On Sunday, May 24, 2015 at 12:38:43 AM UTC-7, Robin Scheibler wrote: > Dear all, > > I have created a custom cape around the STA321MP chip from ST > Microelectronics. It has 6 MEMS microphones and outputs them on an I2S bus > with 3 data lines. I am trying to use mcasp0 on the boneblack side to receive > the data. I am now to the point where the codec configuration happens > correctly (I can see the i2s signals with a logic analyzer) and a soundcard > is detected. However, when I try to record sound with arecord, I get the > following error: > > root@beaglebone:~# arecord -l > **** List of CAPTURE Hardware Devices **** > card 0: EVM [STA321MP EVM], device 0: STA321MP sta321mp-audio-0 [] > Subdevices: 1/1 > Subdevice #0: subdevice #0 > root@beaglebone:~# arecord -D hw:0,0 -f S24_LE -c 6 -r 44100 -t wav test.wav > Recording WAVE 'test.wav' : Signed 24 bit Little Endian, Rate 44100 Hz, > Channels 6 > arecord: pcm_read:1801: read error: Input/output error > > > Let me know provide more details. > The codec is frame and bit clocks masterThe connection to mcasp0 is the > following:Bit clock <=> P9_12 (mcasp0_aclkr_mux3)Frame sync clock (L/R) <=> > P9_27 (mcasp0_fsr)Data <=> P9_28 (mcasp0_axr2) > Data <=> P9_30 (mcasp0_axr0)Data <=> P9_25 (mcasp0_axr3)I am using kernel > 3.14.41 (because 3.8 doesn't have support for mcasp with >2 channels)I am > using dtb-builder to add my device to the device tree > All the code I have added to the kernel (codec and machine code) and to the > device tree is on github. Here are the links to the specific changes I have > made. > kernel: > https://github.com/fakufaku/linux/commit/3a6680960412ef0fc3fbcc6f2c0021350039cc92 > > device tree: > https://github.com/fakufaku/dtb-rebuilder/commit/127dbf3c82c78cc602058308ed72978b170c99a6 > It is my first time trying to code audio driver so please be indulgent :) I > have spent a lot of time on this but it seems I am now completely stuck. I'd > really appreciate some help. I'd be happy to provide more clarifications on > anything. > One thing I do not understand is if I need to add mixer bindings. And also > the audio routing (jack vs codec pins, etc). > > Thank you in advance! > Robin
Hey Robin, I first must say I don't have an answer for you. The reason I am writing is I have in mind to self-publish a free online open-source and organic BBB hacking book, working title "hackin' black" (think AC/DC!). Your topic is broadly interesting, really cool, and relevant as heck. So if you are willing, I would like to include the solution in "hackin' black" when you get it sorted? Think about it, and think of how helpful a free book like that would have been to you right now! Respectfully, JF -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
