arch/arm/mach-omap2/pm24xx.c - kernel/msm-4.19 - Gitiles

 /*
  * OMAP2 Power Management Routines
  *
  * Copyright (C) 2005 Texas Instruments, Inc.
  * Copyright (C) 2006-2008 Nokia Corporation
  *
  * Written by:
  * Richard Woodruff <r-woodruff2@ti.com>
  * Tony Lindgren
  * Juha Yrjola
  * Amit Kucheria <amit.kucheria@nokia.com>
  * Igor Stoppa <igor.stoppa@nokia.com>
  *
  * Based on pm.c for omap1
  *
  * 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/suspend.h>
 #include <linux/sched.h>
 #include <linux/proc_fs.h>
 #include <linux/interrupt.h>
 #include <linux/sysfs.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/irq.h>
 #include <linux/time.h>
 #include <linux/gpio.h>

 #include <asm/mach/time.h>
 #include <asm/mach/irq.h>
 #include <asm/mach-types.h>

 #include <plat/clock.h>
 #include <plat/sram.h>
 #include <plat/dma.h>
 #include <plat/board.h>

 #include <mach/irqs.h>

 #include "common.h"
 #include "prm2xxx_3xxx.h"
 #include "prm-regbits-24xx.h"
 #include "cm2xxx_3xxx.h"
 #include "cm-regbits-24xx.h"
 #include "sdrc.h"
 #include "pm.h"
 #include "control.h"
 #include "powerdomain.h"
 #include "clockdomain.h"

 #ifdef CONFIG_SUSPEND
 static suspend_state_t suspend_state = PM_SUSPEND_ON;
 static inline bool is_suspending(void)
 {
 	return (suspend_state != PM_SUSPEND_ON);
 }
 #else
 static inline bool is_suspending(void)
 {
 	return false;
 }
 #endif

 static void (*omap2_sram_idle)(void);
 static void (*omap2_sram_suspend)(u32 dllctrl, void __iomem *sdrc_dlla_ctrl,
 				  void __iomem *sdrc_power);

 static struct powerdomain *mpu_pwrdm, *core_pwrdm;
 static struct clockdomain *dsp_clkdm, *mpu_clkdm, *wkup_clkdm, *gfx_clkdm;

 static struct clk *osc_ck, *emul_ck;

 static int omap2_fclks_active(void)
 {
 	u32 f1, f2;

 	f1 = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
 	f2 = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);

 	return (f1 | f2) ? 1 : 0;
 }

 static void omap2_enter_full_retention(void)
 {
 	u32 l;

 	/* There is 1 reference hold for all children of the oscillator
 	 * clock, the following will remove it. If no one else uses the
 	 * oscillator itself it will be disabled if/when we enter retention
 	 * mode.
 	 */
 	clk_disable(osc_ck);

 	/* Clear old wake-up events */
 	/* REVISIT: These write to reserved bits? */
 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
 	omap2_prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);

 	/*
 	 * Set MPU powerdomain's next power state to RETENTION;
 	 * preserve logic state during retention
 	 */
 	pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
 	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);

 	/* Workaround to kill USB */
 	l = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0) | OMAP24XX_USBSTANDBYCTRL;
 	omap_ctrl_writel(l, OMAP2_CONTROL_DEVCONF0);

 	omap2_gpio_prepare_for_idle(0);

 	/* One last check for pending IRQs to avoid extra latency due
 	 * to sleeping unnecessarily. */
 	if (omap_irq_pending())
 		goto no_sleep;

 	/* Jump to SRAM suspend code */
 	omap2_sram_suspend(sdrc_read_reg(SDRC_DLLA_CTRL),
 			   OMAP_SDRC_REGADDR(SDRC_DLLA_CTRL),
 			   OMAP_SDRC_REGADDR(SDRC_POWER));

 no_sleep:
 	omap2_gpio_resume_after_idle();

 	clk_enable(osc_ck);

 	/* clear CORE wake-up events */
 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
 	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);

