arch/arm/mach-omap2/cpuidle34xx.c - kernel/msm-4.9 - Gitiles

 /*
  * 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 */

 #define OMAP3_STATE_MAX OMAP3_STATE_C7

 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;

 /*
  * 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 */
 	{1, 2, 2, 5},
 	/* C2 */
 	{1, 10, 10, 30},
 	/* C3 */
 	{1, 50, 50, 300},
 	/* C4 */
 	{1, 1500, 1800, 4000},
 	/* C5 */
 	{1, 2500, 7500, 12000},
 	/* C6 */
 	{1, 3000, 8500, 15000},
 	/* C7 */
 	{1, 10000, 30000, 300000},
 };

 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();

 	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 ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
 }

 /**
  * next_valid_state - Find next valid c-state
  * @dev: cpuidle device
  * @state: Currently selected c-state
  *
  * If the current state is valid, it 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[]).
  */
 static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
 						struct cpuidle_state *curr)
 {
 	struct cpuidle_state *next = NULL;
 	struct omap3_processor_cx *cx;

 	cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);

 	/* Check if current state is valid */
 	if (cx->valid) {
 		return curr;
 	} else {
 		u8 idx = OMAP3_STATE_MAX;

 		/*
 		 * Reach the current state starting at highest C-state
 		 */
 		for (; idx >= OMAP3_STATE_C1; idx--) {
 			if (&dev->states[idx] == curr) {
 				next = &dev->states[idx];
 				break;
 			}
 		}

 		/*
 		 * Should never hit this condition.
 		 */
 		WARN_ON(next == NULL);

 		/*
 		 * Drop to next valid state.
 		 * Start search from the next (lower) state.
 		 */
 		idx--;
 		for (; idx >= OMAP3_STATE_C1; idx--) {
 			struct omap3_processor_cx *cx;

 			cx = cpuidle_get_statedata(&dev->states[idx]);
 			if (cx->valid) {
 				next = &dev->states[idx];
 				break;
 			}
 		}
 		/*
 		 * C1 and C2 are always valid.
 		 * So, no need to check for 'next==NULL' outside this loop.
 		 */
 	}

 	return next;
 }

 /**
  * 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 = next_valid_state(dev, 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_cpuidle_update_states - Update the cpuidle states.
  *
  * Currently, this function toggles the validity of idle states based upon
  * the flag 'enable_off_mode'. When the flag is set all states are valid.
  * Else, states leading to OFF state set to be invalid.
  */
 void omap3_cpuidle_update_states(void)
 {
 	int i;

 	for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
 		struct omap3_processor_cx *cx = &omap3_power_states[i];

 		if (enable_off_mode) {
 			cx->valid = 1;
 		} else {
 			if ((cx->mpu_state == PWRDM_POWER_OFF) ||
 				(cx->core_state	== PWRDM_POWER_OFF))
 				cx->valid = 0;
 		}
 	}
 }

 void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
 {
 	int i;

 	if (!cpuidle_board_params)
 		return;

 	for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
 		cpuidle_params_table[i].valid =
 			cpuidle_board_params[i].valid;
 		cpuidle_params_table[i].sleep_latency =
 			cpuidle_board_params[i].sleep_latency;
 		cpuidle_params_table[i].wake_latency =
 			cpuidle_board_params[i].wake_latency;
 		cpuidle_params_table[i].threshold =
 			cpuidle_board_params[i].threshold;
 	}
 	return;
 }

