ALSA: doc: ReSTize CMIPCI document (95ee717a) · Commits · EulixOS / Software / Kernel

Documentation/sound/alsa/CMIPCI.txt→Documentation/sound/cards/cmipci.rst

+40 −22

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		=================================================
		Brief Notes on C-Media 8338/8738/8768/8770 Driver
		=================================================

		@@ -30,19 +31,20 @@ The rear output can be heard only when "Four Channel Mode" switch is
		disabled. Otherwise no signal will be routed to the rear speakers.
		As default it's turned on.

		* WARNING *
		.. WARNING::
		When "Four Channel Mode" switch is off, the output from rear speakers
		will be FULL VOLUME regardless of Master and PCM volumes.
		will be FULL VOLUME regardless of Master and PCM volumes [#]_.
		This might damage your audio equipment. Please disconnect speakers
		before your turn off this switch.
		* WARNING *

		[ Well.. I once got the output with correct volume (i.e. same with the

		.. [#]
		Well.. I once got the output with correct volume (i.e. same with the
		front one) and was so excited. It was even with "Four Channel" bit
		on and "double DAC" mode. Actually I could hear separate 4 channels
		from front and rear speakers! But.. after reboot, all was gone.
		It's a very pity that I didn't save the register dump at that
		time.. Maybe there is an unknown register to achieve this... ]
		time.. Maybe there is an unknown register to achieve this...

		If your card has an extra output jack for the rear output, the rear
		playback should be routed there as default. If not, there is a
		@@ -73,12 +75,14 @@ cannot operate with full-duplex.

		The 4.0 and 5.1 modes are defined as the pcm "surround40" and "surround51"
		in alsa-lib. For example, you can play a WAV file with 6 channels like
		::

		% aplay -Dsurround51 sixchannels.wav

		For programming the 4/6 channel playback, you need to specify the PCM
		channels as you like and set the format S16LE. For example, for playback
		with 4 channels,
		::

		snd_pcm_hw_params_set_access(pcm, hw, SND_PCM_ACCESS_RW_INTERLEAVED);
		// or mmap if you like
		@@ -89,13 +93,15 @@ and use the interleaved 4 channel data.

		There are some control switches affecting to the speaker connections:

		"Line-In Mode" - an enum control to change the behavior of line-in
		Line-In Mode
		an enum control to change the behavior of line-in
		jack. Either "Line-In", "Rear Output" or "Bass Output" can
		be selected. The last item is available only with model 039
		or newer.
		When "Rear Output" is chosen, the surround channels 3 and 4
		are output to line-in jack.
		"Mic-In Mode" - an enum control to change the behavior of mic-in
		Mic-In Mode
		an enum control to change the behavior of mic-in
		jack. Either "Mic-In" or "Center/LFE Output" can be
		selected.
		When "Center/LFE Output" is chosen, the center and bass
		@@ -111,11 +117,14 @@ The SPDIF playback and capture are done via the third PCM device
		(hw:0,2). Usually this is assigned to the PCM device "spdif".
		The available rates are 44100 and 48000 Hz.
		For playback with aplay, you can run like below:
		::

		% aplay -Dhw:0,2 foo.wav

		or

		::

		% aplay -Dspdif foo.wav

		24bit format is also supported experimentally.
		@@ -140,31 +149,40 @@ off. (Also don't forget to turn on "IEC958 Output Switch", too.)

		Additionally there are relevant control switches:

		"IEC958 Mix Analog" - Mix analog PCM playback and FM-OPL/3 streams and
		IEC958 Mix Analog
		Mix analog PCM playback and FM-OPL/3 streams and
		output through SPDIF. This switch appears only on old chip
		models (CM8738 033 and 037).

		Note: without this control you can output PCM to SPDIF.
		This is "mixing" of streams, so e.g. it's not for AC3 output
		(see the next section).

		"IEC958 In Select" - Select SPDIF input, the internal CD-in (false)
		IEC958 In Select
		Select SPDIF input, the internal CD-in (false)
		and the external input (true).

		"IEC958 Loop" - SPDIF input data is loop back into SPDIF
		IEC958 Loop
		SPDIF input data is loop back into SPDIF
		output (aka bypass)

		"IEC958 Copyright" - Set the copyright bit.
		IEC958 Copyright
		Set the copyright bit.

		"IEC958 5V" - Select 0.5V (coax) or 5V (optical) interface.
		IEC958 5V
		Select 0.5V (coax) or 5V (optical) interface.
		On some cards this doesn't work and you need to change the
		configuration with hardware dip-switch.

		"IEC958 In Monitor" - SPDIF input is routed to DAC.
		IEC958 In Monitor
		SPDIF input is routed to DAC.

		"IEC958 In Phase Inverse" - Set SPDIF input format as inverse.
		IEC958 In Phase Inverse
		Set SPDIF input format as inverse.
		[FIXME: this doesn't work on all chips..]

		"IEC958 In Valid" - Set input validity flag detection.
		IEC958 In Valid
		Set input validity flag detection.

		Note: When "PCM Playback Switch" is on, you'll hear the digital output
		stream through analog line-out.
		@@ -217,7 +235,7 @@ to enable MIDI support. Valid I/O ports are 0x300, 0x310, 0x320 and
		With CMI8738 and newer chips, the MIDI interface is enabled by default
		and the driver automatically chooses a port address.

		There is _no_ hardware wavetable function on this chip (except for
		There is no hardware wavetable function on this chip (except for
		OPL3 synth below).
		What's said as MIDI synth on Windows is a software synthesizer
		emulation. On Linux use TiMidity or other softsynth program for

Documentation/sound/cards/index.rst

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		@@ -5,3 +5,4 @@ Card-Specific Information
		:maxdepth: 2

		joystick
		cmipci