 	/* wakeup domain events - bit 1: GPT1, bit5 GPIO */
 	omap2_prm_clear_mod_reg_bits(0x4 | 0x1, WKUP_MOD, PM_WKST);

 	/* MPU domain wake events */
 	l = omap2_prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
 	if (l & 0x01)
 		omap2_prm_write_mod_reg(0x01, OCP_MOD,
 				  OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
 	if (l & 0x20)
 		omap2_prm_write_mod_reg(0x20, OCP_MOD,
 				  OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);

 	/* Mask future PRCM-to-MPU interrupts */
 	omap2_prm_write_mod_reg(0x0, OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
 }

 static int omap2_i2c_active(void)
 {
 	u32 l;

 	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
 	return l & (OMAP2420_EN_I2C2_MASK | OMAP2420_EN_I2C1_MASK);
 }

 static int sti_console_enabled;

 static int omap2_allow_mpu_retention(void)
 {
 	u32 l;

 	/* Check for MMC, UART2, UART1, McSPI2, McSPI1 and DSS1. */
 	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
 	if (l & (OMAP2420_EN_MMC_MASK | OMAP24XX_EN_UART2_MASK |
 		 OMAP24XX_EN_UART1_MASK | OMAP24XX_EN_MCSPI2_MASK |
 		 OMAP24XX_EN_MCSPI1_MASK | OMAP24XX_EN_DSS1_MASK))
 		return 0;
 	/* Check for UART3. */
 	l = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
 	if (l & OMAP24XX_EN_UART3_MASK)
 		return 0;
 	if (sti_console_enabled)
 		return 0;

 	return 1;
 }

 static void omap2_enter_mpu_retention(void)
 {
 	int only_idle = 0;

 	/* Putting MPU into the WFI state while a transfer is active
 	 * seems to cause the I2C block to timeout. Why? Good question. */
 	if (omap2_i2c_active())
 		return;

 	/* The peripherals seem not to be able to wake up the MPU when
 	 * it is in retention mode. */
 	if (omap2_allow_mpu_retention()) {
 		/* REVISIT: These write to reserved bits? */
 		omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
 		omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
 		omap2_prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);

 		/* Try to enter MPU retention */
 		omap2_prm_write_mod_reg((0x01 << OMAP_POWERSTATE_SHIFT) |
 				  OMAP_LOGICRETSTATE_MASK,
 				  MPU_MOD, OMAP2_PM_PWSTCTRL);
 	} else {
 		/* Block MPU retention */

 		omap2_prm_write_mod_reg(OMAP_LOGICRETSTATE_MASK, MPU_MOD,
 						 OMAP2_PM_PWSTCTRL);
 		only_idle = 1;
 	}

 	omap2_sram_idle();
 }

 static int omap2_can_sleep(void)
 {
 	if (omap2_fclks_active())
 		return 0;
 	if (osc_ck->usecount > 1)
 		return 0;
 	if (omap_dma_running())
 		return 0;

 	return 1;
 }

 static void omap2_pm_idle(void)
 {
 	local_fiq_disable();

 	if (!omap2_can_sleep()) {
 		if (omap_irq_pending())
 			goto out;
 		omap2_enter_mpu_retention();
 		goto out;
 	}

 	if (omap_irq_pending())
 		goto out;

 	omap2_enter_full_retention();

 out:
 	local_fiq_enable();
 }

 #ifdef CONFIG_SUSPEND
 static int omap2_pm_begin(suspend_state_t state)
 {
 	disable_hlt();
 	suspend_state = state;
 	return 0;
 }

 static int omap2_pm_enter(suspend_state_t state)
 {
 	int ret = 0;

 	switch (state) {
 	case PM_SUSPEND_STANDBY:
 	case PM_SUSPEND_MEM:
 		omap2_enter_full_retention();
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static void omap2_pm_end(void)
 {
 	suspend_state = PM_SUSPEND_ON;
 	enable_hlt();
 }

 static const struct platform_suspend_ops omap_pm_ops = {
 	.begin		= omap2_pm_begin,
 	.enter		= omap2_pm_enter,
 	.end		= omap2_pm_end,
 	.valid		= suspend_valid_only_mem,
 };
 #else
 static const struct platform_suspend_ops __initdata omap_pm_ops;
 #endif /* CONFIG_SUSPEND */

 static void __init prcm_setup_regs(void)
 {
 	int i, num_mem_banks;
 	struct powerdomain *pwrdm;

