diff mbox series

[2/9] dt-bindings: phy: qcom,m31: Document qcom,m31 USB phy

Message ID 14f60578e2935c0844537eab162af3afa52ffe39.1686126439.git.quic_varada@quicinc.com
State New
Headers show
Series Enable IPQ5332 USB2 | expand

Commit Message

Varadarajan Narayanan June 7, 2023, 10:56 a.m. UTC 
Document the M31 USB2 phy present in IPQ5332

Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
---
 .../devicetree/bindings/phy/qcom,m31.yaml          | 69 ++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/qcom,m31.yaml

Comments

Varadarajan Narayanan June 15, 2023, 5:27 a.m. UTC | #1 
On Wed, Jun 07, 2023 at 08:31:50PM +0200, Krzysztof Kozlowski wrote:
> On 07/06/2023 12:56, Varadarajan Narayanan wrote:
> > Document the M31 USB2 phy present in IPQ5332
>
> Full stop.

Ok.

> > Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
> > Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> > ---
> >  .../devicetree/bindings/phy/qcom,m31.yaml          | 69 ++++++++++++++++++++++
> >  1 file changed, 69 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/phy/qcom,m31.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/phy/qcom,m31.yaml b/Documentation/devicetree/bindings/phy/qcom,m31.yaml
> > new file mode 100644
> > index 0000000..8ad4ba4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/qcom,m31.yaml
> > @@ -0,0 +1,69 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +
>
> Drop stray blank lines.

Ok.

> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/phy/qcom,m31.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Qualcomm M31 USB PHY
>
> What is M31?

M31 is an external IP integrated into IPQ5332 SoC.

> > +
> > +maintainers:
> > +  - Sricharan Ramabadhran <quic_srichara@quicinc.com>
> > +  - Varadarajan Narayanan <quic_varada@quicinc.org>
> > +
> > +description:
> > +  This file contains documentation for the USB M31 PHY found in Qualcomm
>
> Drop redundant parts ("This file contains documentation for the").

Ok.

> > +  IPQ5018, IPQ5332 SoCs.
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
>
> That's not oneOf.

Ok.

> > +      - items:
>
> No items.

Ok.

> > +          - enum:
> > +              - qcom,m31-usb-hsphy
>
> I am confused what's this. If m31 is coming from some IP block provider,
> then you are using wrong vendor prefix.
> https://www.m31tech.com/download_file/M31_USB.pdf
>
>
> > +              - qcom,ipq5332-m31-usb-hsphy
>
> This confuses me even more. IPQ m31?

Will change this to m31,usb-hsphy and m31,ipq5332-usb-hsphy respectively.
Will that be acceptable?

> > +
> > +  reg:
> > +    description:
> > +      Offset and length of the M31 PHY register set
>
> Drop description, obvious.

Ok.

> > +    maxItems: 2
> > +
> > +  reg-names:
> > +    items:
> > +      - const: m31usb_phy_base
> > +      - const: qscratch_base
>
> Drop "_base" from both.

Ok. Will drop qscratch_base. This is in the controller space.
Should not come here.

> > +
> > +  phy_type:
> > +    oneOf:
> > +      - items:
> > +          - enum:
> > +              - utmi
> > +              - ulpi
>
> This does not belong to phy, but to USB node.

This is used by the driver to set a bit during phy init. Hence
have it as a replication of the USB node's entry. If this is not
permissible, is there some way to get this from the USB node,
or any other alternative mechanism?

> > +
> > +  resets:
> > +    maxItems: 1
> > +    description:
> > +      List of phandles and reset pairs, one for each entry in reset-names.
>
> Drop useless description.

Ok.

> > +
> > +  reset-names:
> > +    items:
> > +      - const:
> > +          usb2_phy_reset
>
> Drop entire reset-names.

Ok.

> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/qcom,ipq5332-gcc.h>
> > +    hs_m31phy_0: hs_m31phy@5b00 {
>
> Node names should be generic. See also explanation and list of examples
> in DT specification:
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>
> Also, no underscores in node names.

Will change this as usbphy0:hs_m31phy@7b000

> > +        compatible = "qcom,m31-usb-hsphy";
> > +        reg = <0x5b000 0x3000>,
>
> This is not what your unit address is saying.

Will change to 0x0007b000.

> > +            <0x08af8800 0x400>;
>
> Align it.

Will drop this. This is in the controller space.

> > +        reg-names = "m31usb_phy_base",
> > +                "qscratch_base";
>
> Align it.

Ok.

> > +        phy_type = "utmi";
> > +        resets = <&gcc GCC_QUSB2_0_PHY_BCR>;
> > +        reset-names = "usb2_phy_reset";
> > +
> > +        status = "ok";
>
> Drop.

Ok. Hopefully will get an alternative for the phy_type.

