On Thu, Nov 26, 2009 at 20:12, Cai, Cliff wrote:
>From: Mike Frysinger [mailto:[email protected]]
>>On Thu, Nov 26, 2009 at 01:02, Cai, Cliff wrote:
>>> Not really,the sport can provide cs by itself.
>>
>>except that MAX_CTRL_CS is specific to the Blackfin SPI
>>controller -- the SPORT does not support 7 different
>>"internal" cs's.  the driver also doesnt explain how exactly
>>"the sport is in charge of it".
>>before your commit, a GPIO CS was always used.  after your
>>commit, the GPIO CS is sometimes used, but otherwise, no
>>"internal" cs changes are apparent.
>
> If we don't use GPIO as CS, then SPORT can provide cs-change-per-word kind of 
> CS.
> And we can't control it.I will add the comments in the driver.

to be frank, such CS functionality is currently (and for the
foreseeable future) completely useless.  the common SPI framework does
not support toggling the cs per-word, only per-transaction.  adding
support to the bus master when nothing out there wants it sounds like
bloat to me.  we should only accept GPIO CS's with the SPORT/SPI
driver.
-mike
_______________________________________________
Linux-kernel-commits mailing list
[email protected]
https://blackfin.uclinux.org/mailman/listinfo/linux-kernel-commits

Reply via email to