Re: [PATCH 20/21] ASoC: codecs: Enable AB8500 CODEC for Device Tree

[Lee Jones]

On 26/07/12 12:50, Mark Brown wrote:
> On Thu, Jul 26, 2012 at 11:28:53AM +0100, Lee Jones wrote:
>
> >   drivers/mfd/ab8500-core.c               |    1 +
> >   include/linux/mfd/abx500/ab8500-codec.h |    6 ++-
> >   sound/soc/codecs/ab8500-codec.c         |   79 +++++++++++++++++++++++++++++++
> >   3 files changed, 84 insertions(+), 2 deletions(-)
>
> Yet again no binding documentation....

RFC. ;)

I'll write the documentation when/if the properties are accepted.

> >   	{
> >   		.name = "ab8500-codec",
> > +		.of_compatible = "stericsson,ab8500-codec",
> >   	},
>
> Why are we doing this?  The MFD cells are a totally Linux specific
> thing, there's no reason to represent them in the device tree unless
> they're in some way reusable and the "ab8500-codec" name suggests that's
> unlikely.  Just put the properties on the parent node and instantiate
> the MFD cell as normal.
>
> > +	/* Has a non-standard Vamic been requested? */
> > +	if(of_get_property(np, "stericsson,amic1a-bias-vamic2", NULL))
>
> Coding style.

Missing space? Sorry, typo, I'll change.

> > +	if (!of_property_read_u32(np, "stericsson,earpeice-cmv", &value)) {
> > +		switch (value) {
> > +		case 950 :
> > +			codec->ear_cmv = EAR_CMV_0_95V;
> > +			break;
> > +		case 1100 :
> > +			codec->ear_cmv = EAR_CMV_1_10V;
> > +			break;
> > +		case 1270 :
> > +			codec->ear_cmv = EAR_CMV_1_27V;
> > +			break;
> > +		case 1580 :
> > +			codec->ear_cmv = EAR_CMV_1_58V;
> > +			break;
> > +		default :
> > +			codec->ear_cmv = EAR_CMV_UNKNOWN;
> > +			dev_err(dev, "Unsuitable earpiece voltage found in DT\n");
>
> The platform data code picks a default, can't the DT code do the same?

No, I don't think that it does? The original code returns -EINVAL unless 
a value is specified.

The original author is keen to have a clear error message in case users 
try to specify non-exact values. I'd rather we fail-out than use 
incorrect values which would be a great deal harder for a user to debug.

--
Lee Jones
Linaro ST-Ericsson Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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