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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9203dd01 RK |
2 | /* |
3 | * PCM DRM helpers | |
9203dd01 RK |
4 | */ |
5 | #include <linux/export.h> | |
6 | #include <linux/types.h> | |
7 | #include <sound/asoundef.h> | |
8 | #include <sound/pcm.h> | |
4a443657 | 9 | #include <sound/pcm_params.h> |
9203dd01 RK |
10 | #include <sound/pcm_iec958.h> |
11 | ||
4a443657 JS |
12 | static int create_iec958_consumer(uint rate, uint sample_width, |
13 | u8 *cs, size_t len) | |
9203dd01 RK |
14 | { |
15 | unsigned int fs, ws; | |
16 | ||
17 | if (len < 4) | |
18 | return -EINVAL; | |
19 | ||
4a443657 | 20 | switch (rate) { |
9203dd01 RK |
21 | case 32000: |
22 | fs = IEC958_AES3_CON_FS_32000; | |
23 | break; | |
24 | case 44100: | |
25 | fs = IEC958_AES3_CON_FS_44100; | |
26 | break; | |
27 | case 48000: | |
28 | fs = IEC958_AES3_CON_FS_48000; | |
29 | break; | |
30 | case 88200: | |
31 | fs = IEC958_AES3_CON_FS_88200; | |
32 | break; | |
33 | case 96000: | |
34 | fs = IEC958_AES3_CON_FS_96000; | |
35 | break; | |
36 | case 176400: | |
37 | fs = IEC958_AES3_CON_FS_176400; | |
38 | break; | |
39 | case 192000: | |
40 | fs = IEC958_AES3_CON_FS_192000; | |
41 | break; | |
42 | default: | |
43 | return -EINVAL; | |
44 | } | |
45 | ||
46 | if (len > 4) { | |
4a443657 | 47 | switch (sample_width) { |
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48 | case 16: |
49 | ws = IEC958_AES4_CON_WORDLEN_20_16; | |
50 | break; | |
51 | case 18: | |
52 | ws = IEC958_AES4_CON_WORDLEN_22_18; | |
53 | break; | |
54 | case 20: | |
55 | ws = IEC958_AES4_CON_WORDLEN_20_16 | | |
56 | IEC958_AES4_CON_MAX_WORDLEN_24; | |
57 | break; | |
58 | case 24: | |
4a462ce0 | 59 | case 32: /* Assume 24-bit width for 32-bit samples. */ |
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60 | ws = IEC958_AES4_CON_WORDLEN_24_20 | |
61 | IEC958_AES4_CON_MAX_WORDLEN_24; | |
62 | break; | |
63 | ||
64 | default: | |
65 | return -EINVAL; | |
66 | } | |
67 | } | |
68 | ||
69 | memset(cs, 0, len); | |
70 | ||
71 | cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE; | |
72 | cs[1] = IEC958_AES1_CON_GENERAL; | |
73 | cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC; | |
74 | cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | fs; | |
75 | ||
76 | if (len > 4) | |
77 | cs[4] = ws; | |
78 | ||
79 | return len; | |
80 | } | |
4a443657 JS |
81 | |
82 | /** | |
83 | * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status | |
84 | * @runtime: pcm runtime structure with ->rate filled in | |
85 | * @cs: channel status buffer, at least four bytes | |
86 | * @len: length of channel status buffer | |
87 | * | |
88 | * Create the consumer format channel status data in @cs of maximum size | |
89 | * @len corresponding to the parameters of the PCM runtime @runtime. | |
90 | * | |
91 | * Drivers may wish to tweak the contents of the buffer after creation. | |
92 | * | |
93 | * Returns: length of buffer, or negative error code if something failed. | |
94 | */ | |
95 | int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs, | |
96 | size_t len) | |
97 | { | |
98 | return create_iec958_consumer(runtime->rate, | |
99 | snd_pcm_format_width(runtime->format), | |
100 | cs, len); | |
101 | } | |
9203dd01 | 102 | EXPORT_SYMBOL(snd_pcm_create_iec958_consumer); |
4a443657 JS |
103 | |
104 | /** | |
105 | * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status | |
106 | * @hw_params: the hw_params instance for extracting rate and sample format | |
107 | * @cs: channel status buffer, at least four bytes | |
108 | * @len: length of channel status buffer | |
109 | * | |
110 | * Create the consumer format channel status data in @cs of maximum size | |
111 | * @len corresponding to the parameters of the PCM runtime @runtime. | |
112 | * | |
113 | * Drivers may wish to tweak the contents of the buffer after creation. | |
114 | * | |
115 | * Returns: length of buffer, or negative error code if something failed. | |
116 | */ | |
117 | int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params, | |
118 | u8 *cs, size_t len) | |
119 | { | |
120 | return create_iec958_consumer(params_rate(params), params_width(params), | |
121 | cs, len); | |
122 | } | |
123 | EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params); |