sound/hda/hda_bus_type.c

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