arch/arm/mach-omap2/cpuidle34xx.c - fp2-dev/kernel/msm - 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 <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;
 }

 /**
  * 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 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]);
 	struct timespec ts_preidle, ts_postidle, ts_idle;
 	u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
 	int idle_time;

 	/* 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;

 	/* 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:
 	getnstimeofday(&ts_postidle);
 	ts_idle = timespec_sub(ts_postidle, ts_preidle);

 	local_irq_enable();
 	local_fiq_enable();

 	idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \
 								USEC_PER_SEC;

 	/* Update cpuidle counters */
 	dev->last_residency = idle_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 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 */
	/*
	* 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;
	}

	/**
	* 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 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]);
	struct timespec ts_preidle, ts_postidle, ts_idle;
	u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
	int idle_time;

	/* 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;

	/* 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:
	getnstimeofday(&ts_postidle);
	ts_idle = timespec_sub(ts_postidle, ts_preidle);

	local_irq_enable();
	local_fiq_enable();

	idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \
	USEC_PER_SEC;

	/* Update cpuidle counters */
	dev->last_residency = idle_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 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 */