OMAP3: PM: introduce a new powerdomain walk helper

[linux-ginger.git] / arch / arm / mach-omap2 / powerdomain.c

/*
 * OMAP powerdomain control
 *
 * Copyright (C) 2007-2008 Texas Instruments, Inc.
 * Copyright (C) 2007-2008 Nokia Corporation
 *
 * Written by Paul Walmsley
 *
 * 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.
 */
#ifdef CONFIG_OMAP_DEBUG_POWERDOMAIN
# define DEBUG
#endif

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

#include <mach/cpu.h>
#include <mach/powerdomain.h>
#include <mach/clockdomain.h>

#include "pm.h"

enum {
        PWRDM_STATE_NOW = 0,
        PWRDM_STATE_PREV,
};

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

/*
 * pwrdm_rwlock protects pwrdm_list add and del ops - also reused to
 * protect pwrdm_clkdms[] during clkdm add/del ops
 */
static DEFINE_RWLOCK(pwrdm_rwlock);


/* Private functions */

static u32 prm_read_mod_bits_shift(s16 domain, s16 idx, u32 mask)
{
        u32 v;

        v = prm_read_mod_reg(domain, idx);
        v &= mask;
        v >>= __ffs(mask);

        return v;
}

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_deps_lookup - look up the specified powerdomain in a pwrdm list */
static struct powerdomain *_pwrdm_deps_lookup(struct powerdomain *pwrdm,
                                              struct pwrdm_dep *deps)
{
        struct pwrdm_dep *pd;

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

        for (pd = deps; pd->pwrdm_name; pd++) {

                if (!omap_chip_is(pd->omap_chip))
                        continue;

                if (!pd->pwrdm && pd->pwrdm_name)
                        pd->pwrdm = pwrdm_lookup(pd->pwrdm_name);

                if (pd->pwrdm == pwrdm)
                        break;

        }

        if (!pd->pwrdm_name)
                return ERR_PTR(-ENOENT);

        return pd->pwrdm;
}

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]++;
                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;
}

static __init void _pwrdm_setup(struct powerdomain *pwrdm)
{
        int i;

        for (i = 0; i < 4; i++)
                pwrdm->state_counter[i] = 0;

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

}

/* Public functions */

/**
 * pwrdm_init - set up the powerdomain layer
 *
 * Loop through the list of powerdomains, 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.
 */
void pwrdm_init(struct powerdomain **pwrdm_list)
{
        struct powerdomain **p = NULL;

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

/**
 * 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.
 */
int pwrdm_register(struct powerdomain *pwrdm)
{
        unsigned long flags;
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

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

        write_lock_irqsave(&pwrdm_rwlock, flags);
        if (_pwrdm_lookup(pwrdm->name)) {
                ret = -EEXIST;
                goto pr_unlock;
        }

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

        pr_debug("powerdomain: registered %s\n", pwrdm->name);
        ret = 0;

pr_unlock:
        write_unlock_irqrestore(&pwrdm_rwlock, flags);

        return ret;
}

/**
 * pwrdm_unregister - unregister a powerdomain
 * @pwrdm: struct powerdomain * to unregister
 *
 * Removes a powerdomain from the internal powerdomain list.  Returns
 * -EINVAL if pwrdm argument is NULL.
 */
int pwrdm_unregister(struct powerdomain *pwrdm)
{
        unsigned long flags;

        if (!pwrdm)
                return -EINVAL;

        write_lock_irqsave(&pwrdm_rwlock, flags);
        list_del(&pwrdm->node);
        write_unlock_irqrestore(&pwrdm_rwlock, flags);

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

        return 0;
}

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

        if (!name)
                return NULL;

        read_lock_irqsave(&pwrdm_rwlock, flags);
        pwrdm = _pwrdm_lookup(name);
        read_unlock_irqrestore(&pwrdm_rwlock, flags);

        return pwrdm;
}

/**
 * pwrdm_for_each_nolock - call function on each registered clockdomain
 * @fn: callback function *
 *
 * Call the supplied function for each registered powerdomain.  The
 * callback function 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_nolock(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_for_each - call function on each registered clockdomain
 * @fn: callback function *
 *
 * This function is the same as 'pwrdm_for_each_nolock()', but keeps the
 * &pwrdm_rwlock locked for reading, so no powerdomain structure manipulation
 * functions should be called from the callback, although hardware powerdomain
 * control functions are fine.
 */
int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
                        void *user)
{
        unsigned long flags;
        int ret;

        read_lock_irqsave(&pwrdm_rwlock, flags);
        ret = pwrdm_for_each_nolock(fn, user);
        read_unlock_irqrestore(&pwrdm_rwlock, flags);

