[PATCH v2 0/2] Add support for Renesas ProXO XP oscillator

[PATCH v2 0/2] Add support for Renesas ProXO XP oscillator

[Alex Helms]

Device tree bindings and a common clock framework device drivers
for the Renesas ProXO XP oscillator.

V2:
 - Fix minor issues in dt bindings
 - Change renesas,xtal to renesas,crystal-frequency

Alex Helms (2):
  dt-bindings: clock: Add bindings for Renesas ProXO
  clk: Add support for Renesas ProXO oscillator

 .../bindings/clock/renesas,proxo.yaml         |  49 +++
 MAINTAINERS                                   |   6 +
 drivers/clk/Kconfig                           |   7 +
 drivers/clk/Makefile                          |   1 +
 drivers/clk/clk-proxo.c                       | 410 ++++++++++++++++++
 5 files changed, 473 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/renesas,proxo.yaml
 create mode 100644 drivers/clk/clk-proxo.c


base-commit: f64b5666e11dce481737208027d4af300c63842d
-- 
2.30.2

[PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Alex Helms]

Add dt bindings for the Renesas ProXO oscillator.

Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
---
 .../bindings/clock/renesas,proxo.yaml         | 49 +++++++++++++++++++
 MAINTAINERS                                   |  5 ++
 2 files changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/renesas,proxo.yaml

diff --git a/Documentation/devicetree/bindings/clock/renesas,proxo.yaml b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
new file mode 100644
index 000000000..79d62f399
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/renesas,proxo.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas ProXO Oscillator Device Tree Bindings
+
+maintainers:
+  - Alex Helms <alexander.helms.jy@renesas.com>
+
+description:
+  Renesas ProXO is a family of programmable ultra-low phase noise
+  quartz-based oscillators.
+
+properties:
+  '#clock-cells':
+    const: 0
+
+  compatible:
+    enum:
+      - renesas,proxo-xp
+
+  reg:
+    maxItems: 1
+
+  renesas,crystal-frequency:
+    description: Internal crystal frequency, default is 50000000 (50MHz)
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+required:
+  - '#clock-cells'
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      proxo: clock-controller@55 {
+        compatible = "renesas,proxo-xp";
+        reg = <0x55>;
+        #clock-cells = <0>;
+      };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 350102355..d52a8a5d2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16080,6 +16080,11 @@ S:	Supported
 F:	Documentation/devicetree/bindings/iio/adc/renesas,rzg2l-adc.yaml
 F:	drivers/iio/adc/rzg2l_adc.c
 
+RENESAS PROXO CLOCK DRIVER
+M:	Alex Helms <alexander.helms.jy@renesas.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/clock/renesas,proxo.yaml
+
 RESET CONTROLLER FRAMEWORK
 M:	Philipp Zabel <p.zabel@pengutronix.de>
 S:	Maintained
-- 
2.30.2

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Rob Herring]

On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
> Add dt bindings for the Renesas ProXO oscillator.
> 
> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
> ---
>  .../bindings/clock/renesas,proxo.yaml         | 49 +++++++++++++++++++
>  MAINTAINERS                                   |  5 ++
>  2 files changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> 
> diff --git a/Documentation/devicetree/bindings/clock/renesas,proxo.yaml b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> new file mode 100644
> index 000000000..79d62f399
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> @@ -0,0 +1,49 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/renesas,proxo.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Renesas ProXO Oscillator Device Tree Bindings
> +
> +maintainers:
> +  - Alex Helms <alexander.helms.jy@renesas.com>
> +
> +description:
> +  Renesas ProXO is a family of programmable ultra-low phase noise
> +  quartz-based oscillators.
> +
> +properties:
> +  '#clock-cells':
> +    const: 0
> +
> +  compatible:
> +    enum:
> +      - renesas,proxo-xp
> +
> +  reg:
> +    maxItems: 1
> +
> +  renesas,crystal-frequency:
> +    description: Internal crystal frequency, default is 50000000 (50MHz)
> +    $ref: /schemas/types.yaml#/definitions/uint32

'clock-frequency' doesn't work here?

Anything else needs '-hz' suffix.

