From patchwork Tue Nov 10 19:40:57 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Albrecht_Dre=C3=9F?= X-Patchwork-Id: 38093 X-Patchwork-Delegate: grant.likely@secretlab.ca Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 70BD1B8529 for ; Wed, 11 Nov 2009 09:09:59 +1100 (EST) Received: by ozlabs.org (Postfix) id AAD5CB7BC5; Wed, 11 Nov 2009 09:09:50 +1100 (EST) Delivered-To: linuxppc-dev@ozlabs.org Received: from smtp5.netcologne.de (smtp5.netcologne.de [194.8.194.25]) by ozlabs.org (Postfix) with ESMTP id 502A1B7B66 for ; Wed, 11 Nov 2009 09:09:50 +1100 (EST) Received: from antares (xdsl-78-34-235-25.netcologne.de [78.34.235.25]) by smtp5.netcologne.de (Postfix) with ESMTP id ECFD440DCCA; Tue, 10 Nov 2009 20:40:57 +0100 (CET) Received: from antares (localhost [127.0.0.1]) by antares (Postfix) with ESMTPS id BCC65BA03E; Tue, 10 Nov 2009 20:40:57 +0100 (CET) Date: Tue, 10 Nov 2009 20:40:57 +0100 From: Albrecht =?iso-8859-1?b?RHJl3w==?= Subject: [PATCH 1/3] mpc52xx/wdt: OF property to enable the WDT on boot To: Linux PPC Development , Grant Likely , devicetree-discuss@lists.ozlabs.org, Wim Van Sebroeck X-Mailer: Balsa 2.4.1 Message-Id: <1257882057.14374.1@antares> MIME-Version: 1.0 Content-Disposition: inline X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Add the "wdt,on-boot" OF property as to reserve a GPT as WDT which may be a requirement in safety-related (e.g. ISO 61508) applications. Signed-off-by: Albrecht Dreß --- Documentation/powerpc/dts-bindings/fsl/mpc5200.txt | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-) diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt index 8447fd7..1eecb06 100644 --- a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt +++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt @@ -103,7 +103,20 @@ fsl,mpc5200-gpt nodes --------------------- On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board design supports the internal wdt, then the device node for GPT0 should -include the empty property 'fsl,has-wdt'. +include the empty property 'fsl,has-wdt'. Note that this does not activate +the watchdog. The timer will function as a GPT if the timer api is used, and +it will function as watchdog if the watchdog device is used. The watchdog +mode has priority over the gpt mode, i.e. if the watchdog is activated, any +gpt api call to this timer will fail with -EBUSY. + +If you add the property + wdt,on-boot = ; +GPT0 will be marked as in-use watchdog, i.e. blocking every gpt access to it. +If n>0, the watchdog is started with a timeout of n seconds. If n=0, the +configuration of the watchdog is not touched. This is useful in two cases: +- just mark GPT0 as watchdog, blocking gpt accesses, and configure it later; +- do not touch a configuration assigned by the boot loader which supervises + the boot process itself. An mpc5200-gpt can be used as a single line GPIO controller. To do so, add the following properties to the gpt node: