Commit | Line | Data |
---|---|---|
9203dd01 RK |
1 | /* |
2 | * PCM DRM helpers | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | #include <linux/export.h> | |
9 | #include <linux/types.h> | |
10 | #include <sound/asoundef.h> | |
11 | #include <sound/pcm.h> | |
12 | #include <sound/pcm_iec958.h> | |
13 | ||
14 | /** | |
15 | * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status | |
16 | * @runtime: pcm runtime structure with ->rate filled in | |
17 | * @cs: channel status buffer, at least four bytes | |
18 | * @len: length of channel status buffer | |
19 | * | |
20 | * Create the consumer format channel status data in @cs of maximum size | |
21 | * @len corresponding to the parameters of the PCM runtime @runtime. | |
22 | * | |
23 | * Drivers may wish to tweak the contents of the buffer after creation. | |
24 | * | |
25 | * Returns: length of buffer, or negative error code if something failed. | |
26 | */ | |
27 | int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs, | |
28 | size_t len) | |
29 | { | |
30 | unsigned int fs, ws; | |
31 | ||
32 | if (len < 4) | |
33 | return -EINVAL; | |
34 | ||
35 | switch (runtime->rate) { | |
36 | case 32000: | |
37 | fs = IEC958_AES3_CON_FS_32000; | |
38 | break; | |
39 | case 44100: | |
40 | fs = IEC958_AES3_CON_FS_44100; | |
41 | break; | |
42 | case 48000: | |
43 | fs = IEC958_AES3_CON_FS_48000; | |
44 | break; | |
45 | case 88200: | |
46 | fs = IEC958_AES3_CON_FS_88200; | |
47 | break; | |
48 | case 96000: | |
49 | fs = IEC958_AES3_CON_FS_96000; | |
50 | break; | |
51 | case 176400: | |
52 | fs = IEC958_AES3_CON_FS_176400; | |
53 | break; | |
54 | case 192000: | |
55 | fs = IEC958_AES3_CON_FS_192000; | |
56 | break; | |
57 | default: | |
58 | return -EINVAL; | |
59 | } | |
60 | ||
61 | if (len > 4) { | |
62 | switch (snd_pcm_format_width(runtime->format)) { | |
63 | case 16: | |
64 | ws = IEC958_AES4_CON_WORDLEN_20_16; | |
65 | break; | |
66 | case 18: | |
67 | ws = IEC958_AES4_CON_WORDLEN_22_18; | |
68 | break; | |
69 | case 20: | |
70 | ws = IEC958_AES4_CON_WORDLEN_20_16 | | |
71 | IEC958_AES4_CON_MAX_WORDLEN_24; | |
72 | break; | |
73 | case 24: | |
74 | ws = IEC958_AES4_CON_WORDLEN_24_20 | | |
75 | IEC958_AES4_CON_MAX_WORDLEN_24; | |
76 | break; | |
77 | ||
78 | default: | |
79 | return -EINVAL; | |
80 | } | |
81 | } | |
82 | ||
83 | memset(cs, 0, len); | |
84 | ||
85 | cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE; | |
86 | cs[1] = IEC958_AES1_CON_GENERAL; | |
87 | cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC; | |
88 | cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs; | |
89 | ||
90 | if (len > 4) | |
91 | cs[4] = ws; | |
92 | ||
93 | return len; | |
94 | } | |
95 | EXPORT_SYMBOL(snd_pcm_create_iec958_consumer); |