[alsa-devel] [PATCH v3 4/4] ASoC: simple-card: Add DT documentation for multi-DAI links
jsarha at ti.com
Mon Mar 17 11:19:46 CET 2014
On 2014-03-15 13:30, Jean-Francois Moine wrote:
> There may be many couples of CPU/CODEC DAI links.
> The example 2 is extracted from the Cubox DT.
> Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
This binding forces all the dai links to share the same card level
properties. I find it problematic in these cases:
>> - simple-audio-card,format : CPU/CODEC common audio format.
>> "i2s", "right_j", "left_j" , "dsp_a"
>> "dsp_b", "ac97", "pdm", "msb", "lsb"
The code allows having the format parameter in sub nodes too, but the
document does no mention it. Adding a mention would solve this problem
at least partly.
Neither does the document mention that
"simple-audio-card,frame-inversion" are also allowed in card level.
Currently the code uses simple bit-wise-or from card-level and dai-level
daifmt parameters, which may lead to broken daifmt setting. However,
this on directly related to this patch.
>> - dai-tdm-slot-num : Please refer to tdm-slot.txt.
>> - dai-tdm-slot-width : Please refer to tdm-slot.txt.
These properties are actually only taken from sub-nodes so the document
is broken but the code is ok.
In general this binding would look better if another sub-node level
would added for dai-link related properties, including the cpu and codec
sub-nodes, but that would break the backwards compatibility.
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