2022-09-14 13:15:48

by Johnson Wang

[permalink] [raw]
Subject: [PATCH v2 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

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

Co-developed-by: Edward-JW Yang <[email protected]>
Signed-off-by: Edward-JW Yang <[email protected]>
Signed-off-by: Johnson Wang <[email protected]>
---
.../bindings/arm/mediatek/mediatek,fhctl.yaml | 47 +++++++++++++++++++
1 file changed, 47 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml

diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
new file mode 100644
index 000000000000..7b0fd0889bb6
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/mediatek/mediatek,fhctl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek frequency hopping and spread spectrum clocking control
+
+maintainers:
+ - Edward-JW Yang <[email protected]>
+
+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.
+
+ mediatek,hopping-ssc-percents:
+ description: The percentage of spread spectrum clocking for one PLL.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 8
+
+required:
+ - compatible
+ - reg
+ - clocks
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/mt8186-clk.h>
+ fhctl: fhctl@1000ce00 {
+ compatible = "mediatek,mt8186-fhctl";
+ reg = <0x1000c000 0xe00>;
+ clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
+ mediatek,hopping-ssc-percents = <3>;
+ };
--
2.18.0


Subject: Re: [PATCH v2 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Il 14/09/22 14:45, Johnson Wang ha scritto:
> Add the new binding documentation for MediaTek frequency hopping
> and spread spectrum clocking control.
>
> Co-developed-by: Edward-JW Yang <[email protected]>
> Signed-off-by: Edward-JW Yang <[email protected]>
> Signed-off-by: Johnson Wang <[email protected]>
> ---
> .../bindings/arm/mediatek/mediatek,fhctl.yaml | 47 +++++++++++++++++++
> 1 file changed, 47 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
>
> diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
> new file mode 100644
> index 000000000000..7b0fd0889bb6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/mediatek/mediatek,fhctl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek frequency hopping and spread spectrum clocking control
> +
> +maintainers:
> + - Edward-JW Yang <[email protected]>
> +
> +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

There are still a few issues in this binding that I can immediately see...

> +
> + clocks:
MT8195 has 23 PLLs, MT8186 has 14, but perhaps in the future we may see
something more than that on some newer SoC, so...

clocks:
maxItems: 30

> + description: Phandles of the PLL with FHCTL hardware capability.
> +
> + mediatek,hopping-ssc-percents:
> + description: The percentage of spread spectrum clocking for one PLL.
> + $ref: /schemas/types.yaml#/definitions/uint32

This is an array, so...
$ref: /schemas/types.yaml#/definitions/uint32-array

...also, maxItems?

and you should also specify:

default: 0 <- because, by default, SSC is disabled
minimum: 0 <- because this is the minimum accepted value


Regards,
Angelo

> + maximum: 8
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/mt8186-clk.h>
> + fhctl: fhctl@1000ce00 {
> + compatible = "mediatek,mt8186-fhctl";
> + reg = <0x1000c000 0xe00>;
> + clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
> + mediatek,hopping-ssc-percents = <3>;
> + };

2022-09-15 04:25:48

by Johnson Wang

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Hi Angelo,

Thanks for your review.

On Wed, 2022-09-14 at 15:46 +0200, AngeloGioacchino Del Regno wrote:
> Il 14/09/22 14:45, Johnson Wang ha scritto:
> > Add the new binding documentation for MediaTek frequency hopping
> > and spread spectrum clocking control.
> >
> > Co-developed-by: Edward-JW Yang <[email protected]>
> > Signed-off-by: Edward-JW Yang <[email protected]>
> > Signed-off-by: Johnson Wang <[email protected]>
> > ---
> > .../bindings/arm/mediatek/mediatek,fhctl.yaml | 47
> > +++++++++++++++++++
> > 1 file changed, 47 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
> > l
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
> > l
> > new file mode 100644
> > index 000000000000..7b0fd0889bb6
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
> > l
> > @@ -0,0 +1,47 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id:
> > https://urldefense.com/v3/__http://devicetree.org/schemas/arm/mediatek/mediatek,fhctl.yaml*__;Iw!!CTRNKA9wMg0ARbw!3sumdhtrK5Ah5_rfIilgm4UUmnwkkqMpc3r_ZfkLfsXsLn-_AKm9ZokhJGD1Fl-gJpckAKHZh-jNVW64KRU8Duv1kg$
> >
> > +$schema:
> > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!3sumdhtrK5Ah5_rfIilgm4UUmnwkkqMpc3r_ZfkLfsXsLn-_AKm9ZokhJGD1Fl-gJpckAKHZh-jNVW64KRWMb8jIsw$
> >
> > +
> > +title: MediaTek frequency hopping and spread spectrum clocking
> > control
> > +
> > +maintainers:
> > + - Edward-JW Yang <[email protected]>
> > +
> > +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
>
> There are still a few issues in this binding that I can immediately
> see...
>
> > +
> > + clocks:
>
> MT8195 has 23 PLLs, MT8186 has 14, but perhaps in the future we may
> see
> something more than that on some newer SoC, so...
>
> clocks:
> maxItems: 30

May I add "minItems: 1" to clocks property?

