]> git.karo-electronics.de Git - karo-tx-linux.git/blob - sound/core/pcm_iec958.c
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
[karo-tx-linux.git] / sound / core / pcm_iec958.c
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);