/*
 * OMAP powerdomain control
 *
 * Copyright (C) 2007-2008 Texas Instruments, Inc.
 * Copyright (C) 2007-2009 Nokia Corporation
 *
 * Written by Paul Walmsley
 * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
 * State counting code by Tero Kristo <tero.kristo@nokia.com>
 *
 * 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.
 */
#undef DEBUG

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/io.h>

#include <asm/atomic.h>

#include "cm.h"
#include "cm-regbits-34xx.h"
#include "cm-regbits-44xx.h"
#include "prm.h"
#include "prm-regbits-34xx.h"
#include "prm-regbits-44xx.h"

#include <plat/cpu.h>
#include <plat/powerdomain.h>
#include <plat/clockdomain.h>
#include <plat/prcm.h>

#include "pm.h"

enum {
        PWRDM_STATE_NOW = 0,
        PWRDM_STATE_PREV,
};

/* Variable holding value of the CPU dependent PWRSTCTRL Register Offset */
static u16 pwrstctrl_reg_offs;

/* Variable holding value of the CPU dependent PWRSTST Register Offset */
static u16 pwrstst_reg_offs;

/* OMAP3 and OMAP4 specific register bit initialisations
 * Notice that the names here are not according to each power
 * domain but the bit mapping used applies to all of them
 */

/* OMAP3 and OMAP4 Memory Onstate Masks (common across all power domains) */
#define OMAP_MEM0_ONSTATE_MASK OMAP3430_SHAREDL1CACHEFLATONSTATE_MASK
#define OMAP_MEM1_ONSTATE_MASK OMAP3430_L1FLATMEMONSTATE_MASK
#define OMAP_MEM2_ONSTATE_MASK OMAP3430_SHAREDL2CACHEFLATONSTATE_MASK
#define OMAP_MEM3_ONSTATE_MASK OMAP3430_L2FLATMEMONSTATE_MASK
#define OMAP_MEM4_ONSTATE_MASK OMAP4430_OCP_NRET_BANK_ONSTATE_MASK

/* OMAP3 and OMAP4 Memory Retstate Masks (common across all power domains) */
#define OMAP_MEM0_RETSTATE_MASK OMAP3430_SHAREDL1CACHEFLATRETSTATE_MASK
#define OMAP_MEM1_RETSTATE_MASK OMAP3430_L1FLATMEMRETSTATE_MASK
#define OMAP_MEM2_RETSTATE_MASK OMAP3430_SHAREDL2CACHEFLATRETSTATE_MASK
#define OMAP_MEM3_RETSTATE_MASK OMAP3430_L2FLATMEMRETSTATE_MASK
#define OMAP_MEM4_RETSTATE_MASK OMAP4430_OCP_NRET_BANK_RETSTATE_MASK

/* OMAP3 and OMAP4 Memory Status bits */
#define OMAP_MEM0_STATEST_MASK OMAP3430_SHAREDL1CACHEFLATSTATEST_MASK
#define OMAP_MEM1_STATEST_MASK OMAP3430_L1FLATMEMSTATEST_MASK
#define OMAP_MEM2_STATEST_MASK OMAP3430_SHAREDL2CACHEFLATSTATEST_MASK
#define OMAP_MEM3_STATEST_MASK OMAP3430_L2FLATMEMSTATEST_MASK
#define OMAP_MEM4_STATEST_MASK OMAP4430_OCP_NRET_BANK_STATEST_MASK

/* pwrdm_list contains all registered struct powerdomains */
static LIST_HEAD(pwrdm_list);

/* Private functions */

static struct powerdomain *_pwrdm_lookup(const char *name)
{
        struct powerdomain *pwrdm, *temp_pwrdm;

        pwrdm = NULL;

        list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
                if (!strcmp(name, temp_pwrdm->name)) {
                        pwrdm = temp_pwrdm;
                        break;
                }
        }

        return pwrdm;
}

/**
 * _pwrdm_register - register a powerdomain
 * @pwrdm: struct powerdomain * to register
 *
 * Adds a powerdomain to the internal powerdomain list.  Returns
 * -EINVAL if given a null pointer, -EEXIST if a powerdomain is
 * already registered by the provided name, or 0 upon success.
 */
static int _pwrdm_register(struct powerdomain *pwrdm)
{
        int i;

        if (!pwrdm)
                return -EINVAL;

        if (!omap_chip_is(pwrdm->omap_chip))
                return -EINVAL;

        if (_pwrdm_lookup(pwrdm->name))
                return -EEXIST;

        list_add(&pwrdm->node, &pwrdm_list);

        /* Initialize the powerdomain's state counter */
        for (i = 0; i < PWRDM_MAX_PWRSTS; i++)
                pwrdm->state_counter[i] = 0;

        pwrdm->ret_logic_off_counter = 0;
        for (i = 0; i < pwrdm->banks; i++)
                pwrdm->ret_mem_off_counter[i] = 0;

        pwrdm_wait_transition(pwrdm);
        pwrdm->state = pwrdm_read_pwrst(pwrdm);
        pwrdm->state_counter[pwrdm->state] = 1;

        pr_debug("powerdomain: registered %s\n", pwrdm->name);

        return 0;
}

static void _update_logic_membank_counters(struct powerdomain *pwrdm)
{
        int i;
        u8 prev_logic_pwrst, prev_mem_pwrst;

        prev_logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
        if ((pwrdm->pwrsts_logic_ret == PWRSTS_OFF_RET) &&
            (prev_logic_pwrst == PWRDM_POWER_OFF))
                pwrdm->ret_logic_off_counter++;

        for (i = 0; i < pwrdm->banks; i++) {
                prev_mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);

                if ((pwrdm->pwrsts_mem_ret[i] == PWRSTS_OFF_RET) &&
                    (prev_mem_pwrst == PWRDM_POWER_OFF))
                        pwrdm->ret_mem_off_counter[i]++;
        }
}

static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag)
{

        int prev;
        int state;

        if (pwrdm == NULL)
                return -EINVAL;

        state = pwrdm_read_pwrst(pwrdm);

        switch (flag) {
        case PWRDM_STATE_NOW:
                prev = pwrdm->state;
                break;
        case PWRDM_STATE_PREV:
                prev = pwrdm_read_prev_pwrst(pwrdm);
                if (pwrdm->state != prev)
                        pwrdm->state_counter[prev]++;
                if (prev == PWRDM_POWER_RET)
                        _update_logic_membank_counters(pwrdm);
                break;
        default:
                return -EINVAL;
        }

        if (state != prev)
                pwrdm->state_counter[state]++;

        pm_dbg_update_time(pwrdm, prev);

        pwrdm->state = state;

        return 0;
}

static int _pwrdm_pre_transition_cb(struct powerdomain *pwrdm, void *unused)
{
        pwrdm_clear_all_prev_pwrst(pwrdm);
        _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
        return 0;
}

static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
{
        _pwrdm_state_switch(pwrdm, PWRDM_STATE_PREV);
        return 0;
}

/* Public functions */

/**
 * pwrdm_init - set up the powerdomain layer
 * @pwrdm_list: array of struct powerdomain pointers to register
 *
 * Loop through the array of powerdomains @pwrdm_list, registering all
 * that are available on the current CPU. If pwrdm_list is supplied
 * and not null, all of the referenced powerdomains will be
 * registered.  No return value.  XXX pwrdm_list is not really a
 * "list"; it is an array.  Rename appropriately.
 */
void pwrdm_init(struct powerdomain **pwrdm_list)
{
        struct powerdomain **p = NULL;

        if (cpu_is_omap24xx() || cpu_is_omap34xx()) {
                pwrstctrl_reg_offs = OMAP2_PM_PWSTCTRL;
                pwrstst_reg_offs = OMAP2_PM_PWSTST;
        } else if (cpu_is_omap44xx()) {
                pwrstctrl_reg_offs = OMAP4_PM_PWSTCTRL;
                pwrstst_reg_offs = OMAP4_PM_PWSTST;
        } else {
                printk(KERN_ERR "Power Domain struct not supported for " \
                                                        "this CPU\n");
                return;
        }

        if (pwrdm_list) {
                for (p = pwrdm_list; *p; p++)
                        _pwrdm_register(*p);
        }
}

