1 ===================
2 ASoC Machine Driver
3 ===================
4
5 The ASoC machine (or board) driver is the code
6 component drivers (e.g. codecs, platforms and
7 relationships between each component which inc
8 interrupts, clocking, jacks and voltage regula
9
10 The machine driver can contain codec and platf
11 the audio subsystem with the kernel as a platf
12 the following struct:-
13 ::
14
15 /* SoC machine */
16 struct snd_soc_card {
17 char *name;
18
19 ...
20
21 int (*probe)(struct platform_device *p
22 int (*remove)(struct platform_device *
23
24 /* the pre and post PM functions are u
25 * after the codec and DAIs do any PM
26 int (*suspend_pre)(struct platform_dev
27 int (*suspend_post)(struct platform_de
28 int (*resume_pre)(struct platform_devi
29 int (*resume_post)(struct platform_dev
30
31 ...
32
33 /* CPU <--> Codec DAI links */
34 struct snd_soc_dai_link *dai_link;
35 int num_links;
36
37 ...
38 };
39
40 probe()/remove()
41 ----------------
42 probe/remove are optional. Do any machine spec
43
44
45 suspend()/resume()
46 ------------------
47 The machine driver has pre and post versions o
48 of any machine audio tasks that have to be don
49 and DMA is suspended and resumed. Optional.
50
51
52 Machine DAI Configuration
53 -------------------------
54 The machine DAI configuration glues all the co
55 also be used to set up the DAI system clock an
56 initialisation e.g. the machine audio map can
57 map, unconnected codec pins can be set as such
58
59 struct snd_soc_dai_link is used to set up each
60 ::
61
62 /* corgi digital audio interface glue - conn
63 static struct snd_soc_dai_link corgi_dai = {
64 .name = "WM8731",
65 .stream_name = "WM8731",
66 .cpu_dai_name = "pxa-is2-dai",
67 .codec_dai_name = "wm8731-hifi",
68 .platform_name = "pxa-pcm-audio",
69 .codec_name = "wm8713-codec.0-001a",
70 .init = corgi_wm8731_init,
71 .ops = &corgi_ops,
72 };
73
74 struct snd_soc_card then sets up the machine w
75 ::
76
77 /* corgi audio machine driver */
78 static struct snd_soc_card snd_soc_corgi = {
79 .name = "Corgi",
80 .dai_link = &corgi_dai,
81 .num_links = 1,
82 };
83
84
85 Machine Power Map
86 -----------------
87
88 The machine driver can optionally extend the c
89 audio power map of the audio subsystem. This a
90 of speaker/HP amplifiers, etc. Codec pins can
91 sockets in the machine init function.
92
93
94 Machine Controls
95 ----------------
96
97 Machine specific audio mixer controls can be a
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