Based on kernel version 6.11
. Page generated on 2024-09-24 08:21 EST
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 | Renesas R-Car sound ============================================= * Modules ============================================= Renesas R-Car and RZ/G sound is constructed from below modules (for Gen2 or later) SCU : Sampling Rate Converter Unit - SRC : Sampling Rate Converter - CMD - CTU : Channel Transfer Unit - MIX : Mixer - DVC : Digital Volume and Mute Function SSIU : Serial Sound Interface Unit SSI : Serial Sound Interface See detail of each module's channels, connection, limitation on datasheet ============================================= * Multi channel ============================================= Multi channel is supported by Multi-SSI, or TDM-SSI. Multi-SSI : 6ch case, you can use stereo x 3 SSI TDM-SSI : 6ch case, you can use TDM ============================================= * Enable/Disable each modules ============================================= See datasheet to check SRC/CTU/MIX/DVC connect-limitation. DT controls enabling/disabling module. ${LINUX}/arch/arm/boot/dts/r8a7790-lager.dts can be good example. This is example of Playback: [MEM] -> [SRC2] -> [DVC0] -> [SSIU0/SSI0] -> [codec] Capture: [MEM] <- [DVC1] <- [SRC3] <- [SSIU1/SSI1] <- [codec] see "Example: simple sound card" You can use below. ${LINUX}/arch/arm/boot/dts/r8a7790.dts can be good example. &src0 &ctu00 &mix0 &dvc0 &ssi0 &src1 &ctu01 &mix1 &dvc1 &ssi1 &src2 &ctu02 &ssi2 &src3 &ctu03 &ssi3 &src4 &ssi4 &src5 &ctu10 &ssi5 &src6 &ctu11 &ssi6 &src7 &ctu12 &ssi7 &src8 &ctu13 &ssi8 &src9 &ssi9 ============================================= * SRC (Sampling Rate Converter) ============================================= [xx]Hz [yy]Hz ------> [SRC] ------> SRC can convert [xx]Hz to [yy]Hz. Then, it has below 2 modes Asynchronous mode: input data / output data are based on different clocks. you can use this mode on Playback / Capture Synchronous mode: input data / output data are based on same clocks. This mode will be used if system doesn't have its input clock, for example digital TV case. you can use this mode on Playback ------------------ ** Asynchronous mode ------------------ You need to use "simple-scu-audio-card" or "audio-graph-scu-card" for it. see "Example: simple sound card for Asynchronous mode" ------------------ ** Synchronous mode ------------------ > amixer set "SRC Out Rate" on > aplay xxxx.wav > amixer set "SRC Out Rate" 48000 > amixer set "SRC Out Rate" 44100 ============================================= * CTU (Channel Transfer Unit) ============================================= [xx]ch [yy]ch ------> [CTU] --------> CTU can convert [xx]ch to [yy]ch, or exchange outputted channel. CTU conversion needs matrix settings. For more detail information, see below Renesas R-Car datasheet - Sampling Rate Converter Unit (SCU) - SCU Operation - CMD Block - Functional Blocks in CMD Renesas R-Car datasheet - Sampling Rate Converter Unit (SCU) - Register Description - CTUn Scale Value exx Register (CTUn_SVxxR) ${LINUX}/sound/soc/sh/rcar/ctu.c - comment of header You need to use "simple-scu-audio-card" or "audio-graph-scu-card" for it. see "Example: simple sound card for channel convert" Ex) Exchange output channel Input -> Output 1ch -> 0ch 0ch -> 1ch example of using matrix output 0ch = (input 0ch x 0) + (input 1ch x 1) output 1ch = (input 0ch x 1) + (input 1ch x 0) amixer set "CTU Reset" on amixer set "CTU Pass" 9,10 amixer set "CTU SV0" 0,4194304 amixer set "CTU SV1" 4194304,0 example of changing connection amixer set "CTU Reset" on amixer set "CTU Pass" 2,1 ============================================= * MIX (Mixer) ============================================= MIX merges 2 sounds path. You can see 2 sound interface on system, and these sounds will be merged by MIX. aplay -D plughw:0,0 xxxx.wav & aplay -D plughw:0,1 yyyy.wav You need to use "simple-scu-audio-card" or "audio-graph-scu-card" for it. Ex) [MEM] -> [SRC1] -> [CTU02] -+-> [MIX0] -> [DVC0] -> [SSI0] | [MEM] -> [SRC2] -> [CTU03] -+ see "Example: simple sound card for MIXer" ============================================= * DVC (Digital Volume and Mute Function) ============================================= DVC controls Playback/Capture volume. Playback Volume amixer set "DVC Out" 100% Capture Volume amixer set "DVC In" 100% Playback Mute amixer set "DVC Out Mute" on Capture Mute amixer set "DVC In Mute" on Volume Ramp amixer set "DVC Out Ramp Up Rate" "0.125 dB/64 steps" amixer set "DVC Out Ramp Down Rate" "0.125 dB/512 steps" amixer set "DVC Out Ramp" on aplay xxx.wav & amixer set "DVC Out" 80% // Volume Down amixer set "DVC Out" 100% // Volume Up ============================================= * SSIU (Serial Sound Interface Unit) ============================================= SSIU can avoid some under/over run error, because it has some buffer. But you can't use it if SSI was PIO mode. In DMA mode, you can select not to use SSIU by using "no-busif" via SSI. SSIU handles BUSIF which will be used for TDM Split mode. This driver is assuming that audio-graph card will be used. TDM Split mode merges 4 sounds. You can see 4 sound interface on system, and these sounds will be merged SSIU/SSI. aplay -D plughw:0,0 xxxx.wav & aplay -D plughw:0,1 xxxx.wav & aplay -D plughw:0,2 xxxx.wav & aplay -D plughw:0,3 xxxx.wav 2ch 8ch [MEM] -> [SSIU 30] -+-> [SSIU 3] --> [Codec] 2ch | [MEM] -> [SSIU 31] -+ 2ch | [MEM] -> [SSIU 32] -+ 2ch | [MEM] -> [SSIU 33] -+ see "Example: simple sound card for TDM Split" ============================================= * SSI (Serial Sound Interface) ============================================= ** PIO mode You can use PIO mode which is for connection check by using. Note: The system will drop non-SSI modules in PIO mode even though if DT is selecting other modules. &ssi0 { pio-transfer }; ** DMA mode without SSIU You can use DMA without SSIU. Note: under/over run, or noise are likely to occur &ssi0 { no-busif; }; ** PIN sharing Each SSI can share WS pin. It is based on platform. This is example if SSI1 want to share WS pin with SSI0 &ssi1 { shared-pin; }; ** Multi-SSI You can use Multi-SSI. This is example of SSI0/SSI1/SSI2 (= for 6ch) see "Example: simple sound card for Multi channel" ** TDM-SSI You can use TDM with SSI. This is example of TDM 6ch. Driver can automatically switches TDM <-> stereo mode in this case. see "Example: simple sound card for TDM" |