Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[muen/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_params.h>
13 #include <sound/pcm_iec958.h>
14
15 static int create_iec958_consumer(uint rate, uint sample_width,
16                                   u8 *cs, size_t len)
17 {
18         unsigned int fs, ws;
19
20         if (len < 4)
21                 return -EINVAL;
22
23         switch (rate) {
24         case 32000:
25                 fs = IEC958_AES3_CON_FS_32000;
26                 break;
27         case 44100:
28                 fs = IEC958_AES3_CON_FS_44100;
29                 break;
30         case 48000:
31                 fs = IEC958_AES3_CON_FS_48000;
32                 break;
33         case 88200:
34                 fs = IEC958_AES3_CON_FS_88200;
35                 break;
36         case 96000:
37                 fs = IEC958_AES3_CON_FS_96000;
38                 break;
39         case 176400:
40                 fs = IEC958_AES3_CON_FS_176400;
41                 break;
42         case 192000:
43                 fs = IEC958_AES3_CON_FS_192000;
44                 break;
45         default:
46                 return -EINVAL;
47         }
48
49         if (len > 4) {
50                 switch (sample_width) {
51                 case 16:
52                         ws = IEC958_AES4_CON_WORDLEN_20_16;
53                         break;
54                 case 18:
55                         ws = IEC958_AES4_CON_WORDLEN_22_18;
56                         break;
57                 case 20:
58                         ws = IEC958_AES4_CON_WORDLEN_20_16 |
59                              IEC958_AES4_CON_MAX_WORDLEN_24;
60                         break;
61                 case 24:
62                 case 32: /* Assume 24-bit width for 32-bit samples. */
63                         ws = IEC958_AES4_CON_WORDLEN_24_20 |
64                              IEC958_AES4_CON_MAX_WORDLEN_24;
65                         break;
66
67                 default:
68                         return -EINVAL;
69                 }
70         }
71
72         memset(cs, 0, len);
73
74         cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE;
75         cs[1] = IEC958_AES1_CON_GENERAL;
76         cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC;
77         cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs;
78
79         if (len > 4)
80                 cs[4] = ws;
81
82         return len;
83 }
84
85 /**
86  * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
87  * @runtime: pcm runtime structure with ->rate filled in
88  * @cs: channel status buffer, at least four bytes
89  * @len: length of channel status buffer
90  *
91  * Create the consumer format channel status data in @cs of maximum size
92  * @len corresponding to the parameters of the PCM runtime @runtime.
93  *
94  * Drivers may wish to tweak the contents of the buffer after creation.
95  *
96  * Returns: length of buffer, or negative error code if something failed.
97  */
98 int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
99         size_t len)
100 {
101         return create_iec958_consumer(runtime->rate,
102                                       snd_pcm_format_width(runtime->format),
103                                       cs, len);
104 }
105 EXPORT_SYMBOL(snd_pcm_create_iec958_consumer);
106
107 /**
108  * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status
109  * @hw_params: the hw_params instance for extracting rate and sample format
110  * @cs: channel status buffer, at least four bytes
111  * @len: length of channel status buffer
112  *
113  * Create the consumer format channel status data in @cs of maximum size
114  * @len corresponding to the parameters of the PCM runtime @runtime.
115  *
116  * Drivers may wish to tweak the contents of the buffer after creation.
117  *
118  * Returns: length of buffer, or negative error code if something failed.
119  */
120 int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
121                                              u8 *cs, size_t len)
122 {
123         return create_iec958_consumer(params_rate(params), params_width(params),
124                                       cs, len);
125 }
126 EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params);