Thanks
Varada

> > +    };
>
> Best regards,
> Krzysztof
>
Krzysztof Kozlowski June 17, 2023, 8:48 a.m. UTC | #2 
On 15/06/2023 07:27, Varadarajan Narayanan wrote:
>>> +          - enum:
>>> +              - qcom,m31-usb-hsphy
>>
>> I am confused what's this. If m31 is coming from some IP block provider,
>> then you are using wrong vendor prefix.
>> https://www.m31tech.com/download_file/M31_USB.pdf
>>
>>
>>> +              - qcom,ipq5332-m31-usb-hsphy
>>
>> This confuses me even more. IPQ m31?
> 
> Will change this to m31,usb-hsphy and m31,ipq5332-usb-hsphy respectively.
> Will that be acceptable?

m31,ipq5332 seems wrong, as m31 did not create ipq5332. Does the m31
device have some name/version/model? If it is not really known, then I
would just propose to go with qcom,ipq5332-usb-hsphy.

Skip generic compatible ("usb-hsphy") entirely.

And then we have... existing bindings qcom,usb-hs-phy.yaml. Don't create
something similar with difference in the hyphen. Just use device
specific compatible thus device specific filename.

> 
>>> +
>>> +  reg:
>>> +    description:
>>> +      Offset and length of the M31 PHY register set
>>
>> Drop description, obvious.
> 
> Ok.
> 
>>> +    maxItems: 2
>>> +
>>> +  reg-names:
>>> +    items:
>>> +      - const: m31usb_phy_base
>>> +      - const: qscratch_base
>>
>> Drop "_base" from both.
> 
> Ok. Will drop qscratch_base. This is in the controller space.
> Should not come here.

Then drop reg-names entirely.

> 
>>> +
>>> +  phy_type:
>>> +    oneOf:
>>> +      - items:
>>> +          - enum:
>>> +              - utmi
>>> +              - ulpi
>>
>> This does not belong to phy, but to USB node.
> 
> This is used by the driver to set a bit during phy init. Hence
> have it as a replication of the USB node's entry. If this is not
> permissible, is there some way to get this from the USB node,
> or any other alternative mechanism?

Shouldn't USB controller choose what type of PHY type it wants?

> 
>>> +
>>> +additionalProperties: false
>>> +
>>> +examples:
>>> +  - |
>>> +    #include <dt-bindings/clock/qcom,ipq5332-gcc.h>
>>> +    hs_m31phy_0: hs_m31phy@5b00 {
>>
>> Node names should be generic. See also explanation and list of examples
>> in DT specification:
>> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
>>
>> Also, no underscores in node names.
> 
> Will change this as usbphy0:hs_m31phy@7b000

This does not solve my comments. I did not write "label" but "node name".

Best regards,
Krzysztof
Varadarajan Narayanan June 20, 2023, 9:32 a.m. UTC | #3 
On Sat, Jun 17, 2023 at 10:48:41AM +0200, Krzysztof Kozlowski wrote:
> On 15/06/2023 07:27, Varadarajan Narayanan wrote:
> >>> +          - enum:
> >>> +              - qcom,m31-usb-hsphy
> >>
> >> I am confused what's this. If m31 is coming from some IP block provider,
> >> then you are using wrong vendor prefix.
> >> https://www.m31tech.com/download_file/M31_USB.pdf
> >>
> >>
> >>> +              - qcom,ipq5332-m31-usb-hsphy
> >>
> >> This confuses me even more. IPQ m31?
> >
> > Will change this to m31,usb-hsphy and m31,ipq5332-usb-hsphy respectively.
> > Will that be acceptable?
>
> m31,ipq5332 seems wrong, as m31 did not create ipq5332. Does the m31
> device have some name/version/model? If it is not really known, then I
> would just propose to go with qcom,ipq5332-usb-hsphy.
>
> Skip generic compatible ("usb-hsphy") entirely.

Ok.

> And then we have... existing bindings qcom,usb-hs-phy.yaml. Don't create
> something similar with difference in the hyphen. Just use device
> specific compatible thus device specific filename.

qcom,usb-hs-phy.yaml seems to be for ULPI mode phy and the
driver we are introducing is for UTMI. We would have to
modify phy-qcom-usb-hs.c to accomodate M31. Will that be
acceptable to phy-qcom-usb-hs.c owners/maintainers?

> >>> +
> >>> +  reg:
> >>> +    description:
> >>> +      Offset and length of the M31 PHY register set
> >>
> >> Drop description, obvious.
> >
> > Ok.
> >
> >>> +    maxItems: 2
> >>> +
> >>> +  reg-names:
> >>> +    items:
> >>> +      - const: m31usb_phy_base
> >>> +      - const: qscratch_base
> >>
> >> Drop "_base" from both.
> >
> > Ok. Will drop qscratch_base. This is in the controller space.
> > Should not come here.
>
> Then drop reg-names entirely.

