From patchwork Thu Nov 12 18:43:47 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: 38266 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 7332C100952 for ; Fri, 13 Nov 2009 05:43:57 +1100 (EST) Received: by ozlabs.org (Postfix) id 109D5B7B95; Fri, 13 Nov 2009 05:43:50 +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 B55BCB7B8F for ; Fri, 13 Nov 2009 05:43:49 +1100 (EST) Received: from antares (xdsl-87-79-232-139.netcologne.de [87.79.232.139]) by smtp5.netcologne.de (Postfix) with ESMTP id 77EDE40D2F1; Thu, 12 Nov 2009 19:43:48 +0100 (CET) Received: from antares (localhost [127.0.0.1]) by antares (Postfix) with ESMTPS id 3B261BA03E; Thu, 12 Nov 2009 19:43:48 +0100 (CET) Date: Thu, 12 Nov 2009 19:43:47 +0100 From: Albrecht =?iso-8859-1?b?RHJl3w==?= Subject: [PATCHv2 1/3] mpc52xx/wdt: OF property to enable the WDT on boot To: "Likely, Grant" , Linux PPC Development , Devicetree Discussions , Wim Van Sebroeck X-Mailer: Balsa 2.4.1 Message-Id: <1258051427.2280.1@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 "fsl,wdt-on-boot" OF property as to reserve a GPT as WDT which may be a requirement in safety-related (e.g. ISO/EN 61508) applications. Signed-off-by: Albrecht Dreß --- Change against v1: rename the new property. Documentation/powerpc/dts-bindings/fsl/mpc5200.txt | 17 ++++++++++++++++- 1 files changed, 16 insertions(+), 1 deletions(-) diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt index 8447fd7..ddd5ee3 100644 --- a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt +++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt @@ -103,7 +103,22 @@ 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 + fsl,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. + +The watchdog will respect the CONFIG_WATCHDOG_NOWAYOUT option. An mpc5200-gpt can be used as a single line GPIO controller. To do so, add the following properties to the gpt node: