Loongson 2K0300 ships a GPIO controller whose input/output control logic
is similar to previous generation of SoCs. Additionally, it acts as an
interrupt-controller supporting both level and edge interrupts and has a
distinct reset signal.

Describe its compatible in devicetree. We enlarge the maximum value of
ngpios to 128, since the controller technically supports at most 128
pins, although only 106 are routed out of the package. Properties for
interrupt-controllers and resets are introduced and limited as 2K0300
only.

Signed-off-by: Yao Zi <ziyao@disroot.org>
---
 .../bindings/gpio/loongson,ls-gpio.yaml       | 28 ++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
index b68159600e2b..69852444df23 100644
--- a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
+++ b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
@@ -14,6 +14,7 @@ properties:
     oneOf:
       - enum:
           - loongson,ls2k-gpio
+          - loongson,ls2k0300-gpio
           - loongson,ls2k0500-gpio0
           - loongson,ls2k0500-gpio1
           - loongson,ls2k2000-gpio0
@@ -36,7 +37,7 @@ properties:
 
   ngpios:
     minimum: 1
-    maximum: 64
+    maximum: 128
 
   "#gpio-cells":
     const: 2
@@ -49,6 +50,14 @@ properties:
     minItems: 1
     maxItems: 64
 
+  "#interrupt-cells":
+    const: 2
+
+  interrupt-controller: true
+
+  resets:
+    maxItems: 1
+
 required:
   - compatible
   - reg
@@ -58,6 +67,23 @@ required:
   - gpio-ranges
   - interrupts
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: loongson,ls2k0300-gpio
+    then:
+      required:
+        - "#interrupt-cells"
+        - interrupt-controller
+        - resets
+    else:
+      properties:
+        "#interrupts-cells": false
+        interrupt-controller: false
+        resets: false
+
 additionalProperties: false
 
 examples:
-- 
2.50.1

On Sat, Aug 16, 2025 at 11:51 AM Yao Zi <ziyao@disroot.org> wrote:
>
> Loongson 2K0300 ships a GPIO controller whose input/output control logic
> is similar to previous generation of SoCs. Additionally, it acts as an
> interrupt-controller supporting both level and edge interrupts and has a
> distinct reset signal.
>
> Describe its compatible in devicetree. We enlarge the maximum value of
> ngpios to 128, since the controller technically supports at most 128
> pins, although only 106 are routed out of the package. Properties for
> interrupt-controllers and resets are introduced and limited as 2K0300
> only.
>
> Signed-off-by: Yao Zi <ziyao@disroot.org>
> ---
>  .../bindings/gpio/loongson,ls-gpio.yaml       | 28 ++++++++++++++++++-
>  1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> index b68159600e2b..69852444df23 100644
> --- a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> +++ b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> @@ -14,6 +14,7 @@ properties:
>      oneOf:
>        - enum:
>            - loongson,ls2k-gpio
> +          - loongson,ls2k0300-gpio
>            - loongson,ls2k0500-gpio0
>            - loongson,ls2k0500-gpio1
>            - loongson,ls2k2000-gpio0
> @@ -36,7 +37,7 @@ properties:
>
>    ngpios:
>      minimum: 1
> -    maximum: 64
> +    maximum: 128
>
>    "#gpio-cells":
>      const: 2
> @@ -49,6 +50,14 @@ properties:
>      minItems: 1
>      maxItems: 64
>
> +  "#interrupt-cells":
> +    const: 2
> +
> +  interrupt-controller: true
ls2k300 supports interrupt-controller while others don't?

Huacai

> +
> +  resets:
> +    maxItems: 1
> +
>  required:
>    - compatible
>    - reg
> @@ -58,6 +67,23 @@ required:
>    - gpio-ranges
>    - interrupts
>
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: loongson,ls2k0300-gpio
> +    then:
> +      required:
> +        - "#interrupt-cells"
> +        - interrupt-controller
> +        - resets
> +    else:
> +      properties:
> +        "#interrupts-cells": false
> +        interrupt-controller: false
> +        resets: false
> +
>  additionalProperties: false
>
>  examples:
> --
> 2.50.1
>

On Sat, Aug 16, 2025 at 10:18:57PM +0800, Huacai Chen wrote:
> On Sat, Aug 16, 2025 at 11:51 AM Yao Zi <ziyao@disroot.org> wrote:
> >
> > Loongson 2K0300 ships a GPIO controller whose input/output control logic
> > is similar to previous generation of SoCs. Additionally, it acts as an
> > interrupt-controller supporting both level and edge interrupts and has a
> > distinct reset signal.
> >
> > Describe its compatible in devicetree. We enlarge the maximum value of
> > ngpios to 128, since the controller technically supports at most 128
> > pins, although only 106 are routed out of the package. Properties for
> > interrupt-controllers and resets are introduced and limited as 2K0300
> > only.
> >
> > Signed-off-by: Yao Zi <ziyao@disroot.org>
> > ---
> >  .../bindings/gpio/loongson,ls-gpio.yaml       | 28 ++++++++++++++++++-
> >  1 file changed, 27 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> > index b68159600e2b..69852444df23 100644
> > --- a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> > +++ b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> > @@ -14,6 +14,7 @@ properties:
> >      oneOf:
> >        - enum:
> >            - loongson,ls2k-gpio
> > +          - loongson,ls2k0300-gpio
> >            - loongson,ls2k0500-gpio0
> >            - loongson,ls2k0500-gpio1
> >            - loongson,ls2k2000-gpio0
> > @@ -36,7 +37,7 @@ properties:
> >
> >    ngpios:
> >      minimum: 1
> > -    maximum: 64
> > +    maximum: 128
> >
> >    "#gpio-cells":
> >      const: 2
> > @@ -49,6 +50,14 @@ properties:
> >      minItems: 1
> >      maxItems: 64
> >
> > +  "#interrupt-cells":
> > +    const: 2
> > +
> > +  interrupt-controller: true
> ls2k300 supports interrupt-controller while others don't?