 	/*
 	 * Enable autoidle
 	 * XXX This should be handled by hwmod code or PRCM init code
 	 */
 	omap2_prm_write_mod_reg(OMAP24XX_AUTOIDLE_MASK, OCP_MOD,
 			  OMAP2_PRCM_SYSCONFIG_OFFSET);

 	/*
 	 * Set CORE powerdomain memory banks to retain their contents
 	 * during RETENTION
 	 */
 	num_mem_banks = pwrdm_get_mem_bank_count(core_pwrdm);
 	for (i = 0; i < num_mem_banks; i++)
 		pwrdm_set_mem_retst(core_pwrdm, i, PWRDM_POWER_RET);

 	/* Set CORE powerdomain's next power state to RETENTION */
 	pwrdm_set_next_pwrst(core_pwrdm, PWRDM_POWER_RET);

 	/*
 	 * Set MPU powerdomain's next power state to RETENTION;
 	 * preserve logic state during retention
 	 */
 	pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
 	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);

 	/* Force-power down DSP, GFX powerdomains */

 	pwrdm = clkdm_get_pwrdm(dsp_clkdm);
 	pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
 	clkdm_sleep(dsp_clkdm);

 	pwrdm = clkdm_get_pwrdm(gfx_clkdm);
 	pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
 	clkdm_sleep(gfx_clkdm);

 	/* Enable hardware-supervised idle for all clkdms */
 	clkdm_for_each(omap_pm_clkdms_setup, NULL);
 	clkdm_add_wkdep(mpu_clkdm, wkup_clkdm);

 	/* REVISIT: Configure number of 32 kHz clock cycles for sys_clk
 	 * stabilisation */
 	omap2_prm_write_mod_reg(15 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
 				OMAP2_PRCM_CLKSSETUP_OFFSET);

 	/* Configure automatic voltage transition */
 	omap2_prm_write_mod_reg(2 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
 				OMAP2_PRCM_VOLTSETUP_OFFSET);
 	omap2_prm_write_mod_reg(OMAP24XX_AUTO_EXTVOLT_MASK |
 				(0x1 << OMAP24XX_SETOFF_LEVEL_SHIFT) |
 				OMAP24XX_MEMRETCTRL_MASK |
 				(0x1 << OMAP24XX_SETRET_LEVEL_SHIFT) |
 				(0x0 << OMAP24XX_VOLT_LEVEL_SHIFT),
 				OMAP24XX_GR_MOD, OMAP2_PRCM_VOLTCTRL_OFFSET);

 	/* Enable wake-up events */
 	omap2_prm_write_mod_reg(OMAP24XX_EN_GPIOS_MASK | OMAP24XX_EN_GPT1_MASK,
 				WKUP_MOD, PM_WKEN);
 }

 static int __init omap2_pm_init(void)
 {
 	u32 l;

 	if (!cpu_is_omap24xx())
 		return -ENODEV;

 	printk(KERN_INFO "Power Management for OMAP2 initializing\n");
 	l = omap2_prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_REVISION_OFFSET);
 	printk(KERN_INFO "PRCM revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);

 	/* Look up important powerdomains */

 	mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
 	if (!mpu_pwrdm)
 		pr_err("PM: mpu_pwrdm not found\n");

 	core_pwrdm = pwrdm_lookup("core_pwrdm");
 	if (!core_pwrdm)
 		pr_err("PM: core_pwrdm not found\n");

 	/* Look up important clockdomains */

 	mpu_clkdm = clkdm_lookup("mpu_clkdm");
 	if (!mpu_clkdm)
 		pr_err("PM: mpu_clkdm not found\n");

 	wkup_clkdm = clkdm_lookup("wkup_clkdm");
 	if (!wkup_clkdm)
 		pr_err("PM: wkup_clkdm not found\n");

 	dsp_clkdm = clkdm_lookup("dsp_clkdm");
 	if (!dsp_clkdm)
 		pr_err("PM: dsp_clkdm not found\n");

 	gfx_clkdm = clkdm_lookup("gfx_clkdm");
 	if (!gfx_clkdm)
 		pr_err("PM: gfx_clkdm not found\n");


 	osc_ck = clk_get(NULL, "osc_ck");
 	if (IS_ERR(osc_ck)) {
 		printk(KERN_ERR "could not get osc_ck\n");
 		return -ENODEV;
 	}

 	if (cpu_is_omap242x()) {
 		emul_ck = clk_get(NULL, "emul_ck");
 		if (IS_ERR(emul_ck)) {
 			printk(KERN_ERR "could not get emul_ck\n");
 			clk_put(osc_ck);
 			return -ENODEV;
 		}
 	}

 	prcm_setup_regs();

 	/* Hack to prevent MPU retention when STI console is enabled. */
 	{
 		const struct omap_sti_console_config *sti;

 		sti = omap_get_config(OMAP_TAG_STI_CONSOLE,
 				      struct omap_sti_console_config);
 		if (sti != NULL && sti->enable)
 			sti_console_enabled = 1;
 	}

 	/*
 	 * We copy the assembler sleep/wakeup routines to SRAM.
 	 * These routines need to be in SRAM as that's the only
 	 * memory the MPU can see when it wakes up.
 	 */
 	if (cpu_is_omap24xx()) {
 		omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend,
 						 omap24xx_idle_loop_suspend_sz);

 		omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend,
 						    omap24xx_cpu_suspend_sz);
 	}

 	suspend_set_ops(&omap_pm_ops);
 	arm_pm_idle = omap2_pm_idle;

 	return 0;
 }

 late_initcall(omap2_pm_init);
	/*
	* OMAP2 Power Management Routines
	*
	* Copyright (C) 2005 Texas Instruments, Inc.
	* Copyright (C) 2006-2008 Nokia Corporation
	*
	* Written by:
	* Richard Woodruff <r-woodruff2@ti.com>
	* Tony Lindgren
	* Juha Yrjola
	* Amit Kucheria <amit.kucheria@nokia.com>
	* Igor Stoppa <igor.stoppa@nokia.com>
	*
	* Based on pm.c for omap1
	*
	* 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/suspend.h>
	#include <linux/sched.h>
	#include <linux/proc_fs.h>
	#include <linux/interrupt.h>
	#include <linux/sysfs.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/clk.h>
	#include <linux/irq.h>
	#include <linux/time.h>
	#include <linux/gpio.h>

	#include <asm/mach/time.h>
	#include <asm/mach/irq.h>
	#include <asm/mach-types.h>

	#include <plat/clock.h>
	#include <plat/sram.h>
	#include <plat/dma.h>
	#include <plat/board.h>

	#include <mach/irqs.h>

	#include "common.h"
	#include "prm2xxx_3xxx.h"
	#include "prm-regbits-24xx.h"
	#include "cm2xxx_3xxx.h"
	#include "cm-regbits-24xx.h"
	#include "sdrc.h"
	#include "pm.h"
	#include "control.h"
	#include "powerdomain.h"
	#include "clockdomain.h"

	#ifdef CONFIG_SUSPEND
	static suspend_state_t suspend_state = PM_SUSPEND_ON;
	static inline bool is_suspending(void)
	{
	return (suspend_state != PM_SUSPEND_ON);
	}
	#else
	static inline bool is_suspending(void)
	{
	return false;
	}
	#endif

	static void (*omap2_sram_idle)(void);
	static void (omap2_sram_suspend)(u32 dllctrl, void __iomem sdrc_dlla_ctrl,
	void __iomem *sdrc_power);

	static struct powerdomain mpu_pwrdm, core_pwrdm;
	static struct clockdomain dsp_clkdm, mpu_clkdm, wkup_clkdm, gfx_clkdm;

	static struct clk osc_ck, emul_ck;

	static int omap2_fclks_active(void)
	{
	u32 f1, f2;

	f1 = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
	f2 = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);

	return (f1 \| f2) ? 1 : 0;
	}

	static void omap2_enter_full_retention(void)
	{
	u32 l;