Without this, dt_binding_check will fail because we don't have enough
clocks in the example. (Both MT8195 and MT8186 don't have 30 PLLs)

>
> > + description: Phandles of the PLL with FHCTL hardware
> > capability.
> > +
> > + mediatek,hopping-ssc-percents:
> > + description: The percentage of spread spectrum clocking for
> > one PLL.
> > + $ref: /schemas/types.yaml#/definitions/uint32
>
> This is an array, so...
> $ref: /schemas/types.yaml#/definitions/uint32-array
>
> ...also, maxItems?

As you know, mediatek,hopping-ssc-percents property is used to specify
ssc rate for matching clocks.

If we have to add maxItems, I think we should specify the same value
as clocks property. Is my understanding wrong?


Thanks!

BRs,
Johnson Wang
>
> and you should also specify:
>
> default: 0 <- because, by default, SSC is disabled
> minimum: 0 <- because this is the minimum accepted value
>
>
> Regards,
> Angelo
>
> > + maximum: 8
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - clocks
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/clock/mt8186-clk.h>
> > + fhctl: fhctl@1000ce00 {
> > + compatible = "mediatek,mt8186-fhctl";
> > + reg = <0x1000c000 0xe00>;
> > + clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
> > + mediatek,hopping-ssc-percents = <3>;
> > + };
>
>

Subject: Re: [PATCH v2 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Il 15/09/22 06:00, Johnson Wang ha scritto:
> Hi Angelo,
>
> Thanks for your review.
>
> On Wed, 2022-09-14 at 15:46 +0200, AngeloGioacchino Del Regno wrote:
>> Il 14/09/22 14:45, Johnson Wang ha scritto:
>>> Add the new binding documentation for MediaTek frequency hopping
>>> and spread spectrum clocking control.
>>>
>>> Co-developed-by: Edward-JW Yang <[email protected]>
>>> Signed-off-by: Edward-JW Yang <[email protected]>
>>> Signed-off-by: Johnson Wang <[email protected]>
>>> ---
>>> .../bindings/arm/mediatek/mediatek,fhctl.yaml | 47
>>> +++++++++++++++++++
>>> 1 file changed, 47 insertions(+)
>>> create mode 100644
>>> Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
>>>
>>> diff --git
>>> a/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
>>> l
>>> b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
>>> l
>>> new file mode 100644
>>> index 000000000000..7b0fd0889bb6
>>> --- /dev/null
>>> +++
>>> b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
>>> l
>>> @@ -0,0 +1,47 @@
>>> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id:
>>> https://urldefense.com/v3/__http://devicetree.org/schemas/arm/mediatek/mediatek,fhctl.yaml*__;Iw!!CTRNKA9wMg0ARbw!3sumdhtrK5Ah5_rfIilgm4UUmnwkkqMpc3r_ZfkLfsXsLn-_AKm9ZokhJGD1Fl-gJpckAKHZh-jNVW64KRU8Duv1kg$
>>>
>>> +$schema:
>>> https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!3sumdhtrK5Ah5_rfIilgm4UUmnwkkqMpc3r_ZfkLfsXsLn-_AKm9ZokhJGD1Fl-gJpckAKHZh-jNVW64KRWMb8jIsw$
>>>
>>> +
>>> +title: MediaTek frequency hopping and spread spectrum clocking
>>> control
>>> +
>>> +maintainers:
>>> + - Edward-JW Yang <[email protected]>
>>> +
>>> +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
>>
>> There are still a few issues in this binding that I can immediately
>> see...
>>
>>> +
>>> + clocks:
>>
>> MT8195 has 23 PLLs, MT8186 has 14, but perhaps in the future we may
>> see
>> something more than that on some newer SoC, so...
>>
>> clocks:
>> maxItems: 30
>
> May I add "minItems: 1" to clocks property?
>

Of course you can! Sorry for the incomplete advice here :-)

> Without this, dt_binding_check will fail because we don't have enough
> clocks in the example. (Both MT8195 and MT8186 don't have 30 PLLs)
>
>>
>>> + description: Phandles of the PLL with FHCTL hardware
>>> capability.
>>> +
>>> + mediatek,hopping-ssc-percents:
>>> + description: The percentage of spread spectrum clocking for
>>> one PLL.
>>> + $ref: /schemas/types.yaml#/definitions/uint32
>>
>> This is an array, so...
>> $ref: /schemas/types.yaml#/definitions/uint32-array
>>
>> ...also, maxItems?
>
> As you know, mediatek,hopping-ssc-percents property is used to specify
> ssc rate for matching clocks.
>
> If we have to add maxItems, I think we should specify the same value
> as clocks property. Is my understanding wrong?
>

Your understanding is right. The number of min/max items on the ssc
percents will be the same as clocks.

Regards,
Angelo

>
> Thanks!
>
> BRs,
> Johnson Wang
>>
>> and you should also specify:
>>
>> default: 0 <- because, by default, SSC is disabled
>> minimum: 0 <- because this is the minimum accepted value
>>
>>
>> Regards,
>> Angelo
>>
>>> + maximum: 8
>>> +
>>> +required:
>>> + - compatible
>>> + - reg
>>> + - clocks
>>> +
>>> +additionalProperties: false
>>> +
>>> +examples:
>>> + - |
>>> + #include <dt-bindings/clock/mt8186-clk.h>
>>> + fhctl: fhctl@1000ce00 {
>>> + compatible = "mediatek,mt8186-fhctl";
>>> + reg = <0x1000c000 0xe00>;
>>> + clocks = <&apmixedsys CLK_APMIXED_MSDCPLL>;
>>> + mediatek,hopping-ssc-percents = <3>;
>>> + };
>>
>>
>

--
AngeloGioacchino Del Regno
Software Engineer

Collabora Ltd.
Platinum Building, St John's Innovation Park, Cambridge CB4 0DS, UK
Registered in England & Wales, no. 5513718

2022-09-18 10:00:03

by Krzysztof Kozlowski

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

On 14/09/2022 13:45, Johnson Wang wrote:
> Add the new binding documentation for MediaTek frequency hopping
> and spread spectrum clocking control.
>
> Co-developed-by: Edward-JW Yang <[email protected]>
> Signed-off-by: Edward-JW Yang <[email protected]>
> Signed-off-by: Johnson Wang <[email protected]>
> ---
> .../bindings/arm/mediatek/mediatek,fhctl.yaml | 47 +++++++++++++++++++
> 1 file changed, 47 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
>
> diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
> new file mode 100644
> index 000000000000..7b0fd0889bb6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml

Name of file matching compatible.

> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/arm/mediatek/mediatek,fhctl.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MediaTek frequency hopping and spread spectrum clocking control
> +
> +maintainers:
> + - Edward-JW Yang <[email protected]>
> +
> +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.

You need constraints here.

> +
> + mediatek,hopping-ssc-percents:

That's not the correct unit suffix name.
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml


> + description: The percentage of spread spectrum clocking for one PLL.
> + $ref: /schemas/types.yaml#/definitions/uint32

Best regards,
Krzysztof

2022-09-28 06:40:35

by Johnson Wang

[permalink] [raw]
Subject: Re: [PATCH v2 2/4] dt-bindings: arm: mediatek: Add new bindings of MediaTek frequency hopping

Hi Krzysztof,

Sorry for the late reply.
Thanks for your review.

On Sun, 2022-09-18 at 10:38 +0100, Krzysztof Kozlowski wrote:
> On 14/09/2022 13:45, Johnson Wang wrote:
> > Add the new binding documentation for MediaTek frequency hopping
> > and spread spectrum clocking control.
> >
> > Co-developed-by: Edward-JW Yang <[email protected]>
> > Signed-off-by: Edward-JW Yang <[email protected]>
> > Signed-off-by: Johnson Wang <[email protected]>
> > ---
> > .../bindings/arm/mediatek/mediatek,fhctl.yaml | 47
> > +++++++++++++++++++
> > 1 file changed, 47 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
> > l
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
> > l
> > new file mode 100644
> > index 000000000000..7b0fd0889bb6
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/arm/mediatek/mediatek,fhctl.yam
> > l
>
> Name of file matching compatible.

I will change file name in the next version.
>
> > @@ -0,0 +1,47 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id:
> > https://urldefense.com/v3/__http://devicetree.org/schemas/arm/mediatek/mediatek,fhctl.yaml*__;Iw!!CTRNKA9wMg0ARbw!3e-QEzJcF8ER6bi9pBinXakWUMDsurZPy-q69INHqalP_evj50meSBC7SN0ukZhfEmO-$
> >
> > +$schema:
> > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!3e-QEzJcF8ER6bi9pBinXakWUMDsurZPy-q69INHqalP_evj50meSBC7SN0ukZLSg9mh$
> >
> > +
> > +title: MediaTek frequency hopping and spread spectrum clocking
> > control
> > +
> > +maintainers:
> > + - Edward-JW Yang <[email protected]>
> > +
> > +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.
>
> You need constraints here.

I will improve this in the next version.

>
> > +
> > + mediatek,hopping-ssc-percents:
>
> That's not the correct unit suffix name.
>
https://urldefense.com/v3/__https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml__;!!CTRNKA9wMg0ARbw!3e-QEzJcF8ER6bi9pBinXakWUMDsurZPy-q69INHqalP_evj50meSBC7SN0ukaKEhFnN$

I will go with "mediatek,hopping-ssc-percent" in the next version.

Thanks!

BRs,
Johnson Wang
>
>
>
> > + description: The percentage of spread spectrum clocking for
> > one PLL.
> > + $ref: /schemas/types.yaml#/definitions/uint32
>
> Best regards,
> Krzysztof