From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.bugwerft.de ([46.23.86.59]:55364 "EHLO mail.bugwerft.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750779AbdH2RCp (ORCPT ); Tue, 29 Aug 2017 13:02:45 -0400 Subject: Re: [PATCH v4 04/21] doc: media/v4l-drivers: Add Qualcomm Camera Subsystem driver document To: Todor Tomov Cc: mchehab@kernel.org, hans.verkuil@cisco.com, s.nawrocki@samsung.com, sakari.ailus@iki.fi, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <1502199018-28250-1-git-send-email-todor.tomov@linaro.org> <1502199018-28250-5-git-send-email-todor.tomov@linaro.org> <7483f716-4240-899f-f9c5-23c6408f39ff@linaro.org> From: Daniel Mack Message-ID: <97228890-39c1-6c85-ed74-0e1e62b83868@zonque.org> Date: Tue, 29 Aug 2017 19:02:42 +0200 MIME-Version: 1.0 In-Reply-To: <7483f716-4240-899f-f9c5-23c6408f39ff@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Todor, On 08/28/2017 09:10 AM, Todor Tomov wrote: > On 25.08.2017 17:10, Daniel Mack wrote: >> I have a userspace test setup that works fine for USB webcams, but when >> operating on any of the video devices exposed by this driver, the >> lowlevel functions such as .s_power of the ISPIF, CSID, CSIPHY and the >> sensor driver layers aren't called into. > > Have you activated the media controller links? The s_power is called > when the subdev is part of a pipeline in which the video device node > is opened. You can see example configurations for the Qualcomm CAMSS > driver on: > https://github.com/96boards/documentation/blob/master/ConsumerEdition/DragonBoard-410c/Guides/CameraModule.md > This will probably answer most of your questions. Yes, it does, thank you! I didn't expect the necessity for any manual setup on this level due to this sentence in the documentation: > Runtime configuration of the hardware (updating settings while > streaming) is not required to implement the currently supported > functionality. I hence assumed there is a fixed mapping that is partly derived from DTS information etc. Anyway, this seems to work now, so thanks a bunch for the pointer! Another thing that confused me for a while is the CCI driver, which also exposes media pads. I have the cameras connected to a regular I2C bus however, and it seems to work fine. That just leaves the question why this CCI driver exists at all. I also have some more questions, but they are even more platform specific, so I'll rather post them in the 96boards forum. Thanks again! Daniel