Merge tag 'locking-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel...

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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * OMAP powerdomain control
 *
 * Copyright (C) 2007-2008, 2011 Texas Instruments, Inc.
 * Copyright (C) 2007-2011 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>
 */
#undef DEBUG

#include <linux/cpu_pm.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <trace/events/power.h>

#include "cm2xxx_3xxx.h"
#include "prcm44xx.h"
#include "cm44xx.h"
#include "prm2xxx_3xxx.h"
#include "prm44xx.h"

#include <asm/cpu.h>

#include "powerdomain.h"
#include "clockdomain.h"
#include "voltage.h"

#include "soc.h"
#include "pm.h"

#define PWRDM_TRACE_STATES_FLAG (1<<31)

void pwrdms_save_context(void);
void pwrdms_restore_context(void);

enum {
        PWRDM_STATE_NOW = 0,
        PWRDM_STATE_PREV,
};

/*
 * Types of sleep_switch used internally in omap_set_pwrdm_state()
 * and its associated static functions
 *
 * XXX Better documentation is needed here
 */
#define ALREADYACTIVE_SWITCH            0
#define FORCEWAKEUP_SWITCH              1
#define LOWPOWERSTATE_SWITCH            2

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

static struct pwrdm_ops *arch_pwrdm;

/* 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;
        struct voltagedomain *voltdm;

        if (!pwrdm || !pwrdm->name)
                return -EINVAL;

        if (cpu_is_omap44xx() &&
            pwrdm->prcm_partition == OMAP4430_INVALID_PRCM_PARTITION) {
                pr_err("powerdomain: %s: missing OMAP4 PRCM partition ID\n",
                       pwrdm->name);
                return -EINVAL;
        }

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_has_voltdm)
                if (!arch_pwrdm->pwrdm_has_voltdm())
                        goto skip_voltdm;

        voltdm = voltdm_lookup(pwrdm->voltdm.name);
        if (!voltdm) {
                pr_err("powerdomain: %s: voltagedomain %s does not exist\n",
                       pwrdm->name, pwrdm->voltdm.name);
                return -EINVAL;
        }
        pwrdm->voltdm.ptr = voltdm;
        INIT_LIST_HEAD(&pwrdm->voltdm_node);
skip_voltdm:
        spin_lock_init(&pwrdm->_lock);

        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;

        if (arch_pwrdm && arch_pwrdm->pwrdm_wait_transition)
                arch_pwrdm->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, next, state, trace_state = 0;

        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);
                /*
                 * If the power domain did not hit the desired state,
                 * generate a trace event with both the desired and hit states
                 */
                next = pwrdm_read_next_pwrst(pwrdm);
                if (next != prev) {
                        trace_state = (PWRDM_TRACE_STATES_FLAG |
                                       ((next & OMAP_POWERSTATE_MASK) << 8) |
                                       ((prev & OMAP_POWERSTATE_MASK) << 0));
                        trace_power_domain_target_rcuidle(pwrdm->name,
                                                          trace_state,
                                                          raw_smp_processor_id());
                }
                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;
}

/**
 * _pwrdm_save_clkdm_state_and_activate - prepare for power state change
 * @pwrdm: struct powerdomain * to operate on
 * @curr_pwrst: current power state of @pwrdm
 * @pwrst: power state to switch to
 *
 * Determine whether the powerdomain needs to be turned on before
 * attempting to switch power states.  Called by
 * omap_set_pwrdm_state().  NOTE that if the powerdomain contains
 * multiple clockdomains, this code assumes that the first clockdomain
 * supports software-supervised wakeup mode - potentially a problem.
 * Returns the power state switch mode currently in use (see the
 * "Types of sleep_switch" comment above).
 */
static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
                                               u8 curr_pwrst, u8 pwrst)
{
        u8 sleep_switch;

        if (curr_pwrst < PWRDM_POWER_ON) {
                if (curr_pwrst > pwrst &&
                    pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
                    arch_pwrdm->pwrdm_set_lowpwrstchange) {
                        sleep_switch = LOWPOWERSTATE_SWITCH;
                } else {
                        clkdm_deny_idle_nolock(pwrdm->pwrdm_clkdms[0]);
                        sleep_switch = FORCEWAKEUP_SWITCH;
                }
        } else {
                sleep_switch = ALREADYACTIVE_SWITCH;
        }

