On Thu, Sep 19, 2013 at 07:34:03PM +0200, Jean-Francois Moine wrote: > Well, first, the codecs hdmi and dmic have no DT support. > Then, from the Cubox point of vue, the codec hdmi offers playback > and capture while the Cubox has only playback (via the tda998x HDMI > transmitter), and, also, the codec spdif transmitter has a lot of > sample rates while the Dove audio device supports only 44.1, 48 and 96 > kHz. All those restrictions should be constrained by either the machine binding or the driver for the SoC side though. I do see why you might want this, I'm just a bit ambivalent about the merits. > So, instead of adding new hdmi and spdif_transmitter codecs, > I thought it could be useful to have a generic codec with DT support. > On the other hand, as the first use of this codec is for the Cubox, > an other solution could be to have the codec included in the kirkwood > driver (declared by DT as either i2s or s/pdif). This would simplify > the use or not of s/pdif in this driver. That'd work too. > > > +Child 'capture' and 'playback' required properties: > > > +- stream-name: name of the stream > > What does this mean in the binding? > Indeed, the stream name could be implicit (either "Playback" or > "Capture"), but, as the users are aware of it, a more friendly > name is nicer ("S/PDIF Playback"). So you need to say that it's for display purposes. > I have no idea about which format is used or not, and there is no > explanation about their meanings in the uapi (but I can search them..). > Otherwise, for Dove, we need at least "s16_le", "s24_le" and "s32_le" > and, perhaps, "iec958_subframe_le" and "iec958_subframe_be". > So, what do you think should be the format set? PCM plus IEC seems fine, it's more the more obscure formats that ring alarm bells. > > > +Rates: > > > + 5512 > > > + 8000 > > This shouldn't be a list of defined rates, it should allow any number, > > and it should support ranges since while some devices do enumerate > > specific rates simpler devices often just support a continuous range of > > rates. > There cannot be any number because the rates are coded by discrete > values in a bitmap. Not quite - _KNOT and _CONTINUOUS are options in that bitmap... in any case this would be a Linux implementation thing. > For the continuous range, I was thinking about the value '0' followed > by the min and max rates. Have you any other syntax in mind? That'd probably work, not sure if there's a more idiomatic way of doing that in DT though.
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