On Tue, Aug 10, 2010 at 03:38:18PM +0200, Sascha Hauer wrote: > I'm wondering what exactly a snd_soc_platform is. Apparently the > snd_pcm_ops/pcm_new/pcm_free are specific to a platform. For my > understanding these operations are more specific to a cpu_dai. Looking > at the tree it seems that each cpu_dai has exactly one possible > platform, which seems logical to me because the cpu_dai knows how to > transfer the data. They're for the DMA bit of the CPU. While most platforms have a single DMA controller (though some have more than one) it's moderately common to have more than one DAI (eg, dedicated I2S and DSP mode controllers rather than a programmable serial port, or an AC'97 controller) so it's useful to share the DMA code. > My problem on i.MX is that I currently have two possible cpu dais > (imx-ssi.[01]) and each can be configured to use dma or fiq depending > on the dma capabilities. So the cpu_dai knows which pcm_ops we have > to use, but currently it's the soc glue code which has to decide in > platform_name. Am I understanding something wrong here? This is mostly a holdover from the existing (current mainline) ASoC structuring at the minute, that also has the DMA configured per machine. This may change depending on future hardware requirements, though. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
