I built a cape using the same codec as the BB Audio Cape Rev B (tlv320aic3104) =, and wired it up the same way to reduce the amount of Linux configuration I'd have to do to get it to work. I finally have it communicating over the i2c bus, and both the codec and the alsa sound card seem to be (mostly) properly configured in the device tree overlay (https://github.com/JetForMe/podtique/blob/v1/bbb/cape/Podtique1/BB-ENABLE-PRU.dts).
But the McASP part of the interface still seems to do nothing. Looking at the pins with an oscilloscope, nothing comes out. I *think* I'm at a point where my ALSA configuration is wrong, but I'm not sure. Lending further credence to the ALSA config culprit theory is the fact that the i2c commands to configure the codec seem to be incorrect. In particular, when I run "speaker-test", the i2c commands that get sent to the codec set it up for DSP mode, not IIS/I2S mode. The DT overlay calls for IIS mode. Other parts of the DT overlay seem to be working very well. Linux enables the power regulators for the CODEC via a GPIO, and takes it out of reset via another GPIO before communicating with it. I watched the I2C traffic with an I2C protocol analyzer, and it looks solid (you can see it here. The first part is the cape enumeration, the codec comms start at transaction 49: http://pastebin.com/2VFPVBbq). On my board, I've got the differential line out L&R going to an on-board audio power amp. I haven't routed any of the other outputs (or inputs) from the CODEC. Anyone got any insight as to why A) the McASP pins never do anything B) the I2C commands to the CODEC set DSP mode, not IIS mode Thanks! -- Rick Mann [email protected] -- 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.
