arch/arm/mach-omap2/omap-mpuss-lowpower.c - maze/linux - Git at Google

 /*
  * OMAP MPUSS low power code
  *
  * Copyright (C) 2011 Texas Instruments, Inc.
  *	Santosh Shilimkar <santosh.shilimkar@ti.com>
  *
  * OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU
  * Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller,
  * CPU0 and CPU1 LPRM modules.
  * CPU0, CPU1 and MPUSS each have there own power domain and
  * hence multiple low power combinations of MPUSS are possible.
  *
  * The CPU0 and CPU1 can't support Closed switch Retention (CSWR)
  * because the mode is not supported by hw constraints of dormant
  * mode. While waking up from the dormant mode, a reset  signal
  * to the Cortex-A9 processor must be asserted by the external
  * power controller.
  *
  * With architectural inputs and hardware recommendations, only
  * below modes are supported from power gain vs latency point of view.
  *
  *	CPU0		CPU1		MPUSS
  *	----------------------------------------------
  *	ON		ON		ON
  *	ON(Inactive)	OFF		ON(Inactive)
  *	OFF		OFF		CSWR
  *	OFF		OFF		OSWR
  *	OFF		OFF		OFF(Device OFF *TBD)
  *	----------------------------------------------
  *
  * Note: CPU0 is the master core and it is the last CPU to go down
  * and first to wake-up when MPUSS low power states are excercised
  *
  *
  * 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/kernel.h>
 #include <linux/io.h>
 #include <linux/errno.h>
 #include <linux/linkage.h>
 #include <linux/smp.h>

 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 #include <asm/smp_scu.h>
 #include <asm/pgalloc.h>
 #include <asm/suspend.h>
 #include <asm/hardware/cache-l2x0.h>

 #include "soc.h"
 #include "common.h"
 #include "omap44xx.h"
 #include "omap4-sar-layout.h"
 #include "pm.h"
 #include "prcm_mpu44xx.h"
 #include "prminst44xx.h"
 #include "prcm44xx.h"
 #include "prm44xx.h"
 #include "prm-regbits-44xx.h"

 #ifdef CONFIG_SMP

 struct omap4_cpu_pm_info {
 	struct powerdomain *pwrdm;
 	void __iomem *scu_sar_addr;
 	void __iomem *wkup_sar_addr;
 	void __iomem *l2x0_sar_addr;
 	void (*secondary_startup)(void);
 };

 /**
  * struct cpu_pm_ops - CPU pm operations
  * @finish_suspend:	CPU suspend finisher function pointer
  * @resume:		CPU resume function pointer
  * @scu_prepare:	CPU Snoop Control program function pointer
  *
  * Structure holds functions pointer for CPU low power operations like
  * suspend, resume and scu programming.
  */
 struct cpu_pm_ops {
 	int (*finish_suspend)(unsigned long cpu_state);
 	void (*resume)(void);
 	void (*scu_prepare)(unsigned int cpu_id, unsigned int cpu_state);
 };

 static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
 static struct powerdomain *mpuss_pd;
 static void __iomem *sar_base;

 static int default_finish_suspend(unsigned long cpu_state)
 {
 	omap_do_wfi();
 	return 0;
 }

 static void dummy_cpu_resume(void)
 {}

 static void dummy_scu_prepare(unsigned int cpu_id, unsigned int cpu_state)
 {}

 struct cpu_pm_ops omap_pm_ops = {
 	.finish_suspend		= default_finish_suspend,
 	.resume			= dummy_cpu_resume,
 	.scu_prepare		= dummy_scu_prepare,
 };

 /*
  * Program the wakeup routine address for the CPU0 and CPU1
  * used for OFF or DORMANT wakeup.
  */
 static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

 	__raw_writel(addr, pm_info->wkup_sar_addr);
 }

 /*
  * Store the SCU power status value to scratchpad memory
  */
 static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
 	u32 scu_pwr_st;

 	switch (cpu_state) {
 	case PWRDM_POWER_RET:
 		scu_pwr_st = SCU_PM_DORMANT;
 		break;
 	case PWRDM_POWER_OFF:
 		scu_pwr_st = SCU_PM_POWEROFF;
 		break;
 	case PWRDM_POWER_ON:
 	case PWRDM_POWER_INACTIVE:
 	default:
 		scu_pwr_st = SCU_PM_NORMAL;
 		break;
 	}

 	__raw_writel(scu_pwr_st, pm_info->scu_sar_addr);
 }

 /* Helper functions for MPUSS OSWR */
 static inline void mpuss_clear_prev_logic_pwrst(void)
 {
 	u32 reg;

 	reg = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
 		OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
 	omap4_prminst_write_inst_reg(reg, OMAP4430_PRM_PARTITION,
 		OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
 }

 static inline void cpu_clear_prev_logic_pwrst(unsigned int cpu_id)
 {
 	u32 reg;

 	if (cpu_id) {
 		reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU1_INST,
 					OMAP4_RM_CPU1_CPU1_CONTEXT_OFFSET);
 		omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU1_INST,
 					OMAP4_RM_CPU1_CPU1_CONTEXT_OFFSET);
 	} else {
 		reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU0_INST,
 					OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET);
 		omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU0_INST,
 					OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET);
 	}
 }

 /*
  * Store the CPU cluster state for L2X0 low power operations.
  */
 static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

 	__raw_writel(save_state, pm_info->l2x0_sar_addr);
 }

 /*
  * Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
  * in every restore MPUSS OFF path.
  */
 #ifdef CONFIG_CACHE_L2X0
 static void save_l2x0_context(void)
 {
 	u32 val;
 	void __iomem *l2x0_base = omap4_get_l2cache_base();
 	if (l2x0_base) {
 		val = __raw_readl(l2x0_base + L2X0_AUX_CTRL);
 		__raw_writel(val, sar_base + L2X0_AUXCTRL_OFFSET);
 		val = __raw_readl(l2x0_base + L2X0_PREFETCH_CTRL);
 		__raw_writel(val, sar_base + L2X0_PREFETCH_CTRL_OFFSET);
 	}
 }
 #else
 static void save_l2x0_context(void)
 {}
 #endif

 /**
  * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
  * The purpose of this function is to manage low power programming
  * of OMAP4 MPUSS subsystem
  * @cpu : CPU ID
  * @power_state: Low power state.
  *
  * MPUSS states for the context save:
  * save_state =
  *	0 - Nothing lost and no need to save: MPUSS INACTIVE
  *	1 - CPUx L1 and logic lost: MPUSS CSWR
  *	2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
  *	3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
  */
 int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
 	unsigned int save_state = 0;
 	unsigned int wakeup_cpu;

 	if (omap_rev() == OMAP4430_REV_ES1_0)
 		return -ENXIO;

 	switch (power_state) {
 	case PWRDM_POWER_ON:
 	case PWRDM_POWER_INACTIVE:
 		save_state = 0;
 		break;
 	case PWRDM_POWER_OFF:
 		save_state = 1;
 		break;
 	case PWRDM_POWER_RET:
 	default:
 		/*
 		 * CPUx CSWR is invalid hardware state. Also CPUx OSWR
 		 * doesn't make much scense, since logic is lost and $L1
 		 * needs to be cleaned because of coherency. This makes
 		 * CPUx OSWR equivalent to CPUX OFF and hence not supported
 		 */
 		WARN_ON(1);
 		return -ENXIO;
 	}

 	pwrdm_pre_transition(NULL);

 	/*
 	 * Check MPUSS next state and save interrupt controller if needed.
 	 * In MPUSS OSWR or device OFF, interrupt controller  contest is lost.
 	 */
 	mpuss_clear_prev_logic_pwrst();
 	if ((pwrdm_read_next_pwrst(mpuss_pd) == PWRDM_POWER_RET) &&
 		(pwrdm_read_logic_retst(mpuss_pd) == PWRDM_POWER_OFF))
 		save_state = 2;

 	cpu_clear_prev_logic_pwrst(cpu);
 	pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
 	set_cpu_wakeup_addr(cpu, virt_to_phys(omap_pm_ops.resume));
 	omap_pm_ops.scu_prepare(cpu, power_state);
 	l2x0_pwrst_prepare(cpu, save_state);

 	/*
 	 * Call low level function  with targeted low power state.
 	 */
 	if (save_state)
 		cpu_suspend(save_state, omap_pm_ops.finish_suspend);
 	else
 		omap_pm_ops.finish_suspend(save_state);

 	if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && cpu)
 		gic_dist_enable();

 	/*
 	 * Restore the CPUx power state to ON otherwise CPUx
 	 * power domain can transitions to programmed low power
 	 * state while doing WFI outside the low powe code. On
 	 * secure devices, CPUx does WFI which can result in
 	 * domain transition
 	 */
 	wakeup_cpu = smp_processor_id();
 	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

 	pwrdm_post_transition(NULL);

 	return 0;
 }

 /**
  * omap4_hotplug_cpu: OMAP4 CPU hotplug entry
  * @cpu : CPU ID
  * @power_state: CPU low power state.
  */
 int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
 {
 	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
 	unsigned int cpu_state = 0;

 	if (omap_rev() == OMAP4430_REV_ES1_0)
 		return -ENXIO;

 	if (power_state == PWRDM_POWER_OFF)
 		cpu_state = 1;

 	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
 	pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
 	set_cpu_wakeup_addr(cpu, virt_to_phys(pm_info->secondary_startup));
 	omap_pm_ops.scu_prepare(cpu, power_state);

 	/*
 	 * CPU never retuns back if targeted power state is OFF mode.
 	 * CPU ONLINE follows normal CPU ONLINE ptah via
 	 * omap4_secondary_startup().
 	 */
 	omap_pm_ops.finish_suspend(cpu_state);

 	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
 	return 0;
 }


 /*
  * Initialise OMAP4 MPUSS
  */
 int __init omap4_mpuss_init(void)
 {
 	struct omap4_cpu_pm_info *pm_info;

 	if (omap_rev() == OMAP4430_REV_ES1_0) {
 		WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
 		return -ENODEV;
 	}

 	sar_base = omap4_get_sar_ram_base();

 	/* Initilaise per CPU PM information */
 	pm_info = &per_cpu(omap4_pm_info, 0x0);
 	pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
 	pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
 	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
 	pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
 	if (!pm_info->pwrdm) {
 		pr_err("Lookup failed for CPU0 pwrdm\n");
 		return -ENODEV;
 	}

 	/* Clear CPU previous power domain state */
 	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
 	cpu_clear_prev_logic_pwrst(0);

 	/* Initialise CPU0 power domain state to ON */
 	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

 	pm_info = &per_cpu(omap4_pm_info, 0x1);
 	pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
 	pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
 	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
 	if (cpu_is_omap446x())
 		pm_info->secondary_startup = omap4460_secondary_startup;
 	else
 		pm_info->secondary_startup = omap4_secondary_startup;

 	pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
 	if (!pm_info->pwrdm) {
 		pr_err("Lookup failed for CPU1 pwrdm\n");
 		return -ENODEV;
 	}

 	/* Clear CPU previous power domain state */
 	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
 	cpu_clear_prev_logic_pwrst(1);

 	/* Initialise CPU1 power domain state to ON */
 	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

 	mpuss_pd = pwrdm_lookup("mpu_pwrdm");
 	if (!mpuss_pd) {
 		pr_err("Failed to lookup MPUSS power domain\n");
 		return -ENODEV;
 	}
 	pwrdm_clear_all_prev_pwrst(mpuss_pd);
 	mpuss_clear_prev_logic_pwrst();

 	/* Save device type on scratchpad for low level code to use */
 	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
 		__raw_writel(1, sar_base + OMAP_TYPE_OFFSET);
 	else
 		__raw_writel(0, sar_base + OMAP_TYPE_OFFSET);

 	save_l2x0_context();

 	if (cpu_is_omap44xx()) {
 		omap_pm_ops.finish_suspend = omap4_finish_suspend;
 		omap_pm_ops.resume = omap4_cpu_resume;
 		omap_pm_ops.scu_prepare = scu_pwrst_prepare;
 	}

 	return 0;
 }

 #endif
	/*
	* OMAP MPUSS low power code
	*
	* Copyright (C) 2011 Texas Instruments, Inc.
	* Santosh Shilimkar <santosh.shilimkar@ti.com>
	*
	* OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU
	* Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller,
	* CPU0 and CPU1 LPRM modules.
	* CPU0, CPU1 and MPUSS each have there own power domain and
	* hence multiple low power combinations of MPUSS are possible.
	*
	* The CPU0 and CPU1 can't support Closed switch Retention (CSWR)
	* because the mode is not supported by hw constraints of dormant
	* mode. While waking up from the dormant mode, a reset signal
	* to the Cortex-A9 processor must be asserted by the external
	* power controller.
	*
	* With architectural inputs and hardware recommendations, only
	* below modes are supported from power gain vs latency point of view.
	*
	* CPU0 CPU1 MPUSS
	* ----------------------------------------------
	* ON ON ON
	* ON(Inactive) OFF ON(Inactive)
	* OFF OFF CSWR
	* OFF OFF OSWR
	* OFF OFF OFF(Device OFF *TBD)
	* ----------------------------------------------
	*
	* Note: CPU0 is the master core and it is the last CPU to go down
	* and first to wake-up when MPUSS low power states are excercised
	*
	*
	* 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/kernel.h>
	#include <linux/io.h>
	#include <linux/errno.h>
	#include <linux/linkage.h>
	#include <linux/smp.h>

	#include <asm/cacheflush.h>
	#include <asm/tlbflush.h>
	#include <asm/smp_scu.h>
	#include <asm/pgalloc.h>
	#include <asm/suspend.h>
	#include <asm/hardware/cache-l2x0.h>

	#include "soc.h"
	#include "common.h"
	#include "omap44xx.h"
	#include "omap4-sar-layout.h"
	#include "pm.h"
	#include "prcm_mpu44xx.h"
	#include "prminst44xx.h"
	#include "prcm44xx.h"
	#include "prm44xx.h"
	#include "prm-regbits-44xx.h"

	#ifdef CONFIG_SMP

	struct omap4_cpu_pm_info {
	struct powerdomain *pwrdm;
	void __iomem *scu_sar_addr;
	void __iomem *wkup_sar_addr;
	void __iomem *l2x0_sar_addr;
	void (*secondary_startup)(void);
	};

	/**
	* struct cpu_pm_ops - CPU pm operations
	* @finish_suspend: CPU suspend finisher function pointer
	* @resume: CPU resume function pointer
	* @scu_prepare: CPU Snoop Control program function pointer
	*
	* Structure holds functions pointer for CPU low power operations like
	* suspend, resume and scu programming.
	*/
	struct cpu_pm_ops {
	int (*finish_suspend)(unsigned long cpu_state);
	void (*resume)(void);
	void (*scu_prepare)(unsigned int cpu_id, unsigned int cpu_state);
	};

	static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
	static struct powerdomain *mpuss_pd;
	static void __iomem *sar_base;

	static int default_finish_suspend(unsigned long cpu_state)
	{
	omap_do_wfi();
	return 0;
	}

	static void dummy_cpu_resume(void)
	{}

	static void dummy_scu_prepare(unsigned int cpu_id, unsigned int cpu_state)
	{}

	struct cpu_pm_ops omap_pm_ops = {
	.finish_suspend = default_finish_suspend,
	.resume = dummy_cpu_resume,
	.scu_prepare = dummy_scu_prepare,
	};

	/*
	* Program the wakeup routine address for the CPU0 and CPU1
	* used for OFF or DORMANT wakeup.
	*/
	static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr)
	{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	__raw_writel(addr, pm_info->wkup_sar_addr);
	}

	/*
	* Store the SCU power status value to scratchpad memory
	*/
	static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
	{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
	u32 scu_pwr_st;

	switch (cpu_state) {
	case PWRDM_POWER_RET:
	scu_pwr_st = SCU_PM_DORMANT;
	break;
	case PWRDM_POWER_OFF:
	scu_pwr_st = SCU_PM_POWEROFF;
	break;
	case PWRDM_POWER_ON:
	case PWRDM_POWER_INACTIVE:
	default:
	scu_pwr_st = SCU_PM_NORMAL;
	break;
	}

	__raw_writel(scu_pwr_st, pm_info->scu_sar_addr);
	}

	/* Helper functions for MPUSS OSWR */
	static inline void mpuss_clear_prev_logic_pwrst(void)
	{
	u32 reg;

	reg = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
	OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
	omap4_prminst_write_inst_reg(reg, OMAP4430_PRM_PARTITION,
	OMAP4430_PRM_MPU_INST, OMAP4_RM_MPU_MPU_CONTEXT_OFFSET);
	}

	static inline void cpu_clear_prev_logic_pwrst(unsigned int cpu_id)
	{
	u32 reg;

	if (cpu_id) {
	reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU1_INST,
	OMAP4_RM_CPU1_CPU1_CONTEXT_OFFSET);
	omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU1_INST,
	OMAP4_RM_CPU1_CPU1_CONTEXT_OFFSET);
	} else {
	reg = omap4_prcm_mpu_read_inst_reg(OMAP4430_PRCM_MPU_CPU0_INST,
	OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET);
	omap4_prcm_mpu_write_inst_reg(reg, OMAP4430_PRCM_MPU_CPU0_INST,
	OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET);
	}
	}

	/*
	* Store the CPU cluster state for L2X0 low power operations.
	*/
	static void l2x0_pwrst_prepare(unsigned int cpu_id, unsigned int save_state)
	{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);

	__raw_writel(save_state, pm_info->l2x0_sar_addr);
	}

	/*
	* Save the L2X0 AUXCTRL and POR value to SAR memory. Its used to
	* in every restore MPUSS OFF path.
	*/
	#ifdef CONFIG_CACHE_L2X0
	static void save_l2x0_context(void)
	{
	u32 val;
	void __iomem *l2x0_base = omap4_get_l2cache_base();
	if (l2x0_base) {
	val = __raw_readl(l2x0_base + L2X0_AUX_CTRL);
	__raw_writel(val, sar_base + L2X0_AUXCTRL_OFFSET);
	val = __raw_readl(l2x0_base + L2X0_PREFETCH_CTRL);
	__raw_writel(val, sar_base + L2X0_PREFETCH_CTRL_OFFSET);
	}
	}
	#else
	static void save_l2x0_context(void)
	{}
	#endif

	/**
	* omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
	* The purpose of this function is to manage low power programming
	* of OMAP4 MPUSS subsystem
	* @cpu : CPU ID
	* @power_state: Low power state.
	*
	* MPUSS states for the context save:
	* save_state =
	* 0 - Nothing lost and no need to save: MPUSS INACTIVE
	* 1 - CPUx L1 and logic lost: MPUSS CSWR
	* 2 - CPUx L1 and logic lost + GIC lost: MPUSS OSWR
	* 3 - CPUx L1 and logic lost + GIC + L2 lost: DEVICE OFF
	*/
	int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
	{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
	unsigned int save_state = 0;
	unsigned int wakeup_cpu;

	if (omap_rev() == OMAP4430_REV_ES1_0)
	return -ENXIO;

	switch (power_state) {
	case PWRDM_POWER_ON:
	case PWRDM_POWER_INACTIVE:
	save_state = 0;
	break;
	case PWRDM_POWER_OFF:
	save_state = 1;
	break;
	case PWRDM_POWER_RET:
	default:
	/*
	* CPUx CSWR is invalid hardware state. Also CPUx OSWR
	* doesn't make much scense, since logic is lost and $L1
	* needs to be cleaned because of coherency. This makes
	* CPUx OSWR equivalent to CPUX OFF and hence not supported
	*/
	WARN_ON(1);
	return -ENXIO;
	}

	pwrdm_pre_transition(NULL);

	/*
	* Check MPUSS next state and save interrupt controller if needed.
	* In MPUSS OSWR or device OFF, interrupt controller contest is lost.
	*/
	mpuss_clear_prev_logic_pwrst();
	if ((pwrdm_read_next_pwrst(mpuss_pd) == PWRDM_POWER_RET) &&
	(pwrdm_read_logic_retst(mpuss_pd) == PWRDM_POWER_OFF))
	save_state = 2;

	cpu_clear_prev_logic_pwrst(cpu);
	pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
	set_cpu_wakeup_addr(cpu, virt_to_phys(omap_pm_ops.resume));
	omap_pm_ops.scu_prepare(cpu, power_state);
	l2x0_pwrst_prepare(cpu, save_state);