        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)
{
        unsigned long flags;
        int i;
        int ret = -EINVAL;

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

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

        write_lock_irqsave(&pwrdm_rwlock, flags);

        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:
        write_unlock_irqrestore(&pwrdm_rwlock, flags);

        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 the clkdm was not associated with the powerdomain, or 0
 * upon success.
 */
int pwrdm_del_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm)
{
        unsigned long flags;
        int ret = -EINVAL;
        int i;

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

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

        write_lock_irqsave(&pwrdm_rwlock, flags);

        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:
        write_unlock_irqrestore(&pwrdm_rwlock, flags);

        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 for each clockdomain in the powerdomain
 * 'pwrdm'.  The callback function can return anything but 0 to bail
 * out early from the iterator.  The callback function is called with
 * the pwrdm_rwlock held for reading, so no powerdomain structure
 * manipulation functions should be called from the callback, although
 * hardware powerdomain control functions are fine.  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))
{
        unsigned long flags;
        int ret = 0;
        int i;

        if (!fn)
                return -EINVAL;

        read_lock_irqsave(&pwrdm_rwlock, flags);

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

        read_unlock_irqrestore(&pwrdm_rwlock, flags);

        return ret;
}


/**
 * pwrdm_add_wkdep - add a wakeup dependency from pwrdm2 to pwrdm1
 * @pwrdm1: wake this struct powerdomain * up (dependent)
 * @pwrdm2: when this struct powerdomain * wakes up (source)
 *
 * When the powerdomain represented by pwrdm2 wakes up (due to an
 * interrupt), wake up pwrdm1.  Implemented in hardware on the OMAP,
 * this feature is designed to reduce wakeup latency of the dependent
 * powerdomain.  Returns -EINVAL if presented with invalid powerdomain
 * pointers, -ENOENT if pwrdm2 cannot wake up pwrdm1 in hardware, or
 * 0 upon success.
 */
int pwrdm_add_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
{
        struct powerdomain *p;

        if (!pwrdm1)
                return -EINVAL;

        p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->wkdep_srcs);
        if (IS_ERR(p)) {
                pr_debug("powerdomain: hardware cannot set/clear wake up of "
                         "%s when %s wakes up\n", pwrdm1->name, pwrdm2->name);
                return IS_ERR(p);
        }

        pr_debug("powerdomain: hardware will wake up %s when %s wakes up\n",
                 pwrdm1->name, pwrdm2->name);

        prm_set_mod_reg_bits((1 << pwrdm2->dep_bit),
                             pwrdm1->prcm_offs, PM_WKDEP);

        return 0;
}

/**
 * pwrdm_del_wkdep - remove a wakeup dependency from pwrdm2 to pwrdm1
 * @pwrdm1: wake this struct powerdomain * up (dependent)
 * @pwrdm2: when this struct powerdomain * wakes up (source)
 *
 * Remove a wakeup dependency that causes pwrdm1 to wake up when pwrdm2
 * wakes up.  Returns -EINVAL if presented with invalid powerdomain
 * pointers, -ENOENT if pwrdm2 cannot wake up pwrdm1 in hardware, or
 * 0 upon success.
 */
int pwrdm_del_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
{
        struct powerdomain *p;

        if (!pwrdm1)
                return -EINVAL;

        p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->wkdep_srcs);
        if (IS_ERR(p)) {
                pr_debug("powerdomain: hardware cannot set/clear wake up of "
                         "%s when %s wakes up\n", pwrdm1->name, pwrdm2->name);
                return IS_ERR(p);
        }

        pr_debug("powerdomain: hardware will no longer wake up %s after %s "
                 "wakes up\n", pwrdm1->name, pwrdm2->name);

        prm_clear_mod_reg_bits((1 << pwrdm2->dep_bit),
                               pwrdm1->prcm_offs, PM_WKDEP);

        return 0;
}

/**
 * pwrdm_read_wkdep - read wakeup dependency state from pwrdm2 to pwrdm1
 * @pwrdm1: wake this struct powerdomain * up (dependent)
 * @pwrdm2: when this struct powerdomain * wakes up (source)
 *
 * Return 1 if a hardware wakeup dependency exists wherein pwrdm1 will be
 * awoken when pwrdm2 wakes up; 0 if dependency is not set; -EINVAL
 * if either powerdomain pointer is invalid; or -ENOENT if the hardware
 * is incapable.
 *
 * REVISIT: Currently this function only represents software-controllable
 * wakeup dependencies.  Wakeup dependencies fixed in hardware are not
 * yet handled here.
 */
int pwrdm_read_wkdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
{
        struct powerdomain *p;

        if (!pwrdm1)
                return -EINVAL;

        p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->wkdep_srcs);
        if (IS_ERR(p)) {
                pr_debug("powerdomain: hardware cannot set/clear wake up of "
                         "%s when %s wakes up\n", pwrdm1->name, pwrdm2->name);
                return IS_ERR(p);
        }

        return prm_read_mod_bits_shift(pwrdm1->prcm_offs, PM_WKDEP,
                                        (1 << pwrdm2->dep_bit));
}

/**
 * pwrdm_add_sleepdep - add a sleep dependency from pwrdm2 to pwrdm1
 * @pwrdm1: prevent this struct powerdomain * from sleeping (dependent)
 * @pwrdm2: when this struct powerdomain * is active (source)
 *
 * Prevent pwrdm1 from automatically going inactive (and then to
 * retention or off) if pwrdm2 is still active.  Returns -EINVAL if
 * presented with invalid powerdomain pointers or called on a machine
 * that does not support software-configurable hardware sleep dependencies,
 * -ENOENT if the specified dependency cannot be set in hardware, or
 * 0 upon success.
 */
int pwrdm_add_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
{
        struct powerdomain *p;

        if (!pwrdm1)
                return -EINVAL;

        if (!cpu_is_omap34xx())
                return -EINVAL;

        p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->sleepdep_srcs);
        if (IS_ERR(p)) {
                pr_debug("powerdomain: hardware cannot set/clear sleep "
                         "dependency affecting %s from %s\n", pwrdm1->name,
                         pwrdm2->name);
                return IS_ERR(p);
        }

        pr_debug("powerdomain: will prevent %s from sleeping if %s is active\n",
                 pwrdm1->name, pwrdm2->name);

        cm_set_mod_reg_bits((1 << pwrdm2->dep_bit),
                            pwrdm1->prcm_offs, OMAP3430_CM_SLEEPDEP);

        return 0;
}

/**
 * pwrdm_del_sleepdep - remove a sleep dependency from pwrdm2 to pwrdm1
 * @pwrdm1: prevent this struct powerdomain * from sleeping (dependent)
 * @pwrdm2: when this struct powerdomain * is active (source)
 *
 * Allow pwrdm1 to automatically go inactive (and then to retention or
 * off), independent of the activity state of pwrdm2.  Returns -EINVAL
 * if presented with invalid powerdomain pointers or called on a machine
 * that does not support software-configurable hardware sleep dependencies,
 * -ENOENT if the specified dependency cannot be cleared in hardware, or
 * 0 upon success.
 */
int pwrdm_del_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
{
        struct powerdomain *p;

        if (!pwrdm1)
                return -EINVAL;

        if (!cpu_is_omap34xx())
                return -EINVAL;

        p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->sleepdep_srcs);
        if (IS_ERR(p)) {
                pr_debug("powerdomain: hardware cannot set/clear sleep "
                         "dependency affecting %s from %s\n", pwrdm1->name,
                         pwrdm2->name);
                return IS_ERR(p);
        }

        pr_debug("powerdomain: will no longer prevent %s from sleeping if "
                 "%s is active\n", pwrdm1->name, pwrdm2->name);

        cm_clear_mod_reg_bits((1 << pwrdm2->dep_bit),
                              pwrdm1->prcm_offs, OMAP3430_CM_SLEEPDEP);

        return 0;
}

/**
 * pwrdm_read_sleepdep - read sleep dependency state from pwrdm2 to pwrdm1
 * @pwrdm1: prevent this struct powerdomain * from sleeping (dependent)
 * @pwrdm2: when this struct powerdomain * is active (source)
 *
 * Return 1 if a hardware sleep dependency exists wherein pwrdm1 will
 * not be allowed to automatically go inactive if pwrdm2 is active;
 * 0 if pwrdm1's automatic power state inactivity transition is independent
 * of pwrdm2's; -EINVAL if either powerdomain pointer is invalid or called
 * on a machine that does not support software-configurable hardware sleep
 * dependencies; or -ENOENT if the hardware is incapable.
 *
 * REVISIT: Currently this function only represents software-controllable
 * sleep dependencies.  Sleep dependencies fixed in hardware are not
 * yet handled here.
 */
int pwrdm_read_sleepdep(struct powerdomain *pwrdm1, struct powerdomain *pwrdm2)
{
        struct powerdomain *p;

        if (!pwrdm1)
                return -EINVAL;

        if (!cpu_is_omap34xx())
                return -EINVAL;

        p = _pwrdm_deps_lookup(pwrdm2, pwrdm1->sleepdep_srcs);
        if (IS_ERR(p)) {
                pr_debug("powerdomain: hardware cannot set/clear sleep "
                         "dependency affecting %s from %s\n", pwrdm1->name,
                         pwrdm2->name);
                return IS_ERR(p);
        }

        return prm_read_mod_bits_shift(pwrdm1->prcm_offs, OMAP3430_CM_SLEEPDEP,
                                        (1 << pwrdm2->dep_bit));
}

/**
 * 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, PM_PWSTCTRL);

        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, PM_PWSTCTRL,
                                        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, PM_PWSTST,
                                        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 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)
{
        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.
         */
        prm_rmw_mod_reg_bits(OMAP3430_LOGICL1CACHERETSTATE,
                             (pwrst << __ffs(OMAP3430_LOGICL1CACHERETSTATE)),
                             pwrdm->prcm_offs, PM_PWSTCTRL);

        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 that memory bank x 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 = OMAP3430_SHAREDL1CACHEFLATONSTATE_MASK;
                break;
        case 1:
                m = OMAP3430_L1FLATMEMONSTATE_MASK;
                break;
        case 2:
                m = OMAP3430_SHAREDL2CACHEFLATONSTATE_MASK;
                break;
        case 3:
                m = OMAP3430_L2FLATMEMONSTATE_MASK;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

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

        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 that memory bank x 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 = OMAP3430_SHAREDL1CACHEFLATRETSTATE;
                break;
        case 1:
                m = OMAP3430_L1FLATMEMRETSTATE;
                break;
        case 2:
                m = OMAP3430_SHAREDL2CACHEFLATRETSTATE;
                break;
        case 3:
                m = OMAP3430_L2FLATMEMRETSTATE;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

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

        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 current power state that the logic portion of
 * powerdomain pwrdm will enter
 * Returns -EINVAL if the powerdomain pointer is null or returns the
 * current 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, PM_PWSTST,
                                        OMAP3430_LOGICSTATEST);
}

/**
 * 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 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);
}

/**
 * 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
 * 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 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;

        /*
         * 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_SHAREDL1CACHEFLATSTATEST_MASK;
                break;
        case 1:
                m = OMAP3430_L1FLATMEMSTATEST_MASK;
                break;
        case 2:
                m = OMAP3430_SHAREDL2CACHEFLATSTATEST_MASK;
                break;
        case 3:
                m = OMAP3430_L2FLATMEMSTATEST_MASK;
                break;
        default:
                WARN_ON(1); /* should never happen */
                return -EEXIST;
        }

        return prm_read_mod_bits_shift(pwrdm->prcm_offs, PM_PWSTST, 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
 * 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 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;

        /*
         * 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_clear_all_prev_pwrst - clear previous powerstate register for a pwrdm
 * @pwrdm: struct powerdomain * to clear
 *
 * Clear the powerdomain's previous power state register.  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 a powerdomain.  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, PM_PWSTCTRL);

        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 a powerdomain.  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, PM_PWSTCTRL);

        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_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, PM_PWSTST) &
                OMAP_INTRANSITION) &&
               (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_clk_state_switch(struct clk *clk)
{
        if (clk != NULL && clk->clkdm != NULL)
                return pwrdm_clkdm_state_switch(clk->clkdm);
        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;
}