Alsa Driver from GPIO.

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1

Hi!

I'm a newbie on ALSA architecture. I would like to known if it would
be possible to create a sound driver for a a PCM sound beeing acquired
by the GPIO of a processor, like the ARM of a Beaglebone Black.

Beaglebone has more than 32 bits of gpio so I intend to acquire the
audio signal through a A/D CI (sigma delta) connected to a FPGA that
would provide it to the Beaglebone Black in parallel form (PCM code),
through the GPIO.

Is that possible?

Regards

2

Hi!

I’m a newbie on ALSA architecture. I would like to known if it would
be possible to create a sound driver for a a PCM sound beeing acquired
by the GPIO of a processor, like the ARM of a Beaglebone Black.

Beaglebone has more than 32 bits of gpio so I intend to acquire the
audio signal through a A/D CI (sigma delta) connected to a FPGA that
would provide it to the Beaglebone Black in parallel form (PCM code),
through the GPIO.

Is that possible?

Clearly it is possible, but you would have to create a driver that would replace /sound/soc/davinci/davinci-mcasp.c. However, I would suggest that you implement I2S interface on your FPGA and use the MCASP to stream your samples. You can implement several I2C streams for increased throughput. Here are some references that might be helpful.

http://processors.wiki.ti.com/index.php/Sitara_Linux_SDK_Audio_DAC_Example
http://www.element14.com/community/community/designcenter/single-board-computers/next-gen_beaglebone/blog/2013/07/06/bbb–building-a-dac
http://processors.wiki.ti.com/index.php/AM335x_Audio_Driver’s_Guide

Regards,
John