> +
> +required:
> +  - '#clock-cells'
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      proxo: clock-controller@55 {
> +        compatible = "renesas,proxo-xp";
> +        reg = <0x55>;
> +        #clock-cells = <0>;
> +      };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 350102355..d52a8a5d2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -16080,6 +16080,11 @@ S:	Supported
>  F:	Documentation/devicetree/bindings/iio/adc/renesas,rzg2l-adc.yaml
>  F:	drivers/iio/adc/rzg2l_adc.c
>  
> +RENESAS PROXO CLOCK DRIVER
> +M:	Alex Helms <alexander.helms.jy@renesas.com>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> +
>  RESET CONTROLLER FRAMEWORK
>  M:	Philipp Zabel <p.zabel@pengutronix.de>
>  S:	Maintained
> -- 
> 2.30.2
> 
> 

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Michal Simek]

Hi Alex,

On 9/27/22 01:04, Rob Herring wrote:
> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
>> Add dt bindings for the Renesas ProXO oscillator.
>>
>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
>> ---
>>   .../bindings/clock/renesas,proxo.yaml         | 49 +++++++++++++++++++
>>   MAINTAINERS                                   |  5 ++
>>   2 files changed, 54 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/clock/renesas,proxo.yaml b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>> new file mode 100644
>> index 000000000..79d62f399
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>> @@ -0,0 +1,49 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/clock/renesas,proxo.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Renesas ProXO Oscillator Device Tree Bindings
>> +
>> +maintainers:
>> +  - Alex Helms <alexander.helms.jy@renesas.com>
>> +
>> +description:
>> +  Renesas ProXO is a family of programmable ultra-low phase noise
>> +  quartz-based oscillators.
>> +
>> +properties:
>> +  '#clock-cells':
>> +    const: 0
>> +
>> +  compatible:
>> +    enum:
>> +      - renesas,proxo-xp
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  renesas,crystal-frequency:
>> +    description: Internal crystal frequency, default is 50000000 (50MHz)
>> +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> 'clock-frequency' doesn't work here?
> 
> Anything else needs '-hz' suffix.
> 


Driver is also using clock-output-names which is not listed here.

Thanks,
Michal

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Geert Uytterhoeven]

Hi Michal,

On Tue, Sep 27, 2022 at 4:10 PM Michal Simek <michal.simek@amd.com> wrote:
> On 9/27/22 01:04, Rob Herring wrote:
> > On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
> >> Add dt bindings for the Renesas ProXO oscillator.
> >>
> >> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>

> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml

> Driver is also using clock-output-names which is not listed here.

... which is deprecated, and thus should not be used by the driver
at all.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Alex Helms]

On 9/27/2022 7:51 AM, Geert Uytterhoeven wrote:
> Hi Michal,
> 
> On Tue, Sep 27, 2022 at 4:10 PM Michal Simek <michal.simek@amd.com> wrote:
>> On 9/27/22 01:04, Rob Herring wrote:
>>> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
>>>> Add dt bindings for the Renesas ProXO oscillator.
>>>>
>>>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
> 
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> 
>> Driver is also using clock-output-names which is not listed here.
> 
> ... which is deprecated, and thus should not be used by the driver
> at all.

Can you point me to somewhere showing it is deprecated? It is in the
current dt clock documentation.

Either way I will just remove it as it isn't important.

-Alex

> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Stephen Boyd]

Quoting Alex Helms (2022-09-28 16:16:04)
> On 9/27/2022 7:51 AM, Geert Uytterhoeven wrote:
> > Hi Michal,
> > 
> > On Tue, Sep 27, 2022 at 4:10 PM Michal Simek <michal.simek@amd.com> wrote:
> >> On 9/27/22 01:04, Rob Herring wrote:
> >>> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
> >>>> Add dt bindings for the Renesas ProXO oscillator.
> >>>>
> >>>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
> > 
> >>>> --- /dev/null
> >>>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> > 
> >> Driver is also using clock-output-names which is not listed here.
> > 
> > ... which is deprecated, and thus should not be used by the driver
> > at all.
> 
> Can you point me to somewhere showing it is deprecated? It is in the
> current dt clock documentation.
> 

I wouldn't say it is deprecated. Instead, it isn't useful if you're able
to use struct clk_parent_data and auto-generated clk names.

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Michal Simek]

On 9/29/22 01:41, Stephen Boyd wrote:
> Quoting Alex Helms (2022-09-28 16:16:04)
>> On 9/27/2022 7:51 AM, Geert Uytterhoeven wrote:
>>> Hi Michal,
>>>
>>> On Tue, Sep 27, 2022 at 4:10 PM Michal Simek <michal.simek@amd.com> wrote:
>>>> On 9/27/22 01:04, Rob Herring wrote:
>>>>> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
>>>>>> Add dt bindings for the Renesas ProXO oscillator.
>>>>>>
>>>>>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
>>>
>>>>>> --- /dev/null
>>>>>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>>>
>>>> Driver is also using clock-output-names which is not listed here.
>>>
>>> ... which is deprecated, and thus should not be used by the driver
>>> at all.
>>
>> Can you point me to somewhere showing it is deprecated? It is in the
>> current dt clock documentation.
>>
> 
> I wouldn't say it is deprecated. Instead, it isn't useful if you're able
> to use struct clk_parent_data and auto-generated clk names.

