[PATCH v4 1/3] dt-bindings: reset: microchip sparx5 reset driver bindings

[PATCH v4 1/3] dt-bindings: reset: microchip sparx5 reset driver bindings

[Steen Hegelund]

Document the Sparx5 reset device driver bindings

The driver uses two syscons on sparx5 for access to
the reset control and the reset status.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
---
 .../bindings/reset/microchip,rst.yaml         | 59 +++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/microchip,rst.yaml

diff --git a/Documentation/devicetree/bindings/reset/microchip,rst.yaml b/Documentation/devicetree/bindings/reset/microchip,rst.yaml
new file mode 100644
index 000000000000..af01016e246f
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/microchip,rst.yaml
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/reset/microchip,rst.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Microchip Sparx5 Switch Reset Controller
+
+maintainers:
+  - Steen Hegelund <steen.hegelund@microchip.com>
+  - Lars Povlsen <lars.povlsen@microchip.com>
+
+description: |
+  The Microchip Sparx5 Switch provides reset control and implements the following
+  functions
+    - One Time Switch Core Reset (Soft Reset)
+
+properties:
+  $nodename:
+    pattern: "^reset-controller@[0-9a-f]+$"
+
+  compatible:
+    const: microchip,sparx5-switch-reset
+
+  reg:
+    maxItems: 1
+
+  "#reset-cells":
+    const: 1
+
+  cpu-syscon:
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+    description: syscon used to access CPU reset
+    maxItems: 1
+
+  gcb-syscon:
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+    description: syscon used to access Global Control Block
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - "#reset-cells"
+  - cpu-syscon
+  - gcb-syscon
+
+additionalProperties: false
+
+examples:
+  - |
+    reset: reset-controller@0 {
+        compatible = "microchip,sparx5-switch-reset";
+        reg = <0x0 0x0>;
+        #reset-cells = <1>;
+        cpu-syscon = <&cpu_ctrl>;
+        gcb-syscon = <&gcb_ctrl>;
+    };
+
-- 
2.29.2

[PATCH v4 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver

[Steen Hegelund]

This provides reset driver support for the Microchip Sparx5 PCB134 and
PCB135 reference boards.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
---
 arch/arm64/boot/dts/microchip/sparx5.dtsi | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi b/arch/arm64/boot/dts/microchip/sparx5.dtsi
index 380281f312d8..4edbb9fcdce0 100644
--- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
+++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
@@ -132,9 +132,17 @@ mux: mux-controller {
 			};
 		};
 
-		reset@611010008 {
-			compatible = "microchip,sparx5-chip-reset";
-			reg = <0x6 0x11010008 0x4>;
+		gcb_ctrl: syscon@611010000 {
+			compatible = "microchip,sparx5-gcb-syscon", "syscon";
+			reg = <0x6 0x11010000 0x10000>;
+		};
+
+		reset: reset-controller@0 {
+			compatible = "microchip,sparx5-switch-reset";
+			reg = <0x6 0x0 0x0>;
+			#reset-cells = <1>;
+			cpu-syscon = <&cpu_ctrl>;
+			gcb-syscon = <&gcb_ctrl>;
 		};
 
 		uart0: serial@600100000 {
-- 
2.29.2

Re: [PATCH v4 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver

[Rob Herring]

On Wed, Jan 20, 2021 at 09:19:21AM +0100, Steen Hegelund wrote:
> This provides reset driver support for the Microchip Sparx5 PCB134 and
> PCB135 reference boards.

This isn't a compatible change. You need an explanation why that's okay 
if that's intended.

> 
> Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
> ---
>  arch/arm64/boot/dts/microchip/sparx5.dtsi | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> index 380281f312d8..4edbb9fcdce0 100644
> --- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
> +++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> @@ -132,9 +132,17 @@ mux: mux-controller {
>  			};
>  		};
>  
> -		reset@611010008 {
> -			compatible = "microchip,sparx5-chip-reset";
> -			reg = <0x6 0x11010008 0x4>;
> +		gcb_ctrl: syscon@611010000 {
> +			compatible = "microchip,sparx5-gcb-syscon", "syscon";
> +			reg = <0x6 0x11010000 0x10000>;
> +		};
> +
> +		reset: reset-controller@0 {
> +			compatible = "microchip,sparx5-switch-reset";
> +			reg = <0x6 0x0 0x0>;

Your register length is 0?

> +			#reset-cells = <1>;
> +			cpu-syscon = <&cpu_ctrl>;

Can't you accomplish the same thing adding these to 
"microchip,sparx5-chip-reset"? Or possibly as a child node.

Define nodes based on h/w blocks, not as containers of things you happen 
to want for some driver.

