[PATCH 5/6] Staging/iio/adc/touchscreen/MXS: add interrupt driven touch detection

Jürgen Beisert jbe at pengutronix.de
Mon Sep 16 04:10:22 EDT 2013


Hi Jonathan,

On Sunday 15 September 2013 12:56:25 Jonathan Cameron wrote:
> On 09/11/13 09:18, Juergen Beisert wrote:
> > For battery driven systems it is a very bad idea to collect the
> > touchscreen data within a kernel busy loop.
> >
> > This change uses the features of the hardware to delay and accumulate
> > samples in hardware to avoid a high interrupt and CPU load.
> >
> > Note: this is only tested on an i.MX23 SoC yet.
> >
> > Signed-off-by: Juergen Beisert <jbe at pengutronix.de>
> > CC: linux-arm-kernel at lists.infradead.org
> > CC: devel at driverdev.osuosl.org
> > CC: Marek Vasut <marex at denx.de>
> > CC: Fabio Estevam <fabio.estevam at freescale.com>
> > CC: Jonathan Cameron <jic23 at cam.ac.uk>
>
> While this driver is placed in IIO within staging at the moment, these
> changes are definitely input related.  Hence I have cc'd Dmitry and the
> input list.
>
> I am personaly a little uncomfortable that we have such a complex bit of
> input code sat within an IIO driver but such is life.

Maybe an MFD for this ADC unit would be a better way to go? Currently I have a 
different problem with this driver, because the ADC unit monitors the battery 
as well. And the charging driver from the power subsystem needs these values 
to charge the battery in a correct manner.

> [...]

Regards,
Juergen

-- 
Pengutronix e.K.                              | Juergen Beisert             |
Linux Solutions for Science and Industry      | http://www.pengutronix.de/  |



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