/**
 * pwrdm_lookup - look up a powerdomain by name, return a pointer
 * @name: name of powerdomain
 *
 * Find a registered powerdomain by its name @name.  Returns a pointer
 * to the struct powerdomain if found, or NULL otherwise.
 */
struct powerdomain *pwrdm_lookup(const char *name)
{
        struct powerdomain *pwrdm;

        if (!name)
                return NULL;

        pwrdm = _pwrdm_lookup(name);

        return pwrdm;
}

/**
 * pwrdm_for_each - call function on each registered clockdomain
 * @fn: callback function *
 *
 * Call the supplied function @fn for each registered powerdomain.
 * The callback function @fn can return anything but 0 to bail out
 * early from the iterator.  Returns the last return value of the
 * callback function, which should be 0 for success or anything else
 * to indicate failure; or -EINVAL if the function pointer is null.
 */
int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
                   void *user)
{
        struct powerdomain *temp_pwrdm;
        int ret = 0;

        if (!fn)
                return -EINVAL;

        list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
                ret = (*fn)(temp_pwrdm, user);
                if (ret)
                        break;
        }

        return ret;
}

/**
 * pwrdm_add_clkdm - add a clockdomain to a powerdomain
 * @pwrdm: struct powerdomain * to add the clockdomain to
 * @clkdm: struct clockdomain * to associate with a powerdomain
 *
 * Associate the clockdomain @clkdm with a powerdomain @pwrdm.  This
 * enables the use of pwrdm_for_each_clkdm().  Returns -EINVAL if
 * presented with invalid pointers; -ENOMEM if memory could not be allocated;
 * or 0 upon success.
 */
int pwrdm_add_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm)
{
        int i;
        int ret = -EINVAL;

        if (!pwrdm || !clkdm)
                return -EINVAL;

        pr_debug("powerdomain: associating clockdomain %s with powerdomain "
                 "%s\n", clkdm->name, pwrdm->name);

        for (i = 0; i < PWRDM_MAX_CLKDMS; i++) {
                if (!pwrdm->pwrdm_clkdms[i])
                        break;
#ifdef DEBUG
                if (pwrdm->pwrdm_clkdms[i] == clkdm) {
                        ret = -EINVAL;
                        goto pac_exit;
                }
#endif
        }

        if (i == PWRDM_MAX_CLKDMS) {
                pr_debug("powerdomain: increase PWRDM_MAX_CLKDMS for "
                         "pwrdm %s clkdm %s\n", pwrdm->name, clkdm->name);
                WARN_ON(1);
                ret = -ENOMEM;
                goto pac_exit;
        }

        pwrdm->pwrdm_clkdms[i] = clkdm;

        ret = 0;

pac_exit:
        return ret;
}

/**
 * pwrdm_del_clkdm - remove a clockdomain from a powerdomain
 * @pwrdm: struct powerdomain * to add the clockdomain to
 * @clkdm: struct clockdomain * to associate with a powerdomain
 *
 * Dissociate the clockdomain @clkdm from the powerdomain
 * @pwrdm. Returns -EINVAL if presented with invalid pointers; -ENOENT
 * if @clkdm was not associated with the powerdomain, or 0 upon
 * success.
 */
int pwrdm_del_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm)
{
        int ret = -EINVAL;
        int i;

        if (!pwrdm || !clkdm)
                return -EINVAL;

        pr_debug("powerdomain: dissociating clockdomain %s from powerdomain "
                 "%s\n", clkdm->name, pwrdm->name);

