Re: [PATCH v8 1/9] mfd: madera: Add register definitions for Cirrus Logic Madera codecs

From: Andy Shevchenko
Date: Mon Feb 26 2018 - 08:46:59 EST


On Mon, Feb 26, 2018 at 3:05 PM, Richard Fitzgerald
<rf@xxxxxxxxxxxxxxxxxxxxx> wrote:
> This patch adds a header file of register definitions for Cirrus
> Logic "Madera" class codecs. These codecs are all based off a common
> set of hardware IP so have a common register map (with a few minor
> device-to-device variations).
>
> The registers.h file is tool-generated directly from the hardware design
> but has been manually stripped down to reduce size (full register
> map is >44000 lines). All names are kept the same as datasheet names
> so that they can be cross-referenced between source and datasheet without
> confusion.
>
> The register map layout is kept fully-defined rather than factored into
> macros and/or block-indexing code. The major reasons for this are:
>
> - #1 is that it makes the source highly greppable, which is important.
> "What does the driver do with register bits XYZ" or "Where does it use
> register bits XYZ" are commonly types of questions. These can be quickly
> answered by a grep. Squashing definitions into generator macros or block-
> indexing code is a way of defeating grep.
>
> - most of the register definitions are used in tables, so a constant value
> is required. Using generator macros make the table definition clunky and
> obscure.
>
> - the code is clearer when it's there in the source exactly what register
> and field it is using
>
> - it is easier to diff the register map of a new (unsupported) codec against
> what is already supported and merge in differences
>
> - it makes the register map available in source for maintenance/debugging
> instead of having to refer back to the datasheet for a register map

...

> +#define MADERA_OTP_HPDET_GRADIENT_1X_MASK 0x0000FF00

> +#define MADERA_OTP_HPDET_GRADIENT_0X_MASK 0x000000FF

GENMASK() for all masks?

--
With Best Regards,
Andy Shevchenko