RE: [ECOS] assabet_BCR

[Gary Thomas <gthomas at cambridge dot redhat dot com>]

On 21-Jun-2001 Trenton D. Adams wrote:
> What's the purpose of this function?  Other than the fact that it
> manipulates the board control register.
> 

The board control register on the Assabet is write-only.  This function
makes it easy for disparate pieces of code to manipulate its contents.

> I assume it's some sort of generic register for various tasks?  Is there
> an equivalent for the EDB7111-2 board?

No.  AFAIK, all the control registers on the EP7212 are read-write, so 
such a function is not necessary.

> 
> I'm writing a PCMCIA Driver so should I just replace this function with
> one that handles the setup of the PCMCIA controller instead then?  I
> would think this would be the best bet since it's more specific, and
> easier to use.
> 

That's what those calls in the Assabet PCMCIA driver are all about, it's
just that control over certain signals in the PCMCIA hardware [realm] are
controlled by that silly write-only register.

> One last question.  Assuming I'm correct about making a function for
> manipulating the PCMCIA controller registers.  Where would should this
> function be implemented?  It would obviously work fine in my driver
> file, but would it need to be used by someone else later on?  If so then
> it would be best to put it somewhere else probably.

If the things you are talking about are platform specific, things like
enabling Vcc to the bus, etc, then they belong in the platform driver.

If you're asking about something else which is specific to a particular
PCMCIA device then that would belong with the device driver.

If it's something that is PCMCIA defined which is not platform specific
and not particular to a card, then it would go in the generic PCMCIA
layer.