Re: [RESEND RFC PATCH 2/3] ASoC: mediatek: Add AFE connection control

[Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

On Sat, Apr 18, 2015 at 06:37:40PM +0100, Mark Brown wrote:
> On Fri, Apr 10, 2015 at 04:14:08PM +0800, Koro Chen wrote:
> 
> > +/*
> > + * The MTK AFE unit has a audio interconnect with MTK_AFE_INTERCONN_NUM_INPUT
> > + * inputs and MTK_AFE_INTERCONN_NUM_OUTPUT outputs. Below table holds the
> > + * register/bits to set to connect an input with an output.
> > + */
> > +static const struct mtk_afe_connection
> > +	connections[MTK_AFE_INTERCONN_NUM_INPUT][MTK_AFE_INTERCONN_NUM_OUTPUT] = {
> > +	[0][0] =   { .creg = 0x020, .cshift =  0, .sreg = 0x020, .sshift = 10},
> > +	[0][1] =   { .creg = 0x020, .cshift = 16, .sreg = 0x020, .sshift = 26},
> 
> What are the constraints on using this - is it one input to one output
> only or can we do mixing or duplication?  The register interface
> definitely does look like something asking for runtime configuration.
> 
> It'd also be nice to have less magic numbers in the table, at least for
> the indexes (which I guess correspond to some of the defines in the
> headers)?

With defines the above two lines would become something like:

#define AFE_CONN0		0x20

#define CONN0_I00_O00_S		0
...
#define CONN0_I00_O00_R		10
...
#define CONN0_I00_O01_s		16
...
#define CONN0_I00_O01_S		26

[0][0] = { .creg = AFE_CONN0, .cshift = CONN0_I00_O00_S, .sreg = AFE_CONN0, .sshift = CONN0_I00_O00_R },
[0][1] = { .creg = AFE_CONN0, .cshift = CONN0_I00_O01_S, .sreg = AFE_CONN0, .sshift = CONN0_I00_O01_S },

For the registers we could use defines, but I think using defines for
the shifts doesn't add much value given they are only used once.

Sascha

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