linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * Generic OPP Interface

 *

 * Copyright (C) 2009-2010 Texas Instruments Incorporated.

 *  Nishanth Menon

 *  Romit Dasgupta

 *  Kevin Hilman

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/clk.h>

#include <linux/errno.h>

#include <linux/err.h>

#include <linux/slab.h>

#include <linux/device.h>

#include <linux/export.h>

#include <linux/pm_domain.h>

#include <linux/regulator/consumer.h>

​

#include "opp.h"

​

/*

 * The root of the list of all opp-tables. All opp_table structures branch off

 * from here, with each opp_table containing the list of opps it supports in

 * various states of availability.

 */

LIST_HEAD(opp_tables);

/* Lock to allow exclusive modification to the device and opp lists */

DEFINE_MUTEX(opp_table_lock);

​

static struct opp_device *_find_opp_dev(const struct device *dev,

                    struct opp_table *opp_table)

{

    struct opp_device *opp_dev;

​

    list_for_each_entry(opp_dev, &opp_table->dev_list, node)

        if (opp_dev->dev == dev)

            return opp_dev;

​

    return NULL;

}

​

static struct opp_table *_find_opp_table_unlocked(struct device *dev)

{

    struct opp_table *opp_table;

    bool found;

​

    list_for_each_entry(opp_table, &opp_tables, node) {

        mutex_lock(&opp_table->lock);

        found = !!_find_opp_dev(dev, opp_table);

        mutex_unlock(&opp_table->lock);

​

        if (found) {

            _get_opp_table_kref(opp_table);

​

            return opp_table;

        }

    }

​

    return ERR_PTR(-ENODEV);

}

​

/**

 * _find_opp_table() - find opp_table struct using device pointer

 * @dev:    device pointer used to lookup OPP table

 *

 * Search OPP table for one containing matching device.

 *

 * Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or

 * -EINVAL based on type of error.

 *

 * The callers must call dev_pm_opp_put_opp_table() after the table is used.

 */

struct opp_table *_find_opp_table(struct device *dev)

{

    struct opp_table *opp_table;

​

    if (IS_ERR_OR_NULL(dev)) {

        pr_err("%s: Invalid parameters\n", __func__);

        return ERR_PTR(-EINVAL);

    }

​

    mutex_lock(&opp_table_lock);

    opp_table = _find_opp_table_unlocked(dev);

    mutex_unlock(&opp_table_lock);

​

    return opp_table;

}

​

/**