Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[Linus Walleij]

On Mon, Jan 9, 2017 at 8:44 PM, David Daney  wrote:
> On 01/09/2017 11:36 AM, Linus Walleij wrote:

>>> +Optional Properties:
>>> +- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding
>>> is used.
>>> +- interrupt-controller: Marks the device node as an interrupt
>>> controller.
>>> +- #interrupt-cells: Must be present and have value of 2 if
>>> +"interrupt-controller" is present.
>>> +  - First cell is the GPIO pin number relative to the controller.
>>> +  - Second cell is triggering flags as defined in interrupts.txt.
>>
>>
>> AFAICT this device has an optional list of interrupts as well?
>> One per pin even?
>
> I'm not sure I understand your question.
>
> The GPIO hardware supports an interrupt on each pin.  The underlying
> interrupt mechanism is via PCI MSI-X, which are fully discoverable by the
> driver, so lack of device tree binding for the these underlying MSI-X is
> fully appropriate.

Sorry I guess I'm just ignorant about how PCI works, that has never
been my strongest subject admittedly.

So what you're saying is that PCI devices do not need specifying
interrupts not interrupt parents in the device tree?

That's fine then.

Yours,
Linus Walleij

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[Linus Walleij]

On Mon, Jan 9, 2017 at 8:44 PM, David Daney  wrote:
> On 01/09/2017 11:36 AM, Linus Walleij wrote:

>>> +Optional Properties:
>>> +- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding
>>> is used.
>>> +- interrupt-controller: Marks the device node as an interrupt
>>> controller.
>>> +- #interrupt-cells: Must be present and have value of 2 if
>>> +"interrupt-controller" is present.
>>> +  - First cell is the GPIO pin number relative to the controller.
>>> +  - Second cell is triggering flags as defined in interrupts.txt.
>>
>>
>> AFAICT this device has an optional list of interrupts as well?
>> One per pin even?
>
> I'm not sure I understand your question.
>
> The GPIO hardware supports an interrupt on each pin.  The underlying
> interrupt mechanism is via PCI MSI-X, which are fully discoverable by the
> driver, so lack of device tree binding for the these underlying MSI-X is
> fully appropriate.

Sorry I guess I'm just ignorant about how PCI works, that has never
been my strongest subject admittedly.

So what you're saying is that PCI devices do not need specifying
interrupts not interrupt parents in the device tree?

That's fine then.

Yours,
Linus Walleij

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[Rob Herring]

On Fri, Jan 06, 2017 at 03:22:58PM -0800, David Daney wrote:
> From: David Daney 
> 
> Signed-off-by: David Daney 
> ---
>  .../devicetree/bindings/gpio/gpio-thunderx.txt | 27 
> ++
>  1 file changed, 27 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-thunderx.txt

Acked-by: Rob Herring 

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[Rob Herring]

On Fri, Jan 06, 2017 at 03:22:58PM -0800, David Daney wrote:
> From: David Daney 
> 
> Signed-off-by: David Daney 
> ---
>  .../devicetree/bindings/gpio/gpio-thunderx.txt | 27 
> ++
>  1 file changed, 27 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-thunderx.txt

Acked-by: Rob Herring 

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[David Daney]

On 01/09/2017 11:36 AM, Linus Walleij wrote:

On Sat, Jan 7, 2017 at 12:22 AM, David Daney  wrote:


From: David Daney 

Signed-off-by: David Daney 

(...)


+Optional Properties:
+- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is used.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Must be present and have value of 2 if
+"interrupt-controller" is present.
+  - First cell is the GPIO pin number relative to the controller.
+  - Second cell is triggering flags as defined in interrupts.txt.


AFAICT this device has an optional list of interrupts as well?
One per pin even?


I'm not sure I understand your question.

The GPIO hardware supports an interrupt on each pin.  The underlying 
interrupt mechanism is via PCI MSI-X, which are fully discoverable by 
the driver, so lack of device tree binding for the these underlying 
MSI-X is fully appropriate.  On the other hand, users of the GPIO 
interrupt pins need this "interrupt-controller" and "#interrupt-cells" 
to be able to properly find and configure the proper interrupts.


I said the "interrupt-controller" property was optional, because some 
systems don't use GPIO interrupts and can function without specifying 
that it is also an interrupt controller.





Yours,
Linus Walleij

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[David Daney]

On 01/09/2017 11:36 AM, Linus Walleij wrote:

On Sat, Jan 7, 2017 at 12:22 AM, David Daney  wrote:


From: David Daney 

Signed-off-by: David Daney 

(...)


+Optional Properties:
+- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is used.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Must be present and have value of 2 if
+"interrupt-controller" is present.
+  - First cell is the GPIO pin number relative to the controller.
+  - Second cell is triggering flags as defined in interrupts.txt.