For these SoCs' GPIO controllers (I didn't carefully check 3A{5,6}00 and
7A{1,2}00), there're three different cases,

1. Controller of 2K0500, 2K1000:

   These controllers have only interrupt enable bits for each GPIO.
   Interrupts are routed directly to the parent interrupt controller and
   there're multiple pins share the same interrupt in the parent, e.g.,
   GPIO 0-31 share interrupt 26 of the second liointc on 2K0500.

   Since we have neither an interrupt status register nor interrupt ack
   bits, it's hard to tell which GPIO line is triggering the interrupt.
   And we even cannot configure the polarity/edge for triggering
   interrupts, thus I don't think these GPIO controller should be
   described as interrupt controllers.

   For these controllers, gpio-loongson-64bit.c implements GPIO
   controller's .to_irq() method which translates GPIO descriptor to
   corresponding IRQ number. This should work as long as there's at most
   one interrupt consumer for each group of GPIOs that share the same
   parent interrupt line.

2. Node controller of 2K1500 and 2K2000:

   These SoCs have GPIO controllers directly attached to the "node" (I
   think it means the CPU core, but am not sure). These controllers are
   similar to the first class, but they have an additional feature that
   the polarity for triggering interrupts could be configured.

   Still we couldn't precisely tell which GPIO line is triggering the
   interrupt, thus it's hard to implement it as a fully-functional
   irqchip, either. But if we don't do so, I cannot come up with a way
   to describe the polarity settings. I'm unsure whether these
   controllers should be implemented as interrupt controllers.

3. South-bridge controller of 2K1500 and 2K2000, and 2K0300's
   controller:

   Reading through the public TRM, I'm sure these're all fully
   functional interrupt controllers, and should be implemented as
   interrupt controllers.

   However, this also means the current binding for 2K1500/2K2000's
   south-bridge controller is WRONG, and a fix it seems to bring in ABI
   breakages (interrupt-controller/interrupt-cells are a must). But
   since I don't have these devices on hand, and they are at least not
   related to the situation of 2K0300, I decided to keep them as-is.

So the answer to the original question is, no, at least 2K1500/2K2000's
south-bridge GPIO controllers are also interrupt controllers according
to their public documentation. But I cannot test my GPIO changes against
them since I don't have such boards, and fixing the binding up may break
the ABI, thus I leave them as-is in this "support for 2K0300" series.

> Huacai

Best regards,
Yao Zi

> > +
> > +  resets:
> > +    maxItems: 1
> > +
> >  required:
> >    - compatible
> >    - reg
> > @@ -58,6 +67,23 @@ required:
> >    - gpio-ranges
> >    - interrupts
> >
> > +allOf:
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            const: loongson,ls2k0300-gpio
> > +    then:
> > +      required:
> > +        - "#interrupt-cells"
> > +        - interrupt-controller
> > +        - resets
> > +    else:
> > +      properties:
> > +        "#interrupts-cells": false
> > +        interrupt-controller: false
> > +        resets: false
> > +
> >  additionalProperties: false
> >
> >  examples:
> > --
> > 2.50.1
> >

