Hi, I am working with beaglebone/am335x and would like to use McASP (Creating human signal generator :)). I think I almost did it but it's not working properly yet.
With a help form Ti-wiki <http://processors.wiki.ti.com/index.php/Sitara_Linux_SDK_Audio_DAC_Example>. I do: - create driver for PCM1690 - build driver to kernel - configure ALSA machine layer - add everything to Device Tree - then enable it in kernel As a platform I use sitarta-TI Linux Image and SDK from TI (great tools thx :P). What is coming out from my processor (measure by oscilloscope): -AHCLKX (~24MHz ~ 512xfs) -FSX (50kHz) -ACLKX(1.6MHz ~ 32xfs) -AXR0 (Some data) And my PCM1690 have register 69 (0x45) which is changing if PCM see any inputs. It's works but I still see no output from my DAC. >From start I have 3 questions: 1. When I play 48kHz wav files (example /usr/share/sound/alsa/Front_left.wav or speaker-test -c 2. My 'fs' is 48kHz right? So why my FSX is 50kHz? Shouldn't be 48kHz? 2. How to set properly AHCLKX? In wiki there was no need to even turn it on. My DAC needs it and I lunch it by adding this 2 lines in davinci-mcasp.c file to section: "case SND_SOC_DAIFMT_CBS_CFS: /* codec is clock and frame slave */" //my code mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AHCLKX); mcasp_set_bits(mcasp, DAVINCI_MCASP_AHCLKXCTL_REG, AHCLKXE); But It's let me only to output 24MHz, but I want to change it depends on my fs rate (I should have exactly 512xfs, now its only close to this) I guess It should be in davinci-evm.c where I set ACLKX. Here is my code where I do this: unsigned int bclk_freq = evm_get_bclk(params); unsigned sysclk = ((struct snd_soc_card_drvdata_davinci *) snd_soc_card_get_drvdata(soc_card))->sysclk; int ret; ret = snd_soc_dai_set_clkdiv(cpu_dai, 1, sysclk/bclk_freq); So I set divider from my sysclk (default 24MHz in sitara-TI procesors). So how to change also AHCLKX (Is there a mirror divider as I do with ACLKX?) 3.Why my PCM not working? xD Or more precise where you advise me to look for mistakes or answers? Maybe I should try with polarity of my signals? Or with PCM169 configuration? If you need any more outputs, informations or even screen from oscilloscope, do not hesitate to ask me. I will replay as fast as I can and with all my knowledge I have/will get. -- 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.