        for (i = 0; i < PWRDM_MAX_CLKDMS; i++)
                if (pwrdm->pwrdm_clkdms[i] == clkdm)
                        break;

        if (i == PWRDM_MAX_CLKDMS) {
                pr_debug("powerdomain: clkdm %s not associated with pwrdm "
                         "%s ?!\n", clkdm->name, pwrdm->name);
                ret = -ENOENT;
                goto pdc_exit;
        }

        pwrdm->pwrdm_clkdms[i] = NULL;

        ret = 0;

pdc_exit:
        return ret;
}

/**
 * pwrdm_for_each_clkdm - call function on each clkdm in a pwrdm
 * @pwrdm: struct powerdomain * to iterate over
 * @fn: callback function *
 *
 * Call the supplied function @fn for each clockdomain in the powerdomain
 * @pwrdm.  The callback function can return anything but 0 to bail
 * out early from the iterator.  Returns -EINVAL if presented with
 * invalid pointers; or passes along the last return value of the
 * callback function, which should be 0 for success or anything else
 * to indicate failure.
 */
int pwrdm_for_each_clkdm(struct powerdomain *pwrdm,
                         int (*fn)(struct powerdomain *pwrdm,
                                   struct clockdomain *clkdm))
{
        int ret = 0;
        int i;

        if (!fn)
                return -EINVAL;

        for (i = 0; i < PWRDM_MAX_CLKDMS && !ret; i++)
                ret = (*fn)(pwrdm, pwrdm->pwrdm_clkdms[i]);

        return ret;
}

/**
 * pwrdm_get_mem_bank_count - get number of memory banks in this powerdomain
 * @pwrdm: struct powerdomain *
 *
 * Return the number of controllable memory banks in powerdomain @pwrdm,
 * starting with 1.  Returns -EINVAL if the powerdomain pointer is null.
 */
int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        return pwrdm->banks;
}

/**
 * pwrdm_set_next_pwrst - set next powerdomain power state
 * @pwrdm: struct powerdomain * to set
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the powerdomain @pwrdm's next power state to @pwrst.  The powerdomain
 * may not enter this state immediately if the preconditions for this state
 * have not been satisfied.  Returns -EINVAL if the powerdomain pointer is
 * null or if the power state is invalid for the powerdomin, or returns 0
 * upon success.
 */
int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
{
        if (!pwrdm)
                return -EINVAL;

        if (!(pwrdm->pwrsts & (1 << pwrst)))
                return -EINVAL;

        pr_debug("powerdomain: setting next powerstate for %s to %0x\n",
                 pwrdm->name, pwrst);

        prm_rmw_mod_reg_bits(OMAP_POWERSTATE_MASK,
                             (pwrst << OMAP_POWERSTATE_SHIFT),
                             pwrdm->prcm_offs, pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_read_next_pwrst - get next powerdomain power state
 * @pwrdm: struct powerdomain * to get power state
 *
 * Return the powerdomain @pwrdm's next power state.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the next power state
 * upon success.
 */
int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        return prm_read_mod_bits_shift(pwrdm->prcm_offs,
                                 pwrstctrl_reg_offs, OMAP_POWERSTATE_MASK);
}

/**
 * pwrdm_read_pwrst - get current powerdomain power state
 * @pwrdm: struct powerdomain * to get power state
 *
 * Return the powerdomain @pwrdm's current power state. Returns -EINVAL
 * if the powerdomain pointer is null or returns the current power state
 * upon success.
 */
int pwrdm_read_pwrst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        return prm_read_mod_bits_shift(pwrdm->prcm_offs,
                                 pwrstst_reg_offs, OMAP_POWERSTATEST_MASK);
}

