Matt Flax flatmax@flatmax.org writes:
This patch adds multitrack capability if in DSP mode A and the codec is master.
In bcm2835_i2s_startup, snd_pcm_hw_constraint_minmax is used to set max channels to 8 if both SND_SOC_DAIFMT_CBM_CFM and SND_SOC_DAIFMT_DSP_A are set. Otherwise, max channels is set to 2. Min channels is always set to 2. These settings are accomplished using the SNDRV_PCM_HW_PARAM_CHANNELS variable.
In bcm2835_i2s_shutdown max channels is set to 2 by default.
In bcm2835_i2s_hw_params, DSP mode A format is now an option. Before replicating the format variable (from ch2 to ch1) for register loading, requested channels are checked to be either 2 or 8. This can be expaneded later to accomodate other channel counts if
"expanded"
supported by the sound card hardware.
This is looking a lot nicer! I'm totally deferring to the audio guys here for deciding if it's the right fix, but for what it's worth, from the platform side:
Acked-by: Eric Anholt eric@anholt.net