	/*
	* Call low level function with targeted low power state.
	*/
	if (save_state)
	cpu_suspend(save_state, omap_pm_ops.finish_suspend);
	else
	omap_pm_ops.finish_suspend(save_state);

	if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && cpu)
	gic_dist_enable();

	/*
	* Restore the CPUx power state to ON otherwise CPUx
	* power domain can transitions to programmed low power
	* state while doing WFI outside the low powe code. On
	* secure devices, CPUx does WFI which can result in
	* domain transition
	*/
	wakeup_cpu = smp_processor_id();
	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

	pwrdm_post_transition(NULL);

	return 0;
	}

	/**
	* omap4_hotplug_cpu: OMAP4 CPU hotplug entry
	* @cpu : CPU ID
	* @power_state: CPU low power state.
	*/
	int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state)
	{
	struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu);
	unsigned int cpu_state = 0;

	if (omap_rev() == OMAP4430_REV_ES1_0)
	return -ENXIO;

	if (power_state == PWRDM_POWER_OFF)
	cpu_state = 1;

	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
	pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
	set_cpu_wakeup_addr(cpu, virt_to_phys(pm_info->secondary_startup));
	omap_pm_ops.scu_prepare(cpu, power_state);

	/*
	* CPU never retuns back if targeted power state is OFF mode.
	* CPU ONLINE follows normal CPU ONLINE ptah via
	* omap4_secondary_startup().
	*/
	omap_pm_ops.finish_suspend(cpu_state);

	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
	return 0;
	}


	/*
	* Initialise OMAP4 MPUSS
	*/
	int __init omap4_mpuss_init(void)
	{
	struct omap4_cpu_pm_info *pm_info;

	if (omap_rev() == OMAP4430_REV_ES1_0) {
	WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
	return -ENODEV;
	}

	sar_base = omap4_get_sar_ram_base();

	/* Initilaise per CPU PM information */
	pm_info = &per_cpu(omap4_pm_info, 0x0);
	pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
	pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET0;
	pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
	if (!pm_info->pwrdm) {
	pr_err("Lookup failed for CPU0 pwrdm\n");
	return -ENODEV;
	}

	/* Clear CPU previous power domain state */
	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
	cpu_clear_prev_logic_pwrst(0);

	/* Initialise CPU0 power domain state to ON */
	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

	pm_info = &per_cpu(omap4_pm_info, 0x1);
	pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
	pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
	pm_info->l2x0_sar_addr = sar_base + L2X0_SAVE_OFFSET1;
	if (cpu_is_omap446x())
	pm_info->secondary_startup = omap4460_secondary_startup;
	else
	pm_info->secondary_startup = omap4_secondary_startup;

	pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
	if (!pm_info->pwrdm) {
	pr_err("Lookup failed for CPU1 pwrdm\n");
	return -ENODEV;
	}

	/* Clear CPU previous power domain state */
	pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
	cpu_clear_prev_logic_pwrst(1);

	/* Initialise CPU1 power domain state to ON */
	pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);

	mpuss_pd = pwrdm_lookup("mpu_pwrdm");
	if (!mpuss_pd) {
	pr_err("Failed to lookup MPUSS power domain\n");
	return -ENODEV;
	}
	pwrdm_clear_all_prev_pwrst(mpuss_pd);
	mpuss_clear_prev_logic_pwrst();

	/* Save device type on scratchpad for low level code to use */
	if (omap_type() != OMAP2_DEVICE_TYPE_GP)
	__raw_writel(1, sar_base + OMAP_TYPE_OFFSET);
	else
	__raw_writel(0, sar_base + OMAP_TYPE_OFFSET);

	save_l2x0_context();

	if (cpu_is_omap44xx()) {
	omap_pm_ops.finish_suspend = omap4_finish_suspend;
	omap_pm_ops.resume = omap4_cpu_resume;
	omap_pm_ops.scu_prepare = scu_pwrst_prepare;
	}

	return 0;
	}

	#endif