;
u8 per_min_state;
u8 flags;
};
static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
/*
* Possible flag bits for struct omap3_idle_statedata.flags:
*
* OMAP_CPUIDLE_CX_NO_CLKDM_IDLE: don't allow the MPU clockdomain to go
* inactive. This in turn prevents the MPU DPLL from entering autoidle
* mode, so wakeup latency is greatly reduced, at the cost of additional
* energy consumption. This also prevents the CORE clockdomain from
* entering idle.
*/
#define OMAP_CPUIDLE_CX_NO_CLKDM_IDLE BIT(0)
/*
* Prevent PER OFF if CORE is not in RETention or OFF as this would
* disable PER wakeups completely.
*/
static struct omap3_idle_statedata omap3_idle_data[] = {
{
.mpu_state = PWRDM_POWER_ON,
.core_state = PWRDM_POWER_ON,
/* In C1 do not allow PER state lower than CORE state */
.per_min_state = PWRDM_POWER_ON,
.flags = OMAP_CPUIDLE_CX_NO_CLKDM_IDLE,
},
{
.mpu_state = PWRDM_POWER_ON,
.core_state = PWRDM_POWER_ON,
.per_min_state = PWRDM_POWER_RET,
},
{
.mpu_state = PWRDM_POWER_RET,
.core_state = PWRDM_POWER_ON,
.per_min_state = PWRDM_POWER_RET,
},
{
.mpu_state = PWRDM_POWER_OFF,
.core_state = PWRDM_POWER_ON,
.per_min_state = PWRDM_POWER_RET,
},
{
.mpu_state = PWRDM_POWER_RET,
.core_state = PWRDM_POWER_RET,
.per_min_state = PWRDM_POWER_OFF,
},
{
.mpu_state = PWRDM_POWER_OFF,
.core_state = PWRDM_POWER_RET,
.per_min_state = PWRDM_POWER_OFF,
},
{
.mpu_state = PWRDM_POWER_OFF,
.core_state = PWRDM_POWER_OFF,
.per_min_state = PWRDM_POWER_OFF,
},
};
/**
* omap3_enter_idle - Programs OMAP3 to enter the specified state
* @dev: cpuidle device
* @drv: cpuidle driver
* @index: the index of state to be entered
*/
static int omap3_enter_idle(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct omap3_idle_statedata *cx = &omap3_idle_data[index];
if (omap_irq_pending() || need_resched())
goto return_sleep_time;
/* Deny idle for C1 */
if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE) {
clkdm_deny_idle(mpu_pd->pwrdm_clkdms[0]);
} else {
pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
pwrdm_set_next_pwrst(core_pd, cx->core_state);
}
/*
* Call idle CPU PM enter notifier chain so that
* VFP context is saved.
*/
if (cx->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 (cx->mpu_state == PWRDM_POWER_OFF &&
pwrdm_read_prev_pwrst(mpu_pd) == PWRDM_POWER_OFF)
cpu_pm_exit();
/* Re-allow idle for C1 */
if (cx->flags & OMAP_CPUIDLE_CX_NO_CLKDM_IDLE)
clkdm_allow_idle(mpu_pd->pwrdm_clkdms[0]);
return_sleep_time:
return index;
}
/**
* 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 omap3_idle_statedata *cx = &omap3_idle_data[index];
u32 mpu_deepest_state = PWRDM_POWER_RET;
u32 core_deepest_state = PWRDM_POWER_RET;
int idx;
int next_index = 0; /* C1 is the default value */
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->mpu_state >= mpu_deepest_state) &&
(cx->core_state >= core_deepest_state))
return index;
/*
* Drop to next valid state.
* Start search from the next (lower) state.
*/
for (idx = index - 1; idx >= 0; idx--) {
cx = &omap3_idle_data[idx];
if ((cx->mpu_state >= mpu_deepest_state) &&
(cx->core_state >= core_deepest_state)) {
next_index = idx;
break;
}
}
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, ret;
u8 per_next_state, per_saved_state;
struct omap3_idle_statedata *cx;
/*
* Use only C1 if CAM is active.
* CAM does not have wakeup capability in OMAP3.
*/
if (pwrdm_read_pwrst(cam_pd) == PWRDM_POWER_ON)
new_state_idx = drv->safe_state_index;
else
new_state_idx = next_valid_state(dev, drv, index);
/*
* 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.
*/
/* Program PER state */
cx = &omap3_idle_data[new_state_idx];
per_next_state = pwrdm_read_next_pwrst(per_pd);
per_saved_state = per_next_state;
if (per_next_state < cx->per_min_state) {
per_next_state = cx->per_min_state;
pwrdm_set_next_pwrst(per_pd, per_next_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;
}
static struct cpuidle_driver omap3_idle_driver = {
.name = "omap3_idle",
.owner = THIS_MODULE,
.states = {
{
.enter = omap3_enter_idle_bm,
.exit_latency = 2 + 2,
.target_residency = 5,
.name = "C1",
.desc = "MPU ON + CORE ON",
},
{
.enter = omap3_enter_idle_bm,
.exit_latency = 10 + 10,
.target_residency = 30,
.name = "C2",
.desc = "MPU ON + CORE ON",
},
{
.enter = omap3_enter_idle_bm,
.exit_latency = 50 + 50,
.target_residency = 300,
.name = "C3",
.desc = "MPU RET + CORE ON",
},
{
.enter = omap3_enter_idle_bm,
.exit_latency = 1500 + 1800,
.target_residency = 4000,
.name = "C4",
.desc = "MPU OFF + CORE ON",
},
{
.enter = omap3_enter_idle_bm,
.exit_latency = 2500 + 7500,
.target_residency = 12000,
.name = "C5",
.desc = "MPU RET + CORE RET",
},
{
.enter = omap3_enter_idle_bm,
.exit_latency = 3000 + 8500,
.target_residency = 15000,
.name = "C6",
.desc = "MPU OFF + CORE RET",
},
{
.enter = omap3_enter_idle_bm,
.exit_latency = 10000 + 30000,
.target_residency = 30000,
.name = "C7",
.desc = "MPU OFF + CORE OFF",
},
},
.state_count = ARRAY_SIZE(omap3_idle_data),
.safe_state_index = 0,
};
/* Public functions */
/**
* 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)
{
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
per_pd = pwrdm_lookup("per_pwrdm");
cam_pd = pwrdm_lookup("cam_pwrdm");
if (!mpu_pd || !core_pd || !per_pd || !cam_pd)
return -ENODEV;
return cpuidle_register(&omap3_idle_driver, NULL);
}