LXR linux/sound/hda/hda_bus

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * HD-audio bus
   4 */
   5#include <linux/init.h>
   6#include <linux/device.h>
   7#include <linux/module.h>
   8#include <linux/mod_devicetable.h>
   9#include <linux/export.h>
  10#include <sound/hdaudio.h>
  11
  12MODULE_DESCRIPTION("HD-audio bus");
  13MODULE_LICENSE("GPL");
  14
  15/**
  16 * hdac_get_device_id - gets the hdac device id entry
  17 * @hdev: HD-audio core device
  18 * @drv: HD-audio codec driver
  19 *
  20 * Compares the hdac device vendor_id and revision_id to the hdac_device
  21 * driver id_table and returns the matching device id entry.
  22 */
  23const struct hda_device_id *
  24hdac_get_device_id(struct hdac_device *hdev, struct hdac_driver *drv)
  25{
  26        if (drv->id_table) {
  27                const struct hda_device_id *id  = drv->id_table;
  28
  29                while (id->vendor_id) {
  30                        if (hdev->vendor_id == id->vendor_id &&
  31                                (!id->rev_id || id->rev_id == hdev->revision_id))
  32                                return id;
  33                        id++;
  34                }
  35        }
  36
  37        return NULL;
  38}
  39EXPORT_SYMBOL_GPL(hdac_get_device_id);
  40
  41static int hdac_codec_match(struct hdac_device *dev, struct hdac_driver *drv)
  42{
  43        if (hdac_get_device_id(dev, drv))
  44                return 1;
  45        else
  46                return 0;
  47}
  48
  49static int hda_bus_match(struct device *dev, struct device_driver *drv)
  50{
  51        struct hdac_device *hdev = dev_to_hdac_dev(dev);
  52        struct hdac_driver *hdrv = drv_to_hdac_driver(drv);
  53
  54        if (hdev->type != hdrv->type)
  55                return 0;
  56
  57        /*
  58         * if driver provided a match function use that otherwise we will
  59         * use hdac_codec_match function
  60         */
  61        if (hdrv->match)
  62                return hdrv->match(hdev, hdrv);
  63        else
  64                return hdac_codec_match(hdev, hdrv);
  65        return 1;
  66}
  67
  68static int hda_uevent(struct device *dev, struct kobj_uevent_env *env)
  69{
  70        char modalias[32];
  71
  72        snd_hdac_codec_modalias(dev_to_hdac_dev(dev), modalias,
  73                                sizeof(modalias));
  74        if (add_uevent_var(env, "MODALIAS=%s", modalias))
  75                return -ENOMEM;
  76        return 0;
  77}
  78
  79struct bus_type snd_hda_bus_type = {
  80        .name = "hdaudio",
  81        .match = hda_bus_match,
  82        .uevent = hda_uevent,
  83};
  84EXPORT_SYMBOL_GPL(snd_hda_bus_type);
  85
  86static int __init hda_bus_init(void)
  87{
  88        return bus_register(&snd_hda_bus_type);
  89}
  90
  91static void __exit hda_bus_exit(void)
  92{
  93        bus_unregister(&snd_hda_bus_type);
  94}
  95
  96subsys_initcall(hda_bus_init);
  97module_exit(hda_bus_exit);
  98