        return sleep_switch;
}

/**
 * _pwrdm_restore_clkdm_state - restore the clkdm hwsup state after pwrst change
 * @pwrdm: struct powerdomain * to operate on
 * @sleep_switch: return value from _pwrdm_save_clkdm_state_and_activate()
 *
 * Restore the clockdomain state perturbed by
 * _pwrdm_save_clkdm_state_and_activate(), and call the power state
 * bookkeeping code.  Called by omap_set_pwrdm_state().  NOTE that if
 * the powerdomain contains multiple clockdomains, this assumes that
 * the first associated clockdomain supports either
 * hardware-supervised idle control in the register, or
 * software-supervised sleep.  No return value.
 */
static void _pwrdm_restore_clkdm_state(struct powerdomain *pwrdm,
                                       u8 sleep_switch)
{
        switch (sleep_switch) {
        case FORCEWAKEUP_SWITCH:
                clkdm_allow_idle_nolock(pwrdm->pwrdm_clkdms[0]);
                break;
        case LOWPOWERSTATE_SWITCH:
                if (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
                    arch_pwrdm->pwrdm_set_lowpwrstchange)
                        arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
                pwrdm_state_switch_nolock(pwrdm);
                break;
        }
}

/* Public functions */

/**
 * pwrdm_register_platform_funcs - register powerdomain implementation fns
 * @po: func pointers for arch specific implementations
 *
 * Register the list of function pointers used to implement the
 * powerdomain functions on different OMAP SoCs.  Should be called
 * before any other pwrdm_register*() function.  Returns -EINVAL if
 * @po is null, -EEXIST if platform functions have already been
 * registered, or 0 upon success.
 */
int pwrdm_register_platform_funcs(struct pwrdm_ops *po)
{
        if (!po)
                return -EINVAL;

        if (arch_pwrdm)
                return -EEXIST;

        arch_pwrdm = po;

        return 0;
}

/**
 * pwrdm_register_pwrdms - register SoC powerdomains
 * @ps: pointer to an array of struct powerdomain to register
 *
 * Register the powerdomains available on a particular OMAP SoC.  Must
 * be called after pwrdm_register_platform_funcs().  May be called
 * multiple times.  Returns -EACCES if called before
 * pwrdm_register_platform_funcs(); -EINVAL if the argument @ps is
 * null; or 0 upon success.
 */
int pwrdm_register_pwrdms(struct powerdomain **ps)
{
        struct powerdomain **p = NULL;

        if (!arch_pwrdm)
                return -EEXIST;

        if (!ps)
                return -EINVAL;

        for (p = ps; *p; p++)
                _pwrdm_register(*p);

        return 0;
}

static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
{
        switch (cmd) {
        case CPU_CLUSTER_PM_ENTER:
                if (enable_off_mode)
                        pwrdms_save_context();
                break;
        case CPU_CLUSTER_PM_EXIT:
                if (enable_off_mode)
                        pwrdms_restore_context();
                break;
        }

        return NOTIFY_OK;
}

/**
 * pwrdm_complete_init - set up the powerdomain layer
 *
 * Do whatever is necessary to initialize registered powerdomains and
 * powerdomain code.  Currently, this programs the next power state
 * for each powerdomain to ON.  This prevents powerdomains from
 * unexpectedly losing context or entering high wakeup latency modes
 * with non-power-management-enabled kernels.  Must be called after
 * pwrdm_register_pwrdms().  Returns -EACCES if called before
 * pwrdm_register_pwrdms(), or 0 upon success.
 */
int pwrdm_complete_init(void)
{
        struct powerdomain *temp_p;
        static struct notifier_block nb;

        if (list_empty(&pwrdm_list))
                return -EACCES;

        list_for_each_entry(temp_p, &pwrdm_list, node)
                pwrdm_set_next_pwrst(temp_p, PWRDM_POWER_ON);

        /* Only AM43XX can lose pwrdm context during rtc-ddr suspend */
        if (soc_is_am43xx()) {
                nb.notifier_call = cpu_notifier;
                cpu_pm_register_notifier(&nb);
        }

        return 0;
}

/**
 * pwrdm_lock - acquire a Linux spinlock on a powerdomain
 * @pwrdm: struct powerdomain * to lock
 *
 * Acquire the powerdomain spinlock on @pwrdm.  No return value.
 */
void pwrdm_lock(struct powerdomain *pwrdm)
        __acquires(&pwrdm->_lock)
{
        spin_lock_irqsave(&pwrdm->_lock, pwrdm->_lock_flags);
}

