Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751937AbdF0DAK (ORCPT ); Mon, 26 Jun 2017 23:00:10 -0400 Received: from mail-yb0-f196.google.com ([209.85.213.196]:35480 "EHLO mail-yb0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751493AbdF0DAC (ORCPT ); Mon, 26 Jun 2017 23:00:02 -0400 MIME-Version: 1.0 In-Reply-To: <20170613203818.17399-2-cbostic@linux.vnet.ibm.com> References: <20170613203818.17399-1-cbostic@linux.vnet.ibm.com> <20170613203818.17399-2-cbostic@linux.vnet.ibm.com> From: Joel Stanley Date: Tue, 27 Jun 2017 12:29:41 +0930 X-Google-Sender-Auth: 7Z424jWYkX79diMBVGEOl3-GogY Message-ID: Subject: Re: [PATCH 1/2] drivers/watchdog: Document new aspeed optional dev tree properties. To: Christopher Bostic Cc: Wim Van Sebroeck , Guenter Roeck , Linux Kernel Mailing List , linux-watchdog@vger.kernel.org, Andrew Jeffery Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2280 Lines: 62 On Wed, Jun 14, 2017 at 6:08 AM, Christopher Bostic wrote: > Describe new optional property 'external-signal'. When present in the > system device tree an exernal signal is generated on watchdog timeout. > > Describe new optional property 'no-system-reset'. When present in the > system device tree no system reset is to occur on watchdog timeout. > System reset in this case is managed by one of the other watchogs > available. > > Signed-off-by: Christopher Bostic > --- > Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt > index c5e74d7..4099ea5 100644 > --- a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt > +++ b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt > @@ -8,9 +8,20 @@ Required properties: > - reg: physical base address of the controller and length of memory mapped > region > > +Optional properties: > + - external-signal: If the property is present then an external signal is to > + be generated on watchdog timeout. If absent, external signal is not > + generated. > + > + - no-system-reset: If the property is present then system will not be reset > + on watchdog timeout. In this case one of the other watchdogs will handle > + reset. If absent then the watchdog resets the system on timeout. I'm not sure that this describes the hardware. The datasheet says: Whenever timeout ocurs, WDT can program to generate 6 types of signals: * ARM reset signal: to reset ARM CPU only * SOC reset signal: to reset SOC part function * System reset signal: to reset full chip * Interrupt signal: to interrupt CPU * Eternal signal: to external reset counter (only WDT1 and WDT2) * Alternate boot signal: to boot from alternate block I think your bindings should describe these modes where possible. Cheers, Joel > + > Example: > > wdt1: watchdog@1e785000 { > compatible = "aspeed,ast2400-wdt"; > reg = <0x1e785000 0x1c>; > + external-signal; > + no-system-reset; > }; > -- > 1.8.2.2 >