From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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) 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 Message-Id: <1257882057.14374.1@antares> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Dre=DF --- 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/Documenta= tion/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 boar= d 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 activat= e +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, an= y +gpt api call to this timer will fail with -EBUSY. + +If you add the property + wdt,on-boot =3D ; +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=3D0, th= e +configuration of the watchdog is not touched. This is useful in two cases= : +- just mark GPT0 as watchdog, blocking gpt accesses, and configure it late= r; +- do not touch a configuration assigned by the boot loader which supervise= s + the boot process itself. =20 An mpc5200-gpt can be used as a single line GPIO controller. To do so, add the following properties to the gpt node: