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 *
hdac_get_device_id(struct hdac_device * hdev,struct hdac_driver * drv)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
hdac_codec_match(struct hdac_device * dev,struct hdac_driver * drv)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
hda_bus_match(struct device * dev,struct device_driver * drv)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
hda_uevent(struct device * dev,struct kobj_uevent_env * env)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
hda_bus_init(void)86 static int __init hda_bus_init(void)
87 {
88 return bus_register(&snd_hda_bus_type);
89 }
90
hda_bus_exit(void)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);
98