/**
 * pwrdm_unlock - release a Linux spinlock on a powerdomain
 * @pwrdm: struct powerdomain * to unlock
 *
 * Release the powerdomain spinlock on @pwrdm.  No return value.
 */
void pwrdm_unlock(struct powerdomain *pwrdm)
        __releases(&pwrdm->_lock)
{
        spin_unlock_irqrestore(&pwrdm->_lock, pwrdm->_lock_flags);
}

/**
 * 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: %s: associating clockdomain %s\n",
                 pwrdm->name, clkdm->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: %s: increase PWRDM_MAX_CLKDMS for 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_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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
                /* Trace the pwrdm desired target state */
                trace_power_domain_target_rcuidle(pwrdm->name, pwrst,
                                                  raw_smp_processor_id());
                /* Program the pwrdm desired target state */
                ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
        }

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_next_pwrst)
                ret = arch_pwrdm->pwrdm_read_next_pwrst(pwrdm);

        return ret;
}

/**
 * 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. Note that if the power domain only supports the ON state
 * then just return ON as the current state.
 */
int pwrdm_read_pwrst(struct powerdomain *pwrdm)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

        if (pwrdm->pwrsts == PWRSTS_ON)
                return PWRDM_POWER_ON;

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_pwrst)
                ret = arch_pwrdm->pwrdm_read_pwrst(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_pwrst)
                ret = arch_pwrdm->pwrdm_read_prev_pwrst(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_set_logic_retst)
                ret = arch_pwrdm->pwrdm_set_logic_retst(pwrdm, pwrst);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

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

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_onst)
                ret = arch_pwrdm->pwrdm_set_mem_onst(pwrdm, bank, pwrst);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

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

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_retst)
                ret = arch_pwrdm->pwrdm_set_mem_retst(pwrdm, bank, pwrst);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_pwrst)
                ret = arch_pwrdm->pwrdm_read_logic_pwrst(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_logic_pwrst)
                ret = arch_pwrdm->pwrdm_read_prev_logic_pwrst(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return -EINVAL;

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_retst)
                ret = arch_pwrdm->pwrdm_read_logic_retst(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return ret;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_pwrst)
                ret = arch_pwrdm->pwrdm_read_mem_pwrst(pwrdm, bank);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return ret;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_mem_pwrst)
                ret = arch_pwrdm->pwrdm_read_prev_mem_pwrst(pwrdm, bank);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return ret;

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_retst)
                ret = arch_pwrdm->pwrdm_read_mem_retst(pwrdm, bank);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return ret;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_clear_all_prev_pwrst)
                ret = arch_pwrdm->pwrdm_clear_all_prev_pwrst(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return ret;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_enable_hdwr_sar)
                ret = arch_pwrdm->pwrdm_enable_hdwr_sar(pwrdm);

        return ret;
}

/**
 * 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)
{
        int ret = -EINVAL;

        if (!pwrdm)
                return ret;

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

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

        if (arch_pwrdm && arch_pwrdm->pwrdm_disable_hdwr_sar)
                ret = arch_pwrdm->pwrdm_disable_hdwr_sar(pwrdm);

        return ret;
}

/**
 * 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;
}

int pwrdm_state_switch_nolock(struct powerdomain *pwrdm)
{
        int ret;

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

        ret = arch_pwrdm->pwrdm_wait_transition(pwrdm);
        if (!ret)
                ret = _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);

        return ret;
}

int __deprecated pwrdm_state_switch(struct powerdomain *pwrdm)
{
        int ret;

        pwrdm_lock(pwrdm);
        ret = pwrdm_state_switch_nolock(pwrdm);
        pwrdm_unlock(pwrdm);

        return ret;
}

int pwrdm_pre_transition(struct powerdomain *pwrdm)
{
        if (pwrdm)
                _pwrdm_pre_transition_cb(pwrdm, NULL);
        else
                pwrdm_for_each(_pwrdm_pre_transition_cb, NULL);

