Messages in this thread | | | Subject | Re: [PATCH v2 02/18] dt-bindings: timer: sp804: add timer-width property | From | Robin Murphy <> | Date | Thu, 17 Mar 2016 19:21:23 +0000 |
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On 17/03/16 19:00, Rob Herring wrote: > On Thu, Mar 17, 2016 at 1:06 PM, Robin Murphy <robin.murphy@arm.com> wrote: >> Hi Rob, >> >> On 17/03/16 17:09, Rob Herring wrote: >>> >>> On Wed, Mar 09, 2016 at 11:24:04AM +0100, Neil Armstrong wrote: >>>> >>>> Add timer-width optional property to specify a different vendor >>>> specific timer counter bit-width. >>>> >>>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> >>>> --- >>>> Documentation/devicetree/bindings/timer/arm,sp804.txt | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/timer/arm,sp804.txt >>>> b/Documentation/devicetree/bindings/timer/arm,sp804.txt >>>> index 5cd8eee7..141e143 100644 >>>> --- a/Documentation/devicetree/bindings/timer/arm,sp804.txt >>>> +++ b/Documentation/devicetree/bindings/timer/arm,sp804.txt >>>> @@ -17,6 +17,8 @@ Optional properties: >>>> - arm,sp804-has-irq = <#>: In the case of only 1 timer irq line >>>> connected, this >>>> specifies if the irq connection is for timer 1 or timer 2. A >>>> value of 1 >>>> or 2 should be used. >>>> +- arm,timer-width: Should contain the width in number of bits of the >>>> counter, >>>> + is considered by default 32 but can be changed for vendor >>>> variants. >>> >>> >>> That would not be an SP804 nor would the vendor be ARM in that case. So >>> add a new compatible string for the vendor that decided to hack up ARM's >>> IP block. >> >> >> By all accounts this is some ancient reference design[1] which later evolved >> _into_ the SP804, so that vendor would probably still be ARM ;) > > Right. > >> A separate compatible string would indeed make more sense, though. Both >> semantically and in terms of letting the driver account for the differences >> automatically. >> >> Robin. >> >> [1]:http://infocenter.arm.com/help/topic/com.arm.doc.ddi0170a/I350250.html > > Humm, same as integrator timers perhaps?
Having had a quick look, what the Integrator/AP manual describes certainly smells like the same basic block as the "AMBA Timer" - 16 bit counters and the same control register layout - albeit in a mutant triple-timer version with a bigger offset between each register set. Integrator/CP, on the other hand, looks much more SP804-like.
Robin.
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