> +			gcb-syscon = <&gcb_ctrl>;
>  		};
>  
>  		uart0: serial@600100000 {
> -- 
> 2.29.2
> 

Re: [PATCH v4 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver

[Steen Hegelund]

Hi Rob,

On Fri, 2021-02-05 at 16:35 -0600, Rob Herring wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
> know the content is safe
> 
> On Wed, Jan 20, 2021 at 09:19:21AM +0100, Steen Hegelund wrote:
> > This provides reset driver support for the Microchip Sparx5 PCB134
> > and
> > PCB135 reference boards.
> 
> This isn't a compatible change. You need an explanation why that's
> okay
> if that's intended.
> 
> > 
> > Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
> > ---
> >  arch/arm64/boot/dts/microchip/sparx5.dtsi | 14 +++++++++++---
> >  1 file changed, 11 insertions(+), 3 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > index 380281f312d8..4edbb9fcdce0 100644
> > --- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > +++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > @@ -132,9 +132,17 @@ mux: mux-controller {
> >                       };
> >               };
> > 
> > -             reset@611010008 {
> > -                     compatible = "microchip,sparx5-chip-reset";
> > -                     reg = <0x6 0x11010008 0x4>;
> > +             gcb_ctrl: syscon@611010000 {
> > +                     compatible = "microchip,sparx5-gcb-syscon",
> > "syscon";
> > +                     reg = <0x6 0x11010000 0x10000>;
> > +             };
> > +
> > +             reset: reset-controller@0 {
> > +                     compatible = "microchip,sparx5-switch-reset";
> > +                     reg = <0x6 0x0 0x0>;
> 
> Your register length is 0?

Yes, I only use the syscons.

> 
> > +                     #reset-cells = <1>;
> > +                     cpu-syscon = <&cpu_ctrl>;
> 
> Can't you accomplish the same thing adding these to
> "microchip,sparx5-chip-reset"? Or possibly as a child node.
> 
> Define nodes based on h/w blocks, not as containers of things you
> happen
> to want for some driver.

Yes - I think the idea of using syscons came from another reset driver,
but it probably makes more sense to just use IO ranges directly.
I will try that out.

> 
> > +                     gcb-syscon = <&gcb_ctrl>;
> >               };
> > 
> >               uart0: serial@600100000 {
> > --
> > 2.29.2
> > 

Thanks for your comments

BR
Steen

Re: [PATCH v4 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver

[Steen Hegelund]

Hi Rob,

On Fri, 2021-02-05 at 16:35 -0600, Rob Herring wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
> know the content is safe
> 
> On Wed, Jan 20, 2021 at 09:19:21AM +0100, Steen Hegelund wrote:
> > This provides reset driver support for the Microchip Sparx5 PCB134
> > and
> > PCB135 reference boards.
> 
> This isn't a compatible change. You need an explanation why that's
> okay
> if that's intended.

I am not entirely sure that I get your point.

The change (adding the reset driver) is new, and it is optional (but
strongly recommended) for the  clients to use it, so will this be a
incompatible change?

I can certainly add a an explanation.  Would that be needed here in the
bindings, or where do you suggest?


> 
> > 
> > Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
> > ---
> >  arch/arm64/boot/dts/microchip/sparx5.dtsi | 14 +++++++++++---
> >  1 file changed, 11 insertions(+), 3 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > index 380281f312d8..4edbb9fcdce0 100644
> > --- a/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > +++ b/arch/arm64/boot/dts/microchip/sparx5.dtsi
> > @@ -132,9 +132,17 @@ mux: mux-controller {
> >                       };
> >               };
> > 
> > -             reset@611010008 {
> > -                     compatible = "microchip,sparx5-chip-reset";
> > -                     reg = <0x6 0x11010008 0x4>;
> > +             gcb_ctrl: syscon@611010000 {
> > +                     compatible = "microchip,sparx5-gcb-syscon",
> > "syscon";
> > +                     reg = <0x6 0x11010000 0x10000>;
> > +             };
> > +
> > +             reset: reset-controller@0 {
> > +                     compatible = "microchip,sparx5-switch-reset";
> > +                     reg = <0x6 0x0 0x0>;
> 
> Your register length is 0?
> 
> > +                     #reset-cells = <1>;
> > +                     cpu-syscon = <&cpu_ctrl>;
> 
> Can't you accomplish the same thing adding these to
> "microchip,sparx5-chip-reset"? Or possibly as a child node.
> 
> Define nodes based on h/w blocks, not as containers of things you
> happen
> to want for some driver.
> 
> > +                     gcb-syscon = <&gcb_ctrl>;
> >               };
> > 
> >               uart0: serial@600100000 {
> > --
> > 2.29.2
> > 

Thanks for your comments

BR
Steen

Re: [PATCH v4 3/3] arm64: dts: reset: add microchip sparx5 switch reset driver

[Rob Herring]

On Mon, Feb 8, 2021 at 7:20 AM Steen Hegelund
<steen.hegelund@microchip.com> wrote:
>
> Hi Rob,
>
> On Fri, 2021-02-05 at 16:35 -0600, Rob Herring wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you
> > know the content is safe
> >
> > On Wed, Jan 20, 2021 at 09:19:21AM +0100, Steen Hegelund wrote:
> > > This provides reset driver support for the Microchip Sparx5 PCB134
> > > and
> > > PCB135 reference boards.
> >
> > This isn't a compatible change. You need an explanation why that's
> > okay
> > if that's intended.
>
> I am not entirely sure that I get your point.
>
> The change (adding the reset driver) is new, and it is optional (but
> strongly recommended) for the  clients to use it, so will this be a
> incompatible change?

I'm assuming something used "microchip,sparx5-chip-reset"?

> I can certainly add a an explanation.  Would that be needed here in the
> bindings, or where do you suggest?

Just need to spell out why dropping that is okay in the commit msg.
But I guess what this looks like will change anyways.

Rob