Patchwork [v4,03/10] of/irq: document properties for wakeup interrupt parent

login
register
mail settings
Submitter Lina Iyer
Date March 13, 2019, 9:18 p.m.
Message ID <20190313211844.29416-4-ilina@codeaurora.org>
Download mbox | patch
Permalink /patch/748427/
State New
Headers show

Comments

Lina Iyer - March 13, 2019, 9:18 p.m.
Some interrupt controllers in a SoC, are always powered on and have a
select interrupts routed to them, so that they can wakeup the SoC from
suspend. Add wakeup-parent DT property to refer to these interrupt
controllers.

If the interrupts routed to the wakeup parent are not sequential, than a
map needs to exist to associate the same interrupt line on multiple
interrupt controllers. Providing this map in every driver is cumbersome.
Let's add this in the device tree and document the properties to map the
interrupt specifiers

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
---
Changes in v4:
	- Added this documentation
---
 .../interrupt-controller/interrupts.txt       | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)
Marc Zyngier - March 18, 2019, 5:42 p.m.
On Wed, 13 Mar 2019 15:18:37 -0600
Lina Iyer <ilina@codeaurora.org> wrote:

Please do Cc Rob when posting DT related patches.

> Some interrupt controllers in a SoC, are always powered on and have a
> select interrupts routed to them, so that they can wakeup the SoC from
> suspend. Add wakeup-parent DT property to refer to these interrupt
> controllers.
> 
> If the interrupts routed to the wakeup parent are not sequential, than a
> map needs to exist to associate the same interrupt line on multiple
> interrupt controllers. Providing this map in every driver is cumbersome.
> Let's add this in the device tree and document the properties to map the
> interrupt specifiers
> 
> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
> ---
> Changes in v4:
> 	- Added this documentation
> ---
>  .../interrupt-controller/interrupts.txt       | 39 +++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> index 8a3c40829899..917b598317f5 100644
> --- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> +++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> @@ -108,3 +108,42 @@ commonly used:
>  			sensitivity = <7>;
>  		};
>  	};
> +
> +3) Interrupt wakeup parent
> +--------------------------
> +
> +Some interrupt controllers in a SoC, are always powered on and have a select
> +interrupts routed to them, so that they can wakeup the SoC from suspend. These
> +interrupt controllers do not fall into the category of a parent interrupt
> +controller and can be specified by the "wakeup-parent" property and contain a
> +single phandle referring to the wakeup capable interrupt controller.
> +
> +   Example:
> +	wakeup-parent = <&pdc_intc>;
> +
> +
> +4) Interrupt mapping
> +--------------------
> +
> +Sometimes interrupts may be detected by more than one interrupt controller
> +(depending on which controller is active). The interrupt controllers may not
> +be in hierarchy and therefore the interrupt controller driver is required to
> +establish the relationship between the same interrupt at different interrupt
> +controllers. If these interrupts are not sequential then a map needs to be
> +specified to help identify these interrupts.
> +
> +Mapping the interrupt specifiers in the device tree can be done using the
> +"irqdomain-map" property. The property contains interrupt specifier at the
> +current interrupt controller followed by the interrupt specifier at the mapped
> +interrupt controller.
> +
> +   irqdomain-map = <incoming-interrupt-specifier mapped-interrupt-specifier>
> +
> +The optional properties "irqdomain-map-mask" and "irqdomain-map-pass-thru" may
> +be provided to help interpret the valid bits of the incoming and mapped
> +interrupt specifiers respectively.
> +
> +   Example:
> +	irqdomain-map = <22 0 &intc 36 0>, <24 0 &intc 37 0>;
> +	irqdomain-map-mask = <0xff 0>;
> +	irqdomain-map-pass-thru = <0 0xff>;


This doesn't quite explain how the mask and pass-thru properties are
used. I guess that the mask is used to define the 'useful bits' on the
incoming side, but pass-thru puzzles me. In your example, does it mean
that incoming lines map to outgoing interrupt <0 0>?

Thanks,

	M.

Patch

diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
index 8a3c40829899..917b598317f5 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
@@ -108,3 +108,42 @@  commonly used:
 			sensitivity = <7>;
 		};
 	};
+
+3) Interrupt wakeup parent
+--------------------------
+
+Some interrupt controllers in a SoC, are always powered on and have a select
+interrupts routed to them, so that they can wakeup the SoC from suspend. These
+interrupt controllers do not fall into the category of a parent interrupt
+controller and can be specified by the "wakeup-parent" property and contain a
+single phandle referring to the wakeup capable interrupt controller.
+
+   Example:
+	wakeup-parent = <&pdc_intc>;
+
+
+4) Interrupt mapping
+--------------------
+
+Sometimes interrupts may be detected by more than one interrupt controller
+(depending on which controller is active). The interrupt controllers may not
+be in hierarchy and therefore the interrupt controller driver is required to
+establish the relationship between the same interrupt at different interrupt
+controllers. If these interrupts are not sequential then a map needs to be
+specified to help identify these interrupts.
+
+Mapping the interrupt specifiers in the device tree can be done using the
+"irqdomain-map" property. The property contains interrupt specifier at the
+current interrupt controller followed by the interrupt specifier at the mapped
+interrupt controller.
+
+   irqdomain-map = <incoming-interrupt-specifier mapped-interrupt-specifier>
+
+The optional properties "irqdomain-map-mask" and "irqdomain-map-pass-thru" may
+be provided to help interpret the valid bits of the incoming and mapped
+interrupt specifiers respectively.
+
+   Example:
+	irqdomain-map = <22 0 &intc 36 0>, <24 0 &intc 37 0>;
+	irqdomain-map-mask = <0xff 0>;
+	irqdomain-map-pass-thru = <0 0xff>;