I am not closely doing clk subsystem but these chips are clock provider without 
any parent. If you mean calling function like this 
of_clk_get_parent_name(client->dev.of_node, 0) then it should return null.
But maybe there is something else what you are referring to.

I see that fixed clock driver is using node->name which is also problematic 
because node name for these devices on i2c will look like clock-controller@XX
where XX could be the same when i2c muxes are used.

And in connection to deprecation. I see only one file which is saying that it is 
deprecated.
Documentation/devicetree/bindings/sound/samsung-i2s.yaml
and it was deprecated before yaml conversion already.

Thanks,
Michal

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Geert Uytterhoeven]

Hi Michal,

On Thu, Sep 29, 2022 at 2:01 PM Michal Simek <michal.simek@amd.com> wrote:
> On 9/29/22 01:41, Stephen Boyd wrote:
> > Quoting Alex Helms (2022-09-28 16:16:04)
> >> On 9/27/2022 7:51 AM, Geert Uytterhoeven wrote:
> >>> On Tue, Sep 27, 2022 at 4:10 PM Michal Simek <michal.simek@amd.com> wrote:
> >>>> On 9/27/22 01:04, Rob Herring wrote:
> >>>>> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
> >>>>>> Add dt bindings for the Renesas ProXO oscillator.
> >>>>>>
> >>>>>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
> >>>
> >>>>>> --- /dev/null
> >>>>>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
> >>>
> >>>> Driver is also using clock-output-names which is not listed here.
> >>>
> >>> ... which is deprecated, and thus should not be used by the driver
> >>> at all.
> >>
> >> Can you point me to somewhere showing it is deprecated? It is in the
> >> current dt clock documentation.
> >
> > I wouldn't say it is deprecated. Instead, it isn't useful if you're able
> > to use struct clk_parent_data and auto-generated clk names.
>
> I am not closely doing clk subsystem but these chips are clock provider without
> any parent. If you mean calling function like this
> of_clk_get_parent_name(client->dev.of_node, 0) then it should return null.
> But maybe there is something else what you are referring to.
>
> I see that fixed clock driver is using node->name which is also problematic
> because node name for these devices on i2c will look like clock-controller@XX
> where XX could be the same when i2c muxes are used.

Indeed, drivers typically use the node name or the driver name instead,
but that may cause conflicts in case of multiple instances.
So you best append ".%u" obtained from e.g. <linux/idr.h>.

> And in connection to deprecation. I see only one file which is saying that it is
> deprecated.
> Documentation/devicetree/bindings/sound/samsung-i2s.yaml
> and it was deprecated before yaml conversion already.

It was deprecated long before the introduction of json-schema (2015?).

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Michal Simek]

Hi Geert,

On 9/29/22 14:20, Geert Uytterhoeven wrote:
> Hi Michal,
> 
> On Thu, Sep 29, 2022 at 2:01 PM Michal Simek <michal.simek@amd.com> wrote:
>> On 9/29/22 01:41, Stephen Boyd wrote:
>>> Quoting Alex Helms (2022-09-28 16:16:04)
>>>> On 9/27/2022 7:51 AM, Geert Uytterhoeven wrote:
>>>>> On Tue, Sep 27, 2022 at 4:10 PM Michal Simek <michal.simek@amd.com> wrote:
>>>>>> On 9/27/22 01:04, Rob Herring wrote:
>>>>>>> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
>>>>>>>> Add dt bindings for the Renesas ProXO oscillator.
>>>>>>>>
>>>>>>>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
>>>>>
>>>>>>>> --- /dev/null
>>>>>>>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>>>>>
>>>>>> Driver is also using clock-output-names which is not listed here.
>>>>>
>>>>> ... which is deprecated, and thus should not be used by the driver
>>>>> at all.
>>>>
>>>> Can you point me to somewhere showing it is deprecated? It is in the
>>>> current dt clock documentation.
>>>
>>> I wouldn't say it is deprecated. Instead, it isn't useful if you're able
>>> to use struct clk_parent_data and auto-generated clk names.
>>
>> I am not closely doing clk subsystem but these chips are clock provider without
>> any parent. If you mean calling function like this
>> of_clk_get_parent_name(client->dev.of_node, 0) then it should return null.
>> But maybe there is something else what you are referring to.
>>
>> I see that fixed clock driver is using node->name which is also problematic
>> because node name for these devices on i2c will look like clock-controller@XX
>> where XX could be the same when i2c muxes are used.
> 
> Indeed, drivers typically use the node name or the driver name instead,
> but that may cause conflicts in case of multiple instances.
> So you best append ".%u" obtained from e.g. <linux/idr.h>.

No doubt about it but with 20 clock providers on the board this will be quite 
messy. And I expect idr assignment will be done based on probe order and can 
change across boots.
So far I am filling clock-output-name with human readable name to clearly 
identify what certain clock is doing. Instead of remembering that clk.5 is ddr4 
clock source, etc.

> 
>> And in connection to deprecation. I see only one file which is saying that it is
>> deprecated.
>> Documentation/devicetree/bindings/sound/samsung-i2s.yaml
>> and it was deprecated before yaml conversion already.
> 
> It was deprecated long before the introduction of json-schema (2015?).

Then I think it would be good to mark it like that in schema to have clear 
message to everything that this property shouldn't be used..

Would be good to have any link to that discussion but not asking you to waste 
time on it. But I would be very surprised that no driver was merged from 2015 to 
the tree when I see also 2k lines in DT in the kernel with this property. It 
looks like that it is quite popular.

Thanks,
Michal

Re: [PATCH v2 1/2] dt-bindings: clock: Add bindings for Renesas ProXO

[Alex Helms]

On 9/26/2022 4:04 PM, Rob Herring wrote:
> On Fri, Sep 23, 2022 at 01:52:50PM -0700, Alex Helms wrote:
>> Add dt bindings for the Renesas ProXO oscillator.
>>
>> Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
>> ---
>>  .../bindings/clock/renesas,proxo.yaml         | 49 +++++++++++++++++++
>>  MAINTAINERS                                   |  5 ++
>>  2 files changed, 54 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/clock/renesas,proxo.yaml b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>> new file mode 100644
>> index 000000000..79d62f399
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>> @@ -0,0 +1,49 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetree.org%2Fschemas%2Fclock%2Frenesas%2Cproxo.yaml%23&amp;data=05%7C01%7Calexander.helms.jy%40renesas.com%7C6b2973fc747e49d4353308daa0137e97%7C53d82571da1947e49cb4625a166a4a2a%7C0%7C0%7C637998302827553694%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=Xk7KWuuUfUfA0xv4oUSEOzvhEMpE5YWKad9YVXsJbXg%3D&amp;reserved=0
>> +$schema: https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetree.org%2Fmeta-schemas%2Fcore.yaml%23&amp;data=05%7C01%7Calexander.helms.jy%40renesas.com%7C6b2973fc747e49d4353308daa0137e97%7C53d82571da1947e49cb4625a166a4a2a%7C0%7C0%7C637998302827553694%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=%2F1uyeDB3%2F9iLv1soU8V2NtEaaeoFkpwI%2FG7cSaZCKbo%3D&amp;reserved=0
>> +
>> +title: Renesas ProXO Oscillator Device Tree Bindings
>> +
>> +maintainers:
>> +  - Alex Helms <alexander.helms.jy@renesas.com>
>> +
>> +description:
>> +  Renesas ProXO is a family of programmable ultra-low phase noise
>> +  quartz-based oscillators.
>> +
>> +properties:
>> +  '#clock-cells':
>> +    const: 0
>> +
>> +  compatible:
>> +    enum:
>> +      - renesas,proxo-xp
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  renesas,crystal-frequency:
>> +    description: Internal crystal frequency, default is 50000000 (50MHz)
>> +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> 'clock-frequency' doesn't work here?

If 'clock-frequency' is commonly used to describe and internal crystal
frequency then I can change it but in my opinion 'crystal-frequency-hz'
is a better name for this parameter as it isn't really a clock, just the
internal crystal that is inside the package.

> 
> Anything else needs '-hz' suffix.

I will add the suffix in the next patch.

> 
>> +
>> +required:
>> +  - '#clock-cells'
>> +  - compatible
>> +  - reg
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    i2c {
>> +      #address-cells = <1>;
>> +      #size-cells = <0>;
>> +
>> +      proxo: clock-controller@55 {
>> +        compatible = "renesas,proxo-xp";
>> +        reg = <0x55>;
>> +        #clock-cells = <0>;
>> +      };
>> +    };
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 350102355..d52a8a5d2 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -16080,6 +16080,11 @@ S:	Supported
>>  F:	Documentation/devicetree/bindings/iio/adc/renesas,rzg2l-adc.yaml
>>  F:	drivers/iio/adc/rzg2l_adc.c
>>  
>> +RENESAS PROXO CLOCK DRIVER
>> +M:	Alex Helms <alexander.helms.jy@renesas.com>
>> +S:	Maintained
>> +F:	Documentation/devicetree/bindings/clock/renesas,proxo.yaml
>> +
>>  RESET CONTROLLER FRAMEWORK
>>  M:	Philipp Zabel <p.zabel@pengutronix.de>
>>  S:	Maintained
>> -- 
>> 2.30.2
>>
>>

[PATCH v2 2/2] clk: Add support for Renesas ProXO oscillator

[Alex Helms]

ProXO is a programmable ultra-low phase noise quartz-based
oscillator with a single output. This driver supports changing
the frequency of the ProXP XP variant.

Signed-off-by: Alex Helms <alexander.helms.jy@renesas.com>
---
 MAINTAINERS             |   1 +
 drivers/clk/Kconfig     |   7 +
 drivers/clk/Makefile    |   1 +
 drivers/clk/clk-proxo.c | 410 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 419 insertions(+)
 create mode 100644 drivers/clk/clk-proxo.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d52a8a5d2..c7f5c0655 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16084,6 +16084,7 @@ RENESAS PROXO CLOCK DRIVER
 M:	Alex Helms <alexander.helms.jy@renesas.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/clock/renesas,proxo.yaml
+F:	drivers/clk/clk-proxo.c
 
 RESET CONTROLLER FRAMEWORK
 M:	Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 8f905df60..31f684d69 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -396,6 +396,13 @@ config COMMON_CLK_K210
 	help
 	  Support for the Canaan Kendryte K210 RISC-V SoC clocks.
 
