Re: [PATCH 21/22] ARM: dt: GIC: add extended SPI specifier

[Nikunj Kela <quic_nkela@xxxxxxxxxxx>]

On 8/29/2024 11:52 AM, Rob Herring wrote:
> On Wed, Aug 28, 2024 at 01:37:20PM -0700, Nikunj Kela wrote:
>> Add interrupt specifier for extended SPI interrupts.
> What's an "extended SPI"? Is this a GIC spec thing? If so, what version?

Extended SPI is an extended range of SPI interrupts supported by GIC.

Excerpt below from
Documentation/devicetree/bindings/interrupt-controller/arm,gic-v3.yaml

"The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI
interrupts, 2 for interrupts in the Extended SPI range, 3 for the
Extended PPI range. Other values are reserved for future use."

"The 2nd cell contains the interrupt number for the interrupt type. SPI
interrupts are in the range [0-987]. PPI interrupts are in the range
[0-15]. Extented SPI interrupts are in the range [0-1023]. Extended PPI
interrupts are in the range [0-127]."

>> Qualcomm SA8255p platform uses extended SPI for SCMI 'a2p' doorbells.
>>
>> Signed-off-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
>> ---
>>  include/dt-bindings/interrupt-controller/arm-gic.h | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/include/dt-bindings/interrupt-controller/arm-gic.h b/include/dt-bindings/interrupt-controller/arm-gic.h
>> index 35b6f69b7db6..9c06248446b7 100644
>> --- a/include/dt-bindings/interrupt-controller/arm-gic.h
>> +++ b/include/dt-bindings/interrupt-controller/arm-gic.h
>> @@ -12,6 +12,7 @@
>>  
>>  #define GIC_SPI 0
>>  #define GIC_PPI 1
>> +#define GIC_ESPI 2
>>  
>>  /*
>>   * Interrupt specifier cell 2.
>> -- 
>> 2.34.1
>>