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