1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * PCM DRM helpers |
4 | */ |
5 | #include <linux/export.h> |
6 | #include <linux/types.h> |
7 | #include <sound/asoundef.h> |
8 | #include <sound/pcm.h> |
9 | #include <sound/pcm_params.h> |
10 | #include <sound/pcm_iec958.h> |
11 | |
12 | /** |
13 | * snd_pcm_create_iec958_consumer_default - create default consumer format IEC958 channel status |
14 | * @cs: channel status buffer, at least four bytes |
15 | * @len: length of channel status buffer |
16 | * |
17 | * Create the consumer format channel status data in @cs of maximum size |
18 | * @len. When relevant, the configuration-dependant bits will be set as |
19 | * unspecified. |
20 | * |
21 | * Drivers should then call einter snd_pcm_fill_iec958_consumer() or |
22 | * snd_pcm_fill_iec958_consumer_hw_params() to replace these unspecified |
23 | * bits by their actual values. |
24 | * |
25 | * Drivers may wish to tweak the contents of the buffer after creation. |
26 | * |
27 | * Returns: length of buffer, or negative error code if something failed. |
28 | */ |
29 | int snd_pcm_create_iec958_consumer_default(u8 *cs, size_t len) |
30 | { |
31 | if (len < 4) |
32 | return -EINVAL; |
33 | |
34 | memset(cs, 0, len); |
35 | |
36 | cs[0] = IEC958_AES0_CON_NOT_COPYRIGHT | IEC958_AES0_CON_EMPHASIS_NONE; |
37 | cs[1] = IEC958_AES1_CON_GENERAL; |
38 | cs[2] = IEC958_AES2_CON_SOURCE_UNSPEC | IEC958_AES2_CON_CHANNEL_UNSPEC; |
39 | cs[3] = IEC958_AES3_CON_CLOCK_1000PPM | IEC958_AES3_CON_FS_NOTID; |
40 | |
41 | if (len > 4) |
42 | cs[4] = IEC958_AES4_CON_WORDLEN_NOTID; |
43 | |
44 | return len; |
45 | } |
46 | EXPORT_SYMBOL_GPL(snd_pcm_create_iec958_consumer_default); |
47 | |
48 | static int fill_iec958_consumer(uint rate, uint sample_width, |
49 | u8 *cs, size_t len) |
50 | { |
51 | if (len < 4) |
52 | return -EINVAL; |
53 | |
54 | if ((cs[3] & IEC958_AES3_CON_FS) == IEC958_AES3_CON_FS_NOTID) { |
55 | unsigned int fs; |
56 | |
57 | switch (rate) { |
58 | case 32000: |
59 | fs = IEC958_AES3_CON_FS_32000; |
60 | break; |
61 | case 44100: |
62 | fs = IEC958_AES3_CON_FS_44100; |
63 | break; |
64 | case 48000: |
65 | fs = IEC958_AES3_CON_FS_48000; |
66 | break; |
67 | case 88200: |
68 | fs = IEC958_AES3_CON_FS_88200; |
69 | break; |
70 | case 96000: |
71 | fs = IEC958_AES3_CON_FS_96000; |
72 | break; |
73 | case 176400: |
74 | fs = IEC958_AES3_CON_FS_176400; |
75 | break; |
76 | case 192000: |
77 | fs = IEC958_AES3_CON_FS_192000; |
78 | break; |
79 | default: |
80 | return -EINVAL; |
81 | } |
82 | |
83 | cs[3] &= ~IEC958_AES3_CON_FS; |
84 | cs[3] |= fs; |
85 | } |
86 | |
87 | if (len > 4 && |
88 | (cs[4] & IEC958_AES4_CON_WORDLEN) == IEC958_AES4_CON_WORDLEN_NOTID) { |
89 | unsigned int ws; |
90 | |
91 | switch (sample_width) { |
92 | case 16: |
93 | ws = IEC958_AES4_CON_WORDLEN_20_16; |
94 | break; |
95 | case 18: |
96 | ws = IEC958_AES4_CON_WORDLEN_22_18; |
97 | break; |
98 | case 20: |
99 | ws = IEC958_AES4_CON_WORDLEN_20_16 | |
100 | IEC958_AES4_CON_MAX_WORDLEN_24; |
101 | break; |
102 | case 24: |
103 | case 32: /* Assume 24-bit width for 32-bit samples. */ |
104 | ws = IEC958_AES4_CON_WORDLEN_24_20 | |
105 | IEC958_AES4_CON_MAX_WORDLEN_24; |
106 | break; |
107 | |
108 | default: |
109 | return -EINVAL; |
110 | } |
111 | |
112 | cs[4] &= ~IEC958_AES4_CON_WORDLEN; |
113 | cs[4] |= ws; |
114 | } |
115 | |
116 | return len; |
117 | } |
118 | |
119 | /** |
120 | * snd_pcm_fill_iec958_consumer - Fill consumer format IEC958 channel status |
121 | * @runtime: pcm runtime structure with ->rate filled in |
122 | * @cs: channel status buffer, at least four bytes |
123 | * @len: length of channel status buffer |
124 | * |
