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[robh,next] dt-bindings: bus: add Broadcom CRU

Message ID 20210309142241.16259-1-zajec5@gmail.com
State Changes Requested, archived
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Series [robh,next] dt-bindings: bus: add Broadcom CRU | expand

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Commit Message

Rafał Miłecki March 9, 2021, 2:22 p.m. UTC
From: Rafał Miłecki <rafal@milecki.pl>

CRU is a block used in Northstar devices. It can be seen in the
bcm5301x.dtsi and this binding documents its proper usage.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 .../devicetree/bindings/bus/brcm,cru.yaml     | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/brcm,cru.yaml

Comments

Rafał Miłecki April 5, 2021, 10:44 p.m. UTC | #1
Hi Rob,

On 09.03.2021 15:22, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> CRU is a block used in Northstar devices. It can be seen in the
> bcm5301x.dtsi and this binding documents its proper usage.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

could you review and push or reject this patch, please?
Rob Herring April 7, 2021, 8:58 p.m. UTC | #2
On Tue, Mar 09, 2021 at 03:22:41PM +0100, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> CRU is a block used in Northstar devices. It can be seen in the
> bcm5301x.dtsi and this binding documents its proper usage.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
>  .../devicetree/bindings/bus/brcm,cru.yaml     | 41 +++++++++++++++++++
>  1 file changed, 41 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/brcm,cru.yaml
> 
> diff --git a/Documentation/devicetree/bindings/bus/brcm,cru.yaml b/Documentation/devicetree/bindings/bus/brcm,cru.yaml
> new file mode 100644
> index 000000000000..c3b1ca53a443
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/brcm,cru.yaml
> @@ -0,0 +1,41 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/bus/brcm,cru.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Broadcom CRU
> +
> +maintainers:
> +  - Rafał Miłecki <rafal@milecki.pl>
> +
> +description: |
> +  Broadcom CRU ("Clock and Reset Unit" or "Central Resource Unit") is a hardware
> +  block grouping smaller blocks. It contains e.g. clocks, pinctrl, USB PHY and

Are these really separate blocks? I really need to see a complete 
binding for the block.

> +  thermal.
> +
> +allOf:
> +  - $ref: /schemas/simple-bus.yaml#

I don't think this should be a 'simple-bus'. Maybe 'simple-mfd' instead.

> +
> +properties:
> +  compatible:
> +    contains:
> +      const: brcm,cru

This should be SoC specific.

> +
> +  reg:
> +    description: CRU registers
> +
> +unevaluatedProperties: false
> +
> +required:
> +  - reg
> +
> +examples:
> +  - |
> +    cru-bus@1800c100 {
> +      compatible = "brcm,cru", "simple-bus";
> +      reg = <0x1800c100 0x1d0>;
> +      ranges;
> +      #address-cells = <1>;
> +      #size-cells = <1>;
> +    };
> -- 
> 2.26.2
>
Florian Fainelli April 7, 2021, 9:43 p.m. UTC | #3
On 4/7/2021 1:58 PM, Rob Herring wrote:
> On Tue, Mar 09, 2021 at 03:22:41PM +0100, Rafał Miłecki wrote:
>> From: Rafał Miłecki <rafal@milecki.pl>
>>
>> CRU is a block used in Northstar devices. It can be seen in the
>> bcm5301x.dtsi and this binding documents its proper usage.
>>
>> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
>> ---
>>  .../devicetree/bindings/bus/brcm,cru.yaml     | 41 +++++++++++++++++++
>>  1 file changed, 41 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/bus/brcm,cru.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/bus/brcm,cru.yaml b/Documentation/devicetree/bindings/bus/brcm,cru.yaml
>> new file mode 100644
>> index 000000000000..c3b1ca53a443
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/bus/brcm,cru.yaml
>> @@ -0,0 +1,41 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/bus/brcm,cru.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Broadcom CRU
>> +
>> +maintainers:
>> +  - Rafał Miłecki <rafal@milecki.pl>
>> +
>> +description: |
>> +  Broadcom CRU ("Clock and Reset Unit" or "Central Resource Unit") is a hardware
>> +  block grouping smaller blocks. It contains e.g. clocks, pinctrl, USB PHY and
> 
> Are these really separate blocks? I really need to see a complete 
> binding for the block.

The situation is a bit confusing because the CRU that is being described
here is not the CRU that is being described in the datasheet as a
block... but the registers are still prefixed CRU because they have a
clocking and reset component/function.

There are CRU registers within the DMU (Device Management Unit) and the
DMU is a sundry of various things containing:

- an internal MDIO bus controller (PCU_MDIO_MGT, PCU_MDIO_CMD)
- 4 registers to control and show the internal regulator status
- a collection of PLL and clock controls from 0x1800_c100 through 0x180_c180
- reset controls
- internal MDIO mux
- GPIO/pinmux/drive strength controls
- switch register interrupts
- adaptive voltage scaling registers
- gap
- crystal control

The 0x1d0 size would span all registers mentioned above and end
somewhere in the gap between AVS and XTAL.

> 
>> +  thermal.
>> +
>> +allOf:
>> +  - $ref: /schemas/simple-bus.yaml#
> 
> I don't think this should be a 'simple-bus'. Maybe 'simple-mfd' instead.
> 
>> +
>> +properties:
>> +  compatible:
>> +    contains:
>> +      const: brcm,cru
> 
> This should be SoC specific.

Yes agreed, brcm,bcm5301x-cru at least sine this is common to all
Northstar platforms.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/bus/brcm,cru.yaml b/Documentation/devicetree/bindings/bus/brcm,cru.yaml
new file mode 100644
index 000000000000..c3b1ca53a443
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/brcm,cru.yaml
@@ -0,0 +1,41 @@ 
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/brcm,cru.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom CRU
+
+maintainers:
+  - Rafał Miłecki <rafal@milecki.pl>
+
+description: |
+  Broadcom CRU ("Clock and Reset Unit" or "Central Resource Unit") is a hardware
+  block grouping smaller blocks. It contains e.g. clocks, pinctrl, USB PHY and
+  thermal.
+
+allOf:
+  - $ref: /schemas/simple-bus.yaml#
+
+properties:
+  compatible:
+    contains:
+      const: brcm,cru
+
+  reg:
+    description: CRU registers
+
+unevaluatedProperties: false
+
+required:
+  - reg
+
+examples:
+  - |
+    cru-bus@1800c100 {
+      compatible = "brcm,cru", "simple-bus";
+      reg = <0x1800c100 0x1d0>;
+      ranges;
+      #address-cells = <1>;
+      #size-cells = <1>;
+    };