From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Subject: Re: [PATCH v2 1/2] powerpc/mpic: Add Open-PIC global timer document Date: Tue, 14 Aug 2012 16:18:40 -0500 Message-ID: <502AC0B0.5030801@freescale.com> References: <1344578002-8057-1-git-send-email-Dongsheng.wang@freescale.com> <50255F49.5050500@freescale.com> <50293BEA.90401@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Wang Dongsheng-B40534 Cc: Wood Scott-B07421 , Li Yang-R58472 , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "paulus-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org" , Gala Kumar-B11780 , "linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" List-Id: devicetree@vger.kernel.org On 08/13/2012 09:40 PM, Wang Dongsheng-B40534 wrote: >>>> +Example 2: >>>>> + >>>>> + timer: timer@010f0 { >>>>> + compatible = "open-pic,global-timer"; >>>>> + device_type = "open-pic"; >>>>> + reg = <0x010f0 4 0x01100 0x100>; >>>>> + interrupts = <0 0 3 0 >>>>> + 1 0 3 0 >>>>> + 2 0 3 0 >>>>> + 3 0 3 0>; >>>>> + }; >>>> >>>> 4-cell interrupt specifiers are specific to Freescale MPICs. This >>>> means there's no way to describe the timer interrupt on a non- >> Freescale openpic. >>>> Again, I suggest we not bother with this in the absence of an actual >>>> need to support the timer on non-Freescale openpic in partitioned >> scenarios. >>>> The existing openpic node is sufficient to describe the >>>> hardware in the absence of partitioning. We could have an >>>> "openpic-no-timer" property to indicate that we're describing it >>>> separately, so that the absence of a timer node isn't ambiguous as to >>>> whether it's an old tree or a partitioned scenario. An fsl,mpic >>>> compatible would imply openpic-no-timer. >>>> >>>> Note that I believe many of the non-Freescale openpic nodes are going >>>> to be found on systems with real Open Firmware, so we can't go >>>> changing the device tree for them. >>> [Wang Dongsheng] In the Open-PIC specification, there are four timer. >>> interrupts = <0 0 3 0 >>> 1 0 3 0 >>> 2 0 3 0 >>> 3 0 3 0>; >>> >>> The "interrupts" just let user know there are four timers. Usage based >> "interrupts" >>> binding to change dts. >> >> I can't understand the above or how it's a response to what I wrote. >> > [Wang Dongsheng] I mean this just to tell how many timers to support in Open-PIC > specification. If someone needs to write "interrupts" into dts, this must comply > with the specification of the interrupt to write. this is based on the pic driver > should be changed in different platforms. My point (beyond that examples provided should be valid for *some* system) is there is no valid thing to put in the interrupts property here when the interrupt controller is not "fsl,mpic", so this doesn't work. -Scott