[v4] Introduce MediaTek frequency hopping driver

[PATCH v4 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Posted by Johnson Wang 1 year, 11 months ago

Add the new binding documentation for MediaTek frequency hopping
and spread spectrum clocking control.

Co-developed-by: Edward-JW Yang <edward-jw.yang@mediatek.com>
Signed-off-by: Edward-JW Yang <edward-jw.yang@mediatek.com>
Signed-off-by: Johnson Wang <johnson.wang@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../arm/mediatek/mediatek,mt8186-fhctl.yaml   | 53 +++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml

diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml
new file mode 100644
index 000000000000..59111946966c
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml
@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/mediatek/mediatek,mt8186-fhctl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek frequency hopping and spread spectrum clocking control
+
+maintainers:
+  - Edward-JW Yang <edward-jw.yang@mediatek.com>
+
+description: |
+  Frequency hopping control (FHCTL) is a piece of hardware that control
+  some PLLs to adopt "hopping" mechanism to adjust their frequency.
+  Spread spectrum clocking (SSC) is another function provided by this hardware.
+
+properties:
+  compatible:
+    const: mediatek,mt8186-fhctl
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description: Phandles of the PLL with FHCTL hardware capability.
+    minItems: 1
+    maxItems: 30
+
+  mediatek,hopping-ssc-percent:
+    description: The percentage of spread spectrum clocking for one PLL.
+    minItems: 1
+    maxItems: 30
+    items:
+      default: 0
+      minimum: 0
+      maximum: 8
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/mt8186-clk.h>
+    fhctl: fhctl@1000ce00 {
+        compatible = "mediatek,mt8186-fhctl";
+        reg = <0x1000ce00 0x200>;
+        clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
+        mediatek,hopping-ssc-percent = <3>;
+    };
-- 
2.18.0

Re: [PATCH v4 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Posted by Stephen Boyd 1 year, 11 months ago

Quoting Johnson Wang (2022-10-13 04:23:34)
> Add the new binding documentation for MediaTek frequency hopping
> and spread spectrum clocking control.
> 
> Co-developed-by: Edward-JW Yang <edward-jw.yang@mediatek.com>
> Signed-off-by: Edward-JW Yang <edward-jw.yang@mediatek.com>
> Signed-off-by: Johnson Wang <johnson.wang@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---
>  .../arm/mediatek/mediatek,mt8186-fhctl.yaml   | 53 +++++++++++++++++++
>  1 file changed, 53 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml
> 
> diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml
> new file mode 100644
> index 000000000000..59111946966c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-fhctl.yaml
> @@ -0,0 +1,53 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/mediatek/mediatek,mt8186-fhctl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek frequency hopping and spread spectrum clocking control

The driver patch is in drivers/clk so why not put the binding in
bindings/clock as well?

> +
> +maintainers:
> +  - Edward-JW Yang <edward-jw.yang@mediatek.com>
> +
[...]
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/mt8186-clk.h>
> +    fhctl: fhctl@1000ce00 {

Is it a clock-controller? 'fhctl' isn't a generic node name.

> +        compatible = "mediatek,mt8186-fhctl";
> +        reg = <0x1000ce00 0x200>;
> +        clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
> +        mediatek,hopping-ssc-percent = <3>;

Re: [PATCH v4 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Posted by Johnson Wang (王聖鑫) 1 year, 11 months ago

On Fri, 2022-10-14 at 13:42 -0700, Stephen Boyd wrote:
> Quoting Johnson Wang (2022-10-13 04:23:34)
> > Add the new binding documentation for MediaTek frequency hopping
> > and spread spectrum clocking control.
> > 
> > Co-developed-by: Edward-JW Yang <edward-jw.yang@mediatek.com>
> > Signed-off-by: Edward-JW Yang <edward-jw.yang@mediatek.com>
> > Signed-off-by: Johnson Wang <johnson.wang@mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@collabora.com>
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > ---
> >  .../arm/mediatek/mediatek,mt8186-fhctl.yaml   | 53
> > +++++++++++++++++++
> >  1 file changed, 53 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-
> > fhctl.yaml
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-
> > fhctl.yaml
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-
> > fhctl.yaml
> > new file mode 100644
> > index 000000000000..59111946966c
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mt8186-
> > fhctl.yaml
> > @@ -0,0 +1,53 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: 
> > https://urldefense.com/v3/__http://devicetree.org/schemas/arm/mediatek/mediatek,mt8186-fhctl.yaml*__;Iw!!CTRNKA9wMg0ARbw!yfDH4W14Pek7w3YBrdcBAGj3OSSWGlWk8av4DmHT69Ej4ax75zKqpy89ZvX1Z_aKDPzu$
> >  
> > +$schema: 
> > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!yfDH4W14Pek7w3YBrdcBAGj3OSSWGlWk8av4DmHT69Ej4ax75zKqpy89ZvX1Z9gRczPi$
> >  
> > +
> > +title: MediaTek frequency hopping and spread spectrum clocking
> > control
> 
> The driver patch is in drivers/clk so why not put the binding in
> bindings/clock as well?
> 
Hi Stephen,

Sure, I will move this binding in the next version.

> > +
> > +maintainers:
> > +  - Edward-JW Yang <edward-jw.yang@mediatek.com>
> > +
> 
> [...]
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - clocks
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/mt8186-clk.h>
> > +    fhctl: fhctl@1000ce00 {
> 
> Is it a clock-controller? 'fhctl' isn't a generic node name.
> 

This node is used for determining if PLLs adopt "hopping" method to
adjust their frequency.
It doesn't provide any clock but actually change the behavior of some
PLLs with new .set_rate callback.
Do you think this node acts like one kind of clock-controller?


BRs,
Johnson Wang
> > +        compatible = "mediatek,mt8186-fhctl";
> > +        reg = <0x1000ce00 0x200>;
> > +        clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
> > +        mediatek,hopping-ssc-percent = <3>;