Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935597AbdGTJSi (ORCPT ); Thu, 20 Jul 2017 05:18:38 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:36698 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933731AbdGTJSd (ORCPT ); Thu, 20 Jul 2017 05:18:33 -0400 From: Hugues FRUCHET To: "H. Nikolaus Schaller" , Sakari Ailus , Sylwester Nawrocki , "Hans Verkuil" CC: Guennadi Liakhovetski , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre TORGUE , Mauro Carvalho Chehab , devicetree , LKML , "Yannick FERTRE" , Benjamin Gaignard , linux-arm-kernel , "linux-media@vger.kernel.org" Subject: Re: [PATCH v2 0/7] Add support of OV9655 camera Thread-Topic: [PATCH v2 0/7] Add support of OV9655 camera Thread-Index: AQHTATOiVYGpWvrFrECxVsekz0rcDaJcTiEA Date: Thu, 20 Jul 2017 09:17:38 +0000 Message-ID: <8050f688-fc6e-c3c0-460a-93ad3ae8d735@st.com> References: <1499073368-31905-1-git-send-email-hugues.fruchet@st.com> <8157da84-1484-8375-1f2b-9831973915b4@kernel.org> <956f17e6-36dd-6733-0d35-9b801ed4244d@xs4all.nl> <2dd3402e-55b0-231d-878f-5ba95ee8cb36@st.com> <20170718195223.zrqfrefxxzqfsojd@valkosipuli.retiisi.org.uk> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.44] Content-Type: text/plain; charset="utf-8" Content-ID: <6EB4E3EF8784074DAD57E64B1F57A9ED@st.com> MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-20_04:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by nfs id v6K9IjnC007726 Content-Length: 4297 Lines: 104 On 07/20/2017 10:37 AM, H. Nikolaus Schaller wrote: > Hi, > >> Am 18.07.2017 um 21:52 schrieb Sakari Ailus : >> >> On Tue, Jul 18, 2017 at 12:53:12PM +0000, Hugues FRUCHET wrote: >>> >>> >>> On 07/18/2017 02:17 PM, H. Nikolaus Schaller wrote: >>>> Hi, >>>> >>>>> Am 18.07.2017 um 13:59 schrieb Hans Verkuil : >>>>> >>>>> On 12/07/17 22:01, Sylwester Nawrocki wrote: >>>>>> Hi Hugues, >>>>>> >>>>>> On 07/03/2017 11:16 AM, Hugues Fruchet wrote: >>>>>>> This patchset enables OV9655 camera support. >>>>>>> >>>>>>> OV9655 support has been tested using STM32F4DIS-CAM extension board >>>>>>> plugged on connector P1 of STM32F746G-DISCO board. >>>>>>> Due to lack of OV9650/52 hardware support, the modified related code >>>>>>> could not have been checked for non-regression. >>>>>>> >>>>>>> First patches upgrade current support of OV9650/52 to prepare then >>>>>>> introduction of OV9655 variant patch. >>>>>>> Because of OV9655 register set slightly different from OV9650/9652, >>>>>>> not all of the driver features are supported (controls). Supported >>>>>>> resolutions are limited to VGA, QVGA, QQVGA. >>>>>>> Supported format is limited to RGB565. >>>>>>> Controls are limited to color bar test pattern for test purpose. >>>>>> >>>>>> I appreciate your efforts towards making a common driver but IMO it would be >>>>>> better to create a separate driver for the OV9655 sensor. The original driver >>>>>> is 1576 lines of code, your patch set adds half of that (816). There are >>>>>> significant differences in the feature set of both sensors, there are >>>>>> differences in the register layout. I would go for a separate driver, we >>>>>> would then have code easier to follow and wouldn't need to worry about possible >>>>>> regressions. I'm afraid I have lost the camera module and won't be able >>>>>> to test the patch set against regressions. >>>>>> >>>>>> IMHO from maintenance POV it's better to make a separate driver. In the end >>>>>> of the day we wouldn't be adding much more code than it is being done now. >>>>> >>>>> I agree. We do not have great experiences in the past with trying to support >>>>> multiple variants in a single driver (unless the diffs are truly small). >>>> >>>> Well, >>>> IMHO the diffs in ov965x are smaller (but untestable because nobody seems >>>> to have an ov9650/52 board) than within the bq27xxx chips, but I can dig out >>>> an old pdata based separate ov9655 driver and extend that to become DT compatible. >>>> >>>> I had abandoned that separate approach in favour of extending the ov965x driver. >>>> >>>> Have to discuss with Hugues how to proceed. >>>> >>>> BR and thanks, >>>> Nikolaus >>>> >>> >>> As Sylwester and Hans, I'm also in flavour of a separate driver, the >>> fact that register set seems similar but in fact is not and that we >>> cannot test for non-regression of 9650/52 are killer for me to continue >>> on a single driver. >>> We can now restart from a new fresh state of the art sensor driver >>> getting rid of legacy (pdata, old gpio, etc...). >> >> Agreed. I bet the result will look cleaner indeed although this wasn't one >> of the complex drivers. > > I finally managed to find the bug why mplayer did select-timeout on the GTA04. > Was a bug in pinmux setup of the GTA04 for the omap3isp. > > And I have resurrected our years old 3.12 camera driver, which was based on the > MT9P031 code. It was already separate from ov9650/52. > > I have extended it to support DT by including some parts of Hugues' work. > > It still needs some cleanup and discussion but will be a simple patch (one > for ov9655.c + Kconfig + Makefile) and one for bindings (I hope it includes > all your comments). > > I will post v1 in the next days. > > BR, > Nikolaus > Thanks Nikolaus, I was ready to push the new version in new file ov9655.c with all comments included, but as my version is very minimal and I suspect that yours is more complete, let's merge things together. Can I consider that you now take ownership of this driver upstream ? If so I'll send to you my current patchset so you can compare, double-check review comments and add missing support on your side (RGB565 and VGA/QVGA resolution matter on my side). Thanks again Nikolaus for this work, BR, Hugues.