Hi Sven, On Wed, Aug 25, 2010 at 04:39:51PM +0200, Sven Zeisberg wrote: > Hi, > > has anybody succeeded to transfer more than 2 audio channels between > i.MX25 and a CODEC throught the i.MX25 SSI Port? > > We have succeeded to set the CODEC (AD1938) as Master to the required > mode (TDM with 8 Timeslots and 32 Bit per Timeslot). However, as soon as > we start to play a wav file with aplay, we can see on the logic analyzer > that the data format on the SSI lines is reset to a stereo mode (2 > channels with frame sync changing level between channels). > > In the imx-ssi driver, I can see that .channel_max = 2 - therefore my > question: does this driver support more than two channels at all? You have to call snd_soc_dai_set_tdm_slot() with the correct parameters. This function is currently relatively untested, so expect bugs here. I would try something like: snd_soc_dai_set_tdm_slot(cpu_dai, 0xfffff00, 0xfffff00, 8, 32); slot_width is currently not handled in this function, this may be wrong. I don't know whether a slot length of 32bit is supported at all in the hardware. I only tested this driver with 2 channels since I have no access to a codec supporting something else. Hope that helps Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
