Merge branch 'omap/headers4' into next/dt

[linux-2.6.git] / arch / arm / mach-omap2 / pm34xx.c

/*
 * OMAP3 Power Management Routines
 *
 * Copyright (C) 2006-2008 Nokia Corporation
 * Tony Lindgren <tony@atomide.com>
 * Jouni Hogander
 *
 * Copyright (C) 2007 Texas Instruments, Inc.
 * Rajendra Nayak <rnayak@ti.com>
 *
 * Copyright (C) 2005 Texas Instruments, Inc.
 * Richard Woodruff <r-woodruff2@ti.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/pm.h>
#include <linux/suspend.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/platform_data/gpio-omap.h>

#include <trace/events/power.h>

#include <asm/fncpy.h>
#include <asm/suspend.h>
#include <asm/system_misc.h>

#include "clockdomain.h"
#include "powerdomain.h"
#include <plat/prcm.h>
#include <plat-omap/dma-omap.h>

#include "soc.h"
#include "common.h"
#include "cm2xxx_3xxx.h"
#include "cm-regbits-34xx.h"
#include "gpmc.h"
#include "prm-regbits-34xx.h"

#include "prm2xxx_3xxx.h"
#include "pm.h"
#include "sdrc.h"
#include "sram.h"
#include "control.h"

/* pm34xx errata defined in pm.h */
u16 pm34xx_errata;

struct power_state {
        struct powerdomain *pwrdm;
        u32 next_state;
#ifdef CONFIG_SUSPEND
        u32 saved_state;
#endif
        struct list_head node;
};

static LIST_HEAD(pwrst_list);

static int (*_omap_save_secure_sram)(u32 *addr);
void (*omap3_do_wfi_sram)(void);

static struct powerdomain *mpu_pwrdm, *neon_pwrdm;
static struct powerdomain *core_pwrdm, *per_pwrdm;

static void omap3_core_save_context(void)
{
        omap3_ctrl_save_padconf();

        /*
         * Force write last pad into memory, as this can fail in some
         * cases according to errata 1.157, 1.185
         */
        omap_ctrl_writel(omap_ctrl_readl(OMAP343X_PADCONF_ETK_D14),
                OMAP343X_CONTROL_MEM_WKUP + 0x2a0);

        /* Save the Interrupt controller context */
        omap_intc_save_context();
        /* Save the GPMC context */
        omap3_gpmc_save_context();
        /* Save the system control module context, padconf already save above*/
        omap3_control_save_context();
        omap_dma_global_context_save();
}

static void omap3_core_restore_context(void)
{
        /* Restore the control module context, padconf restored by h/w */
        omap3_control_restore_context();
        /* Restore the GPMC context */
        omap3_gpmc_restore_context();
        /* Restore the interrupt controller context */
        omap_intc_restore_context();
        omap_dma_global_context_restore();
}

/*
 * FIXME: This function should be called before entering off-mode after
 * OMAP3 secure services have been accessed. Currently it is only called
 * once during boot sequence, but this works as we are not using secure
 * services.
 */
static void omap3_save_secure_ram_context(void)
{
        u32 ret;
        int mpu_next_state = pwrdm_read_next_pwrst(mpu_pwrdm);

        if (omap_type() != OMAP2_DEVICE_TYPE_GP) {
                /*
                 * MPU next state must be set to POWER_ON temporarily,
                 * otherwise the WFI executed inside the ROM code
                 * will hang the system.
                 */
                pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);
                ret = _omap_save_secure_sram((u32 *)
                                __pa(omap3_secure_ram_storage));
                pwrdm_set_next_pwrst(mpu_pwrdm, mpu_next_state);
                /* Following is for error tracking, it should not happen */
                if (ret) {
                        pr_err("save_secure_sram() returns %08x\n", ret);
                        while (1)
                                ;
                }
        }
}

/*
 * PRCM Interrupt Handler Helper Function
 *
 * The purpose of this function is to clear any wake-up events latched
 * in the PRCM PM_WKST_x registers. It is possible that a wake-up event
 * may occur whilst attempting to clear a PM_WKST_x register and thus
 * set another bit in this register. A while loop is used to ensure
 * that any peripheral wake-up events occurring while attempting to
 * clear the PM_WKST_x are detected and cleared.
 */
static int prcm_clear_mod_irqs(s16 module, u8 regs, u32 ignore_bits)
{
        u32 wkst, fclk, iclk, clken;
        u16 wkst_off = (regs == 3) ? OMAP3430ES2_PM_WKST3 : PM_WKST1;
        u16 fclk_off = (regs == 3) ? OMAP3430ES2_CM_FCLKEN3 : CM_FCLKEN1;
        u16 iclk_off = (regs == 3) ? CM_ICLKEN3 : CM_ICLKEN1;
        u16 grpsel_off = (regs == 3) ?
                OMAP3430ES2_PM_MPUGRPSEL3 : OMAP3430_PM_MPUGRPSEL;
        int c = 0;

        wkst = omap2_prm_read_mod_reg(module, wkst_off);
        wkst &= omap2_prm_read_mod_reg(module, grpsel_off);
        wkst &= ~ignore_bits;
        if (wkst) {
                iclk = omap2_cm_read_mod_reg(module, iclk_off);
                fclk = omap2_cm_read_mod_reg(module, fclk_off);
                while (wkst) {
                        clken = wkst;
                        omap2_cm_set_mod_reg_bits(clken, module, iclk_off);
                        /*
                         * For USBHOST, we don't know whether HOST1 or
                         * HOST2 woke us up, so enable both f-clocks
                         */
                        if (module == OMAP3430ES2_USBHOST_MOD)
                                clken |= 1 << OMAP3430ES2_EN_USBHOST2_SHIFT;
                        omap2_cm_set_mod_reg_bits(clken, module, fclk_off);
                        omap2_prm_write_mod_reg(wkst, module, wkst_off);
                        wkst = omap2_prm_read_mod_reg(module, wkst_off);
                        wkst &= ~ignore_bits;
                        c++;
                }
                omap2_cm_write_mod_reg(iclk, module, iclk_off);
                omap2_cm_write_mod_reg(fclk, module, fclk_off);
        }

        return c;
}

static irqreturn_t _prcm_int_handle_io(int irq, void *unused)
{
        int c;

        c = prcm_clear_mod_irqs(WKUP_MOD, 1,
                ~(OMAP3430_ST_IO_MASK | OMAP3430_ST_IO_CHAIN_MASK));

        return c ? IRQ_HANDLED : IRQ_NONE;
}

static irqreturn_t _prcm_int_handle_wakeup(int irq, void *unused)
{
        int c;

        /*
         * Clear all except ST_IO and ST_IO_CHAIN for wkup module,
         * these are handled in a separate handler to avoid acking
         * IO events before parsing in mux code
         */
        c = prcm_clear_mod_irqs(WKUP_MOD, 1,
                OMAP3430_ST_IO_MASK | OMAP3430_ST_IO_CHAIN_MASK);
        c += prcm_clear_mod_irqs(CORE_MOD, 1, 0);
        c += prcm_clear_mod_irqs(OMAP3430_PER_MOD, 1, 0);
        if (omap_rev() > OMAP3430_REV_ES1_0) {
                c += prcm_clear_mod_irqs(CORE_MOD, 3, 0);
                c += prcm_clear_mod_irqs(OMAP3430ES2_USBHOST_MOD, 1, 0);
        }

        return c ? IRQ_HANDLED : IRQ_NONE;
}

static void omap34xx_save_context(u32 *save)
{
        u32 val;

        /* Read Auxiliary Control Register */
        asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (val));
        *save++ = 1;
        *save++ = val;

        /* Read L2 AUX ctrl register */
        asm("mrc p15, 1, %0, c9, c0, 2" : "=r" (val));
        *save++ = 1;
        *save++ = val;
}

static int omap34xx_do_sram_idle(unsigned long save_state)
{
        omap34xx_cpu_suspend(save_state);
        return 0;
}

void omap_sram_idle(void)
{
        /* Variable to tell what needs to be saved and restored
         * in omap_sram_idle*/
        /* save_state = 0 => Nothing to save and restored */
        /* save_state = 1 => Only L1 and logic lost */
        /* save_state = 2 => Only L2 lost */
        /* save_state = 3 => L1, L2 and logic lost */
        int save_state = 0;
        int mpu_next_state = PWRDM_POWER_ON;
        int per_next_state = PWRDM_POWER_ON;
        int core_next_state = PWRDM_POWER_ON;
        int per_going_off;
        int core_prev_state;
        u32 sdrc_pwr = 0;

        mpu_next_state = pwrdm_read_next_pwrst(mpu_pwrdm);
        switch (mpu_next_state) {
        case PWRDM_POWER_ON:
        case PWRDM_POWER_RET:
                /* No need to save context */
                save_state = 0;
                break;
        case PWRDM_POWER_OFF:
                save_state = 3;
                break;
        default:
                /* Invalid state */
                pr_err("Invalid mpu state in sram_idle\n");
                return;
        }

        /* NEON control */
        if (pwrdm_read_pwrst(neon_pwrdm) == PWRDM_POWER_ON)
                pwrdm_set_next_pwrst(neon_pwrdm, mpu_next_state);

        /* Enable IO-PAD and IO-CHAIN wakeups */
        per_next_state = pwrdm_read_next_pwrst(per_pwrdm);
        core_next_state = pwrdm_read_next_pwrst(core_pwrdm);

        pwrdm_pre_transition(NULL);

        /* PER */
        if (per_next_state < PWRDM_POWER_ON) {
                per_going_off = (per_next_state == PWRDM_POWER_OFF) ? 1 : 0;
                omap2_gpio_prepare_for_idle(per_going_off);
        }

        /* CORE */
        if (core_next_state < PWRDM_POWER_ON) {
                if (core_next_state == PWRDM_POWER_OFF) {
                        omap3_core_save_context();
                        omap3_cm_save_context();
                }
        }

        omap3_intc_prepare_idle();

        /*
         * On EMU/HS devices ROM code restores a SRDC value
         * from scratchpad which has automatic self refresh on timeout
         * of AUTO_CNT = 1 enabled. This takes care of erratum ID i443.
         * Hence store/restore the SDRC_POWER register here.
         */
        if (cpu_is_omap3430() && omap_rev() >= OMAP3430_REV_ES3_0 &&
            (omap_type() == OMAP2_DEVICE_TYPE_EMU ||
             omap_type() == OMAP2_DEVICE_TYPE_SEC) &&
            core_next_state == PWRDM_POWER_OFF)
                sdrc_pwr = sdrc_read_reg(SDRC_POWER);

        /*
         * omap3_arm_context is the location where some ARM context
         * get saved. The rest is placed on the stack, and restored
         * from there before resuming.
         */
        if (save_state)
                omap34xx_save_context(omap3_arm_context);
        if (save_state == 1 || save_state == 3)
                cpu_suspend(save_state, omap34xx_do_sram_idle);
        else
                omap34xx_do_sram_idle(save_state);

        /* Restore normal SDRC POWER settings */
        if (cpu_is_omap3430() && omap_rev() >= OMAP3430_REV_ES3_0 &&
            (omap_type() == OMAP2_DEVICE_TYPE_EMU ||
             omap_type() == OMAP2_DEVICE_TYPE_SEC) &&
            core_next_state == PWRDM_POWER_OFF)
                sdrc_write_reg(sdrc_pwr, SDRC_POWER);

        /* CORE */
        if (core_next_state < PWRDM_POWER_ON) {
                core_prev_state = pwrdm_read_prev_pwrst(core_pwrdm);
                if (core_prev_state == PWRDM_POWER_OFF) {
                        omap3_core_restore_context();
                        omap3_cm_restore_context();
                        omap3_sram_restore_context();
                        omap2_sms_restore_context();
                }
                if (core_next_state == PWRDM_POWER_OFF)
                        omap2_prm_clear_mod_reg_bits(OMAP3430_AUTO_OFF_MASK,
                                               OMAP3430_GR_MOD,
                                               OMAP3_PRM_VOLTCTRL_OFFSET);
        }
        omap3_intc_resume_idle();

        pwrdm_post_transition(NULL);

        /* PER */
        if (per_next_state < PWRDM_POWER_ON)
                omap2_gpio_resume_after_idle();
}

static void omap3_pm_idle(void)
{
        local_fiq_disable();

        if (omap_irq_pending())
                goto out;

        trace_power_start(POWER_CSTATE, 1, smp_processor_id());
        trace_cpu_idle(1, smp_processor_id());

        omap_sram_idle();

        trace_power_end(smp_processor_id());
        trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());

out:
        local_fiq_enable();
}

#ifdef CONFIG_SUSPEND
static int omap3_pm_suspend(void)
{
        struct power_state *pwrst;
        int state, ret = 0;

        /* Read current next_pwrsts */
        list_for_each_entry(pwrst, &pwrst_list, node)
                pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
        /* Set ones wanted by suspend */
        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state))
                        goto restore;
                if (pwrdm_clear_all_prev_pwrst(pwrst->pwrdm))
                        goto restore;
        }

        omap3_intc_suspend();

        omap_sram_idle();

restore:
        /* Restore next_pwrsts */
        list_for_each_entry(pwrst, &pwrst_list, node) {
                state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
                if (state > pwrst->next_state) {
                        pr_info("Powerdomain (%s) didn't enter target state %d\n",
                                pwrst->pwrdm->name, pwrst->next_state);
                        ret = -1;
                }
                omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
        }
        if (ret)
                pr_err("Could not enter target state in pm_suspend\n");
        else
                pr_info("Successfully put all powerdomains to target state\n");

        return ret;
}

#endif /* CONFIG_SUSPEND */


/**
 * omap3_iva_idle(): ensure IVA is in idle so it can be put into
 *                   retention
 *
 * In cases where IVA2 is activated by bootcode, it may prevent
 * full-chip retention or off-mode because it is not idle.  This
 * function forces the IVA2 into idle state so it can go
 * into retention/off and thus allow full-chip retention/off.
 *
 **/
static void __init omap3_iva_idle(void)
{
        /* ensure IVA2 clock is disabled */
        omap2_cm_write_mod_reg(0, OMAP3430_IVA2_MOD, CM_FCLKEN);

        /* if no clock activity, nothing else to do */
        if (!(omap2_cm_read_mod_reg(OMAP3430_IVA2_MOD, OMAP3430_CM_CLKSTST) &
              OMAP3430_CLKACTIVITY_IVA2_MASK))
                return;

        /* Reset IVA2 */
        omap2_prm_write_mod_reg(OMAP3430_RST1_IVA2_MASK |
                          OMAP3430_RST2_IVA2_MASK |
                          OMAP3430_RST3_IVA2_MASK,
                          OMAP3430_IVA2_MOD, OMAP2_RM_RSTCTRL);

        /* Enable IVA2 clock */
        omap2_cm_write_mod_reg(OMAP3430_CM_FCLKEN_IVA2_EN_IVA2_MASK,
                         OMAP3430_IVA2_MOD, CM_FCLKEN);

        /* Set IVA2 boot mode to 'idle' */
        omap_ctrl_writel(OMAP3_IVA2_BOOTMOD_IDLE,
                         OMAP343X_CONTROL_IVA2_BOOTMOD);

        /* Un-reset IVA2 */
        omap2_prm_write_mod_reg(0, OMAP3430_IVA2_MOD, OMAP2_RM_RSTCTRL);

        /* Disable IVA2 clock */
        omap2_cm_write_mod_reg(0, OMAP3430_IVA2_MOD, CM_FCLKEN);

        /* Reset IVA2 */
        omap2_prm_write_mod_reg(OMAP3430_RST1_IVA2_MASK |
                          OMAP3430_RST2_IVA2_MASK |
                          OMAP3430_RST3_IVA2_MASK,
                          OMAP3430_IVA2_MOD, OMAP2_RM_RSTCTRL);
}

static void __init omap3_d2d_idle(void)
{
        u16 mask, padconf;

        /* In a stand alone OMAP3430 where there is not a stacked
         * modem for the D2D Idle Ack and D2D MStandby must be pulled
         * high. S CONTROL_PADCONF_SAD2D_IDLEACK and
         * CONTROL_PADCONF_SAD2D_MSTDBY to have a pull up. */
        mask = (1 << 4) | (1 << 3); /* pull-up, enabled */
        padconf = omap_ctrl_readw(OMAP3_PADCONF_SAD2D_MSTANDBY);
        padconf |= mask;
        omap_ctrl_writew(padconf, OMAP3_PADCONF_SAD2D_MSTANDBY);

        padconf = omap_ctrl_readw(OMAP3_PADCONF_SAD2D_IDLEACK);
        padconf |= mask;
        omap_ctrl_writew(padconf, OMAP3_PADCONF_SAD2D_IDLEACK);

