On Thu, Jul 14, 2016 at 03:07:20PM +0200, Chemsi Mehdi wrote: > > Why codec driver of ASOC are always I2C based ?, is codec driver role is > only control of audio hardware(set/reset registers only)? That is not true, there are few SPI based and one i wrote which was a different method altogether. Mostly the audio embedded industry uses I2C codecs so they are very common > There should be three drivers : machine driver, platform driver and > codec driver , all of them have .probe and . remove , what is relation > between all the probes? removes ? All of these have two probes :) First one in hardware probe. Nothing unusual here. Second is the ASoC probe. Each of these registers a component. The ASoC core will create the sound card only when all of these components are present. At that time the ASoC probe in invoked signalling card creation to driver > As far I know McBSP is source of audio coming from host and I2C/ McBSP > have no direct relation so why we connect platform driver (McBSP) with > codec driver(I2C) Via DAI ? You will have to ask driver authors that, pls cc them > When calling snd_pcm_open from userspace which kernel API is called ? > snd_pcm_lib_ioctl or snd_stm_spdif_player_open ? if > snd_stm_spdif_player_open so when called snd_pcm_lib_ioctl ? system call open() > How ALSA KERNELAPI is connected to ALSA SOC CORE, via which > calls/mechanism ? The alsa provides driver callbacks. See struct snd_pcm_ops. ASoC provides the same to asoc driver as well! Additionally we have dai_ops as well. ASoC has its own ops for card and then it invokes platform, codec pcm and dai_ops. See sound/soc/soc-pcm.c -- ~Vinod _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
