root/sound/hda/core/ext/bus.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  hdac-ext-bus.c - HD-audio extended core bus functions.
 *
 *  Copyright (C) 2014-2015 Intel Corp
 *  Author: Jeeja KP <jeeja.kp@intel.com>
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <sound/hdaudio_ext.h>

MODULE_DESCRIPTION("HDA extended core");
MODULE_LICENSE("GPL v2");

/**
 * snd_hdac_ext_bus_init - initialize a HD-audio extended bus
 * @bus: the pointer to HDAC bus object
 * @dev: device pointer
 * @ops: bus verb operators
 * @ext_ops: operators used for ASoC HDA codec drivers
 *
 * Returns 0 if successful, or a negative error code.
 */
int snd_hdac_ext_bus_init(struct hdac_bus *bus, struct device *dev,
                        const struct hdac_bus_ops *ops,
                        const struct hdac_ext_bus_ops *ext_ops)
{
        int ret;

        ret = snd_hdac_bus_init(bus, dev, ops);
        if (ret < 0)
                return ret;

        bus->ext_ops = ext_ops;
        /* FIXME:
         * Currently only one bus is supported, if there is device with more
         * buses, bus->idx should be greater than 0, but there needs to be a
         * reliable way to always assign same number.
         */
        bus->idx = 0;
        bus->cmd_dma_state = true;

        return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_init);

/**
 * snd_hdac_ext_bus_exit - clean up a HD-audio extended bus
 * @bus: the pointer to HDAC bus object
 */
void snd_hdac_ext_bus_exit(struct hdac_bus *bus)
{
        snd_hdac_bus_exit(bus);
        WARN_ON(!list_empty(&bus->hlink_list));
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_exit);

/**
 * snd_hdac_ext_bus_device_remove - remove HD-audio extended codec base devices
 *
 * @bus: the pointer to HDAC bus object
 */
void snd_hdac_ext_bus_device_remove(struct hdac_bus *bus)
{
        struct hdac_device *codec, *__codec;
        /*
         * we need to remove all the codec devices objects created in the
         * snd_hdac_ext_bus_device_init
         */
        list_for_each_entry_safe(codec, __codec, &bus->codec_list, list) {
                snd_hdac_device_unregister(codec);
                put_device(&codec->dev);
        }
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_bus_device_remove);
#define dev_to_hdac(dev) (container_of((dev), \
                        struct hdac_device, dev))

static inline struct hdac_driver *get_hdrv(struct device *dev)
{
        struct hdac_driver *hdrv = drv_to_hdac_driver(dev->driver);
        return hdrv;
}

static inline struct hdac_device *get_hdev(struct device *dev)
{
        struct hdac_device *hdev = dev_to_hdac_dev(dev);
        return hdev;
}

static int hda_ext_drv_probe(struct device *dev)
{
        return (get_hdrv(dev))->probe(get_hdev(dev));
}

static int hdac_ext_drv_remove(struct device *dev)
{
        return (get_hdrv(dev))->remove(get_hdev(dev));
}

static void hdac_ext_drv_shutdown(struct device *dev)
{
        return (get_hdrv(dev))->shutdown(get_hdev(dev));
}

/**
 * snd_hda_ext_driver_register - register a driver for ext hda devices
 *
 * @drv: ext hda driver structure
 */
int snd_hda_ext_driver_register(struct hdac_driver *drv)
{
        drv->type = HDA_DEV_ASOC;
        drv->driver.bus = &snd_hda_bus_type;
        /* we use default match */

        if (drv->probe)
                drv->driver.probe = hda_ext_drv_probe;
        if (drv->remove)
                drv->driver.remove = hdac_ext_drv_remove;
        if (drv->shutdown)
                drv->driver.shutdown = hdac_ext_drv_shutdown;

        return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(snd_hda_ext_driver_register);

/**
 * snd_hda_ext_driver_unregister - unregister a driver for ext hda devices
 *
 * @drv: ext hda driver structure
 */
void snd_hda_ext_driver_unregister(struct hdac_driver *drv)
{
        driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(snd_hda_ext_driver_unregister);