AFAICT this device has an optional list of interrupts as well?
One per pin even?


I'm not sure I understand your question.

The GPIO hardware supports an interrupt on each pin.  The underlying 
interrupt mechanism is via PCI MSI-X, which are fully discoverable by 
the driver, so lack of device tree binding for the these underlying 
MSI-X is fully appropriate.  On the other hand, users of the GPIO 
interrupt pins need this "interrupt-controller" and "#interrupt-cells" 
to be able to properly find and configure the proper interrupts.


I said the "interrupt-controller" property was optional, because some 
systems don't use GPIO interrupts and can function without specifying 
that it is also an interrupt controller.





Yours,
Linus Walleij

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[Linus Walleij]

On Sat, Jan 7, 2017 at 12:22 AM, David Daney  wrote:

> From: David Daney 
>
> Signed-off-by: David Daney 
(...)

> +Optional Properties:
> +- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is 
> used.
> +- interrupt-controller: Marks the device node as an interrupt controller.
> +- #interrupt-cells: Must be present and have value of 2 if
> +"interrupt-controller" is present.
> +  - First cell is the GPIO pin number relative to the controller.
> +  - Second cell is triggering flags as defined in interrupts.txt.

AFAICT this device has an optional list of interrupts as well?
One per pin even?

Yours,
Linus Walleij

Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[Linus Walleij]

On Sat, Jan 7, 2017 at 12:22 AM, David Daney  wrote:

> From: David Daney 
>
> Signed-off-by: David Daney 
(...)

> +Optional Properties:
> +- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is 
> used.
> +- interrupt-controller: Marks the device node as an interrupt controller.
> +- #interrupt-cells: Must be present and have value of 2 if
> +"interrupt-controller" is present.
> +  - First cell is the GPIO pin number relative to the controller.
> +  - Second cell is triggering flags as defined in interrupts.txt.

AFAICT this device has an optional list of interrupts as well?
One per pin even?

Yours,
Linus Walleij

[PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[David Daney]

From: David Daney 

Signed-off-by: David Daney 
---
 .../devicetree/bindings/gpio/gpio-thunderx.txt | 27 ++
 1 file changed, 27 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-thunderx.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-thunderx.txt 
b/Documentation/devicetree/bindings/gpio/gpio-thunderx.txt
new file mode 100644
index 000..3f883ae
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-thunderx.txt
@@ -0,0 +1,27 @@
+Cavium ThunderX/OCTEON-TX GPIO controller bindings
+
+Required Properties:
+- reg: The controller bus address.
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells: Must be 2.
+  - First cell is the GPIO pin number relative to the controller.
+  - Second cell is a standard generic flag bitfield as described in gpio.txt.
+
+Optional Properties:
+- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is used.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Must be present and have value of 2 if
+"interrupt-controller" is present.
+  - First cell is the GPIO pin number relative to the controller.
+  - Second cell is triggering flags as defined in interrupts.txt.
+
+Example:
+
+gpio_6_0: gpio@6,0 {
+   compatible = "cavium,thunder-8890-gpio";
+   reg = <0x3000 0 0 0 0>; /*  DEVFN = 0x30 (6:0) */
+   gpio-controller;
+   #gpio-cells = <2>;
+   interrupt-controller;
+   #interrupt-cells = <2>;
+};
-- 
1.8.3.1

[PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx

[David Daney]

From: David Daney 

Signed-off-by: David Daney 
---
 .../devicetree/bindings/gpio/gpio-thunderx.txt | 27 ++
 1 file changed, 27 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-thunderx.txt

diff --git a/Documentation/devicetree/bindings/gpio/gpio-thunderx.txt 
b/Documentation/devicetree/bindings/gpio/gpio-thunderx.txt
new file mode 100644
index 000..3f883ae
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-thunderx.txt
@@ -0,0 +1,27 @@
+Cavium ThunderX/OCTEON-TX GPIO controller bindings
+
+Required Properties:
+- reg: The controller bus address.
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells: Must be 2.
+  - First cell is the GPIO pin number relative to the controller.
+  - Second cell is a standard generic flag bitfield as described in gpio.txt.
+
+Optional Properties:
+- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is used.
+- interrupt-controller: Marks the device node as an interrupt controller.
+- #interrupt-cells: Must be present and have value of 2 if
+"interrupt-controller" is present.
+  - First cell is the GPIO pin number relative to the controller.
+  - Second cell is triggering flags as defined in interrupts.txt.
+
+Example:
+
+gpio_6_0: gpio@6,0 {
+   compatible = "cavium,thunder-8890-gpio";
+   reg = <0x3000 0 0 0 0>; /*  DEVFN = 0x30 (6:0) */
+   gpio-controller;
+   #gpio-cells = <2>;
+   interrupt-controller;
+   #interrupt-cells = <2>;
+};
-- 
1.8.3.1