        /* reset modem */
        omap2_prm_write_mod_reg(OMAP3430_RM_RSTCTRL_CORE_MODEM_SW_RSTPWRON_MASK |
                          OMAP3430_RM_RSTCTRL_CORE_MODEM_SW_RST_MASK,
                          CORE_MOD, OMAP2_RM_RSTCTRL);
        omap2_prm_write_mod_reg(0, CORE_MOD, OMAP2_RM_RSTCTRL);
}

static void __init prcm_setup_regs(void)
{
        u32 omap3630_en_uart4_mask = cpu_is_omap3630() ?
                                        OMAP3630_EN_UART4_MASK : 0;
        u32 omap3630_grpsel_uart4_mask = cpu_is_omap3630() ?
                                        OMAP3630_GRPSEL_UART4_MASK : 0;

        /* XXX This should be handled by hwmod code or SCM init code */
        omap_ctrl_writel(OMAP3430_AUTOIDLE_MASK, OMAP2_CONTROL_SYSCONFIG);

        /*
         * Enable control of expternal oscillator through
         * sys_clkreq. In the long run clock framework should
         * take care of this.
         */
        omap2_prm_rmw_mod_reg_bits(OMAP_AUTOEXTCLKMODE_MASK,
                             1 << OMAP_AUTOEXTCLKMODE_SHIFT,
                             OMAP3430_GR_MOD,
                             OMAP3_PRM_CLKSRC_CTRL_OFFSET);

        /* setup wakup source */
        omap2_prm_write_mod_reg(OMAP3430_EN_IO_MASK | OMAP3430_EN_GPIO1_MASK |
                          OMAP3430_EN_GPT1_MASK | OMAP3430_EN_GPT12_MASK,
                          WKUP_MOD, PM_WKEN);
        /* No need to write EN_IO, that is always enabled */
        omap2_prm_write_mod_reg(OMAP3430_GRPSEL_GPIO1_MASK |
                          OMAP3430_GRPSEL_GPT1_MASK |
                          OMAP3430_GRPSEL_GPT12_MASK,
                          WKUP_MOD, OMAP3430_PM_MPUGRPSEL);

        /* Enable PM_WKEN to support DSS LPR */
        omap2_prm_write_mod_reg(OMAP3430_PM_WKEN_DSS_EN_DSS_MASK,
                                OMAP3430_DSS_MOD, PM_WKEN);

        /* Enable wakeups in PER */
        omap2_prm_write_mod_reg(omap3630_en_uart4_mask |
                          OMAP3430_EN_GPIO2_MASK | OMAP3430_EN_GPIO3_MASK |
                          OMAP3430_EN_GPIO4_MASK | OMAP3430_EN_GPIO5_MASK |
                          OMAP3430_EN_GPIO6_MASK | OMAP3430_EN_UART3_MASK |
                          OMAP3430_EN_MCBSP2_MASK | OMAP3430_EN_MCBSP3_MASK |
                          OMAP3430_EN_MCBSP4_MASK,
                          OMAP3430_PER_MOD, PM_WKEN);
        /* and allow them to wake up MPU */
        omap2_prm_write_mod_reg(omap3630_grpsel_uart4_mask |
                          OMAP3430_GRPSEL_GPIO2_MASK |
                          OMAP3430_GRPSEL_GPIO3_MASK |
                          OMAP3430_GRPSEL_GPIO4_MASK |
                          OMAP3430_GRPSEL_GPIO5_MASK |
                          OMAP3430_GRPSEL_GPIO6_MASK |
                          OMAP3430_GRPSEL_UART3_MASK |
                          OMAP3430_GRPSEL_MCBSP2_MASK |
                          OMAP3430_GRPSEL_MCBSP3_MASK |
                          OMAP3430_GRPSEL_MCBSP4_MASK,
                          OMAP3430_PER_MOD, OMAP3430_PM_MPUGRPSEL);

        /* Don't attach IVA interrupts */
        if (omap3_has_iva()) {
                omap2_prm_write_mod_reg(0, WKUP_MOD, OMAP3430_PM_IVAGRPSEL);
                omap2_prm_write_mod_reg(0, CORE_MOD, OMAP3430_PM_IVAGRPSEL1);
                omap2_prm_write_mod_reg(0, CORE_MOD, OMAP3430ES2_PM_IVAGRPSEL3);
                omap2_prm_write_mod_reg(0, OMAP3430_PER_MOD,
                                        OMAP3430_PM_IVAGRPSEL);
        }

        /* Clear any pending 'reset' flags */
        omap2_prm_write_mod_reg(0xffffffff, MPU_MOD, OMAP2_RM_RSTST);
        omap2_prm_write_mod_reg(0xffffffff, CORE_MOD, OMAP2_RM_RSTST);
        omap2_prm_write_mod_reg(0xffffffff, OMAP3430_PER_MOD, OMAP2_RM_RSTST);
        omap2_prm_write_mod_reg(0xffffffff, OMAP3430_EMU_MOD, OMAP2_RM_RSTST);
        omap2_prm_write_mod_reg(0xffffffff, OMAP3430_NEON_MOD, OMAP2_RM_RSTST);
        omap2_prm_write_mod_reg(0xffffffff, OMAP3430_DSS_MOD, OMAP2_RM_RSTST);
        omap2_prm_write_mod_reg(0xffffffff, OMAP3430ES2_USBHOST_MOD, OMAP2_RM_RSTST);

        /* Clear any pending PRCM interrupts */
        omap2_prm_write_mod_reg(0, OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET);

        if (omap3_has_iva())
                omap3_iva_idle();

        omap3_d2d_idle();
}

void omap3_pm_off_mode_enable(int enable)
{
        struct power_state *pwrst;
        u32 state;

        if (enable)
                state = PWRDM_POWER_OFF;
        else
                state = PWRDM_POWER_RET;

        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583) &&
                                pwrst->pwrdm == core_pwrdm &&
                                state == PWRDM_POWER_OFF) {
                        pwrst->next_state = PWRDM_POWER_RET;
                        pr_warn("%s: Core OFF disabled due to errata i583\n",
                                __func__);
                } else {
                        pwrst->next_state = state;
                }
                omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
        }
}

int omap3_pm_get_suspend_state(struct powerdomain *pwrdm)
{
        struct power_state *pwrst;

        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (pwrst->pwrdm == pwrdm)
                        return pwrst->next_state;
        }
        return -EINVAL;
}

int omap3_pm_set_suspend_state(struct powerdomain *pwrdm, int state)
{
        struct power_state *pwrst;

        list_for_each_entry(pwrst, &pwrst_list, node) {
                if (pwrst->pwrdm == pwrdm) {
                        pwrst->next_state = state;
                        return 0;
                }
        }
        return -EINVAL;
}

static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
{
        struct power_state *pwrst;

        if (!pwrdm->pwrsts)
                return 0;

        pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
        if (!pwrst)
                return -ENOMEM;
        pwrst->pwrdm = pwrdm;
        pwrst->next_state = PWRDM_POWER_RET;
        list_add(&pwrst->node, &pwrst_list);

        if (pwrdm_has_hdwr_sar(pwrdm))
                pwrdm_enable_hdwr_sar(pwrdm);

        return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
}

/*
 * Push functions to SRAM
 *
 * The minimum set of functions is pushed to SRAM for execution:
 * - omap3_do_wfi for erratum i581 WA,
 * - save_secure_ram_context for security extensions.
 */
void omap_push_sram_idle(void)
{
        omap3_do_wfi_sram = omap_sram_push(omap3_do_wfi, omap3_do_wfi_sz);

        if (omap_type() != OMAP2_DEVICE_TYPE_GP)
                _omap_save_secure_sram = omap_sram_push(save_secure_ram_context,
                                save_secure_ram_context_sz);
}

static void __init pm_errata_configure(void)
{
        if (cpu_is_omap3630()) {
                pm34xx_errata |= PM_RTA_ERRATUM_i608;
                /* Enable the l2 cache toggling in sleep logic */
                enable_omap3630_toggle_l2_on_restore();
                if (omap_rev() < OMAP3630_REV_ES1_2)
                        pm34xx_errata |= (PM_SDRC_WAKEUP_ERRATUM_i583 |
                                          PM_PER_MEMORIES_ERRATUM_i582);
        } else if (cpu_is_omap34xx()) {
                pm34xx_errata |= PM_PER_MEMORIES_ERRATUM_i582;
        }
}

int __init omap3_pm_init(void)
{
        struct power_state *pwrst, *tmp;
        struct clockdomain *neon_clkdm, *mpu_clkdm, *per_clkdm, *wkup_clkdm;
        int ret;

        if (!omap3_has_io_chain_ctrl())
                pr_warning("PM: no software I/O chain control; some wakeups may be lost\n");

        pm_errata_configure();

