bindings/sound/renesas%2Crsnd.txt

1 Renesas R-Car sound
7 Renesas R-Car and RZ/G sound is constructed from below modules
11   - SRC		: Sampling Rate Converter
12   - CMD
13    - CTU	: Channel Transfer Unit
14    - MIX	: Mixer
15    - DVC	: Digital Volume and Mute Function
22 * Multi channel
25 Multi channel is supported by Multi-SSI, or TDM-SSI.
27  Multi-SSI	: 6ch case, you can use stereo x 3 SSI
28  TDM-SSI	: 6ch case, you can use TDM
34 See datasheet to check SRC/CTU/MIX/DVC connect-limitation.
36 ${LINUX}/arch/arm/boot/dts/r8a7790-lager.dts can be good example.
39 Playback: [MEM] -> [SRC2] -> [DVC0] -> [SSIU0/SSI0] -> [codec]
40 Capture:  [MEM] <- [DVC1] <- [SRC3] <- [SSIU1/SSI1] <- [codec]
63  ------> [SRC] ------>
67  Asynchronous mode:	input data / output data are based on different clocks.
68 			you can use this mode on Playback / Capture
69  Synchronous mode:	input data / output data are based on same clocks.
70 			This mode will be used if system doesn't have its input clock,
72 			you can use this mode on Playback
74 ------------------
75 **     Asynchronous mode
76 ------------------
78 You need to use "simple-scu-audio-card" or "audio-graph-scu-card" for it.
79 see "Example: simple sound card for Asynchronous mode"
81 ------------------
82 **     Synchronous mode
83 ------------------
95  ------> [CTU] -------->
101 	Renesas R-Car datasheet
102 	 - Sampling Rate Converter Unit (SCU)
103 	  - SCU Operation
104 	   - CMD Block
105 	    - Functional Blocks in CMD
107 	Renesas R-Car datasheet
108 	 - Sampling Rate Converter Unit (SCU)
109 	  - Register Description
110 	   - CTUn Scale Value exx Register (CTUn_SVxxR)
113 	 - comment of header
115 You need to use "simple-scu-audio-card" or "audio-graph-scu-card" for it.
119  Input -> Output
120   1ch  ->  0ch
121   0ch  ->  1ch
143 	aplay -D plughw:0,0 xxxx.wav &
144 	aplay -D plughw:0,1 yyyy.wav
146 You need to use "simple-scu-audio-card" or "audio-graph-scu-card" for it.
148 	[MEM] -> [SRC1] -> [CTU02] -+-> [MIX0] -> [DVC0] -> [SSI0]
150 	[MEM] -> [SRC2] -> [CTU03] -+
185 But you can't use it if SSI was PIO mode.
186 In DMA mode, you can select not to use SSIU by using "no-busif" via SSI.
188 SSIU handles BUSIF which will be used for TDM Split mode.
189 This driver is assuming that audio-graph card will be used.
191 TDM Split mode merges 4 sounds. You can see 4 sound interface on system,
194 	aplay -D plughw:0,0 xxxx.wav &
195 	aplay -D plughw:0,1 xxxx.wav &
196 	aplay -D plughw:0,2 xxxx.wav &
197 	aplay -D plughw:0,3 xxxx.wav
200 	[MEM] -> [SSIU 30] -+-> [SSIU 3] --> [Codec]
202 	[MEM] -> [SSIU 31] -+
204 	[MEM] -> [SSIU 32] -+
206 	[MEM] -> [SSIU 33] -+
214 **  PIO mode
216 You can use PIO mode which is for connection check by using.
217 Note: The system will drop non-SSI modules in PIO mode
221 		pio-transfer
224 ** DMA mode without SSIU
230 		no-busif;
233 ** PIN sharing
235 Each SSI can share WS pin. It is based on platform.
236 This is example if SSI1 want to share WS pin with SSI0
239 		shared-pin;
242 ** Multi-SSI
244 You can use Multi-SSI.
247 see "Example: simple sound card for Multi channel"
249 ** TDM-SSI
253 Driver can automatically switches TDM <-> stereo mode in this case.