What I don't understand is the sequence of init. of the driver. I think that I need to : init dma to transfer from ssi1 (what file???) init ssi1 with a clock and a mode (i2s master) (i think fsl_ssi or imx-ssi file?? ) init audmux to put ssi1 (port 1) to port 4 (is a clock needed?) (imx-audmux module??) init iomux to put port4 output on output pin (I need to set pin direction also or is automatic???) (only in dts? what function set that?) and where those init are? and what file/function does the actual memory transfer? and ... last how I can check separately all those things?? I can init ssi for example without audio as a "serial port" and test it??? or I can Init the output port as gpio and set pins to test if its initializated?? How I can read the cpu register back from linux to check that are correctly initializated (for example I can read iomux registers????) The documentation/tutorial on alsa driver are very scarse, and freescale community is not of help Thanks for your help Nicola _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel