[U-Boot] [PATCH 1/5] Tegra2: Add bitfield access macros

[Simon Glass]

On Mon, Jun 6, 2011 at 11:50 AM, Wolfgang Denk <wd at denx.de> wrote:
> Dear Simon Glass,
>
[big snip]

Hi Wolfgang,

OK I understand, thank you. How about this approach: we could add a
new macro to io.h, something like:

#define clrsetfield_le32(bitfield, addr, value)  ...

Then caller can define these in a header file:

#define FIELD_MASK 0xf0000
#define FIELD_SHIFT 16

And use this macro to set the bitfield to 6, for example:

clrsetfield_le32(FIELD, &my_device->ctrl, 6)

(this will simply shift the value left 16 bits and apply the supplied mask)

This captures the essence of bitfields, in that we are abstracting the
field under a single name. The change would just add this macro to the
io.h header file.

Does this sound better?

Regards,
Simon

>
> Best regards,
>
> Wolfgang Denk
>
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