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? Not everyone using lradc would be necessarily interested in the touchscreen functionality, so better to let it optional. Thanks, Fabio Estevam -- 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
