Dear Fabio Estevam, > On Fri, Dec 7, 2012 at 1:24 PM, Marek Vasut <marex@xxxxxxx> wrote: > > This patch implements support for sampling of a touchscreen into > > the MXS LRADC driver. The LRADC block allows configuring some of > > it's channels into special mode where they either output the drive > > voltage or sample it, allowing it to operate a 4-wire or 5-wire > > resistive touchscreen. > > > > In case the touchscreen mode is enabled, the LRADC slot #7 is > > reserved for touchscreen only, therefore it is not possible to > > sample 8 LRADC channels at time, but only 7 channels. > > > > The touchscreen controller is configured such that the PENDOWN event > > disables touchscreen interrupts and triggers execution of worker > > thread, which then polls the touchscreen controller for X, Y and > > Pressure values. This reduces the overhead of interrupt-driven > > operation. Upon the PENUP event, the worker thread re-enables the > > PENDOWN detection interrupt and exits. > > > > Signed-off-by: Marek Vasut <marex@xxxxxxx> > > Cc: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx> > > Cc: Jonathan Cameron <jic23@xxxxxxxxxx> > > Cc: Shawn Guo <shawn.guo@xxxxxxxxxx> > > --- > > > > .../bindings/staging/iio/adc/mxs-lradc.txt | 6 + > > drivers/staging/iio/adc/mxs-lradc.c | 435 > > +++++++++++++++++++- > > What about adding the touchscreen support into a separate file, so > that users can select/deselect it via Kconfig option? The touchscreen is way too intertwined with the LRADC, that's why I kept it in single file. Separating it away would only spawn third lradc.h header file with all the shared data etc. I'll elaborate on it more in the other email. > Not everyone using lradc would be necessarily interested in the > touchscreen functionality, so better to let it optional. You can actually disable it via device tree property (and it's disabled by default). > Thanks, > > Fabio Estevam Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