On Sun, Aug 17, 2025 at 12:08 AM Yao Zi <ziyao@disroot.org> wrote:
>
> On Sat, Aug 16, 2025 at 10:18:57PM +0800, Huacai Chen wrote:
> > On Sat, Aug 16, 2025 at 11:51 AM Yao Zi <ziyao@disroot.org> wrote:
> > >
> > > Loongson 2K0300 ships a GPIO controller whose input/output control logic
> > > is similar to previous generation of SoCs. Additionally, it acts as an
> > > interrupt-controller supporting both level and edge interrupts and has a
> > > distinct reset signal.
> > >
> > > Describe its compatible in devicetree. We enlarge the maximum value of
> > > ngpios to 128, since the controller technically supports at most 128
> > > pins, although only 106 are routed out of the package. Properties for
> > > interrupt-controllers and resets are introduced and limited as 2K0300
> > > only.
> > >
> > > Signed-off-by: Yao Zi <ziyao@disroot.org>
> > > ---
> > >  .../bindings/gpio/loongson,ls-gpio.yaml       | 28 ++++++++++++++++++-
> > >  1 file changed, 27 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> > > index b68159600e2b..69852444df23 100644
> > > --- a/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> > > +++ b/Documentation/devicetree/bindings/gpio/loongson,ls-gpio.yaml
> > > @@ -14,6 +14,7 @@ properties:
> > >      oneOf:
> > >        - enum:
> > >            - loongson,ls2k-gpio
> > > +          - loongson,ls2k0300-gpio
> > >            - loongson,ls2k0500-gpio0
> > >            - loongson,ls2k0500-gpio1
> > >            - loongson,ls2k2000-gpio0
> > > @@ -36,7 +37,7 @@ properties:
> > >
> > >    ngpios:
> > >      minimum: 1
> > > -    maximum: 64
> > > +    maximum: 128
> > >
> > >    "#gpio-cells":
> > >      const: 2
> > > @@ -49,6 +50,14 @@ properties:
> > >      minItems: 1
> > >      maxItems: 64
> > >
> > > +  "#interrupt-cells":
> > > +    const: 2
> > > +
> > > +  interrupt-controller: true
> > ls2k300 supports interrupt-controller while others don't?
>
> For these SoCs' GPIO controllers (I didn't carefully check 3A{5,6}00 and
> 7A{1,2}00), there're three different cases,
>
> 1. Controller of 2K0500, 2K1000:
>
>    These controllers have only interrupt enable bits for each GPIO.
>    Interrupts are routed directly to the parent interrupt controller and
>    there're multiple pins share the same interrupt in the parent, e.g.,
>    GPIO 0-31 share interrupt 26 of the second liointc on 2K0500.
>
>    Since we have neither an interrupt status register nor interrupt ack
>    bits, it's hard to tell which GPIO line is triggering the interrupt.
>    And we even cannot configure the polarity/edge for triggering
>    interrupts, thus I don't think these GPIO controller should be
>    described as interrupt controllers.
>
>    For these controllers, gpio-loongson-64bit.c implements GPIO
>    controller's .to_irq() method which translates GPIO descriptor to
>    corresponding IRQ number. This should work as long as there's at most
>    one interrupt consumer for each group of GPIOs that share the same
>    parent interrupt line.
>
> 2. Node controller of 2K1500 and 2K2000:
>
>    These SoCs have GPIO controllers directly attached to the "node" (I
>    think it means the CPU core, but am not sure). These controllers are
>    similar to the first class, but they have an additional feature that
>    the polarity for triggering interrupts could be configured.
>
>    Still we couldn't precisely tell which GPIO line is triggering the
>    interrupt, thus it's hard to implement it as a fully-functional
>    irqchip, either. But if we don't do so, I cannot come up with a way
>    to describe the polarity settings. I'm unsure whether these
>    controllers should be implemented as interrupt controllers.
>
> 3. South-bridge controller of 2K1500 and 2K2000, and 2K0300's
>    controller:
>
>    Reading through the public TRM, I'm sure these're all fully
>    functional interrupt controllers, and should be implemented as
>    interrupt controllers.
>
>    However, this also means the current binding for 2K1500/2K2000's
>    south-bridge controller is WRONG, and a fix it seems to bring in ABI
>    breakages (interrupt-controller/interrupt-cells are a must). But
>    since I don't have these devices on hand, and they are at least not
>    related to the situation of 2K0300, I decided to keep them as-is.
>
> So the answer to the original question is, no, at least 2K1500/2K2000's
> south-bridge GPIO controllers are also interrupt controllers according
> to their public documentation. But I cannot test my GPIO changes against
> them since I don't have such boards, and fixing the binding up may break
> the ABI, thus I leave them as-is in this "support for 2K0300" series.
Then I think more SOCs rather than LS2K0300 support
interrupt-controller. Though the driver is not support yet, they can
be improved later (of course unnecessary in this series), so in my
opinion just keep the dt-binding in the same file is reasonable.


Huacai

>
> > Huacai
>
> Best regards,
> Yao Zi
>
> > > +
> > > +  resets:
> > > +    maxItems: 1
> > > +
> > >  required:
> > >    - compatible
> > >    - reg
> > > @@ -58,6 +67,23 @@ required:
> > >    - gpio-ranges
> > >    - interrupts
> > >
> > > +allOf:
> > > +  - if:
> > > +      properties:
> > > +        compatible:
> > > +          contains:
> > > +            const: loongson,ls2k0300-gpio
> > > +    then:
> > > +      required:
> > > +        - "#interrupt-cells"
> > > +        - interrupt-controller
> > > +        - resets
> > > +    else:
> > > +      properties:
> > > +        "#interrupts-cells": false
> > > +        interrupt-controller: false
> > > +        resets: false
> > > +
> > >  additionalProperties: false
> > >
> > >  examples:
> > > --
> > > 2.50.1
> > >

On 16/08/2025 05:50, Yao Zi wrote:
>  
> +  "#interrupt-cells":
> +    const: 2
> +
> +  interrupt-controller: true
> +
> +  resets:
> +    maxItems: 1
> +
You should have probably separate binding if you need three new properties.


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof