Re: [RFC 10/29] xen/arm: Add helpers to retrieve an interrupt description from the device tree

[Julien Grall <julien.grall@linaro.org>]

On 04/29/2013 04:28 PM, Ian Campbell wrote:

> On Mon, 2013-04-29 at 00:01 +0100, Julien Grall wrote:
>> diff --git a/xen/include/xen/irq.h b/xen/include/xen/irq.h
>> index 7386358..42dc172 100644
>> --- a/xen/include/xen/irq.h
>> +++ b/xen/include/xen/irq.h
>> @@ -33,6 +33,31 @@ struct irqaction {
>>  #define NEVER_ASSIGN_IRQ        (-2)
>>  #define FREE_TO_ASSIGN_IRQ      (-3)
>>
>> +/**
>> + * IRQ line type.
>> + *
>> + * IRQ_TYPE_NONE            - default, unspecified type
>> + * IRQ_TYPE_EDGE_RISING     - rising edge triggered
>> + * IRQ_TYPE_EDGE_FALLING    - falling edge triggered
>> + * IRQ_TYPE_EDGE_BOTH       - rising and falling edge triggered
>> + * IRQ_TYPE_LEVEL_HIGH      - high level triggered
>> + * IRQ_TYPE_LEVEL_LOW       - low level triggered
>> + * IRQ_TYPE_LEVEL_MASK      - Mask to filter out the level bits
>> + * IRQ_TYPE_SENSE_MASK      - Mask for all the above bits
>> + */
>> +#define IRQ_TYPE_NONE           0x00000000
>> +#define IRQ_TYPE_EDGE_RISING    0x00000001
>> +#define IRQ_TYPE_EDGE_FALLING   0x00000002
>> +#define IRQ_TYPE_EDGE_BOTH      (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)
>> +#define IRQ_TYPE_LEVEL_HIGH     0x00000004
>> +#define IRQ_TYPE_LEVEL_LOW      0x00000008
>> +#define IRQ_TYPE_LEVEL_MASK     (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)
>> +#define IRQ_TYPE_SENSE_MASK     0x0000000f
>> +
>> +/* If type == IRQ_TYPE_NONE, assume we use level triggered */
>> +#define irq_is_level_trigger(irq)                                          \
>> +    (((irq)->type & IRQ_TYPE_LEVEL_MASK) || ((irq)->type == IRQ_TYPE_NONE))
> 
> What is the type of irq here? None of the structs in this irq.h have a
> type member, so I must be looking in the wrong place.

It's specified if an IRQ will be edge-triggered or level-triggered.

Except the irq_is_level_trigger macro, all this code is copied from
include/linux/irq.h in linux. That's why I have put this code here.

> Or is it struct dt_irq? If so then can we put these in a DT (or ARM)

> specific header and add a DT_ prefix, rather than pollute the non-DT
> headers, e.g. these defines have no meaning on x86 AFAICT.


Yes. I will move to device_tree.h.

-- 
Julien