        return 0;
}

int pwrdm_post_transition(struct powerdomain *pwrdm)
{
        if (pwrdm)
                _pwrdm_post_transition_cb(pwrdm, NULL);
        else
                pwrdm_for_each(_pwrdm_post_transition_cb, NULL);

        return 0;
}

/**
 * pwrdm_get_valid_lp_state() - Find best match deep power state
 * @pwrdm:      power domain for which we want to find best match
 * @is_logic_state: Are we looking for logic state match here? Should
 *                  be one of PWRDM_xxx macro values
 * @req_state:  requested power state
 *
 * Returns: closest match for requested power state. default fallback
 * is RET for logic state and ON for power state.
 *
 * This does a search from the power domain data looking for the
 * closest valid power domain state that the hardware can achieve.
 * PRCM definitions for PWRSTCTRL allows us to program whatever
 * configuration we'd like, and PRCM will actually attempt such
 * a transition, however if the powerdomain does not actually support it,
 * we endup with a hung system. The valid power domain states are already
 * available in our powerdomain data files. So this function tries to do
 * the following:
 * a) find if we have an exact match to the request - no issues.
 * b) else find if a deeper power state is possible.
 * c) failing which, it tries to find closest higher power state for the
 * request.
 */
u8 pwrdm_get_valid_lp_state(struct powerdomain *pwrdm,
                            bool is_logic_state, u8 req_state)
{
        u8 pwrdm_states = is_logic_state ? pwrdm->pwrsts_logic_ret :
                        pwrdm->pwrsts;
        /* For logic, ret is highest and others, ON is highest */
        u8 default_pwrst = is_logic_state ? PWRDM_POWER_RET : PWRDM_POWER_ON;
        u8 new_pwrst;
        bool found;

        /* If it is already supported, nothing to search */
        if (pwrdm_states & BIT(req_state))
                return req_state;

        if (!req_state)
                goto up_search;

        /*
         * So, we dont have a exact match
         * Can we get a deeper power state match?
         */
        new_pwrst = req_state - 1;
        found = true;
        while (!(pwrdm_states & BIT(new_pwrst))) {
                /* No match even at OFF? Not available */
                if (new_pwrst == PWRDM_POWER_OFF) {
                        found = false;
                        break;
                }
                new_pwrst--;
        }

        if (found)
                goto done;

up_search:
        /* OK, no deeper ones, can we get a higher match? */
        new_pwrst = req_state + 1;
        while (!(pwrdm_states & BIT(new_pwrst))) {
                if (new_pwrst > PWRDM_POWER_ON) {
                        WARN(1, "powerdomain: %s: Fix max powerstate to ON\n",
                             pwrdm->name);
                        return PWRDM_POWER_ON;
                }

                if (new_pwrst == default_pwrst)
                        break;
                new_pwrst++;
        }
done:
        return new_pwrst;
}

/**
 * omap_set_pwrdm_state - change a powerdomain's current power state
 * @pwrdm: struct powerdomain * to change the power state of
 * @pwrst: power state to change to
 *
 * Change the current hardware power state of the powerdomain
 * represented by @pwrdm to the power state represented by @pwrst.
 * Returns -EINVAL if @pwrdm is null or invalid or if the
 * powerdomain's current power state could not be read, or returns 0
 * upon success or if @pwrdm does not support @pwrst or any
 * lower-power state.  XXX Should not return 0 if the @pwrdm does not
 * support @pwrst or any lower-power state: this should be an error.
 */
int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
{
        u8 next_pwrst, sleep_switch;
        int curr_pwrst;
        int ret = 0;

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

        while (!(pwrdm->pwrsts & (1 << pwrst))) {
                if (pwrst == PWRDM_POWER_OFF)
                        return ret;
                pwrst--;
        }

        pwrdm_lock(pwrdm);

        curr_pwrst = pwrdm_read_pwrst(pwrdm);
        if (curr_pwrst < 0) {
                ret = -EINVAL;
                goto osps_out;
        }

        next_pwrst = pwrdm_read_next_pwrst(pwrdm);
        if (curr_pwrst == pwrst && next_pwrst == pwrst)
                goto osps_out;

        sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
                                                            pwrst);

        ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
        if (ret)
                pr_err("%s: unable to set power state of powerdomain: %s\n",
                       __func__, pwrdm->name);

