From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Bostic Subject: Re: [PATCH v2 1/2] drivers/watchdog: Add optional ASPEED device tree properties Date: Tue, 27 Jun 2017 16:42:24 -0500 Message-ID: <6f2a77e0-e64c-70b7-812a-6a5e8a0b5e6f@linux.vnet.ibm.com> References: <20170627211734.60477-1-cbostic@linux.vnet.ibm.com> <20170627211734.60477-2-cbostic@linux.vnet.ibm.com> <20170627213216.GA4132@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170627213216.GA4132-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck Cc: wim-IQzOog9fTRqzQB+pC5nmwQ@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org, linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 6/27/17 4:32 PM, Guenter Roeck wrote: > On Tue, Jun 27, 2017 at 04:17:33PM -0500, Christopher Bostic wrote: >> Describe device tree optional properties: >> >> * aspeed,arm-reet - ARM CPU reset on signal >> * aspeed,soc-reset - SOC reset on signal >> * aspeed,sys-reset - System reset on signal >> Disabling system reset may be required in situations where >> one of the other watchdog engines in the system is responsible >> for this. >> * aspeed,interrupt - Interrupt CPU on signal >> * aspeed,external-signal - Generate external signal (WDT1 and WDT2 only) >> * aspeed,alt-boot - Boot from alternate block on signal >> >> Signed-off-by: Christopher Bostic >> --- >> v2 - Add 'aspeed,' prefix to all optional properties >> - Add arm-reset, soc-reset, interrupt, alt-boot properties >> --- >> .../devicetree/bindings/watchdog/aspeed-wdt.txt | 25 ++++++++++++++++++++++ >> 1 file changed, 25 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt >> index c5e74d7..555b8b4 100644 >> --- a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt >> +++ b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt >> @@ -8,9 +8,34 @@ Required properties: >> - reg: physical base address of the controller and length of memory mapped >> region >> >> +Optional properties: >> + Signal behavior - Whenever a timeout occurs, the watchdog can be programmed >> + to generate 6 types of signals: >> + >> + - aspeed,arm-reset: If property is present then reset ARM CPU only. >> + >> + - aspeed,soc-reset: If property is present then reset SOC. >> + >> + - aspeed,sys-reset: If property is present then reset the entire chip. >> + In cases where one of the other watchdog engines >> + in the system is responsible for system reset it >> + may be required to not specify this property. >> + >> + - aspeed,interrupt: If property is present then interrupt CPU. >> + >> + - aspeed,external-signal: If property is present then signal is sent to >> + external reset counter (only WDT1 and WDT2). >> + - aspeed,alt-boot: If property is present then boot from alternate block. >> + >> Example: >> >> wdt1: watchdog@1e785000 { >> compatible = "aspeed,ast2400-wdt"; >> reg = <0x1e785000 0x1c>; >> + aspeed,arm-reset; >> + aspeed,soc-reset; >> + aspeed,sys-reset; >> + aspeed,interrupt; >> + aspeed,external-signal; >> + aspeed,alt-boot; > Is that a bit mask or a value ? I would have thought that, > for example, a complete system reset would include the SoC reset, > and a SoC reset would include the ARM reset. Generating an > interrupt while at the same time resetting the system (or > part of it) doesn't seem to make much sense either. No these aren't bitmasks. The example was intended to indicate what could be used. In practice only a subset of each of these properties would make any sense. How would you suggest the example be formatted to convey that? Multiple examples I suppose. Thanks, Chris > Guenter > -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html