 /* 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 =
 			cpuidle_params_table[OMAP3_STATE_C1].valid;
 	omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
 	omap3_power_states[OMAP3_STATE_C1].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C1].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C1].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C1].wake_latency;
 	omap3_power_states[OMAP3_STATE_C1].threshold =
 			cpuidle_params_table[OMAP3_STATE_C1].threshold;
 	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 =
 			cpuidle_params_table[OMAP3_STATE_C2].valid;
 	omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
 	omap3_power_states[OMAP3_STATE_C2].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C2].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C2].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C2].wake_latency;
 	omap3_power_states[OMAP3_STATE_C2].threshold =
 			cpuidle_params_table[OMAP3_STATE_C2].threshold;
 	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 =
 			cpuidle_params_table[OMAP3_STATE_C3].valid;
 	omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
 	omap3_power_states[OMAP3_STATE_C3].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C3].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C3].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C3].wake_latency;
 	omap3_power_states[OMAP3_STATE_C3].threshold =
 			cpuidle_params_table[OMAP3_STATE_C3].threshold;
 	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 =
 			cpuidle_params_table[OMAP3_STATE_C4].valid;
 	omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
 	omap3_power_states[OMAP3_STATE_C4].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C4].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C4].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C4].wake_latency;
 	omap3_power_states[OMAP3_STATE_C4].threshold =
 			cpuidle_params_table[OMAP3_STATE_C4].threshold;
 	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 =
 			cpuidle_params_table[OMAP3_STATE_C5].valid;
 	omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
 	omap3_power_states[OMAP3_STATE_C5].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C5].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C5].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C5].wake_latency;
 	omap3_power_states[OMAP3_STATE_C5].threshold =
 			cpuidle_params_table[OMAP3_STATE_C5].threshold;
 	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 =
 			cpuidle_params_table[OMAP3_STATE_C6].valid;
 	omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
 	omap3_power_states[OMAP3_STATE_C6].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C6].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C6].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C6].wake_latency;
 	omap3_power_states[OMAP3_STATE_C6].threshold =
 			cpuidle_params_table[OMAP3_STATE_C6].threshold;
 	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 =
 			cpuidle_params_table[OMAP3_STATE_C7].valid;
 	omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
 	omap3_power_states[OMAP3_STATE_C7].sleep_latency =
 			cpuidle_params_table[OMAP3_STATE_C7].sleep_latency;
 	omap3_power_states[OMAP3_STATE_C7].wakeup_latency =
 			cpuidle_params_table[OMAP3_STATE_C7].wake_latency;
 	omap3_power_states[OMAP3_STATE_C7].threshold =
 			cpuidle_params_table[OMAP3_STATE_C7].threshold;
 	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;

 	omap3_cpuidle_update_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 */
	/*
	* 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 */

	#define OMAP3_STATE_MAX OMAP3_STATE_C7

	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;

	/*
	* 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 */
	{1, 2, 2, 5},
	/* C2 */
	{1, 10, 10, 30},
	/* C3 */
	{1, 50, 50, 300},
	/* C4 */
	{1, 1500, 1800, 4000},
	/* C5 */
	{1, 2500, 7500, 12000},
	/* C6 */
	{1, 3000, 8500, 15000},
	/* C7 */
	{1, 10000, 30000, 300000},
	};

	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();

	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 ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
	}

	/**
	* next_valid_state - Find next valid c-state
	* @dev: cpuidle device
	* @state: Currently selected c-state
	*
	* If the current state is valid, it 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[]).
	*/
	static struct cpuidle_state next_valid_state(struct cpuidle_device dev,
	struct cpuidle_state *curr)
	{
	struct cpuidle_state *next = NULL;
	struct omap3_processor_cx *cx;

	cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);

	/* Check if current state is valid */
	if (cx->valid) {
	return curr;
	} else {
	u8 idx = OMAP3_STATE_MAX;

	/*
	* Reach the current state starting at highest C-state
	*/
	for (; idx >= OMAP3_STATE_C1; idx--) {
	if (&dev->states[idx] == curr) {
	next = &dev->states[idx];
	break;
	}
	}

	/*
	* Should never hit this condition.
	*/
	WARN_ON(next == NULL);

	/*
	* Drop to next valid state.
	* Start search from the next (lower) state.
	*/
	idx--;
	for (; idx >= OMAP3_STATE_C1; idx--) {
	struct omap3_processor_cx *cx;

	cx = cpuidle_get_statedata(&dev->states[idx]);
	if (cx->valid) {
	next = &dev->states[idx];
	break;
	}
	}
	/*
	* C1 and C2 are always valid.
	* So, no need to check for 'next==NULL' outside this loop.
	*/
	}

	return next;
	}

	/**
	* 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 = next_valid_state(dev, 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_cpuidle_update_states - Update the cpuidle states.
	*
	* Currently, this function toggles the validity of idle states based upon
	* the flag 'enable_off_mode'. When the flag is set all states are valid.
	* Else, states leading to OFF state set to be invalid.
	*/
	void omap3_cpuidle_update_states(void)
	{
	int i;

	for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
	struct omap3_processor_cx *cx = &omap3_power_states[i];

	if (enable_off_mode) {
	cx->valid = 1;
	} else {
	if ((cx->mpu_state == PWRDM_POWER_OFF) \|\|
	(cx->core_state == PWRDM_POWER_OFF))
	cx->valid = 0;
	}
	}
	}

	void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
	{
	int i;

	if (!cpuidle_board_params)
	return;

	for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
	cpuidle_params_table[i].valid =
	cpuidle_board_params[i].valid;
	cpuidle_params_table[i].sleep_latency =
	cpuidle_board_params[i].sleep_latency;
	cpuidle_params_table[i].wake_latency =
	cpuidle_board_params[i].wake_latency;
	cpuidle_params_table[i].threshold =
	cpuidle_board_params[i].threshold;
	}
	return;
	}

	/* 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 =
	cpuidle_params_table[OMAP3_STATE_C1].valid;
	omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
	omap3_power_states[OMAP3_STATE_C1].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C1].sleep_latency;
	omap3_power_states[OMAP3_STATE_C1].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C1].wake_latency;
	omap3_power_states[OMAP3_STATE_C1].threshold =
	cpuidle_params_table[OMAP3_STATE_C1].threshold;
	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 =
	cpuidle_params_table[OMAP3_STATE_C2].valid;
	omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
	omap3_power_states[OMAP3_STATE_C2].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C2].sleep_latency;
	omap3_power_states[OMAP3_STATE_C2].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C2].wake_latency;
	omap3_power_states[OMAP3_STATE_C2].threshold =
	cpuidle_params_table[OMAP3_STATE_C2].threshold;
	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 =
	cpuidle_params_table[OMAP3_STATE_C3].valid;
	omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
	omap3_power_states[OMAP3_STATE_C3].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C3].sleep_latency;
	omap3_power_states[OMAP3_STATE_C3].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C3].wake_latency;
	omap3_power_states[OMAP3_STATE_C3].threshold =
	cpuidle_params_table[OMAP3_STATE_C3].threshold;
	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 =
	cpuidle_params_table[OMAP3_STATE_C4].valid;
	omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
	omap3_power_states[OMAP3_STATE_C4].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C4].sleep_latency;
	omap3_power_states[OMAP3_STATE_C4].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C4].wake_latency;
	omap3_power_states[OMAP3_STATE_C4].threshold =
	cpuidle_params_table[OMAP3_STATE_C4].threshold;
	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 =
	cpuidle_params_table[OMAP3_STATE_C5].valid;
	omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
	omap3_power_states[OMAP3_STATE_C5].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C5].sleep_latency;
	omap3_power_states[OMAP3_STATE_C5].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C5].wake_latency;
	omap3_power_states[OMAP3_STATE_C5].threshold =
	cpuidle_params_table[OMAP3_STATE_C5].threshold;
	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 =
	cpuidle_params_table[OMAP3_STATE_C6].valid;
	omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
	omap3_power_states[OMAP3_STATE_C6].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C6].sleep_latency;
	omap3_power_states[OMAP3_STATE_C6].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C6].wake_latency;
	omap3_power_states[OMAP3_STATE_C6].threshold =
	cpuidle_params_table[OMAP3_STATE_C6].threshold;
	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 =
	cpuidle_params_table[OMAP3_STATE_C7].valid;
	omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
	omap3_power_states[OMAP3_STATE_C7].sleep_latency =
	cpuidle_params_table[OMAP3_STATE_C7].sleep_latency;
	omap3_power_states[OMAP3_STATE_C7].wakeup_latency =
	cpuidle_params_table[OMAP3_STATE_C7].wake_latency;
	omap3_power_states[OMAP3_STATE_C7].threshold =
	cpuidle_params_table[OMAP3_STATE_C7].threshold;
	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;

	omap3_cpuidle_update_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 */