From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:37379 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751165Ab2JZCFA (ORCPT ); Thu, 25 Oct 2012 22:05:00 -0400 From: Laurent Pinchart To: Sylwester Nawrocki Cc: Guennadi Liakhovetski , Linux Media Mailing List , Hans Verkuil , Sylwester Nawrocki , Magnus Damm , linux-sh@vger.kernel.org Subject: Re: [PATCH 1/2] media: V4L2: add temporary clock helpers Date: Fri, 26 Oct 2012 04:05:50 +0200 Message-ID: <4703902.UfQghhBIJp@avalon> In-Reply-To: <50844465.40007@gmail.com> References: <50844465.40007@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hello, On Sunday 21 October 2012 20:52:21 Sylwester Nawrocki wrote: > On 10/20/2012 12:20 AM, Guennadi Liakhovetski wrote: > > Typical video devices like camera sensors require an external clock > > source. Many such devices cannot even access their hardware registers > > without a running clock. These clock sources should be controlled by their > > consumers. This should be performed, using the generic clock framework. > > Unfortunately so far only very few systems have been ported to that > > framework. This patch adds a set of temporary helpers, mimicking the > > generic clock API, to V4L2. Platforms, adopting the clock API, should > > switch to using it. Eventually this temporary API should be removed. > > So I gave this patch a try this weekend. I would have a few comments/ > questions. Thank you for sharing this! I've finally found time to give it a try, and I can report successful results. My development target here is a Beagleboard-xM with an MT9P031 sensor. With this patch and Sylwester's additional patches [1], I've been able to remove the board code callback from the mt9p031 driver platform data, as well as the last omap3-isp platform callback. The result is available in the devel/v4l2-clock branch of http://git.linuxtv.org/pinchartl/media.git. Sylwester, that branch includes a minor fix titled "v4l2-clk: Fix clock id matching" for your "v4l2-clk: Rework to accept more than one clock with null clock id" patch. Could you please have a look at it ? On the downside, there's now a circular dependency between the mt9p031 and omap3-isp drivers, so neither of them can be removed. That will need to be fixed. [1] http://git.linuxtv.org/snawrocki/media.git/shortlog/refs/heads/s3c-camif- devel -- Regards, Laurent Pinchart