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    SubjectRe: [PATCH 4/4] ASoC: TWL4030: Driver registration via twl4030_codec MFD
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    On Tuesday 20 October 2009 13:25:40 ext Mark Brown wrote:
    > On Mon, Oct 19, 2009 at 03:42:20PM +0300, Peter Ujfalusi wrote:
    > > TWL4030 codec is now using the device registration via
    > > tlw4030_codec MFD device.
    >
    > This looks pretty good but obviously depends on the MFD changes.

    Thanks, yes it all depends on the MFD changes.

    > The major thing that jumps out at me is the removal of the register
    > definitions from the ASoC headers - it might be nice to have that done
    > as part of the MFD patch, or as a separate patch.

    The reason why I have done it like this is that with one patch I only touch one
    subsystem at the time:
    1. MFD changes only
    2. OMAP related changes
    3. soc codec driver change

    In patch 1, the register definitions had to be added, so that the twl4030_codec
    driver knows the registers (and there could be the vibra driver placed
    separately from the soc codec driver).
    In patch 3, where I modify the soc codec driver to use the new method, than I
    remove the definitions and use the existing header file, introduced by the first
    patch.
    All in all, after each patch the kernel can be builds, boots and works as
    before.

    >
    > You've also got the bias being brought up when the ASoC system comes up
    > rather than when the driver comes up. To be honest it doesn't really
    > make any difference either way, it's just slightly different to other
    > drivers.

    I was thinking that if you built the kernel with SND_SOC_ALL_CODECS on OMAP
    platform for some reason and you don't actually use the twl4030 as audio device
    -> no machine driver, which would use it, than the codec part would be off.
    But yes, probably I can move the povering up to the probe function.

    > What is useful with things like twl4030 which take a little
    > while to come up is if you can do the bias bringup out of line from
    > device probe, avoiding blocking system startup on CODEC bringup. That's
    > definitely a separate patch, I'm just mentioning it for interest here.

    I'm sure there will be another round for this series, so I can make this change
    at the same time within the patch, since this anyway changes the way how the
    driver is loaded/probed.

    >
    > There's also a couple of debug prints (like in the remove function) and

    I'll get rid of them.
    But at least this time I did not had those unneeded casts, which I usually have
    ;)

    >
    > > +MODULE_ALIAS("platform:twl4030_codec:audio");
    >
    > Is that second colon right given...

    I'm not sure about it at all either. I did not found any other 'nested MFD'
    drivers around, so this is just a guess
    Should it be:

    +MODULE_ALIAS("platform:twl4030_codec_audio");


    >
    > > + .driver = {
    > > + .name = "twl4030_codec_audio",
    > > + .owner = THIS_MODULE,
    >
    > this.
    >

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    Péter
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