/**
 * pwrdm_read_prev_pwrst - get previous powerdomain power state
 * @pwrdm: struct powerdomain * to get previous power state
 *
 * Return the powerdomain @pwrdm's previous power state.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the previous power state
 * upon success.
 */
int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        return prm_read_mod_bits_shift(pwrdm->prcm_offs, OMAP3430_PM_PREPWSTST,
                                        OMAP3430_LASTPOWERSTATEENTERED_MASK);
}

/**
 * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
 * @pwrdm: struct powerdomain * to set
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the next power state @pwrst that the logic portion of the
 * powerdomain @pwrdm will enter when the powerdomain enters retention.
 * This will be either RETENTION or OFF, if supported.  Returns
 * -EINVAL if the powerdomain pointer is null or the target power
 * state is not not supported, or returns 0 upon success.
 */
int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
{
        u32 v;

        if (!pwrdm)
                return -EINVAL;

        if (!(pwrdm->pwrsts_logic_ret & (1 << pwrst)))
                return -EINVAL;

        pr_debug("powerdomain: setting next logic powerstate for %s to %0x\n",
                 pwrdm->name, pwrst);

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        v = pwrst << __ffs(OMAP3430_LOGICL1CACHERETSTATE_MASK);
        prm_rmw_mod_reg_bits(OMAP3430_LOGICL1CACHERETSTATE_MASK, v,
                             pwrdm->prcm_offs, pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_set_mem_onst - set memory power state while powerdomain ON
 * @pwrdm: struct powerdomain * to set
 * @bank: memory bank number to set (0-3)
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the next power state @pwrst that memory bank @bank of the
 * powerdomain @pwrdm will enter when the powerdomain enters the ON
 * state.  @bank will be a number from 0 to 3, and represents different
 * types of memory, depending on the powerdomain.  Returns -EINVAL if
 * the powerdomain pointer is null or the target power state is not
 * not supported for this memory bank, -EEXIST if the target memory
 * bank does not exist or is not controllable, or returns 0 upon
 * success.
 */
int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
{
        u32 m;

        if (!pwrdm)
                return -EINVAL;

        if (pwrdm->banks < (bank + 1))
                return -EEXIST;

        if (!(pwrdm->pwrsts_mem_on[bank] & (1 << pwrst)))
                return -EINVAL;

        pr_debug("powerdomain: setting next memory powerstate for domain %s "
                 "bank %0x while pwrdm-ON to %0x\n", pwrdm->name, bank, pwrst);

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        switch (bank) {
        case 0:
                m = OMAP_MEM0_ONSTATE_MASK;
                break;
        case 1:
                m = OMAP_MEM1_ONSTATE_MASK;
                break;
        case 2:
                m = OMAP_MEM2_ONSTATE_MASK;
                break;
        case 3:
                m = OMAP_MEM3_ONSTATE_MASK;
                break;
        case 4:
                m = OMAP_MEM4_ONSTATE_MASK;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

        prm_rmw_mod_reg_bits(m, (pwrst << __ffs(m)),
                             pwrdm->prcm_offs, pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_set_mem_retst - set memory power state while powerdomain in RET
 * @pwrdm: struct powerdomain * to set
 * @bank: memory bank number to set (0-3)
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the next power state @pwrst that memory bank @bank of the
 * powerdomain @pwrdm will enter when the powerdomain enters the
 * RETENTION state.  Bank will be a number from 0 to 3, and represents
 * different types of memory, depending on the powerdomain.  @pwrst
 * will be either RETENTION or OFF, if supported.  Returns -EINVAL if
 * the powerdomain pointer is null or the target power state is not
 * not supported for this memory bank, -EEXIST if the target memory
 * bank does not exist or is not controllable, or returns 0 upon
 * success.
 */
int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
{
        u32 m;

        if (!pwrdm)
                return -EINVAL;

        if (pwrdm->banks < (bank + 1))
                return -EEXIST;

        if (!(pwrdm->pwrsts_mem_ret[bank] & (1 << pwrst)))
                return -EINVAL;

        pr_debug("powerdomain: setting next memory powerstate for domain %s "
                 "bank %0x while pwrdm-RET to %0x\n", pwrdm->name, bank, pwrst);

