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(dev: hdev, drv: hdrv); |
65 | return 1; |
66 | } |
67 | |
68 | static int hda_uevent(const struct device *dev, struct kobj_uevent_env *env) |
69 | { |
70 | char modalias[32]; |
71 | |
72 | snd_hdac_codec_modalias(dev_to_hdac_dev(dev), buf: modalias, |
73 | size: sizeof(modalias)); |
74 | if (add_uevent_var(env, format: "MODALIAS=%s" , modalias)) |
75 | return -ENOMEM; |
76 | return 0; |
77 | } |
78 | |
79 | const 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(bus: &snd_hda_bus_type); |
89 | } |
90 | |
91 | static void __exit hda_bus_exit(void) |
92 | { |
93 | bus_unregister(bus: &snd_hda_bus_type); |
94 | } |
95 | |
96 | subsys_initcall(hda_bus_init); |
97 | module_exit(hda_bus_exit); |
98 | |