Re: [spi-devel-general] [PATCH] Input: Add tsc2046 touchscreen driver

[David Brownell <david-b@pacbell.net>]

--- On Sun, 5/30/10, Cory Maccarrone <darkstar6262@gmail.com> wrote:

I don't see the point in having a separate driver
for this chip ... it's just an updated ADS7846,
and the ads7846 driver has handled it for quite
a few years now, as I recall.  There's no need for
 second driver.

> >> This driver differs from the ADS7846 in that it
> >> uses 16-bit commands instead of 8-bit,

The reason the ads7846 code uses 8-bit messaging
is portability ... it works with SPI controllers
which don't support 16-bit words.  The commands are
of necessity 16-bits.  Using 16-bit words means this
driver won't run on as many systems; folk will still
need to use the ads7846 driver with tsc2046 chips..
 


 and does not include
> temerature
> >> or voltage sensing capabilities.

Another reason not to have a separate driver: this
one is less capable (as well as less portable)


> >> additions that allow
> >> the injection of pointercal parameters from tslib through /sys. 

Something the ads7846 driver could benefit from
too ... again, two drivers is counterproductive.

- Dave