        /* XXX prcm_setup_regs needs to be before enabling hw
         * supervised mode for powerdomains */
        prcm_setup_regs();

        ret = request_irq(omap_prcm_event_to_irq("wkup"),
                _prcm_int_handle_wakeup, IRQF_NO_SUSPEND, "pm_wkup", NULL);

        if (ret) {
                pr_err("pm: Failed to request pm_wkup irq\n");
                goto err1;
        }

        /* IO interrupt is shared with mux code */
        ret = request_irq(omap_prcm_event_to_irq("io"),
                _prcm_int_handle_io, IRQF_SHARED | IRQF_NO_SUSPEND, "pm_io",
                omap3_pm_init);
        enable_irq(omap_prcm_event_to_irq("io"));

        if (ret) {
                pr_err("pm: Failed to request pm_io irq\n");
                goto err2;
        }

        ret = pwrdm_for_each(pwrdms_setup, NULL);
        if (ret) {
                pr_err("Failed to setup powerdomains\n");
                goto err3;
        }

        (void) clkdm_for_each(omap_pm_clkdms_setup, NULL);

        mpu_pwrdm = pwrdm_lookup("mpu_pwrdm");
        if (mpu_pwrdm == NULL) {
                pr_err("Failed to get mpu_pwrdm\n");
                ret = -EINVAL;
                goto err3;
        }

        neon_pwrdm = pwrdm_lookup("neon_pwrdm");
        per_pwrdm = pwrdm_lookup("per_pwrdm");
        core_pwrdm = pwrdm_lookup("core_pwrdm");

        neon_clkdm = clkdm_lookup("neon_clkdm");
        mpu_clkdm = clkdm_lookup("mpu_clkdm");
        per_clkdm = clkdm_lookup("per_clkdm");
        wkup_clkdm = clkdm_lookup("wkup_clkdm");

#ifdef CONFIG_SUSPEND
        omap_pm_suspend = omap3_pm_suspend;
#endif

        arm_pm_idle = omap3_pm_idle;
        omap3_idle_init();

        /*
         * RTA is disabled during initialization as per erratum i608
         * it is safer to disable RTA by the bootloader, but we would like
         * to be doubly sure here and prevent any mishaps.
         */
        if (IS_PM34XX_ERRATUM(PM_RTA_ERRATUM_i608))
                omap3630_ctrl_disable_rta();

        /*
         * The UART3/4 FIFO and the sidetone memory in McBSP2/3 are
         * not correctly reset when the PER powerdomain comes back
         * from OFF or OSWR when the CORE powerdomain is kept active.
         * See OMAP36xx Erratum i582 "PER Domain reset issue after
         * Domain-OFF/OSWR Wakeup".  This wakeup dependency is not a
         * complete workaround.  The kernel must also prevent the PER
         * powerdomain from going to OSWR/OFF while the CORE
         * powerdomain is not going to OSWR/OFF.  And if PER last
         * power state was off while CORE last power state was ON, the
         * UART3/4 and McBSP2/3 SIDETONE devices need to run a
         * self-test using their loopback tests; if that fails, those
         * devices are unusable until the PER/CORE can complete a transition
         * from ON to OSWR/OFF and then back to ON.
         *
         * XXX Technically this workaround is only needed if off-mode
         * or OSWR is enabled.
         */
        if (IS_PM34XX_ERRATUM(PM_PER_MEMORIES_ERRATUM_i582))
                clkdm_add_wkdep(per_clkdm, wkup_clkdm);

        clkdm_add_wkdep(neon_clkdm, mpu_clkdm);
        if (omap_type() != OMAP2_DEVICE_TYPE_GP) {
                omap3_secure_ram_storage =
                        kmalloc(0x803F, GFP_KERNEL);
                if (!omap3_secure_ram_storage)
                        pr_err("Memory allocation failed when allocating for secure sram context\n");

                local_irq_disable();
                local_fiq_disable();

                omap_dma_global_context_save();
                omap3_save_secure_ram_context();
                omap_dma_global_context_restore();

                local_irq_enable();
                local_fiq_enable();
        }

        omap3_save_scratchpad_contents();
        return ret;

err3:
        list_for_each_entry_safe(pwrst, tmp, &pwrst_list, node) {
                list_del(&pwrst->node);
                kfree(pwrst);
        }
        free_irq(omap_prcm_event_to_irq("io"), omap3_pm_init);
err2:
        free_irq(omap_prcm_event_to_irq("wkup"), NULL);
err1:
        return ret;
}