diff mbox series

[v2,06/10] dt-bindings: irqchip: Introduce TISCI Interrupt router bindings

Message ID 20181018154017.7112-7-lokeshvutla@ti.com
State Changes Requested, archived
Headers show
Series Add support for TISCI irqchip drivers | expand

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Commit Message

Lokesh Vutla Oct. 18, 2018, 3:40 p.m. UTC 
Add the DT binding documentation for Interrupt router driver.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
Changes since v1:
- Drop dependency on GIC
- Updated supported interrupt types.

 .../interrupt-controller/ti,sci-intr.txt      | 81 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 82 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt

Comments

Rob Herring (Arm) Oct. 25, 2018, 6:45 p.m. UTC | #1 
On Thu, Oct 18, 2018 at 09:10:13PM +0530, Lokesh Vutla wrote:
> Add the DT binding documentation for Interrupt router driver.
> 
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> ---
> Changes since v1:
> - Drop dependency on GIC
> - Updated supported interrupt types.
> 
>  .../interrupt-controller/ti,sci-intr.txt      | 81 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 82 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
> 
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
> new file mode 100644
> index 000000000000..276bb4f0ad12
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
> @@ -0,0 +1,81 @@
> +Texas Instruments K3 Interrupt Router
> +=====================================
> +
> +The Interrupt Router (INTR) module provides a mechanism to mux M
> +interrupt inputs to N interrupt outputs, where all M inputs are selectable
> +to be driven per N output. There is one register per output (MUXCNTL_N) that
> +controls the selection.
> +
> +
> +                                 Interrupt Router
> +                             +----------------------+
> +                             |  Inputs     Outputs  |
> +        +-------+            | +------+             |
> +        | GPIO  |----------->| | irq0 |             |       Host IRQ
> +        +-------+            | +------+             |      controller
> +                             |    .        +-----+  |      +-------+
> +        +-------+            |    .        |  0  |  |----->|  IRQ  |
> +        | INTA  |----------->|    .        +-----+  |      +-------+
> +        +-------+            |    .          .      |
> +                             | +------+      .      |
> +                             | | irqM |    +-----+  |
> +                             | +------+    |  N  |  |
> +                             |             +-----+  |
> +                             +----------------------+
> +
> +Configuration of these MUXCNTL_N registers is done by a system controller
> +(like the Device Memory and Security Controller on K3 AM654 SoC). System
> +controller will keep track of the used and unused registers within the Router.
> +Driver should request the system controller to get the range of GIC IRQs
> +assigned to the requesting hosts. It is the drivers responsibility to keep
> +track of Host IRQs.
> +
> +Communication between the host processor running an OS and the system
> +controller happens through a protocol called TI System Control Interface
> +(TISCI protocol). For more details refer:
> +Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
> +
> +TISCI Interrupt Router Node:
> +----------------------------
> +- compatible:		Must be "ti,sci-intr".
> +- interrupt-controller:	Identifies the node as an interrupt controller
> +- #interrupt-cells:	Specifies the number of cells needed to encode an
> +			interrupt source. The value should be 3.
> +			First cell should contain the TISCI device ID of source
> +			Second cell should contain the interrupt source offset
> +			within the device
> +			Third cell specifies the trigger type as defined
> +			in interrupts.txt in this directory. Only level
> +			sensitive trigger types are supported.
> +- interrupt-parent:	phandle of irq parent for TISCI intr.

This is implied and could be in a parent node.

> +- ti,sci:		Phandle to TI-SCI compatible System controller node.
> +- ti,sci-dst-id:	TISCI device ID of the destination IRQ controller.
> +- ti,sci-rm-range-girq:	TISCI subtype id representing the host irqs assigned
> +			to this interrupt router.

These need a better explanation and there's still some questions on v1 
asked of me that I tried to answer.

