From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966835Ab3E2URt (ORCPT ); Wed, 29 May 2013 16:17:49 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:61537 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965519Ab3E2URl (ORCPT ); Wed, 29 May 2013 16:17:41 -0400 Message-ID: <51A66262.7000305@gmail.com> Date: Wed, 29 May 2013 21:17:38 +0100 From: Jon Hunter User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Stephen Warren CC: Afzal Mohammed , Russell King , linux-doc@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org, Rob Herring , Grant Likely , Benoit Cousson , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 11/14] Documentation: dt: binding: omap: am43x timer References: <223d90dc9eeab13d8496690d336cdf0f7d27cd22.1369658705.git.afzal@ti.com> <51A520B5.8040803@gmail.com> <51A52A16.1040204@wwwdotorg.org> In-Reply-To: <51A52A16.1040204@wwwdotorg.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/05/13 23:05, Stephen Warren wrote: > On 05/28/2013 03:25 PM, Jon Hunter wrote: >> >> On 27/05/13 15:37, Afzal Mohammed wrote: >>> AM43x timer bindings. >>> >>> Signed-off-by: Afzal Mohammed >>> --- >>> Documentation/devicetree/bindings/arm/omap/timer.txt | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/arm/omap/timer.txt b/Documentation/devicetree/bindings/arm/omap/timer.txt >>> index d02e27c..70cb398 100644 >>> --- a/Documentation/devicetree/bindings/arm/omap/timer.txt >>> +++ b/Documentation/devicetree/bindings/arm/omap/timer.txt >>> @@ -14,6 +14,8 @@ Required properties: >>> ti,omap5430-timer (applicable to OMAP543x devices) >>> ti,am335x-timer (applicable to AM335x devices) >>> ti,am335x-timer-1ms (applicable to AM335x devices) >>> + "ti,am4372-timer-1ms", "ti,am335x-timer-1ms" for AM43x 1ms timer >>> + "ti,am4372-timer", "ti,am335x-timer" for AM43x timers other than 1ms one >>> >>> - reg: Contains timer register address range (base address and >>> length). >> >> If you are adding more compatibility strings, then this implies that the >> AM43x timers are not 100% compatible with any other device listed (such >> as am335x or any omap device). That's fine but you should state that in >> the changelog. If the AM43x timer registers are 100% compatible with >> existing devices you should not add these. > > I'm not sure that's true; .dts files should always include a compatible > value that describes the most specific model of the HW, plus any > baseline compatible value that the HW is compatible with. This allows > any required quirks/fixes/... to be applied for the specific HW model > later even if nobody knows right now they'll be needed. Hence, defining > new compatible values doesn't necessarily mean incompatible HW. Yes that does seem to agree with what Grant had told me in the past [1]. So this is ok then. However, I still think that the changelog needs to be vastly improved and more explicit about the changes. Cheers Jon [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/90551/focus=26447 From mboxrd@z Thu Jan 1 00:00:00 1970 From: jgchunter@gmail.com (Jon Hunter) Date: Wed, 29 May 2013 21:17:38 +0100 Subject: [PATCH v2 11/14] Documentation: dt: binding: omap: am43x timer In-Reply-To: <51A52A16.1040204@wwwdotorg.org> References: <223d90dc9eeab13d8496690d336cdf0f7d27cd22.1369658705.git.afzal@ti.com> <51A520B5.8040803@gmail.com> <51A52A16.1040204@wwwdotorg.org> Message-ID: <51A66262.7000305@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 28/05/13 23:05, Stephen Warren wrote: > On 05/28/2013 03:25 PM, Jon Hunter wrote: >> >> On 27/05/13 15:37, Afzal Mohammed wrote: >>> AM43x timer bindings. >>> >>> Signed-off-by: Afzal Mohammed >>> --- >>> Documentation/devicetree/bindings/arm/omap/timer.txt | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/arm/omap/timer.txt b/Documentation/devicetree/bindings/arm/omap/timer.txt >>> index d02e27c..70cb398 100644 >>> --- a/Documentation/devicetree/bindings/arm/omap/timer.txt >>> +++ b/Documentation/devicetree/bindings/arm/omap/timer.txt >>> @@ -14,6 +14,8 @@ Required properties: >>> ti,omap5430-timer (applicable to OMAP543x devices) >>> ti,am335x-timer (applicable to AM335x devices) >>> ti,am335x-timer-1ms (applicable to AM335x devices) >>> + "ti,am4372-timer-1ms", "ti,am335x-timer-1ms" for AM43x 1ms timer >>> + "ti,am4372-timer", "ti,am335x-timer" for AM43x timers other than 1ms one >>> >>> - reg: Contains timer register address range (base address and >>> length). >> >> If you are adding more compatibility strings, then this implies that the >> AM43x timers are not 100% compatible with any other device listed (such >> as am335x or any omap device). That's fine but you should state that in >> the changelog. If the AM43x timer registers are 100% compatible with >> existing devices you should not add these. > > I'm not sure that's true; .dts files should always include a compatible > value that describes the most specific model of the HW, plus any > baseline compatible value that the HW is compatible with. This allows > any required quirks/fixes/... to be applied for the specific HW model > later even if nobody knows right now they'll be needed. Hence, defining > new compatible values doesn't necessarily mean incompatible HW. Yes that does seem to agree with what Grant had told me in the past [1]. So this is ok then. However, I still think that the changelog needs to be vastly improved and more explicit about the changes. Cheers Jon [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/90551/focus=26447