diff mbox series

[V4,3/5] dt-bindings: gpio: Add bindings for gpio-virtio

Message ID acf7402ef4aabc0ad6295c32846f2bef1cd9b56a.1627362340.git.viresh.kumar@linaro.org
State Accepted
Commit f3a66dcdf2390f8434622a4e20a1af7413502623
Headers show
Series virtio: Add virtio-device bindings | expand

Commit Message

Viresh Kumar July 27, 2021, 5:23 a.m. UTC
This patch adds binding for virtio GPIO controller, it is based on
virtio-device bindings.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 .../devicetree/bindings/gpio/gpio-virtio.yaml | 59 +++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

Comments

Rob Herring Aug. 2, 2021, 7:40 p.m. UTC | #1
On Tue, Jul 27, 2021 at 10:53:50AM +0530, Viresh Kumar wrote:
> This patch adds binding for virtio GPIO controller, it is based on

> virtio-device bindings.

> 

> Reviewed-by: Arnd Bergmann <arnd@arndb.de>

> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> ---

>  .../devicetree/bindings/gpio/gpio-virtio.yaml | 59 +++++++++++++++++++

>  1 file changed, 59 insertions(+)

>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

> 

> diff --git a/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

> new file mode 100644

> index 000000000000..601d85754577

> --- /dev/null

> +++ b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml

> @@ -0,0 +1,59 @@

> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

> +%YAML 1.2

> +---

> +$id: http://devicetree.org/schemas/gpio/gpio-virtio.yaml#

> +$schema: http://devicetree.org/meta-schemas/core.yaml#

> +

> +title: Virtio GPIO controller

> +

> +maintainers:

> +  - Viresh Kumar <viresh.kumar@linaro.org>

> +

> +allOf:

> +  - $ref: /schemas/virtio/virtio-device.yaml#

> +

> +description:

> +  Virtio GPIO controller, see /schemas/virtio/virtio-device.yaml for more

> +  details.

> +

> +properties:

> +  $nodename:

> +    const: gpio

> +

> +  compatible:

> +    const: virtio,device29

> +

> +  gpio-controller: true

> +

> +  "#gpio-cells":

> +    const: 2

> +

> +  interrupt-controller: true

> +

> +  "#interrupt-cells":

> +    const: 2


Humm, how does one implement interrupts without a parent interrupt? It 
uses the parent virtio,mmio interrupt?

> +

> +required:

> +  - compatible

> +  - gpio-controller

> +  - "#gpio-cells"

> +

> +unevaluatedProperties: false

> +

> +examples:

> +  - |

> +    virtio@3000 {

> +        compatible = "virtio,mmio";

> +        reg = <0x3000 0x100>;

> +        interrupts = <41>;

> +

> +        gpio {

> +            compatible = "virtio,device29";

> +            gpio-controller;

> +            #gpio-cells = <2>;

> +            interrupt-controller;

> +            #interrupt-cells = <2>;

> +        };

> +    };

> +

> +...

> -- 

> 2.31.1.272.g89b43f80a514

> 

>
Viresh Kumar Aug. 3, 2021, 4:30 a.m. UTC | #2
On 02-08-21, 13:40, Rob Herring wrote:
> Humm, how does one implement interrupts without a parent interrupt? It 
> uses the parent virtio,mmio interrupt?

Kind of, yeah, but not necessarily.

The interrupt information is passed over buffers shared between host and guest.
Now the guest may process the buffers when it receives a notification from the
host, that will be at downpath of an interrupt for virtio,mmio. Or the guest may
poll on the virtqueue and process any buffers as soon as they are made
available, no interrupts then.
Rob Herring Aug. 3, 2021, 3:47 p.m. UTC | #3
n Mon, Aug 2, 2021 at 10:30 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>

> On 02-08-21, 13:40, Rob Herring wrote:

> > Humm, how does one implement interrupts without a parent interrupt? It

> > uses the parent virtio,mmio interrupt?

>

> Kind of, yeah, but not necessarily.

>

> The interrupt information is passed over buffers shared between host and guest.

> Now the guest may process the buffers when it receives a notification from the

> host, that will be at downpath of an interrupt for virtio,mmio. Or the guest may

> poll on the virtqueue and process any buffers as soon as they are made

> available, no interrupts then.


Okay, thanks for the explanation.

Reviewed-by: Rob Herring <robh@kernel.org>


Rob
Viresh Kumar Aug. 4, 2021, 3:49 a.m. UTC | #4
On 03-08-21, 09:47, Rob Herring wrote:
> n Mon, Aug 2, 2021 at 10:30 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:

> >

> > On 02-08-21, 13:40, Rob Herring wrote:

> > > Humm, how does one implement interrupts without a parent interrupt? It

> > > uses the parent virtio,mmio interrupt?

> >

> > Kind of, yeah, but not necessarily.

> >

> > The interrupt information is passed over buffers shared between host and guest.

> > Now the guest may process the buffers when it receives a notification from the

> > host, that will be at downpath of an interrupt for virtio,mmio. Or the guest may

> > poll on the virtqueue and process any buffers as soon as they are made

> > available, no interrupts then.

> 

> Okay, thanks for the explanation.

> 

> Reviewed-by: Rob Herring <robh@kernel.org>


Thanks for reviewing this Rob.

-- 
viresh
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
new file mode 100644
index 000000000000..601d85754577
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-virtio.yaml
@@ -0,0 +1,59 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/gpio-virtio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Virtio GPIO controller
+
+maintainers:
+  - Viresh Kumar <viresh.kumar@linaro.org>
+
+allOf:
+  - $ref: /schemas/virtio/virtio-device.yaml#
+
+description:
+  Virtio GPIO controller, see /schemas/virtio/virtio-device.yaml for more
+  details.
+
+properties:
+  $nodename:
+    const: gpio
+
+  compatible:
+    const: virtio,device29
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+
+required:
+  - compatible
+  - gpio-controller
+  - "#gpio-cells"
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    virtio@3000 {
+        compatible = "virtio,mmio";
+        reg = <0x3000 0x100>;
+        interrupts = <41>;
+
+        gpio {
+            compatible = "virtio,device29";
+            gpio-controller;
+            #gpio-cells = <2>;
+            interrupt-controller;
+            #interrupt-cells = <2>;
+        };
+    };
+
+...