Liam Girdwood wrote: >> On big-endian platforms like mine, CS4270_FORMATS will be SNDRV_PCM_FORMAT_S24_BE and on >> little-endian platforms it will be SNDRV_PCM_FORMAT_S24_LE. Assuming the I2S registers >> are the same endian as the platform, will this work? >> > > I think this probably depends on how your audio FIFO's align the data > received from memory/DMA. They should do any bit reordering based on > the audio format, and size etc set in the control register. (Although, > ymmv.) Ok, I'm a little confused. I was going to specify the SNDRV_PCM_FORMAT_S24_BE for my I2C device because the actual 32-bit memory-mapped registers are big-endian. The structure definition even uses __be32 for each field. My goal was to specify a single value (i.e. SNDRV_PCM_FORMAT_S24_BE) such that ALSA would give me a 32-bit quantity that exactly matches what my device expects. I wish asound.h had more documentation. I don't know what any of these macros *really* mean. >> #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S24_BE) >> >> That would tell ALSA that the CS4270 supports both formats, which isn't technically true, >> but it wouldn't matter because the I2S interface is what determines the actual >> "endianness" of the serial data. > > This looks fine as a workaround atm, I'll try and have a look at this > bug tomorrow so we don't need to do this. Ok, I'll do this for now. -- Timur Tabi Linux Kernel Developer @ Freescale _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