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        switch (bank) {
        case 0:
                m = OMAP_MEM0_RETSTATE_MASK;
                break;
        case 1:
                m = OMAP_MEM1_RETSTATE_MASK;
                break;
        case 2:
                m = OMAP_MEM2_RETSTATE_MASK;
                break;
        case 3:
                m = OMAP_MEM3_RETSTATE_MASK;
                break;
        case 4:
                m = OMAP_MEM4_RETSTATE_MASK;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

        prm_rmw_mod_reg_bits(m, (pwrst << __ffs(m)), pwrdm->prcm_offs,
                             pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_read_logic_pwrst - get current powerdomain logic retention power state
 * @pwrdm: struct powerdomain * to get current logic retention power state
 *
 * Return the power state that the logic portion of powerdomain @pwrdm
 * will enter when the powerdomain enters retention.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the logic retention
 * power state upon success.
 */
int pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        return prm_read_mod_bits_shift(pwrdm->prcm_offs, pwrstst_reg_offs,
                                       OMAP3430_LOGICSTATEST_MASK);
}

/**
 * pwrdm_read_prev_logic_pwrst - get previous powerdomain logic power state
 * @pwrdm: struct powerdomain * to get previous logic power state
 *
 * Return the powerdomain @pwrdm's previous logic power state.  Returns
 * -EINVAL if the powerdomain pointer is null or returns the previous
 * logic power state upon success.
 */
int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        return prm_read_mod_bits_shift(pwrdm->prcm_offs, OMAP3430_PM_PREPWSTST,
                                        OMAP3430_LASTLOGICSTATEENTERED_MASK);
}

/**
 * pwrdm_read_logic_retst - get next powerdomain logic power state
 * @pwrdm: struct powerdomain * to get next logic power state
 *
 * Return the powerdomain pwrdm's logic power state.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the next logic
 * power state upon success.
 */
int pwrdm_read_logic_retst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        return prm_read_mod_bits_shift(pwrdm->prcm_offs, pwrstctrl_reg_offs,
                                       OMAP3430_LOGICSTATEST_MASK);
}

/**
 * pwrdm_read_mem_pwrst - get current memory bank power state
 * @pwrdm: struct powerdomain * to get current memory bank power state
 * @bank: memory bank number (0-3)
 *
 * Return the powerdomain @pwrdm's current memory power state for bank
 * @bank.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
 * the target memory bank does not exist or is not controllable, or
 * returns the current memory power state upon success.
 */
int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
{
        u32 m;

        if (!pwrdm)
                return -EINVAL;

        if (pwrdm->banks < (bank + 1))
                return -EEXIST;

        if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
                bank = 1;

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        switch (bank) {
        case 0:
                m = OMAP_MEM0_STATEST_MASK;
                break;
        case 1:
                m = OMAP_MEM1_STATEST_MASK;
                break;
        case 2:
                m = OMAP_MEM2_STATEST_MASK;
                break;
        case 3:
                m = OMAP_MEM3_STATEST_MASK;
                break;
        case 4:
                m = OMAP_MEM4_STATEST_MASK;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

        return prm_read_mod_bits_shift(pwrdm->prcm_offs,
                                         pwrstst_reg_offs, m);
}

/**
 * pwrdm_read_prev_mem_pwrst - get previous memory bank power state
 * @pwrdm: struct powerdomain * to get previous memory bank power state
 * @bank: memory bank number (0-3)
 *
 * Return the powerdomain @pwrdm's previous memory power state for
 * bank @bank.  Returns -EINVAL if the powerdomain pointer is null,
 * -EEXIST if the target memory bank does not exist or is not
 * controllable, or returns the previous memory power state upon
 * success.
 */
int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
{
        u32 m;

        if (!pwrdm)
                return -EINVAL;

        if (pwrdm->banks < (bank + 1))
                return -EEXIST;

        if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
                bank = 1;

