sound/cards/cmipci.rst

2 Brief Notes on C-Media 8338/8738/8768/8770 Driver
8 Front/Rear Multi-channel Playback
9 ---------------------------------
13 DACs, both streams are handled independently unlike the 4/6ch multi-
18 (hw:0,1) is assigned to the second DAC for rear playback.
22 - The first DAC supports U8 and S16LE formats, while the second DAC
24 - The second DAC supports only two channel stereo.
31 disabled.  Otherwise no signal will be routed to the rear speakers.
47   time..  Maybe there is an unknown register to achieve this...
51 control switch in the driver "Line-In As Rear", which you can change
52 via alsamixer or somewhat else.  When this switch is on, line-in jack
55 There are two more controls regarding to the rear output.
56 The "Exchange DAC" switch is used to exchange front and rear playback
60 4/6 Multi-Channel Playback
61 --------------------------
63 The recent CM8738 chips support for the 4/6 multi-channel playback
66 When the multi-channel is supported, the driver name has a suffix
67 "-MC" such like "CMI8738-MC6".  You can check this name from
70 When the 4/6-ch output is enabled, the second DAC accepts up to 6 (or
72 formats, the 4/6-ch playback supports only the same condition for all
73 channels.  Since the multi-channel playback mode uses both DACs, you
74 cannot operate with full-duplex.
77 in alsa-lib.  For example, you can play a WAV file with 6 channels like
80 	% aplay -Dsurround51 sixchannels.wav
82 For programming the 4/6 channel playback, you need to specify the PCM
94 There are some control switches affecting to the speaker connections:
96 Line-In Mode
97 	an enum control to change the behavior of line-in
98 	jack.  Either "Line-In", "Rear Output" or "Bass Output" can
102 	are output to line-in jack.
103 Mic-In Mode
104 	an enum control to change the behavior of mic-in
105 	jack.  Either "Mic-In" or "Center/LFE Output" can be
108 	channels (channels 5 and 6) are output to mic-in jack.
110 Digital I/O
111 -----------
117 (hw:0,2).  Usually this is assigned to the PCM device "spdif".
122 	% aplay -Dhw:0,2 foo.wav
128 	% aplay -Dspdif foo.wav
133 respectively, so you cannot playback both analog and digital streams
136 To enable SPDIF output, you need to turn on "IEC958 Output Switch"
138 so-called S/PDIF).  Then you'll see the red light on from the card so
141 from line-out with "IEC958 In Monitor" switch at any time (see
147 off.  (Also don't forget to turn on "IEC958 Output Switch", too.)
153 	Mix analog PCM playback and FM-OPL/3 streams and
157 	Note: without this control you can output PCM to SPDIF.
162 	Select SPDIF input, the internal CD-in (false)
174 	On some cards this doesn't work and you need to change the
175 	configuration with hardware dip-switch.
178 	SPDIF input is routed to DAC.
187 Note: When "PCM Playback Switch" is on, you'll hear the digital output
188 stream through analog line-out.
191 The AC3 (RAW DIGITAL) OUTPUT
192 ----------------------------
194 The driver supports raw digital (typically AC3) i/o over SPDIF.  This
195 can be toggled via IEC958 playback control, but usually you need to
196 access it via alsa-lib.  See alsa-lib documents for more details.
198 On the raw digital mode, the "PCM Playback Switch" is automatically
199 turned off so that non-audio data is heard from the analog line-out.
202 device automatically to the previous state.
205 the alsa-lib.  If you need to bypass the software conversion of IEC958
211 ----------------------
213 The mixer interface on CM8x38 is similar to SB16.
218 In addition to the standard SB mixer, CM8x38 provides more functions.
219 - PCM playback switch
220 - PCM capture switch (to capture the data sent to DAC)
221 - Mic Boost switch
222 - Mic capture volume
223 - Aux playback volume/switch and capture switch
224 - 3D control switch
228 ---------------
230 With CMI8338 chips, the MPU401-UART interface is disabled as default.
231 You need to set the module option "mpu_port" to a valid I/O port address
232 to enable MIDI support.  Valid I/O ports are 0x300, 0x310, 0x320 and
246 --------------
258 ------------------
260 The legacy joystick is supported.  To enable the joystick support, pass
261 joystick_port=1 module option.  The value 1 means the auto-detection.
262 If the auto-detection fails, try to pass the exact I/O address.
268 ---------------------