On Monday 01 December 2014 19:29:23 Boris Brezillon wrote:
> Hi Arnd,
>
> On Mon, 01 Dec 2014 17:26:27 +0100
> Arnd Bergmann <a...@arndb.de> wrote:
>
> > On Monday 01 December 2014 11:27:21 Boris Brezillon wrote:
> > > The EBI (External Bus Interface) is used to access external peripherals
> > > (NOR, SRAM, NAND, and other specific devices like ethernet controllers).
> > > Each device is assigned a CS line and an address range and can have its
> > > own configuration (timings, access mode, bus width, ...).
> > > This driver provides a generic DT binding to configure a device according
> > > to its requirements.
> > > For specific device controllers (like the NAND one) the SMC timings
> > > should be configured by the controller driver through the matrix and
> > > smc syscon regmaps.
> >
> > Nice!
> >
> > > +
> > > +#define AT91_EBICSA_REGFIELD(soc) \
> > > + REG_FIELD(soc ## _MATRIX_EBICSA_OFF, 0, \
> > > + AT91_MATRIX_EBI_NUM_CS - 1)
> > > +
> > > +#define AT91_MULTI_EBICSA_REGFIELD(soc, n) \
> > > + REG_FIELD(soc ## _MATRIX_EBI ## n ## CSA_OFF, \
> > > + 0, AT91_MATRIX_EBI_NUM_CS - 1)
> >
> > I don't like the use macros that concatenate symbol names like
> > this. Why not do either
> >
> > - open-code the macro contents in the few uses, to allow
> > grepping for them, or
>
> I'm not sure to get this one, are you suggesting to do something like
> this:
>
> #define AT91_EBICSA_REGFIELD(off) \
> REG_FIELD(ebicsa_off, AT91_MATRIX_EBI_NUM_CS - 1)
>
That would be acceptable too, but what I really meant is one step further:
static const struct reg_field at91sam9260_ebi_csa =
REG_FIELD(AT91SAM9260_MATRIX_EBICSA_OFF, 0, AT91_MATRIX_EBI_NUM_CS - 1);
> > - put the register number in the syscon reference and look it
> > up from there (this would be slightly more complicated for the
> > second macro)
>
> I've told several times not to encode register offsets or register ids
> in the DT :-) (and if I'm not mistaken that's what you're suggesting
> here).
I think it's actually fine for syscon references, although in general
I would agree with that. The difference in my opinion is that syscon
by nature is a set of registers.
Arnd
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