Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755662AbZFATCT (ORCPT ); Mon, 1 Jun 2009 15:02:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751891AbZFATCH (ORCPT ); Mon, 1 Jun 2009 15:02:07 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:42067 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751346AbZFATCF (ORCPT ); Mon, 1 Jun 2009 15:02:05 -0400 Date: Mon, 1 Jun 2009 16:02:01 -0300 From: Mauro Carvalho Chehab To: "Aguirre Rodriguez, Sergio Alberto" Cc: "Paulraj, Sandeep" , "linux-media@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "Grosen, Mark" Subject: Re: New Driver for DaVinci DM355/DM365/DM6446 Message-ID: <20090601160201.4f3bdd56@pedra.chehab.org> In-Reply-To: References: X-Mailer: Claws Mail 3.3.1 (GTK+ 2.10.4; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2072 Lines: 43 Em Mon, 1 Jun 2009 13:38:37 -0500 "Aguirre Rodriguez, Sergio Alberto" escreveu: > > From: linux-media-owner@vger.kernel.org [linux-media-owner@vger.kernel.org] On Behalf Of Paulraj, Sandeep > > Sent: Monday, June 01, 2009 5:56 PM > > To: linux-media@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org; Grosen, Mark > > Subject: New Driver for DaVinci DM355/DM365/DM6446 > > > > Hello, > > > > WE have a module(H3A) on Davinci DM6446,DM355 and DM365. > > > > Customers require a way to collect the data required to perform the Auto Exposure (AE), Auto Focus(AF), and Auto White balance (AWB) in hardware as opposed to software. > This is primarily for performance reasons as there is not enough software processing MIPS (to do 3A statistics) available in > > an imaging/video system. > > > > Including this block in hardware reduces the load on the processor and bandwidth to the memory as the data is collected on the fly from the imager. > > > > This modules collects statistics and we currently implement it as a character driver. > > This also exists in OMAP3 chips, and is part of the ISP module. > > I maintain, along with Sakari Ailus, a V4L2 camera driver, which is currently just shared through a gitorious repository: > > http://gitorious.org/omap3camera > > The way we offer an interface for the user to be able to request this statistics is with the usage of private IOCTLs declared inside the same V4L2 capturing device driver. > > So, that way we have a V4L2 driver which has a private call, instead of having it separately from the capture driver. This seems to be a much better approach, provided that the private IOCTL's will be properly documented on a public document. If there are enough usage for they, we may even add them as an optional part of V4L2 API. Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/