From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail1.matrix-vision.com ([78.47.19.71]:53992 "EHLO mail1.matrix-vision.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755614Ab2CTKFz (ORCPT ); Tue, 20 Mar 2012 06:05:55 -0400 Message-ID: <4F6856C0.4070404@matrix-vision.de> Date: Tue, 20 Mar 2012 11:06:56 +0100 From: Michael Jones MIME-Version: 1.0 To: Laurent Pinchart CC: linux-media ML Subject: Re: reading config parameters of omap3-isp subdevs References: <4F6348D7.9070409@matrix-vision.de> <6085689.3CUf0tMs8E@avalon> In-Reply-To: <6085689.3CUf0tMs8E@avalon> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Laurent, On 03/20/2012 12:22 AM, Laurent Pinchart wrote: > Hi Michael, > > On Friday 16 March 2012 15:06:15 Michael Jones wrote: [snip] > > Adding a R/W bit to the flag argument should indeed work. However, I'm > wondering what your use case for reading parameters back is. The simplest use case in my mind is that after the user has fiddled around with config parameters, they should be able to set them back to their original state. For that, they need to know what the original state was. > The preview > engine parameter structures seem pretty-much self-contained to me, I'm not > sure it would make sense to only modify one of the parameters. Why doesn't it make sense to write to only e.g. 'COEF3' in the PRV_WBGAIN register? Especially considering the sparse documentation of many of these registers, I would like to be able to tweak the existing parameters from their defaults, rather than start from scratch. -Michael MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner, Erhard Meier