Ok.

> >>> +
> >>> +  phy_type:
> >>> +    oneOf:
> >>> +      - items:
> >>> +          - enum:
> >>> +              - utmi
> >>> +              - ulpi
> >>
> >> This does not belong to phy, but to USB node.
> >
> > This is used by the driver to set a bit during phy init. Hence
> > have it as a replication of the USB node's entry. If this is not
> > permissible, is there some way to get this from the USB node,
> > or any other alternative mechanism?
>
> Shouldn't USB controller choose what type of PHY type it wants?

Will remove this. IPQ5332 uses it in UTMI mode only.

> >>> +
> >>> +additionalProperties: false
> >>> +
> >>> +examples:
> >>> +  - |
> >>> +    #include <dt-bindings/clock/qcom,ipq5332-gcc.h>
> >>> +    hs_m31phy_0: hs_m31phy@5b00 {
> >>
> >> Node names should be generic. See also explanation and list of examples
> >> in DT specification:
> >> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
> >>
> >> Also, no underscores in node names.
> >
> > Will change this as usbphy0:hs_m31phy@7b000
>
> This does not solve my comments. I did not write "label" but "node name".

Sorry. will fix it.

Thanks
Varada
Krzysztof Kozlowski June 21, 2023, 8:43 a.m. UTC | #4 
On 20/06/2023 11:32, Varadarajan Narayanan wrote:

> 
>> And then we have... existing bindings qcom,usb-hs-phy.yaml. Don't create
>> something similar with difference in the hyphen. Just use device
>> specific compatible thus device specific filename.
> 
> qcom,usb-hs-phy.yaml seems to be for ULPI mode phy and the
> driver we are introducing is for UTMI. We would have to
> modify phy-qcom-usb-hs.c to accomodate M31. Will that be
> acceptable to phy-qcom-usb-hs.c owners/maintainers?

We don't talk about drivers here but bindings. Why would you need to
modify the driver when introducing new binding for different device?



Best regards,
Krzysztof
Varadarajan Narayanan June 21, 2023, 10:12 a.m. UTC | #5 
On Wed, Jun 21, 2023 at 10:43:38AM +0200, Krzysztof Kozlowski wrote:
> On 20/06/2023 11:32, Varadarajan Narayanan wrote:
>
> >
> >> And then we have... existing bindings qcom,usb-hs-phy.yaml. Don't create
> >> something similar with difference in the hyphen. Just use device
> >> specific compatible thus device specific filename.
> >
> > qcom,usb-hs-phy.yaml seems to be for ULPI mode phy and the
> > driver we are introducing is for UTMI. We would have to
> > modify phy-qcom-usb-hs.c to accomodate M31. Will that be
> > acceptable to phy-qcom-usb-hs.c owners/maintainers?
>
> We don't talk about drivers here but bindings. Why would you need to
> modify the driver when introducing new binding for different device?

Sorry. I misunderstood your feedback as "use the existing bindings".

Will name the bindings file as qcom,ipq5332-usb-hsphy.yaml and post
the next version.

Thanks
Varada
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/phy/qcom,m31.yaml b/Documentation/devicetree/bindings/phy/qcom,m31.yaml
new file mode 100644
index 0000000..8ad4ba4
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/qcom,m31.yaml
@@ -0,0 +1,69 @@ 
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/qcom,m31.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm M31 USB PHY
+
+maintainers:
+  - Sricharan Ramabadhran <quic_srichara@quicinc.com>
+  - Varadarajan Narayanan <quic_varada@quicinc.org>
+
+description:
+  This file contains documentation for the USB M31 PHY found in Qualcomm
+  IPQ5018, IPQ5332 SoCs.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - qcom,m31-usb-hsphy
+              - qcom,ipq5332-m31-usb-hsphy
+
+  reg:
+    description:
+      Offset and length of the M31 PHY register set
+    maxItems: 2
+
+  reg-names:
+    items:
+      - const: m31usb_phy_base
+      - const: qscratch_base
+
+  phy_type:
+    oneOf:
+      - items:
+          - enum:
+              - utmi
+              - ulpi
+
+  resets:
+    maxItems: 1
+    description:
+      List of phandles and reset pairs, one for each entry in reset-names.
+
+  reset-names:
+    items:
+      - const:
+          usb2_phy_reset
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,ipq5332-gcc.h>
+    hs_m31phy_0: hs_m31phy@5b00 {
+        compatible = "qcom,m31-usb-hsphy";
+        reg = <0x5b000 0x3000>,
+            <0x08af8800 0x400>;
+        reg-names = "m31usb_phy_base",
+                "qscratch_base";
+        phy_type = "utmi";
+        resets = <&gcc GCC_QUSB2_0_PHY_BCR>;
+        reset-names = "usb2_phy_reset";
+
+        status = "ok";
+    };