From mboxrd@z Thu Jan 1 00:00:00 1970 From: lauri.hintsala@bluegiga.com (Lauri Hintsala) Date: Fri, 11 Jan 2013 10:31:46 +0200 Subject: [PATCH 1/2 V3] iio: mxs: Implement support for touchscreen In-Reply-To: <1357861431-8978-1-git-send-email-marex@denx.de> References: <1357861431-8978-1-git-send-email-marex@denx.de> Message-ID: <50EFCDF2.7090207@bluegiga.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 01/11/2013 01:43 AM, Marek Vasut 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 > Cc: Dmitry Torokhov > Cc: Fabio Estevam > Cc: Jonathan Cameron > Cc: Shawn Guo > --- > .../bindings/staging/iio/adc/mxs-lradc.txt | 6 + > drivers/staging/iio/adc/mxs-lradc.c | 473 +++++++++++++++++++- > 2 files changed, 455 insertions(+), 24 deletions(-) Works fine with apx4devkit. Tested-by: Lauri Hintsala Best Regards, Lauri Hintsala