From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Cameron Subject: Re: [PATCH 5/6] Staging/iio/adc/touchscreen/MXS: add interrupt driven touch detection Date: Mon, 16 Sep 2013 16:30:32 +0100 Message-ID: <0fb59809-c835-49b0-bd82-e791db1a9db7@email.android.com> References: <1378887511-24530-1-git-send-email-jbe@pengutronix.de> <1378887511-24530-6-git-send-email-jbe@pengutronix.de> <52359259.8010202@kernel.org> <201309161010.22151.jbe@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <201309161010.22151.jbe-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?ISO-8859-1?Q?J=FCrgen_Beisert?= , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b@public.gmane.org, marex-ynQEQJNshbs@public.gmane.org, fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org, jic23-KWPb1pKIrIJaa/9Udqfwiw@public.gmane.org, Torokhov , "linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-input@vger.kernel.org "J=C3=BCrgen Beisert" wrote: >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 >> > CC: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org >> > CC: devel-gWbeCf7V1WCQmaza687I9mD2FQJk+8+b@public.gmane.org >> > CC: Marek Vasut >> > CC: Fabio Estevam >> > CC: Jonathan Cameron >> >> 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 bi= t >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? That would be great and is definitely the preferred method. Currently I >have a=20 >different problem with this driver, because the ADC unit monitors the >battery=20 >as well. And the charging driver from the power subsystem needs these >values=20 >to charge the battery in a correct manner. There is an iio client battery driver as generic_ADC_battery.c but it i= s currently only doing polled access. Not too hard to add buffered acce= ss though ideally we would want a generic way of combining consumers do= ing polled and interrupt driven accesses. > >> [...] > >Regards, >Juergen --=20 Sent from my Android phone with K-9 Mail. Please excuse my brevity.