RE: [ECOS] assabet_BCR

["Trenton D. Adams" <tadams at extremeeng dot com>]

> -----Original Message-----
> From: gary@chez-thomas.org [mailto:gary@chez-thomas.org] On 
> Behalf Of Gary Thomas
> Sent: Thursday, June 21, 2001 1:11 PM
> To: Trenton D. Adams
> Cc: eCos
> Subject: RE: [ECOS] assabet_BCR
> 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.

Is enabling of the bus always necessary?  From what I've read in the
documentation for my board so far, I don't need to do this.  I'll write
a new email on the initialization sequence for the PCMCIA device on my
board.

> 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. 
>