+config COMMON_CLK_PROXO
+	bool "Clock driver for Renesas ProXO"
+	depends on I2C && OF
+	select REGMAP_I2C
+	help
+	  Support for the Renesas ProXO oscillator clock.
+
 source "drivers/clk/actions/Kconfig"
 source "drivers/clk/analogbits/Kconfig"
 source "drivers/clk/baikal-t1/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 99941b4a3..be6e28cc4 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_ARCH_NSPIRE)		+= clk-nspire.o
 obj-$(CONFIG_COMMON_CLK_OXNAS)		+= clk-oxnas.o
 obj-$(CONFIG_COMMON_CLK_PALMAS)		+= clk-palmas.o
 obj-$(CONFIG_CLK_LS1028A_PLLDIG)	+= clk-plldig.o
+obj-$(CONFIG_COMMON_CLK_PROXO)		+= clk-proxo.o
 obj-$(CONFIG_COMMON_CLK_PWM)		+= clk-pwm.o
 obj-$(CONFIG_CLK_QORIQ)			+= clk-qoriq.o
 obj-$(CONFIG_COMMON_CLK_RK808)		+= clk-rk808.o
diff --git a/drivers/clk/clk-proxo.c b/drivers/clk/clk-proxo.c
new file mode 100644
index 000000000..f70fb8681
--- /dev/null
+++ b/drivers/clk/clk-proxo.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common clock framework driver for the ProXO family of quartz-based oscillators.
+ *
+ * Copyright (c) 2022 Renesas Electronics Corporation
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/swab.h>
+
+/* Most ProXO products have a 50MHz xtal, can be overridden in device tree */
+#define PROXO_DEFAULT_XTAL	50000000
+
+/* VCO range is 6.86 GHz to 8.65 GHz */
+#define PROXO_FVCO_MIN		6860000000ULL
+#define PROXO_FVCO_MAX		8650000000ULL
+
+/* Output range is 15MHz to 2.1GHz */
+#define PROXO_FOUT_MIN		15000000UL
+#define PROXO_FOUT_MAX		2100000000UL
+
+#define PROXO_FRAC_BITS		24
+#define PROXO_FRAC_DIVISOR	BIT(PROXO_FRAC_BITS)
+
+/* Disable the doubler if the crystal is > 80MHz */
+#define PROXO_FDBL_MAX		80000000U
+
+#define PROXO_OUTDIV_MIN	4
+#define PROXO_OUTDIV_MAX	511
+#define PROXO_FB_MIN		41
+
+#define PROXO_REG_FREQ0		0x10
+#define PROXO_REG_XO		0x51
+#define PROXO_REG_TRIG		0x62
+
+#define OUTDIV_8_MASK		0x80
+#define FBDIV_INT_8_7_MASK	0x30
+#define FBDIV_INT_6_0_MASK	0x7f
+#define DOUBLE_DIS_MASK		0x80
+#define CP_MASK			0x0e
+#define PLL_MODE_MASK		0x01
+
+enum proxo_model {
+	PROXO_XP,
+};
+
+enum proxo_pll_mode {
+	PLL_MODE_FRAC,
+	PLL_MODE_INT,
+};
+
+struct clk_proxo {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	struct i2c_client *i2c_client;
+	enum proxo_model model;
+	u32 fxtal;
+	u64 fvco;
+	u32 fout;
+	u8 double_dis;
+	u16 fb_int;
+	u32 fb_frac;
+	u16 out_div;
+};
+
+#define to_clk_proxo(_hw)	container_of(_hw, struct clk_proxo, hw)
+
+static u8 proxo_get_cp_value(u64 fvco)
+{
+	if (fvco < 7000000000ULL)
+		return 5;
+	else if (fvco >= 7000000000ULL && fvco < 7400000000ULL)
+		return 4;
+	else if (fvco >= 7400000000ULL && fvco < 7800000000ULL)
+		return 3;
+	else
+		return 2;
+}
+
+static u64 proxo_calc_fvco(u32 fxtal, u8 double_dis, u16 fb_int, u32 fb_frac)
+{
+	u64 fref, fvco;
+	u8 doubler;
+
+	doubler = double_dis ? 1 : 2;
+	fref = (u64)fxtal * doubler;
+	fvco = (fref * fb_int) + div_u64(fref * fb_frac, PROXO_FRAC_DIVISOR);
+
+	return fvco;
+}
+
+static int proxo_get_divs(struct clk_proxo *proxo, u16 *out_div, u16 *fb_int, u32 *fb_frac,
+			  u8 *double_dis)
+{
+	int ret;
+	u8 reg[6];
+	unsigned int xo;
+
+	ret = regmap_bulk_read(proxo->regmap, PROXO_REG_FREQ0, reg, ARRAY_SIZE(reg));
+	if (ret)
+		return ret;
+
+	ret = regmap_read(proxo->regmap, PROXO_REG_XO, &xo);
+	if (ret)
+		return ret;
+
+	*out_div = (u16_get_bits(reg[1], OUTDIV_8_MASK) << 8) + reg[0];
+	*fb_int = (u16_get_bits(reg[2], FBDIV_INT_8_7_MASK) << 7) + (reg[1] & FBDIV_INT_6_0_MASK);
+	*fb_frac = ((u32)reg[5] << 16) + ((u32)reg[4] << 8) + reg[3];
+	*double_dis = !!(xo & DOUBLE_DIS_MASK);
+
+	if (*fb_frac > (PROXO_FRAC_DIVISOR >> 1))
+		(*fb_int)--;
+
+	pr_debug("%s - out_div: %u, fb_int: %u, fb_frac: %u, doubler_dis: %u\n",
+		 __func__, *out_div, *fb_int, *fb_frac, *double_dis);
+
+	return ret;
+}
+