125 | * Fill the unspecified bits in an IEC958 status bits array using the |
126 | * parameters of the PCM runtime @runtime. |
127 | * |
128 | * Drivers may wish to tweak the contents of the buffer after its been |
129 | * filled. |
130 | * |
131 | * Returns: length of buffer, or negative error code if something failed. |
132 | */ |
133 | int snd_pcm_fill_iec958_consumer(struct snd_pcm_runtime *runtime, |
134 | u8 *cs, size_t len) |
135 | { |
136 | return fill_iec958_consumer(rate: runtime->rate, |
137 | sample_width: snd_pcm_format_width(format: runtime->format), |
138 | cs, len); |
139 | } |
140 | EXPORT_SYMBOL_GPL(snd_pcm_fill_iec958_consumer); |
141 | |
142 | /** |
143 | * snd_pcm_fill_iec958_consumer_hw_params - Fill consumer format IEC958 channel status |
144 | * @params: the hw_params instance for extracting rate and sample format |
145 | * @cs: channel status buffer, at least four bytes |
146 | * @len: length of channel status buffer |
147 | * |
148 | * Fill the unspecified bits in an IEC958 status bits array using the |
149 | * parameters of the PCM hardware parameters @params. |
150 | * |
151 | * Drivers may wish to tweak the contents of the buffer after its been |
152 | * filled.. |
153 | * |
154 | * Returns: length of buffer, or negative error code if something failed. |
155 | */ |
156 | int snd_pcm_fill_iec958_consumer_hw_params(struct snd_pcm_hw_params *params, |
157 | u8 *cs, size_t len) |
158 | { |
159 | return fill_iec958_consumer(rate: params_rate(p: params), sample_width: params_width(p: params), cs, len); |
160 | } |
161 | EXPORT_SYMBOL_GPL(snd_pcm_fill_iec958_consumer_hw_params); |
162 | |
163 | /** |
164 | * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status |
165 | * @runtime: pcm runtime structure with ->rate filled in |
166 | * @cs: channel status buffer, at least four bytes |
167 | * @len: length of channel status buffer |
168 | * |
169 | * Create the consumer format channel status data in @cs of maximum size |
170 | * @len corresponding to the parameters of the PCM runtime @runtime. |
171 | * |
172 | * Drivers may wish to tweak the contents of the buffer after creation. |
173 | * |
174 | * Returns: length of buffer, or negative error code if something failed. |
175 | */ |
176 | int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs, |
177 | size_t len) |
178 | { |
179 | int ret; |
180 | |
181 | ret = snd_pcm_create_iec958_consumer_default(cs, len); |
182 | if (ret < 0) |
183 | return ret; |
184 | |
185 | return snd_pcm_fill_iec958_consumer(runtime, cs, len); |
186 | } |
187 | EXPORT_SYMBOL(snd_pcm_create_iec958_consumer); |
188 | |
189 | /** |
190 | * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status |
191 | * @params: the hw_params instance for extracting rate and sample format |
192 | * @cs: channel status buffer, at least four bytes |
193 | * @len: length of channel status buffer |
194 | * |
195 | * Create the consumer format channel status data in @cs of maximum size |
196 | * @len corresponding to the parameters of the PCM runtime @runtime. |
197 | * |
198 | * Drivers may wish to tweak the contents of the buffer after creation. |
199 | * |
200 | * Returns: length of buffer, or negative error code if something failed. |
201 | */ |
202 | int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params, |
203 | u8 *cs, size_t len) |
204 | { |
205 | int ret; |
206 | |
207 | ret = snd_pcm_create_iec958_consumer_default(cs, len); |
208 | if (ret < 0) |
209 | return ret; |
210 | |
211 | return fill_iec958_consumer(rate: params_rate(p: params), sample_width: params_width(p: params), cs, len); |
212 | } |
213 | EXPORT_SYMBOL(snd_pcm_create_iec958_consumer_hw_params); |
214 | |