[U-Boot] [PATCH 1/3] Add support for PCA953x I2C gpio devices

[Peter Tyser]

Hi Wolfgang,

On Tue, 2008-11-18 at 22:33 +0100, Wolfgang Denk wrote:
> Dear Peter Tyser,
> 
> In message <1224800639-31350-2-git-send-email-ptyser at xes-inc.com> you wrote:
> > Initial support for NXP's 4 and 8 bit I2C gpio expanders
> > (eg pca9537, pca9557, etc). The CONFIG_PCA953X define
> > enables support for the devices while the CONFIG_CMD_PCA953X
> > define enables the pca953x command.
> 
> I'm not sure if we need such a detailed  level  of  access  to  these
> chips.  We  already  have  a  couple of similar I/O expanders in some
> boards, for example implemente in some PICs. See for example the "pic
> read" / "pic write" conde in board/lwmon/lwmon.c etc.
> 
> I think we should generalize this - and more than read / write isn't
> really needed, or is it?

What do you mean by "we should generalize this"?

I view the read/write/invert commands as necessary to easily
configure/read/write the GPIO pins, and the info command is nice, but
not necessary.

The info command is nice to get an idea of what's going on at a high
level - eg is the input on pin 2 being inverted?  What pins are
currently being driven low? etc.  I've found the iopinfo command useful
for the 82xx boards and tried to replicate similar functionality in this
driver.  I like the info command but understand if others want it
removed.

Let me know if you'd like me to change it.

Thanks,
Peter