> +
> +Example:
> +--------
> +The following example demonstrates both interrupt router node and the consumer
> +node(main gpio) on the AM654 SoC:
> +
> +main_intr: interrupt-controller@1 {
> +	compatible = "ti,sci-intr";
> +	interrupt-controller;
> +	interrupt-parent = <&gic>;
> +	#interrupt-cells = <3>;
> +	ti,sci = <&dmsc>;
> +	ti,sci-dst-id = <56>;
> +	ti,sci-rm-range-girq = <0x1>;
> +};
> +
> +main_gpio0:  main_gpio0@600000 {

gpio@...

> +	...
> +	interrupt-parent = <&main_intr>;
> +	interrupts = <57 256 IRQ_TYPE_EDGE_RISING>,
> +			<57 257 IRQ_TYPE_EDGE_RISING>,
> +			<57 258 IRQ_TYPE_EDGE_RISING>,
> +			<57 259 IRQ_TYPE_EDGE_RISING>,
> +			<57 260 IRQ_TYPE_EDGE_RISING>,
> +			<57 261 IRQ_TYPE_EDGE_RISING>;
> +	...
> +};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 06966772cad4..710cf728b9d0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14686,6 +14686,7 @@ F:	Documentation/devicetree/bindings/reset/ti,sci-reset.txt
>  F:	Documentation/devicetree/bindings/clock/ti,sci-clk.txt
>  F:	drivers/clk/keystone/sci-clk.c
>  F:	drivers/reset/reset-ti-sci.c
> +F:	Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
>  
>  THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
>  M:	Hans Verkuil <hverkuil@xs4all.nl>
> -- 
> 2.19.1
>
Lokesh Vutla Oct. 26, 2018, 6:38 a.m. UTC | #2 
Hi Rob,

On Friday 26 October 2018 12:15 AM, Rob Herring wrote:
> On Thu, Oct 18, 2018 at 09:10:13PM +0530, Lokesh Vutla wrote:
>> Add the DT binding documentation for Interrupt router driver.
>>
>> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
>> ---
>> Changes since v1:
>> - Drop dependency on GIC
>> - Updated supported interrupt types.
>>
>>   .../interrupt-controller/ti,sci-intr.txt      | 81 +++++++++++++++++++
>>   MAINTAINERS                                   |  1 +
>>   2 files changed, 82 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
>>
>> diff --git a/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
>> new file mode 100644
>> index 000000000000..276bb4f0ad12
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
>> @@ -0,0 +1,81 @@
>> +Texas Instruments K3 Interrupt Router
>> +=====================================
>> +
>> +The Interrupt Router (INTR) module provides a mechanism to mux M
>> +interrupt inputs to N interrupt outputs, where all M inputs are selectable
>> +to be driven per N output. There is one register per output (MUXCNTL_N) that
>> +controls the selection.
>> +
>> +
>> +                                 Interrupt Router
>> +                             +----------------------+
>> +                             |  Inputs     Outputs  |
>> +        +-------+            | +------+             |
>> +        | GPIO  |----------->| | irq0 |             |       Host IRQ
>> +        +-------+            | +------+             |      controller
>> +                             |    .        +-----+  |      +-------+
>> +        +-------+            |    .        |  0  |  |----->|  IRQ  |
>> +        | INTA  |----------->|    .        +-----+  |      +-------+
>> +        +-------+            |    .          .      |
>> +                             | +------+      .      |
>> +                             | | irqM |    +-----+  |
>> +                             | +------+    |  N  |  |
>> +                             |             +-----+  |
>> +                             +----------------------+
>> +
>> +Configuration of these MUXCNTL_N registers is done by a system controller
>> +(like the Device Memory and Security Controller on K3 AM654 SoC). System
>> +controller will keep track of the used and unused registers within the Router.
>> +Driver should request the system controller to get the range of GIC IRQs
>> +assigned to the requesting hosts. It is the drivers responsibility to keep
>> +track of Host IRQs.
>> +
>> +Communication between the host processor running an OS and the system
>> +controller happens through a protocol called TI System Control Interface
>> +(TISCI protocol). For more details refer:
>> +Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
>> +
>> +TISCI Interrupt Router Node:
>> +----------------------------
>> +- compatible:		Must be "ti,sci-intr".
>> +- interrupt-controller:	Identifies the node as an interrupt controller
>> +- #interrupt-cells:	Specifies the number of cells needed to encode an
>> +			interrupt source. The value should be 3.
>> +			First cell should contain the TISCI device ID of source
>> +			Second cell should contain the interrupt source offset
>> +			within the device
>> +			Third cell specifies the trigger type as defined
>> +			in interrupts.txt in this directory. Only level
>> +			sensitive trigger types are supported.
>> +- interrupt-parent:	phandle of irq parent for TISCI intr.
> 
> This is implied and could be in a parent node.

okay, will drop it in next version.

> 
>> +- ti,sci:		Phandle to TI-SCI compatible System controller node.
>> +- ti,sci-dst-id:	TISCI device ID of the destination IRQ controller.
>> +- ti,sci-rm-range-girq:	TISCI subtype id representing the host irqs assigned
>> +			to this interrupt router.
> 
> These need a better explanation and there's still some questions on v1
> asked of me that I tried to answer.

Before I jump into the details, I would like to provide a brief on TISCI 
resource management:

- Host_id: Typically it is the representation of the host processing entities 
(example: A53 cores running in a VM) as identified by the TISCI.[1]
- Device_id: Each Device in SoC is uniquely identified by TISCI using an ID.
- Each device has Resources like interrupts, DMA channels etc. A simple example 
would be Interrupt Router and GIC($subject). There are n physical GIC interrupts 
connected to Interrupt Router. Such resources are are uniquely identified by 
TISCI using a type ID.[2]

For the sake of simplicity lets consider an Interrupt Router(IR) to which GIC 
line 32-63 are connected. Considering Isolation for each VM in picture, TISCI 
allows for a certain range within [32-63] to be assigned to a specific Host_ID. 
This is mainly to provide the ability for OSs running in virtual machines to be 
able to independently communicate with the firmware without the need going 
through a hypervisor.

- Now for Linux to know the GIC irq range that can be used by this Interrupt 
router, IR driver should send a message to system-controller using TISCI 
protocol with the resource type as parameter.
- For configuring the IRQ,(i.e. attaching an input to IR to a GIC irq), IR 
driver should send a message to system-controller using TISCI protocol with 
gic-device-id and an irq from the provided range as parameters.

For covering the above two scenarios, ti,sci-dst-id and ti,sci-rm-range-girq is 
introduced in DT.

[1] http://downloads.ti.com/tisci/esd/latest/5_soc_doc/am6x/hosts.html
[2] http://downloads.ti.com/tisci/esd/latest/5_soc_doc/am6x/resasg_types.html

> 
>> +
>> +Example:
>> +--------
>> +The following example demonstrates both interrupt router node and the consumer
>> +node(main gpio) on the AM654 SoC:
>> +
>> +main_intr: interrupt-controller@1 {
>> +	compatible = "ti,sci-intr";
>> +	interrupt-controller;
>> +	interrupt-parent = <&gic>;
>> +	#interrupt-cells = <3>;
>> +	ti,sci = <&dmsc>;
>> +	ti,sci-dst-id = <56>;
>> +	ti,sci-rm-range-girq = <0x1>;
>> +};
>> +
>> +main_gpio0:  main_gpio0@600000 {
> 
> gpio@...

Sure, will fix it in next version.

Thanks and regards,
Lokesh
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
new file mode 100644
index 000000000000..276bb4f0ad12
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
@@ -0,0 +1,81 @@ 
+Texas Instruments K3 Interrupt Router
+=====================================
+
+The Interrupt Router (INTR) module provides a mechanism to mux M
+interrupt inputs to N interrupt outputs, where all M inputs are selectable
+to be driven per N output. There is one register per output (MUXCNTL_N) that
+controls the selection.
+
+
+                                 Interrupt Router
+                             +----------------------+
+                             |  Inputs     Outputs  |
+        +-------+            | +------+             |
+        | GPIO  |----------->| | irq0 |             |       Host IRQ
+        +-------+            | +------+             |      controller
+                             |    .        +-----+  |      +-------+
+        +-------+            |    .        |  0  |  |----->|  IRQ  |
+        | INTA  |----------->|    .        +-----+  |      +-------+
+        +-------+            |    .          .      |
+                             | +------+      .      |
+                             | | irqM |    +-----+  |
+                             | +------+    |  N  |  |
+                             |             +-----+  |
+                             +----------------------+
+
+Configuration of these MUXCNTL_N registers is done by a system controller
+(like the Device Memory and Security Controller on K3 AM654 SoC). System
+controller will keep track of the used and unused registers within the Router.
+Driver should request the system controller to get the range of GIC IRQs
+assigned to the requesting hosts. It is the drivers responsibility to keep
+track of Host IRQs.
+
+Communication between the host processor running an OS and the system
+controller happens through a protocol called TI System Control Interface
+(TISCI protocol). For more details refer:
+Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
+
+TISCI Interrupt Router Node:
+----------------------------
+- compatible:		Must be "ti,sci-intr".
+- interrupt-controller:	Identifies the node as an interrupt controller
+- #interrupt-cells:	Specifies the number of cells needed to encode an
+			interrupt source. The value should be 3.
+			First cell should contain the TISCI device ID of source
+			Second cell should contain the interrupt source offset
+			within the device
+			Third cell specifies the trigger type as defined
+			in interrupts.txt in this directory. Only level
+			sensitive trigger types are supported.
+- interrupt-parent:	phandle of irq parent for TISCI intr.
+- ti,sci:		Phandle to TI-SCI compatible System controller node.
+- ti,sci-dst-id:	TISCI device ID of the destination IRQ controller.
+- ti,sci-rm-range-girq:	TISCI subtype id representing the host irqs assigned
+			to this interrupt router.
+
+Example:
+--------
+The following example demonstrates both interrupt router node and the consumer
+node(main gpio) on the AM654 SoC:
+
+main_intr: interrupt-controller@1 {
+	compatible = "ti,sci-intr";
+	interrupt-controller;
+	interrupt-parent = <&gic>;
+	#interrupt-cells = <3>;
+	ti,sci = <&dmsc>;
+	ti,sci-dst-id = <56>;
+	ti,sci-rm-range-girq = <0x1>;
+};
+
+main_gpio0:  main_gpio0@600000 {
+	...
+	interrupt-parent = <&main_intr>;
+	interrupts = <57 256 IRQ_TYPE_EDGE_RISING>,
+			<57 257 IRQ_TYPE_EDGE_RISING>,
+			<57 258 IRQ_TYPE_EDGE_RISING>,
+			<57 259 IRQ_TYPE_EDGE_RISING>,
+			<57 260 IRQ_TYPE_EDGE_RISING>,
+			<57 261 IRQ_TYPE_EDGE_RISING>;
+	...
+};
diff --git a/MAINTAINERS b/MAINTAINERS
index 06966772cad4..710cf728b9d0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14686,6 +14686,7 @@  F:	Documentation/devicetree/bindings/reset/ti,sci-reset.txt
 F:	Documentation/devicetree/bindings/clock/ti,sci-clk.txt
 F:	drivers/clk/keystone/sci-clk.c
 F:	drivers/reset/reset-ti-sci.c
+F:	Documentation/devicetree/bindings/interrupt-controller/ti,sci-intr.txt
 
 THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
 M:	Hans Verkuil <hverkuil@xs4all.nl>