	/* There is 1 reference hold for all children of the oscillator
	* clock, the following will remove it. If no one else uses the
	* oscillator itself it will be disabled if/when we enter retention
	* mode.
	*/
	clk_disable(osc_ck);

	/* Clear old wake-up events */
	/* REVISIT: These write to reserved bits? */
	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
	omap2_prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);

	/*
	* Set MPU powerdomain's next power state to RETENTION;
	* preserve logic state during retention
	*/
	pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);

	/* Workaround to kill USB */
	l = omap_ctrl_readl(OMAP2_CONTROL_DEVCONF0) \| OMAP24XX_USBSTANDBYCTRL;
	omap_ctrl_writel(l, OMAP2_CONTROL_DEVCONF0);

	omap2_gpio_prepare_for_idle(0);

	/* One last check for pending IRQs to avoid extra latency due
	* to sleeping unnecessarily. */
	if (omap_irq_pending())
	goto no_sleep;

	/* Jump to SRAM suspend code */
	omap2_sram_suspend(sdrc_read_reg(SDRC_DLLA_CTRL),
	OMAP_SDRC_REGADDR(SDRC_DLLA_CTRL),
	OMAP_SDRC_REGADDR(SDRC_POWER));

	no_sleep:
	omap2_gpio_resume_after_idle();

	clk_enable(osc_ck);

	/* clear CORE wake-up events */
	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);

	/* wakeup domain events - bit 1: GPT1, bit5 GPIO */
	omap2_prm_clear_mod_reg_bits(0x4 \| 0x1, WKUP_MOD, PM_WKST);

	/* MPU domain wake events */
	l = omap2_prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
	if (l & 0x01)
	omap2_prm_write_mod_reg(0x01, OCP_MOD,
	OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
	if (l & 0x20)
	omap2_prm_write_mod_reg(0x20, OCP_MOD,
	OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);

	/* Mask future PRCM-to-MPU interrupts */
	omap2_prm_write_mod_reg(0x0, OCP_MOD, OMAP2_PRCM_IRQSTATUS_MPU_OFFSET);
	}

	static int omap2_i2c_active(void)
	{
	u32 l;

	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
	return l & (OMAP2420_EN_I2C2_MASK \| OMAP2420_EN_I2C1_MASK);
	}

	static int sti_console_enabled;

	static int omap2_allow_mpu_retention(void)
	{
	u32 l;

	/* Check for MMC, UART2, UART1, McSPI2, McSPI1 and DSS1. */
	l = omap2_cm_read_mod_reg(CORE_MOD, CM_FCLKEN1);
	if (l & (OMAP2420_EN_MMC_MASK \| OMAP24XX_EN_UART2_MASK \|
	OMAP24XX_EN_UART1_MASK \| OMAP24XX_EN_MCSPI2_MASK \|
	OMAP24XX_EN_MCSPI1_MASK \| OMAP24XX_EN_DSS1_MASK))
	return 0;
	/* Check for UART3. */
	l = omap2_cm_read_mod_reg(CORE_MOD, OMAP24XX_CM_FCLKEN2);
	if (l & OMAP24XX_EN_UART3_MASK)
	return 0;
	if (sti_console_enabled)
	return 0;

	return 1;
	}

	static void omap2_enter_mpu_retention(void)
	{
	int only_idle = 0;

	/* Putting MPU into the WFI state while a transfer is active
	* seems to cause the I2C block to timeout. Why? Good question. */
	if (omap2_i2c_active())
	return;

	/* The peripherals seem not to be able to wake up the MPU when
	* it is in retention mode. */
	if (omap2_allow_mpu_retention()) {
	/* REVISIT: These write to reserved bits? */
	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, PM_WKST1);
	omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP24XX_PM_WKST2);
	omap2_prm_write_mod_reg(0xffffffff, WKUP_MOD, PM_WKST);