+static int proxo_get_defaults(struct clk_proxo *proxo)
+{
+	int ret;
+
+	ret = proxo_get_divs(proxo, &proxo->out_div, &proxo->fb_int, &proxo->fb_frac,
+			     &proxo->double_dis);
+	if (ret)
+		return ret;
+
+	proxo->fvco = proxo_calc_fvco(proxo->fxtal, proxo->double_dis, proxo->fb_int,
+				      proxo->fb_frac);
+	proxo->fout = div_u64(proxo->fvco, proxo->out_div);
+
+	pr_debug("%s - out_div: %u, fb_int: %u, fb_frac: %u, doubler_dis: %u, fvco: %llu, fout: %u\n",
+		 __func__, proxo->out_div, proxo->fb_int, proxo->fb_frac, proxo->double_dis,
+		 proxo->fvco, proxo->fout);
+
+	return ret;
+}
+
+static int proxo_calc_divs(unsigned long frequency, struct clk_proxo *proxo, u32 *fout,
+			   u16 *out_div, u16 *fb_int, u32 *fb_frac, u8 *double_dis)
+{
+	int i;
+	u8 doubler;
+	u16 out_div_start;
+	u32 fref;
+	u64 fvco;
+	bool found = false, allow_frac = false;
+
+	out_div_start = 1 + div64_u64(PROXO_FVCO_MIN, frequency);
+	doubler = proxo->fxtal <= PROXO_FDBL_MAX ? 2 : 1;
+	fref = proxo->fxtal * doubler;
+	*fout = (u32)max(PROXO_FOUT_MIN, min(PROXO_FOUT_MAX, (unsigned long)*fout));
+	*out_div = PROXO_OUTDIV_MIN;
+	*fb_int = PROXO_FB_MIN;
+	*fb_frac = 0;
+	*double_dis = doubler == 1 ? 1 : 0;
+
+retry:
+	for (i = out_div_start; i <= PROXO_OUTDIV_MAX; ++i) {
+		*out_div = i;
+		fvco = frequency * *out_div;
+		if (fvco > PROXO_FVCO_MAX) {
+			allow_frac = true;
+			goto retry;
+		}
+		*fb_int = div_u64_rem(fvco, fref, fb_frac);
+		if (*fb_frac == 0) {
+			found = true;
+			break;
+		}
+		if (allow_frac) {
+			*fb_frac = 1 + (u32)div_u64((u64)*fb_frac << PROXO_FRAC_BITS, fref);
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	if (fvco < PROXO_FVCO_MIN || fvco > PROXO_FVCO_MAX)
+		return -EINVAL;
+
+	fvco = ((u64)fref * *fb_int) + div_u64((u64)fref * *fb_frac, PROXO_FRAC_DIVISOR);
+	*fout = div_u64(fvco, *out_div);
+
+	return 0;
+}
+
+static int proxo_update_frequency(struct clk_proxo *proxo)
+{
+	enum proxo_pll_mode pll_mode;
+	u8 cp_value;
+	u16 fb_int;
+	u8 reg[6];
+
+	cp_value = proxo_get_cp_value(proxo->fvco);
+	pll_mode = proxo->fb_frac == 0 ? PLL_MODE_INT : PLL_MODE_FRAC;
+	fb_int = proxo->fb_frac > (PROXO_FRAC_DIVISOR >> 1) ? proxo->fb_int + 1 : proxo->fb_int;
+
+	reg[0] = proxo->out_div & 0xff;
+	reg[1] = ((proxo->out_div >> 1) & OUTDIV_8_MASK) + (fb_int & FBDIV_INT_6_0_MASK);
+	reg[2] = (fb_int >> 3) & FBDIV_INT_8_7_MASK;
+	reg[2] = u8_replace_bits(reg[2], cp_value, CP_MASK);
+	reg[2] = u8_replace_bits(reg[2], pll_mode, PLL_MODE_MASK);
+	reg[3] = proxo->fb_frac & 0xff;
+	reg[4] = (proxo->fb_frac >> 8) & 0xff;
+	reg[5] = (proxo->fb_frac >> 16) & 0xff;
+
+	return regmap_bulk_write(proxo->regmap, PROXO_REG_FREQ0, reg, ARRAY_SIZE(reg));
+}
+
+static int proxo_set_frequency(struct clk_proxo *proxo, unsigned long frequency)
+{
+	int ret;
+
+	ret = proxo_calc_divs(frequency, proxo, &proxo->fout, &proxo->out_div, &proxo->fb_int,
+			      &proxo->fb_frac, &proxo->double_dis);
+	if (ret)
+		return ret;
+
+	proxo->fvco = proxo_calc_fvco(proxo->fxtal, proxo->double_dis, proxo->fb_int,
+				      proxo->fb_frac);
+	proxo->fout = div_u64(proxo->fvco, proxo->out_div);
+
+	pr_debug("%s - out_div: %u, fb_int: %u, fb_frac: %u, doubler_dis: %u, fvco: %llu, fout: %u\n",
+		 __func__, proxo->out_div, proxo->fb_int, proxo->fb_frac,
+	proxo->double_dis, proxo->fvco, proxo->fout);
+
+	proxo_update_frequency(proxo);
+
+	/* trigger frequency change */
+	regmap_write(proxo->regmap, PROXO_REG_TRIG, 0x00);
+	regmap_write(proxo->regmap, PROXO_REG_TRIG, 0x01);
+	regmap_write(proxo->regmap, PROXO_REG_TRIG, 0x00);
+
+	return ret;
+}
+
+static unsigned long proxo_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct clk_proxo *proxo = to_clk_proxo(hw);
+	int ret;
+	u8 double_dis;
+	u16 out_div, fb_int;
+	u32 fout, fb_frac;
+	u64 fvco;
+
+	ret = proxo_get_divs(proxo, &out_div, &fb_int, &fb_frac, &double_dis);
