-----Original Message-----
From: Wood Scott-B07421
Sent: Wednesday, August 15, 2012 5:19 AM
To: Wang Dongsheng-B40534
Cc: Wood Scott-B07421; benh@kernel.crashing.org; paulus@samba.org;
linuxppc-dev@lists.ozlabs.org; devicetree-discuss@lists.ozlabs.org; Gala
Kumar-B11780; Li Yang-R58472
Subject: Re: [PATCH v2 1/2] powerpc/mpic: Add Open-PIC global timer
document

On 08/13/2012 09:40 PM, Wang Dongsheng-B40534 wrote:

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+Example 2:

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+
+	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.

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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.

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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

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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

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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

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"interrupts"

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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

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specification. If someone needs to write "interrupts" into dts, this

must comply

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with the specification of the interrupt to write. this is based on the

pic driver

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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.

[Wang Dongsheng] Fine, I will remove this document of Open-PIC global timer.
We only support mpic timer. Driver will be compatible with OPEN-PIC
specification. Let someone who cares about ordinary OpenPIC drivers add
support?

-Scott