1================================= 2Notes on Maya44 USB Audio Support 3================================= 4 5.. note:: 6 The following is the original document of Rainer's patch that the 7 current maya44 code based on. Some contents might be obsoleted, but I 8 keep here as reference -- tiwai 9 10Feb 14, 2008 11 12Rainer Zimmermann <mail@lightshed.de> 13 14STATE OF DEVELOPMENT 15==================== 16 17This driver is being developed on the initiative of Piotr Makowski (oponek@gmail.com) and financed by Lars Bergmann. 18Development is carried out by Rainer Zimmermann (mail@lightshed.de). 19 20ESI provided a sample Maya44 card for the development work. 21 22However, unfortunately it has turned out difficult to get detailed programming information, so I (Rainer Zimmermann) had to find out some card-specific information by experiment and conjecture. Some information (in particular, several GPIO bits) is still missing. 23 24This is the first testing version of the Maya44 driver released to the alsa-devel mailing list (Feb 5, 2008). 25 26 27The following functions work, as tested by Rainer Zimmermann and Piotr Makowski: 28 29- playback and capture at all sampling rates 30- input/output level 31- crossmixing 32- line/mic switch 33- phantom power switch 34- analogue monitor a.k.a bypass 35 36 37The following functions *should* work, but are not fully tested: 38 39- Channel 3+4 analogue - S/PDIF input switching 40- S/PDIF output 41- all inputs/outputs on the M/IO/DIO extension card 42- internal/external clock selection 43 44 45*In particular, we would appreciate testing of these functions by anyone who has access to an M/IO/DIO extension card.* 46 47 48Things that do not seem to work: 49 50- The level meters ("multi track") in 'alsamixer' do not seem to react to signals in (if this is a bug, it would probably be in the existing ICE1724 code). 51 52- Ardour 2.1 seems to work only via JACK, not using ALSA directly or via OSS. This still needs to be tracked down. 53 54 55DRIVER DETAILS 56============== 57 58the following files were added: 59 60* pci/ice1724/maya44.c - Maya44 specific code 61* pci/ice1724/maya44.h 62* pci/ice1724/ice1724.patch 63* pci/ice1724/ice1724.h.patch - PROPOSED patch to ice1724.h (see SAMPLING RATES) 64* i2c/other/wm8776.c - low-level access routines for Wolfson WM8776 codecs 65* include/wm8776.h 66 67 68Note that the wm8776.c code is meant to be card-independent and does not actually register the codec with the ALSA infrastructure. 69This is done in maya44.c, mainly because some of the WM8776 controls are used in Maya44-specific ways, and should be named appropriately. 70 71 72the following files were created in pci/ice1724, simply #including the corresponding file from the alsa-kernel tree: 73 74* wtm.h 75* vt1720_mobo.h 76* revo.h 77* prodigy192.h 78* pontis.h 79* phase.h 80* maya44.h 81* juli.h 82* aureon.h 83* amp.h 84* envy24ht.h 85* se.h 86* prodigy_hifi.h 87 88 89*I hope this is the correct way to do things.* 90 91 92SAMPLING RATES 93============== 94 95The Maya44 card (or more exactly, the Wolfson WM8776 codecs) allow a maximum sampling rate of 192 kHz for playback and 92 kHz for capture. 96 97As the ICE1724 chip only allows one global sampling rate, this is handled as follows: 98 99* setting the sampling rate on any open PCM device on the maya44 card will always set the *global* sampling rate for all playback and capture channels. 100 101* In the current state of the driver, setting rates of up to 192 kHz is permitted even for capture devices. 102 103*AVOID CAPTURING AT RATES ABOVE 96kHz*, even though it may appear to work. The codec cannot actually capture at such rates, meaning poor quality. 104 105 106I propose some additional code for limiting the sampling rate when setting on a capture pcm device. However because of the global sampling rate, this logic would be somewhat problematic. 107 108The proposed code (currently deactivated) is in ice1712.h.patch, ice1724.c and maya44.c (in pci/ice1712). 109 110 111SOUND DEVICES 112============= 113 114PCM devices correspond to inputs/outputs as follows (assuming Maya44 is card #0): 115 116* hw:0,0 input - stereo, analog input 1+2 117* hw:0,0 output - stereo, analog output 1+2 118* hw:0,1 input - stereo, analog input 3+4 OR S/PDIF input 119* hw:0,1 output - stereo, analog output 3+4 (and SPDIF out) 120 121 122NAMING OF MIXER CONTROLS 123======================== 124 125(for more information about the signal flow, please refer to the block diagram on p.24 of the ESI Maya44 manual, or in the ESI windows software). 126 127 128PCM 129 (digital) output level for channel 1+2 130PCM 1 131 same for channel 3+4 132 133Mic Phantom+48V 134 switch for +48V phantom power for electrostatic microphones on input 1/2. 135 136 Make sure this is not turned on while any other source is connected to input 1/2. 137 It might damage the source and/or the maya44 card. 138 139Mic/Line input 140 if switch is on, input jack 1/2 is microphone input (mono), otherwise line input (stereo). 141 142Bypass 143 analogue bypass from ADC input to output for channel 1+2. Same as "Monitor" in the windows driver. 144Bypass 1 145 same for channel 3+4. 146 147Crossmix 148 cross-mixer from channels 1+2 to channels 3+4 149Crossmix 1 150 cross-mixer from channels 3+4 to channels 1+2 151 152IEC958 Output 153 switch for S/PDIF output. 154 155 This is not supported by the ESI windows driver. 156 S/PDIF should output the same signal as channel 3+4. [untested!] 157 158 159Digital output selectors 160 These switches allow a direct digital routing from the ADCs to the DACs. 161 Each switch determines where the digital input data to one of the DACs comes from. 162 They are not supported by the ESI windows driver. 163 For normal operation, they should all be set to "PCM out". 164 165H/W 166 Output source channel 1 167H/W 1 168 Output source channel 2 169H/W 2 170 Output source channel 3 171H/W 3 172 Output source channel 4 173 174H/W 4 ... H/W 9 175 unknown function, left in to enable testing. 176 177 Possibly some of these control S/PDIF output(s). 178 If these turn out to be unused, they will go away in later driver versions. 179 180Selectable values for each of the digital output selectors are: 181 182PCM out 183 DAC output of the corresponding channel (default setting) 184Input 1 ... Input 4 185 direct routing from ADC output of the selected input channel 186 187