Re: [patch 2.6.24-rc6] ads7846: simplify support of external vREF (and ads7843)

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Wed, Jan 16, 2008 at 09:16:16AM -0800, David Brownell wrote:
> > Date: Wed, 16 Jan 2008 10:09:10 -0500
> > From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> >
> > On Sat, Jan 05, 2008 at 02:10:19PM -0800, David Brownell wrote:
> > > This updates the ads7846 driver to handle external vREF (required
> > > on boards using ads7843 chips) without module parameters, and also
> > > removes a needless variable with its associated bogus gcc warning.
> >
> > Is there any concern about people already using this module parameter
> > in the field?
> 
> Users of ads7846 chips mostly won't need it; they use the internal vREF.
> 
> Users of ads7843 chips tend to not provide it (given the debug messages
> I periodically see!), and accordingly don't get the two general purpose
> ADC channels (via hwmon).  There aren't many ads7843 users yet; mostly
> users of two Atmel devel boards.

OK.

> 
> 
> >    Should it still be present to allow users to override
> > platform default?
> 
> There *is* no platform default ... there'd be a board-specific
> value (e.g. "3.3V" or "2.8V") that makes no sense to ever change,
> since it's hard-wired.  If there's no such value, those two ADC
> channels just won't be available.
> 
> I'd really rather just get rid of it.  The module param is hardly
> used, and doing it that way has always been a hack.  None of the
> other board-specific values use that error-prone mechanism.
> 

OK, fair enough. Queued for 2.6.25.

Thank you Dave.

-- 
Dmitry