+	if (ret) {
+		dev_err(&proxo->i2c_client->dev, "unable to recalc rate\n");
+		return 0;
+	}
+
+	fvco = proxo_calc_fvco(proxo->fxtal, double_dis, fb_int, fb_frac);
+	fout = div_u64(fvco, out_div);
+
+	return fout;
+}
+
+static long proxo_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate)
+{
+	struct clk_proxo *proxo = to_clk_proxo(hw);
+	int ret;
+	u8 double_dis;
+	u16 out_div, fb_int;
+	u32 fout, fb_frac;
+
+	if (!rate)
+		return 0;
+
+	ret = proxo_calc_divs(rate, proxo, &fout, &out_div, &fb_int, &fb_frac, &double_dis);
+	if (ret) {
+		dev_err(&proxo->i2c_client->dev, "unable to round rate\n");
+		return 0;
+	}
+
+	return fout;
+}
+
+static int proxo_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate)
+{
+	struct clk_proxo *proxo = to_clk_proxo(hw);
+
+	if (rate < PROXO_FOUT_MIN || rate > PROXO_FOUT_MAX) {
+		dev_err(&proxo->i2c_client->dev, "requested frequency %lu Hz is out of range\n",
+			rate);
+		return -EINVAL;
+	}
+
+	return proxo_set_frequency(proxo, rate);
+}
+
+static const struct clk_ops proxo_clk_ops = {
+	.recalc_rate = proxo_recalc_rate,
+	.round_rate = proxo_round_rate,
+	.set_rate = proxo_set_rate,
+};
+
+static const struct i2c_device_id proxo_i2c_id[] = {
+	{ "proxo-xp", PROXO_XP },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, proxo_i2c_id);
+
+static const struct regmap_config proxo_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x63,
+	.cache_type = REGCACHE_RBTREE,
+	.use_single_write = true,
+	.use_single_read = true,
+};
+
+static int proxo_probe(struct i2c_client *client)
+{
+	struct clk_proxo *proxo;
+	struct clk_init_data init;
+	const struct i2c_device_id *id = i2c_match_id(proxo_i2c_id, client);
+	int ret;
+
+	proxo = devm_kzalloc(&client->dev, sizeof(*proxo), GFP_KERNEL);
+	if (!proxo)
+		return -ENOMEM;
+
+	init.ops = &proxo_clk_ops;
+	init.flags = 0;
+	init.num_parents = 0;
+	proxo->hw.init = &init;
+	proxo->i2c_client = client;
+	proxo->model = id->driver_data;
+
+	if (of_property_read_string(client->dev.of_node, "clock-output-names", &init.name))
+		init.name = client->dev.of_node->name;
+
+	if (of_property_read_u32(client->dev.of_node, "renesas,crystal-frequency", &proxo->fxtal))
+		proxo->fxtal = PROXO_DEFAULT_XTAL;
+
+	proxo->regmap = devm_regmap_init_i2c(client, &proxo_regmap_config);
+	if (IS_ERR(proxo->regmap))
+		return PTR_ERR(proxo->regmap);
+
+	i2c_set_clientdata(client, proxo);
+
+	ret = proxo_get_defaults(proxo);
+	if (ret) {
+		dev_err(&client->dev, "getting defaults failed\n");
+		return ret;
+	}
+
+	ret = devm_clk_hw_register(&client->dev, &proxo->hw);
+	if (ret) {
+		dev_err(&client->dev, "clock registration failed\n");
+		return ret;
+	}
+
+	ret = of_clk_add_hw_provider(client->dev.of_node, of_clk_hw_simple_get, &proxo->hw);
+	if (ret) {
+		dev_err(&client->dev, "unable to add clk provider\n");
+		return ret;
+	}
+
+	ret = clk_set_rate_range(proxo->hw.clk, PROXO_FOUT_MIN, PROXO_FOUT_MAX);
+	if (ret) {
+		dev_err(&client->dev, "clk_set_rate_range failed\n");
+		return ret;
+	}
+
+	dev_info(&client->dev, "registered, current frequency %u Hz\n", proxo->fout);
+
+	return ret;
+}
+
+static int proxo_remove(struct i2c_client *client)
+{
+	of_clk_del_provider(client->dev.of_node);
+	return 0;
+}
+
+static const struct of_device_id proxo_of_match[] = {
+	{ .compatible = "renesas,proxo-xp" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, proxo_of_match);
+
+static struct i2c_driver proxo_i2c_driver = {
+	.driver = {
+		.name = "proxo",
+		.of_match_table = proxo_of_match,
+	},
+	.probe_new = proxo_probe,
+	.remove = proxo_remove,
+	.id_table = proxo_i2c_id,
+};
+module_i2c_driver(proxo_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alex Helms <alexander.helms.jy@renesas.com");
+MODULE_DESCRIPTION("Renesas ProXO common clock framework driver");
-- 
2.30.2