From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751413AbaK1WXF (ORCPT ); Fri, 28 Nov 2014 17:23:05 -0500 Received: from mout.kundenserver.de ([212.227.126.130]:55603 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751176AbaK1WXD (ORCPT ); Fri, 28 Nov 2014 17:23:03 -0500 From: Arnd Bergmann To: Stefan Agner Cc: linux-arm-kernel@lists.infradead.org, shawn.guo@linaro.org, kernel@pengutronix.de, linux@roeck-us.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] ARM: imx: src: support vf610 system reset controller Date: Fri, 28 Nov 2014 23:22:57 +0100 Message-ID: <18555848.LVhqYu0kXL@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <6341b31998ff843d236bc2a3e34537b0@agner.ch> References: <1417193015-6033-1-git-send-email-stefan@agner.ch> <2716009.DOfHfaSPkY@wuerfel> <6341b31998ff843d236bc2a3e34537b0@agner.ch> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:OfWiSOJRuRiYt2grqFtM2ODglCA1DL2PEtDCv7pSbEM UyM+pzIMgRnTUX3RJJyPLD8EHckNP0QgWqHFRCSjVlTMRUKUs3 tIl+I56YJWDtnnpV9g6B/83B9TpwDn4CCxIAXEH1MFaxLvBKA8 RT2sSaMDiqgTTyPL15I8/g0o+2LONHKN/jWChbGz2xqLhbkhUy 17YrjT1j21iAG8HpFs+/BOVds3Qqld4Z8hkTMpbVtpxO2Cip2I BHPIccZBaqMNlRKjBTT54JbXOb2kJlpbNPVqR8rmVu0BYeYCQ3 /VH2xOc6OcHyP1av1tjYNwokVh8jrK/G5vWG2qUwW10Hg/dnVN 3w3+KQJ7xaWJjyN1096k= X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 28 November 2014 23:09:09 Stefan Agner wrote: > On 2014-11-28 22:24, Arnd Bergmann wrote: > > On Friday 28 November 2014 22:02:01 Stefan Agner wrote: > > > >> > If the SRC is also capable of resetting individual blocks instead of just > >> > the entire machine, it would be a reset driver in drivers/reset instead. > >> > >> Beside the system reset, there is only a mask functionality for the > >> watchdogs (there are two watchdogs, one for Cortex-A5 and one for the > >> M4). This makes the SRC module in the Vybrid a bit different then what > >> is available on other i.MX SoC's... > > > > If you already have the watchdog registers in there and want to have > > a watchdog driver too, the easiest way would be to register the reboot > > handler from the watchdog driver. > > Hm, not sure we speak about the same here. The SRC module has two > (multi-)bit fields to mask the watchdog reset event for each watchdog. > Beside that, there are two full watchdog register maps, which are in > different areas. There is already a driver for this watchdogs. I'm not > sure what the idea behind this is exactly, I guess it would easily allow > to (temporary) mask the other CPU's watchdog. However, I don't think we > need that functionality, so I don't care about that right now. Ok, I see, thanks for the clarification! > There is also a restart handler in the watchdog driver, but I prefer to > use the reset capabilities of the SRC since it has immediate effect. > > Lets get to the big picture again: I could register the whole SRC > register map as a syscon device and then access the registers from my > suspend/resume implementation later on. And similar in the restart > driver, I would use syscon_regmap_lookup_by_compatible to check if it > contains the vf610-src compatible string and register the restart > driver/handler if available. Correct, and also in the watchdog driver, I guess. Instead of syscon_regmap_lookup_by_compatible, please use syscon_regmap_lookup_by_phandle and put the link to the syscon device into the device accessing it. Also, see if you can use or extend drivers/power/reset/syscon-reboot.c for your use case. Arnd