On Mon, Jun 6, 2011 at 11:50 AM, Wolfgang Denk wd@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
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de It is impractical for the standard to attempt to constrain the behavior of code that does not obey the constraints of the standard. - Doug Gwyn