xref: /openbmc/linux/sound/hda/hda_bus_type.c (revision 6189f1b0)
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);
84