// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 2014 Linaro Ltd
 *
 * Author: Ulf Hansson <ulf.hansson@linaro.org>
 *
 *  MMC power sequence management
 */
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/of.h>

#include <linux/mmc/host.h>

#include "pwrseq.h"

static DEFINE_MUTEX(pwrseq_list_mutex);
static LIST_HEAD(pwrseq_list);

int mmc_pwrseq_alloc(struct mmc_host *host)
{
        struct device_node *np;
        struct mmc_pwrseq *p;

        np = of_parse_phandle(host->parent->of_node, "mmc-pwrseq", 0);
        if (!np)
                return 0;

        mutex_lock(&pwrseq_list_mutex);
        list_for_each_entry(p, &pwrseq_list, pwrseq_node) {
                if (device_match_of_node(p->dev, np)) {
                        if (!try_module_get(p->owner))
                                dev_err(host->parent,
                                        "increasing module refcount failed\n");
                        else
                                host->pwrseq = p;

                        break;
                }
        }

        of_node_put(np);
        mutex_unlock(&pwrseq_list_mutex);

        if (!host->pwrseq)
                return -EPROBE_DEFER;

        dev_info(host->parent, "allocated mmc-pwrseq\n");

        return 0;
}

void mmc_pwrseq_pre_power_on(struct mmc_host *host)
{
        struct mmc_pwrseq *pwrseq = host->pwrseq;

        if (pwrseq && pwrseq->ops->pre_power_on)
                pwrseq->ops->pre_power_on(host);
}

void mmc_pwrseq_post_power_on(struct mmc_host *host)
{
        struct mmc_pwrseq *pwrseq = host->pwrseq;

        if (pwrseq && pwrseq->ops->post_power_on)
                pwrseq->ops->post_power_on(host);
}

void mmc_pwrseq_power_off(struct mmc_host *host)
{
        struct mmc_pwrseq *pwrseq = host->pwrseq;

        if (pwrseq && pwrseq->ops->power_off)
                pwrseq->ops->power_off(host);
}

void mmc_pwrseq_reset(struct mmc_host *host)
{
        struct mmc_pwrseq *pwrseq = host->pwrseq;

        if (pwrseq && pwrseq->ops->reset)
                pwrseq->ops->reset(host);
}

void mmc_pwrseq_free(struct mmc_host *host)
{
        struct mmc_pwrseq *pwrseq = host->pwrseq;

        if (pwrseq) {
                module_put(pwrseq->owner);
                host->pwrseq = NULL;
        }
}

int mmc_pwrseq_register(struct mmc_pwrseq *pwrseq)
{
        if (!pwrseq || !pwrseq->ops || !pwrseq->dev)
                return -EINVAL;

        mutex_lock(&pwrseq_list_mutex);
        list_add(&pwrseq->pwrseq_node, &pwrseq_list);
        mutex_unlock(&pwrseq_list_mutex);

        return 0;
}
EXPORT_SYMBOL_GPL(mmc_pwrseq_register);

void mmc_pwrseq_unregister(struct mmc_pwrseq *pwrseq)
{
        if (pwrseq) {
                mutex_lock(&pwrseq_list_mutex);
                list_del(&pwrseq->pwrseq_node);
                mutex_unlock(&pwrseq_list_mutex);
        }
}
EXPORT_SYMBOL_GPL(mmc_pwrseq_unregister);