On Fri, Jul 19, 2013 at 07:34:45PM +0000, Gupta, Pekon wrote:

> > Maybe it would make more sense to have a spi-rx-width and spi-tx-width
> > than can be set to 1, 2, 4, etc. bits instead of a bunch of properties
> > that are mutually exclusive?  Sooner or later someone is going to want
> > 8 bits.

> Then it would not remain a serial interface (Serial Peripheral Interface),
> rather it would be more of parallel memory like interface.
> And you would not like to use SPI controller for it, instead you would use
> On-chip General Purpose External Interface controllers (like GPMC)
> because it gives you more options to tweak and configure.

It's still not beyoond the bounds of possibility, and of course some
bright spark might decide to use 3 wires.  Unless it's expensive to do
so in some way it seems better to keep the interface as generic as
possible even if we've no expectation that some of the flexibility will
be used.