From: wmb@firmworks•com (Mitch Bradley)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 0/3] GIC OF bindings
Date: Tue, 20 Sep 2011 18:58:12 -1000 [thread overview]
Message-ID: <4E796EE4.6070704@firmworks.com> (raw)
In-Reply-To: <CACxGe6t7Mdr+w+aGFPM2-FEAQaYHuG8Za9dybLgMo-5-whLyNQ@mail.gmail.com>
On 9/20/2011 6:14 PM, Grant Likely wrote:
> On Tue, Sep 20, 2011 at 8:49 PM, David Miller<davem@davemloft•net> wrote:
>> From: Rob Herring<robherring2@gmail•com>
>> Date: Tue, 20 Sep 2011 15:24:01 -0500
>>
>>> Hopefully, this is the final or near final version of GIC binding support.
>>>
>>> Changes from the previous version:
>>> - SPIs and PPIs are numbered starting at 0. Now the gic has it's own irq
>>> domain translate function instead of the simple domain one.
>>> - interrupt cell format has changed based on Grant's proposal.
>>> - Dropped "ARM: gic: allow irq_start to be 0". Instead, the first 16 irqs
>>> are skipped and the domain irq_base adjusted accordingly.
>>> - Added a fix to of_irq_find_parent when the parent == child.
>>> - Renamed intc_desc.parent to intc_desc.interrupt_parent.
>>> - Implemented Grant's algorithm for walking the list of interrupt
>>> controllers. Added a return value to interrupt init functions, so they
>>> don't get added to the parent list on a init failure.
>>>
>>> The changes are significant enough that I did not include previous
>>> acked/reviewed/tested-by's.
>>
>> Just out of curiosity where does this "interrupt-parent" property
>> come from?
>>
>> On platforms I am familiar with, the parent path is walked to the root
>> and we stop at device nodes that have "interrupt-map" and
>> "interrupt-map-mask" properties.
>>
>> The map and mask are applied to the "reg" property of the device in
>> question to see which map entry matches, if a match is found the map
>> entry contains the translated interrupt.
>>
>> And this process continues over and over all the way to the root to get
>> the system interrupt that processor actually deals with.
>>
>> The mechanism shown here seems overly simplistic and not able to handle
>> the cases handled by existing OF property schemes in use for several
>> years on real systems.
>
> interrupt-parent has been implemented for years on powerpc. I don't
> know if it was ever an Open Firmware thing, but it is in ePAPR [1],
> and ARM isn't doing anything novel in that regard.
interrupt-parent has been part of the interrupt mapping spec from the
inception of same.
http://www.openfirmware.info/docs/rec.intmap.d09.pdf
>
> [1] section 2.4, page 30,
> https://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.1.pdf
>
> It is true that is cannot handle all situations, but for those
> interrupt-map is still available.
>
> g.
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/devicetree-discuss
>
>
next prev parent reply other threads:[~2011-09-21 4:58 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-20 20:24 [PATCH 0/3] GIC OF bindings Rob Herring
2011-09-20 20:24 ` [PATCH 1/3] of/irq: of_irq_find_parent: check for parent equal to child Rob Herring
2011-09-20 21:01 ` Grant Likely
2011-09-20 20:24 ` [PATCH 2/3] of/irq: introduce of_irq_init Rob Herring
2011-09-20 23:00 ` Grant Likely
2011-09-21 10:01 ` Jamie Iles
2011-09-23 2:21 ` [PATCH v3] " Rob Herring
2011-09-23 5:14 ` Grant Likely
2011-09-26 19:24 ` [PATCH v4] " Rob Herring
2011-09-27 1:53 ` Grant Likely
2011-09-27 13:03 ` Rob Herring
2011-09-27 21:24 ` Grant Likely
2011-09-20 20:24 ` [PATCH 3/3] ARM: gic: add OF based initialization Rob Herring
2011-09-20 23:08 ` Grant Likely
2011-09-21 1:54 ` Rob Herring
2011-09-21 17:15 ` Cousson, Benoit
2011-09-21 17:55 ` Rob Herring
2011-09-21 19:28 ` Cousson, Benoit
2011-09-21 20:27 ` Cousson, Benoit
2011-09-26 19:57 ` Jamie Iles
2011-09-26 20:49 ` Rob Herring
2011-09-26 21:11 ` Jamie Iles
2011-09-26 21:32 ` Rob Herring
2011-09-26 22:00 ` Jamie Iles
2011-09-26 22:29 ` Jamie Iles
2011-09-21 2:49 ` [PATCH 0/3] GIC OF bindings David Miller
2011-09-21 4:14 ` Grant Likely
2011-09-21 4:58 ` Mitch Bradley [this message]
2011-09-21 5:21 ` David Miller
2011-09-21 7:11 ` Mitch Bradley
2011-09-21 5:16 ` Segher Boessenkool
2011-09-21 9:43 ` Shawn Guo
-- strict thread matches above, loose matches on Subject: below --
2011-09-30 19:27 Rob Herring
2011-10-04 16:15 ` Rob Herring
2011-10-08 14:04 ` Thomas Abraham
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