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        switch (bank) {
        case 0:
                m = OMAP3430_LASTMEM1STATEENTERED_MASK;
                break;
        case 1:
                m = OMAP3430_LASTMEM2STATEENTERED_MASK;
                break;
        case 2:
                m = OMAP3430_LASTSHAREDL2CACHEFLATSTATEENTERED_MASK;
                break;
        case 3:
                m = OMAP3430_LASTL2FLATMEMSTATEENTERED_MASK;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

        return prm_read_mod_bits_shift(pwrdm->prcm_offs,
                                        OMAP3430_PM_PREPWSTST, m);
}

/**
 * pwrdm_read_mem_retst - get next memory bank power state
 * @pwrdm: struct powerdomain * to get mext memory bank power state
 * @bank: memory bank number (0-3)
 *
 * Return the powerdomain pwrdm's next memory power state for bank
 * x.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
 * the target memory bank does not exist or is not controllable, or
 * returns the next memory power state upon success.
 */
int pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
{
        u32 m;

        if (!pwrdm)
                return -EINVAL;

        if (pwrdm->banks < (bank + 1))
                return -EEXIST;

        /*
         * The register bit names below may not correspond to the
         * actual names of the bits in each powerdomain's register,
         * but the type of value returned is the same for each
         * powerdomain.
         */
        switch (bank) {
        case 0:
                m = OMAP_MEM0_RETSTATE_MASK;
                break;
        case 1:
                m = OMAP_MEM1_RETSTATE_MASK;
                break;
        case 2:
                m = OMAP_MEM2_RETSTATE_MASK;
                break;
        case 3:
                m = OMAP_MEM3_RETSTATE_MASK;
                break;
        case 4:
                m = OMAP_MEM4_RETSTATE_MASK;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

        return prm_read_mod_bits_shift(pwrdm->prcm_offs,
                                        pwrstctrl_reg_offs, m);
}

/**
 * pwrdm_clear_all_prev_pwrst - clear previous powerstate register for a pwrdm
 * @pwrdm: struct powerdomain * to clear
 *
 * Clear the powerdomain's previous power state register @pwrdm.
 * Clears the entire register, including logic and memory bank
 * previous power states.  Returns -EINVAL if the powerdomain pointer
 * is null, or returns 0 upon success.
 */
int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        /*
         * XXX should get the powerdomain's current state here;
         * warn & fail if it is not ON.
         */

        pr_debug("powerdomain: clearing previous power state reg for %s\n",
                 pwrdm->name);

        prm_write_mod_reg(0, pwrdm->prcm_offs, OMAP3430_PM_PREPWSTST);

        return 0;
}

/**
 * pwrdm_enable_hdwr_sar - enable automatic hardware SAR for a pwrdm
 * @pwrdm: struct powerdomain *
 *
 * Enable automatic context save-and-restore upon power state change
 * for some devices in the powerdomain @pwrdm.  Warning: this only
 * affects a subset of devices in a powerdomain; check the TRM
 * closely.  Returns -EINVAL if the powerdomain pointer is null or if
 * the powerdomain does not support automatic save-and-restore, or
 * returns 0 upon success.
 */
int pwrdm_enable_hdwr_sar(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
                return -EINVAL;

        pr_debug("powerdomain: %s: setting SAVEANDRESTORE bit\n",
                 pwrdm->name);

        prm_rmw_mod_reg_bits(0, 1 << OMAP3430ES2_SAVEANDRESTORE_SHIFT,
                             pwrdm->prcm_offs, pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_disable_hdwr_sar - disable automatic hardware SAR for a pwrdm
 * @pwrdm: struct powerdomain *
 *
 * Disable automatic context save-and-restore upon power state change
 * for some devices in the powerdomain @pwrdm.  Warning: this only
 * affects a subset of devices in a powerdomain; check the TRM
 * closely.  Returns -EINVAL if the powerdomain pointer is null or if
 * the powerdomain does not support automatic save-and-restore, or
 * returns 0 upon success.
 */
int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
                return -EINVAL;

        pr_debug("powerdomain: %s: clearing SAVEANDRESTORE bit\n",
                 pwrdm->name);

        prm_rmw_mod_reg_bits(1 << OMAP3430ES2_SAVEANDRESTORE_SHIFT, 0,
                             pwrdm->prcm_offs, pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_has_hdwr_sar - test whether powerdomain supports hardware SAR
 * @pwrdm: struct powerdomain *
 *
 * Returns 1 if powerdomain @pwrdm supports hardware save-and-restore
 * for some devices, or 0 if it does not.
 */
bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm)
{
        return (pwrdm && pwrdm->flags & PWRDM_HAS_HDWR_SAR) ? 1 : 0;
}

/**
 * pwrdm_set_lowpwrstchange - Request a low power state change
 * @pwrdm: struct powerdomain *
 *
 * Allows a powerdomain to transtion to a lower power sleep state
 * from an existing sleep state without waking up the powerdomain.
 * Returns -EINVAL if the powerdomain pointer is null or if the
 * powerdomain does not support LOWPOWERSTATECHANGE, or returns 0
 * upon success.
 */
int pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
{
        if (!pwrdm)
                return -EINVAL;

        if (!(pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE))
                return -EINVAL;

        pr_debug("powerdomain: %s: setting LOWPOWERSTATECHANGE bit\n",

                 pwrdm->name);

        prm_rmw_mod_reg_bits(OMAP4430_LOWPOWERSTATECHANGE_MASK,
                             (1 << OMAP4430_LOWPOWERSTATECHANGE_SHIFT),
                             pwrdm->prcm_offs, pwrstctrl_reg_offs);

        return 0;
}

/**
 * pwrdm_wait_transition - wait for powerdomain power transition to finish
 * @pwrdm: struct powerdomain * to wait for
 *
 * If the powerdomain @pwrdm is in the process of a state transition,
 * spin until it completes the power transition, or until an iteration
 * bailout value is reached. Returns -EINVAL if the powerdomain
 * pointer is null, -EAGAIN if the bailout value was reached, or
 * returns 0 upon success.
 */
int pwrdm_wait_transition(struct powerdomain *pwrdm)
{
        u32 c = 0;

        if (!pwrdm)
                return -EINVAL;

        /*
         * REVISIT: pwrdm_wait_transition() may be better implemented
         * via a callback and a periodic timer check -- how long do we expect
         * powerdomain transitions to take?
         */

        /* XXX Is this udelay() value meaningful? */
        while ((prm_read_mod_reg(pwrdm->prcm_offs, pwrstst_reg_offs) &
                OMAP_INTRANSITION_MASK) &&
               (c++ < PWRDM_TRANSITION_BAILOUT))
                        udelay(1);

        if (c > PWRDM_TRANSITION_BAILOUT) {
                printk(KERN_ERR "powerdomain: waited too long for "
                       "powerdomain %s to complete transition\n", pwrdm->name);
                return -EAGAIN;
        }

        pr_debug("powerdomain: completed transition in %d loops\n", c);

        return 0;
}

int pwrdm_state_switch(struct powerdomain *pwrdm)
{
        return _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
}

int pwrdm_clkdm_state_switch(struct clockdomain *clkdm)
{
        if (clkdm != NULL && clkdm->pwrdm.ptr != NULL) {
                pwrdm_wait_transition(clkdm->pwrdm.ptr);
                return pwrdm_state_switch(clkdm->pwrdm.ptr);
        }

        return -EINVAL;
}

int pwrdm_pre_transition(void)
{
        pwrdm_for_each(_pwrdm_pre_transition_cb, NULL);
        return 0;
}

int pwrdm_post_transition(void)
{
        pwrdm_for_each(_pwrdm_post_transition_cb, NULL);
        return 0;
}