	/* Try to enter MPU retention */
	omap2_prm_write_mod_reg((0x01 << OMAP_POWERSTATE_SHIFT) \|
	OMAP_LOGICRETSTATE_MASK,
	MPU_MOD, OMAP2_PM_PWSTCTRL);
	} else {
	/* Block MPU retention */

	omap2_prm_write_mod_reg(OMAP_LOGICRETSTATE_MASK, MPU_MOD,
	OMAP2_PM_PWSTCTRL);
	only_idle = 1;
	}

	omap2_sram_idle();
	}

	static int omap2_can_sleep(void)
	{
	if (omap2_fclks_active())
	return 0;
	if (osc_ck->usecount > 1)
	return 0;
	if (omap_dma_running())
	return 0;

	return 1;
	}

	static void omap2_pm_idle(void)
	{
	local_fiq_disable();

	if (!omap2_can_sleep()) {
	if (omap_irq_pending())
	goto out;
	omap2_enter_mpu_retention();
	goto out;
	}

	if (omap_irq_pending())
	goto out;

	omap2_enter_full_retention();

	out:
	local_fiq_enable();
	}

	#ifdef CONFIG_SUSPEND
	static int omap2_pm_begin(suspend_state_t state)
	{
	disable_hlt();
	suspend_state = state;
	return 0;
	}

	static int omap2_pm_enter(suspend_state_t state)
	{
	int ret = 0;

	switch (state) {
	case PM_SUSPEND_STANDBY:
	case PM_SUSPEND_MEM:
	omap2_enter_full_retention();
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static void omap2_pm_end(void)
	{
	suspend_state = PM_SUSPEND_ON;
	enable_hlt();
	}

	static const struct platform_suspend_ops omap_pm_ops = {
	.begin = omap2_pm_begin,
	.enter = omap2_pm_enter,
	.end = omap2_pm_end,
	.valid = suspend_valid_only_mem,
	};
	#else
	static const struct platform_suspend_ops __initdata omap_pm_ops;
	#endif /* CONFIG_SUSPEND */

	static void __init prcm_setup_regs(void)
	{
	int i, num_mem_banks;
	struct powerdomain *pwrdm;

	/*
	* Enable autoidle
	* XXX This should be handled by hwmod code or PRCM init code
	*/
	omap2_prm_write_mod_reg(OMAP24XX_AUTOIDLE_MASK, OCP_MOD,
	OMAP2_PRCM_SYSCONFIG_OFFSET);

	/*
	* Set CORE powerdomain memory banks to retain their contents
	* during RETENTION
	*/
	num_mem_banks = pwrdm_get_mem_bank_count(core_pwrdm);
	for (i = 0; i < num_mem_banks; i++)
	pwrdm_set_mem_retst(core_pwrdm, i, PWRDM_POWER_RET);

	/* Set CORE powerdomain's next power state to RETENTION */
	pwrdm_set_next_pwrst(core_pwrdm, PWRDM_POWER_RET);

	/*
	* Set MPU powerdomain's next power state to RETENTION;
	* preserve logic state during retention
	*/
	pwrdm_set_logic_retst(mpu_pwrdm, PWRDM_POWER_RET);
	pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_RET);

	/* Force-power down DSP, GFX powerdomains */

	pwrdm = clkdm_get_pwrdm(dsp_clkdm);
	pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
	clkdm_sleep(dsp_clkdm);

	pwrdm = clkdm_get_pwrdm(gfx_clkdm);
	pwrdm_set_next_pwrst(pwrdm, PWRDM_POWER_OFF);
	clkdm_sleep(gfx_clkdm);

	/* Enable hardware-supervised idle for all clkdms */
	clkdm_for_each(omap_pm_clkdms_setup, NULL);
	clkdm_add_wkdep(mpu_clkdm, wkup_clkdm);

	/* REVISIT: Configure number of 32 kHz clock cycles for sys_clk
	* stabilisation */
	omap2_prm_write_mod_reg(15 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
	OMAP2_PRCM_CLKSSETUP_OFFSET);

