From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH v2 1/5] iio: mxs-lradc: change the realbits to 12 Date: Fri, 19 Jul 2013 15:56:46 +0200 Message-ID: <201307191556.46857.marex@denx.de> References: <1374225208-28940-1-git-send-email-hector.palacios@digi.com> <1374225208-28940-2-git-send-email-hector.palacios@digi.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1374225208-28940-2-git-send-email-hector.palacios-i7dp0qKlBMg@public.gmane.org> Sender: linux-iio-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Hector Palacios Cc: linux-iio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org, fabio.estevam-KZfg59tc24xl57MIdRCFDg@public.gmane.org List-Id: devicetree@vger.kernel.org Dear Hector Palacios, > The LRADC virtual channels have an 18 bit field to store the sum of up > to 2^5 accumulated samples. The read_raw function however only operates > over a single sample (12 bit resolution). > In order to use this field for scaling operations, we need it to be the > exact resolution value of the LRADC. > Besides, the driver was using an 18 bit mask (LRADC_CH_VALUE_MASK) to > report touch coordinates to userland. A 12 bit mask should be used instead > or else the touch libraries will expect a coordinates range between 0 > and 0x3ffff (18 bits), instead of between 0 and 0xfff (12 bits). > > Signed-off-by: Hector Palacios Acked-by: Marek Vasut Best regards, Marek Vasut