Re: [PATCH 2/3] Input: gpio-keys - allow setting wakeup interrupt trigger type in DT

On Fri, Feb 09, 2018 at 03:42:47PM -0800, Brian Norris wrote:

Hi Jeffy,

On Fri, Feb 09, 2018 at 07:55:09PM +0800, Jeffy Chen wrote:

quoted

Allow specifying a different interrupt trigger type for wakeup when
using the gpio-keys input device as a wakeup source.

Signed-off-by: Jeffy Chen <redacted>
---

 Documentation/devicetree/bindings/input/gpio-keys.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/gpio-keys.txt b/Documentation/devicetree/bindings/input/gpio-keys.txt
index a94940481e55..61926cef708f 100644
--- a/Documentation/devicetree/bindings/input/gpio-keys.txt
+++ b/Documentation/devicetree/bindings/input/gpio-keys.txt

@@ -26,6 +26,15 @@ Optional subnode-properties:
 	  If not specified defaults to 5.
 	- wakeup-source: Boolean, button can wake-up the system.
 			 (Legacy property supported: "gpio-key,wakeup")
+	- wakeup-trigger-type: Specifies the interrupt trigger type for wakeup.
+		 The value is defined in <dt-bindings/interrupt-controller/irq.h>

Do you really want to codify interrupt triggers here? It seems like most
of the information about edge vs. level is already codified elsewhere,
so this becomes a little redundant. And in fact, some bindings may be
specifying a "gpio", not technically an interrupt (at least not
directly), so it feels weird to apply IRQ_* flags to them right here.
Anyway, I think he only piece you really want to describe here is, do we
wake on "event asserted", "event deasserted", or both. (The "none" case
would just mean you shouldn't have the "wakeup-source" property.)

So maybe:

	wakeup-trigger-type: Specifies whether the key should wake the
	system when asserted, when deasserted, or both. This property is
	only valid for keys that wake up the system (e.g., when the
	"wakeup-source" property is also provided). Supported values
	are:
	  1: asserted

As wakeup is an IRQ, that's assumed.

	  2: deasserted

Just invert the flags for the IRQ.

	  3: both asserted and deasserted

I don't see what would be the usecase. But wouldn't this be any edge 
(because level certainly doesn't make sense)?

? We could still make macros out of those, if we want
(input/linux-event-codes.h?). And then leave it up to the driver to
determine how to translate that into the appropriate edge or level
triggers.

Brian

quoted

+		 Only the following flags are supported:
+			IRQ_TYPE_NONE
+			IRQ_TYPE_EDGE_RISING
+			IRQ_TYPE_EDGE_FALLING
+			IRQ_TYPE_EDGE_BOTH
+			IRQ_TYPE_LEVEL_HIGH
+			IRQ_TYPE_LEVEL_LOW
 	- linux,can-disable: Boolean, indicates that button is connected
 	  to dedicated (not shared) interrupt which can be disabled to
 	  suppress events from the button.
-- 
2.11.0