	/* Configure automatic voltage transition */
	omap2_prm_write_mod_reg(2 << OMAP_SETUP_TIME_SHIFT, OMAP24XX_GR_MOD,
	OMAP2_PRCM_VOLTSETUP_OFFSET);
	omap2_prm_write_mod_reg(OMAP24XX_AUTO_EXTVOLT_MASK \|
	(0x1 << OMAP24XX_SETOFF_LEVEL_SHIFT) \|
	OMAP24XX_MEMRETCTRL_MASK \|
	(0x1 << OMAP24XX_SETRET_LEVEL_SHIFT) \|
	(0x0 << OMAP24XX_VOLT_LEVEL_SHIFT),
	OMAP24XX_GR_MOD, OMAP2_PRCM_VOLTCTRL_OFFSET);

	/* Enable wake-up events */
	omap2_prm_write_mod_reg(OMAP24XX_EN_GPIOS_MASK \| OMAP24XX_EN_GPT1_MASK,
	WKUP_MOD, PM_WKEN);
	}

	static int __init omap2_pm_init(void)
	{
	u32 l;

	if (!cpu_is_omap24xx())
	return -ENODEV;

	printk(KERN_INFO "Power Management for OMAP2 initializing\n");
	l = omap2_prm_read_mod_reg(OCP_MOD, OMAP2_PRCM_REVISION_OFFSET);
	printk(KERN_INFO "PRCM revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);

	/* Look up important powerdomains */

	mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
	if (!mpu_pwrdm)
	pr_err("PM: mpu_pwrdm not found\n");

	core_pwrdm = pwrdm_lookup("core_pwrdm");
	if (!core_pwrdm)
	pr_err("PM: core_pwrdm not found\n");

	/* Look up important clockdomains */

	mpu_clkdm = clkdm_lookup("mpu_clkdm");
	if (!mpu_clkdm)
	pr_err("PM: mpu_clkdm not found\n");

	wkup_clkdm = clkdm_lookup("wkup_clkdm");
	if (!wkup_clkdm)
	pr_err("PM: wkup_clkdm not found\n");

	dsp_clkdm = clkdm_lookup("dsp_clkdm");
	if (!dsp_clkdm)
	pr_err("PM: dsp_clkdm not found\n");

	gfx_clkdm = clkdm_lookup("gfx_clkdm");
	if (!gfx_clkdm)
	pr_err("PM: gfx_clkdm not found\n");


	osc_ck = clk_get(NULL, "osc_ck");
	if (IS_ERR(osc_ck)) {
	printk(KERN_ERR "could not get osc_ck\n");
	return -ENODEV;
	}

	if (cpu_is_omap242x()) {
	emul_ck = clk_get(NULL, "emul_ck");
	if (IS_ERR(emul_ck)) {
	printk(KERN_ERR "could not get emul_ck\n");
	clk_put(osc_ck);
	return -ENODEV;
	}
	}

	prcm_setup_regs();

	/* Hack to prevent MPU retention when STI console is enabled. */
	{
	const struct omap_sti_console_config *sti;

	sti = omap_get_config(OMAP_TAG_STI_CONSOLE,
	struct omap_sti_console_config);
	if (sti != NULL && sti->enable)
	sti_console_enabled = 1;
	}

	/*
	* We copy the assembler sleep/wakeup routines to SRAM.
	* These routines need to be in SRAM as that's the only
	* memory the MPU can see when it wakes up.
	*/
	if (cpu_is_omap24xx()) {
	omap2_sram_idle = omap_sram_push(omap24xx_idle_loop_suspend,
	omap24xx_idle_loop_suspend_sz);

	omap2_sram_suspend = omap_sram_push(omap24xx_cpu_suspend,
	omap24xx_cpu_suspend_sz);
	}

	suspend_set_ops(&omap_pm_ops);
	arm_pm_idle = omap2_pm_idle;

	return 0;
	}

	late_initcall(omap2_pm_init);