[PATCHv2 00/10] Add memory mapped support for ti qspi, m25p80 serial flash.

Marek Vasut marex at denx.de
Tue Dec 10 13:34:01 EST 2013


On Tuesday, December 10, 2013 at 07:29:04 PM, Mark Brown wrote:
> On Tue, Dec 10, 2013 at 07:22:10PM +0100, Marek Vasut wrote:
> > On Tuesday, December 10, 2013 at 05:11:43 PM, Mark Brown wrote:
> > > There is some stuff that pushes up into the controller in that while
> > > the device is in memory mapped mode as far as I can tell it's not safe
> > > to do other accesses so if someone's put more than one device on the
> > > SPI bus we need to handle interactions there.
> > 
> > OK, so it's either-or . That seems OK, you might want to have two drivers
> > for this ip block, one to handle it as a SPI block and one to handle it
> > as a SPI-NOR block. ... that is of course, if these two modes can't work
> > together.
> 
> Or the client disables the memory map when it's not actively being used
> and the stops other transfers starting while the mapping is in place.
> I'd expect we'll have to cope with shared use at some point, hardware
> engineers will probably build such systems.

Aren't we fixing the problem at the wrong place ? Maybe it's about time to fix 
the engineers ;-)

Best regards,
Marek Vasut



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