root/sound/hda/hda_bus_type.c

DEFINITIONS

1. hdac_get_device_id
2. hdac_codec_match
3. hda_bus_match
4. hda_uevent
5. hda_bus_init
6. hda_bus_exit

   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 
  12 MODULE_DESCRIPTION("HD-audio bus");
  13 MODULE_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  */
  23 const struct hda_device_id *
  24 hdac_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 }
  39 EXPORT_SYMBOL_GPL(hdac_get_device_id);
  40 
  41 static 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 
  49 static 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 
  68 static 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 
  79 struct bus_type snd_hda_bus_type = {
  80         .name = "hdaudio",
  81         .match = hda_bus_match,
  82         .uevent = hda_uevent,
  83 };
  84 EXPORT_SYMBOL_GPL(snd_hda_bus_type);
  85 
  86 static int __init hda_bus_init(void)
  87 {
  88         return bus_register(&snd_hda_bus_type);
  89 }
  90 
  91 static void __exit hda_bus_exit(void)
  92 {
  93         bus_unregister(&snd_hda_bus_type);
  94 }
  95 
  96 subsys_initcall(hda_bus_init);
  97 module_exit(hda_bus_exit);