From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:51943 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753518Ab3IWNjX convert rfc822-to-8bit (ORCPT ); Mon, 23 Sep 2013 09:39:23 -0400 From: =?utf-8?q?J=C3=BCrgen_Beisert?= To: linux-arm-kernel@lists.infradead.org Subject: Re: [PATCHv5] staging/iio/adc: change the MXS touchscreen driver implementation Date: Mon, 23 Sep 2013 15:40:46 +0200 Cc: Marek Vasut , devel@driverdev.osuosl.org, fabio.estevam@freescale.com, linux-iio@vger.kernel.org, jic23@cam.ac.uk, Lothar =?utf-8?q?Wa=C3=9Fmann?= References: <1379593369-22010-1-git-send-email-jbe@pengutronix.de> <21056.12306.714098.398250@ipc1.ka-ro> <201309231524.38008.jbe@pengutronix.de> In-Reply-To: <201309231524.38008.jbe@pengutronix.de> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Message-Id: <201309231540.46470.jbe@pengutronix.de> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On Monday 23 September 2013 15:24:37 Jürgen Beisert wrote: > Hi Lothar, > > On Monday 23 September 2013 14:12:02 Lothar Waßmann wrote: > > [...] > > > > > @Lothar: What kernel revision did you use? I had to go back to 3.9 to > > > get a > > > > Current linux-next (3.12-rc1). > > Okay. > > > > working kernel on the MX28EVK. More recent vanilla kernels stop working > > > (MMC and network fail here). > > > > I'm seeing some messages: > > |mxs-mmc 80010000.ssp: dummy supplies not allowed > > |fec 800f0000.ethernet: dummy supplies not allowed > > It was my fault. I'm also working with 3.12-rc1 now. > > > But without any apparent consequences. Maybe that's a problem with the > > MX28EVK? > > It seems the LRADC delay feature does not work. The touch detection > interrupt happens and the driver switches to the Y plate measurement, arms > the LRADC delay unit ... and nothing more happens. The LRADC delay unit > should start a conversion on ADC channel 4. But it does not. Never. > > The i.MX28 manual says the LRADC delay unit is driven by a 2 kHz clock, but > does not say what kind of clock it is (or is derived from). I guess now, > this clock isn't enabled and thus the delay unit can't work. At least on > the MX28EVK. On your TX28 platform the clock seems enabled and the delay > unit can do its job and drive the state machine. Hmmm: 24 MHz / 750 = CLK_32K / 16 = CLK_LRADC2K Regards, Juergen -- Pengutronix e.K.                              | Juergen Beisert             | Linux Solutions for Science and Industry      | Phone: +49-5121-206917-5128 | Peiner Str. 6-8, 31137 Hildesheim, Germany    | Fax:   +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686              | http://www.pengutronix.de/  |