        _pwrdm_restore_clkdm_state(pwrdm, sleep_switch);

osps_out:
        pwrdm_unlock(pwrdm);

        return ret;
}

/**
 * pwrdm_get_context_loss_count - get powerdomain's context loss count
 * @pwrdm: struct powerdomain * to wait for
 *
 * Context loss count is the sum of powerdomain off-mode counter, the
 * logic off counter and the per-bank memory off counter.  Returns negative
 * (and WARNs) upon error, otherwise, returns the context loss count.
 */
int pwrdm_get_context_loss_count(struct powerdomain *pwrdm)
{
        int i, count;

        if (!pwrdm) {
                WARN(1, "powerdomain: %s: pwrdm is null\n", __func__);
                return -ENODEV;
        }

        count = pwrdm->state_counter[PWRDM_POWER_OFF];
        count += pwrdm->ret_logic_off_counter;

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

        /*
         * Context loss count has to be a non-negative value. Clear the sign
         * bit to get a value range from 0 to INT_MAX.
         */
        count &= INT_MAX;

        pr_debug("powerdomain: %s: context loss count = %d\n",
                 pwrdm->name, count);

        return count;
}

/**
 * pwrdm_can_ever_lose_context - can this powerdomain ever lose context?
 * @pwrdm: struct powerdomain *
 *
 * Given a struct powerdomain * @pwrdm, returns 1 if the powerdomain
 * can lose either memory or logic context or if @pwrdm is invalid, or
 * returns 0 otherwise.  This function is not concerned with how the
 * powerdomain registers are programmed (i.e., to go off or not); it's
 * concerned with whether it's ever possible for this powerdomain to
 * go off while some other part of the chip is active.  This function
 * assumes that every powerdomain can go to either ON or INACTIVE.
 */
bool pwrdm_can_ever_lose_context(struct powerdomain *pwrdm)
{
        int i;

        if (!pwrdm) {
                pr_debug("powerdomain: %s: invalid powerdomain pointer\n",
                         __func__);
                return 1;
        }

        if (pwrdm->pwrsts & PWRSTS_OFF)
                return 1;

        if (pwrdm->pwrsts & PWRSTS_RET) {
                if (pwrdm->pwrsts_logic_ret & PWRSTS_OFF)
                        return 1;

                for (i = 0; i < pwrdm->banks; i++)
                        if (pwrdm->pwrsts_mem_ret[i] & PWRSTS_OFF)
                                return 1;
        }

        for (i = 0; i < pwrdm->banks; i++)
                if (pwrdm->pwrsts_mem_on[i] & PWRSTS_OFF)
                        return 1;

        return 0;
}

/**
 * pwrdm_save_context - save powerdomain registers
 *
 * Register state is going to be lost due to a suspend or hibernate
 * event. Save the powerdomain registers.
 */
static int pwrdm_save_context(struct powerdomain *pwrdm, void *unused)
{
        if (arch_pwrdm && arch_pwrdm->pwrdm_save_context)
                arch_pwrdm->pwrdm_save_context(pwrdm);
        return 0;
}

/**
 * pwrdm_save_context - restore powerdomain registers
 *
 * Restore powerdomain control registers after a suspend or resume
 * event.
 */
static int pwrdm_restore_context(struct powerdomain *pwrdm, void *unused)
{
        if (arch_pwrdm && arch_pwrdm->pwrdm_restore_context)
                arch_pwrdm->pwrdm_restore_context(pwrdm);
        return 0;
}

static int pwrdm_lost_power(struct powerdomain *pwrdm, void *unused)
{
        int state;

        /*
         * Power has been lost across all powerdomains, increment the
         * counter.
         */

        state = pwrdm_read_pwrst(pwrdm);
        if (state != PWRDM_POWER_OFF) {
                pwrdm->state_counter[state]++;
                pwrdm->state_counter[PWRDM_POWER_OFF]++;
        }
        pwrdm->state = state;

        return 0;
}

void pwrdms_save_context(void)
{
        pwrdm_for_each(pwrdm_save_context, NULL);
}

void pwrdms_restore_context(void)
{
        pwrdm_for_each(pwrdm_restore_context, NULL);
}

void pwrdms_lost_power(void)
{
        pwrdm_for_each(pwrdm_lost_power, NULL);
}