irq: Add IRQ_TYPE_DEFAULT for use by PIC drivers

This is meant typically to allow a PIC driver's irq domain map() callback
to establish sane defaults for the interrupt (and make sure that the HW
and the irq_desc are in sync as far as the trigger is concerned).

The irq core may not call the set_trigger callback if it thinks the
trigger is already set to the right setting, so we need to ensure new
descriptors are properly synchronized with the hardware.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 7810406f3d8..b27cfcfd3a5 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -49,6 +49,12 @@ typedef	void (*irq_preflow_handler_t)(struct irq_data *data);
  * 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
+ * IRQ_TYPE_DEFAULT             - For use by some PICs to ask irq_set_type
+ *                                to setup the HW to a sane default (used
+ *                                by irqdomain map() callbacks to synchronize
+ *                                the HW state and SW flags for a newly
+ *                                allocated descriptor).
+ *
  * IRQ_TYPE_PROBE               - Special flag for probing in progress
  *
  * Bits which can be modified via irq_set/clear/modify_status_flags()
@@ -77,6 +83,7 @@ enum {
         IRQ_TYPE_LEVEL_LOW      = 0x00000008,
         IRQ_TYPE_LEVEL_MASK     = (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH),
         IRQ_TYPE_SENSE_MASK     = 0x0000000f,
+        IRQ_TYPE_DEFAULT        = IRQ_TYPE_SENSE_MASK,
 
         IRQ_TYPE_PROBE          = 0x00000010,