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[v3,2/2] dt-bindings: hwmon: isl68137: add bindings to support voltage dividers

Message ID 2cc99616ff3dd9bcecb1309cd4d103d70aea862b.1729715599.git.grantpeltier93@gmail.com
State Changes Requested
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Series dt-bindings: hwmon: pmbus: add bindings for isl68137 | expand

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Commit Message

Grant Peltier Oct. 23, 2024, 8:53 p.m. UTC
Add devicetree bindings to support declaring optional voltage dividers to
the rail outputs of supported digital multiphase regulators. Some
applications require Vout to exceed the voltage range that the Vsense pin
can detect. This binding definition allows users to define the
characteristics of a voltage divider placed between Vout and the Vsense
pin for any rail powered by the device.

Signed-off-by: Grant Peltier <grantpeltier93@gmail.com>
---
 .../hwmon/pmbus/renesas,isl68137.yaml         | 131 ++++++++++++++++++
 1 file changed, 131 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml

Comments

Conor Dooley Oct. 24, 2024, 5:01 p.m. UTC | #1
On Wed, Oct 23, 2024 at 03:53:51PM -0500, Grant Peltier wrote:
> Add devicetree bindings to support declaring optional voltage dividers to
> the rail outputs of supported digital multiphase regulators. Some
> applications require Vout to exceed the voltage range that the Vsense pin
> can detect. This binding definition allows users to define the
> characteristics of a voltage divider placed between Vout and the Vsense
> pin for any rail powered by the device.
> 
> Signed-off-by: Grant Peltier <grantpeltier93@gmail.com>
> ---
>  .../hwmon/pmbus/renesas,isl68137.yaml         | 131 ++++++++++++++++++
>  1 file changed, 131 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml
> new file mode 100644
> index 000000000000..af10c55d547f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml
> @@ -0,0 +1,131 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +
> +$id: http://devicetree.org/schemas/hwmon/pmbus/renesas,isl68137.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Renesas Digital Multiphase Voltage Regulators with PMBus
> +
> +maintainers:
> +  - Grant Peltier <grant.peltier.jg@renesas.com>
> +
> +description: |
> +  Renesas digital multiphase voltage regulators with PMBus.
> +  https://www.renesas.com/en/products/power-management/multiphase-power/multiphase-dcdc-switching-controllers
> +
> +properties:
> +  compatible:
> +    enum:
> +      - renesas,isl68220
> +      - renesas,isl68221
> +      - renesas,isl68222
> +      - renesas,isl68223
> +      - renesas,isl68224
> +      - renesas,isl68225
> +      - renesas,isl68226
> +      - renesas,isl68227
> +      - renesas,isl68229
> +      - renesas,isl68233
> +      - renesas,isl68239
> +      - renesas,isl69222
> +      - renesas,isl69223
> +      - renesas,isl69224
> +      - renesas,isl69225
> +      - renesas,isl69227
> +      - renesas,isl69228
> +      - renesas,isl69234
> +      - renesas,isl69236
> +      - renesas,isl69239
> +      - renesas,isl69242
> +      - renesas,isl69243
> +      - renesas,isl69247
> +      - renesas,isl69248
> +      - renesas,isl69254
> +      - renesas,isl69255
> +      - renesas,isl69256
> +      - renesas,isl69259
> +      - renesas,isl69260
> +      - renesas,isl69268
> +      - renesas,isl69269
> +      - renesas,isl69298
> +      - renesas,raa228000
> +      - renesas,raa228004
> +      - renesas,raa228006
> +      - renesas,raa228228
> +      - renesas,raa229001
> +      - renesas,raa229004

Damn, that;s a list and a half, innit! Looking briefly at the driver
change, the match data implies that quite a few of these actually would
be suitable for fallback compatibles.

> +
> +  reg:
> +    maxItems: 1
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +patternProperties:
> +  "^channel@([0-3])$":
> +    type: object
> +    description:
> +      Container for properties specific to a particular channel (rail).
> +
> +    properties:
> +      reg:
> +        description: The channel (rail) index.
> +        items:
> +          minimum: 0
> +          maximum: 3
> +
> +      renesas,vout-voltage-divider:

There's already a binding for voltage dividers: voltage-divider.yaml
That said, I have no idea how that would work with an extant driver for
the hardware like we have here. I'd imagine it would really have to be
used with iio-hwmon? + Peter and Jonathan, since I don't know how the
driver side of using the voltage divider works.

> +        description:
> +          Resistances of a voltage divider placed between Vout and the voltage
> +          sense pin for the given channel (rail). It has two numbers
> +          representing the resistances of the voltage divider provided as
> +          <R1 R2> which yields an adjusted Vout as
> +          Vout_adj = Vout * (R1 + R2) / R2 given the original Vout as reported
> +          by the Vsense pin.
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        minItems: 2
> +        maxItems: 2
> +
> +    required:
> +      - reg
> +
> +    additionalProperties: false
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      isl68239@60 {
> +        compatible = "renesas,isl68239";
> +        reg = <0x60>;
> +      };
> +    };

Without any channels, what does this actually do? If you've got no
channels you cannot measure anything making this example invalid?

Thanks,
Conor.

> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      isl68239@60 {
> +        compatible = "renesas,isl68239";
> +        reg = <0x60>;
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        channel@0 {
> +          reg = <0>;
> +          renesas,vout-voltage-divider = <1000 1000>;  // Reported Vout/Pout would be scaled by 2
> +        };
> +      };
> +    };
> -- 
> 2.39.5
> 
>
Grant Peltier Oct. 24, 2024, 6:32 p.m. UTC | #2
Hi Conor,

Thank you for your review!

On Thu, Oct 24, 2024 at 06:01:11PM +0100, Conor Dooley wrote:
> On Wed, Oct 23, 2024 at 03:53:51PM -0500, Grant Peltier wrote:
> > + [...]
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - renesas,isl68220
> > +      - renesas,isl68221
> > +      - renesas,isl68222
> > +      - renesas,isl68223
> > +      - renesas,isl68224
> > +      - renesas,isl68225
> > +      - renesas,isl68226
> > +      - renesas,isl68227
> > +      - renesas,isl68229
> > +      - renesas,isl68233
> > +      - renesas,isl68239
> > +      - renesas,isl69222
> > +      - renesas,isl69223
> > +      - renesas,isl69224
> > +      - renesas,isl69225
> > +      - renesas,isl69227
> > +      - renesas,isl69228
> > +      - renesas,isl69234
> > +      - renesas,isl69236
> > +      - renesas,isl69239
> > +      - renesas,isl69242
> > +      - renesas,isl69243
> > +      - renesas,isl69247
> > +      - renesas,isl69248
> > +      - renesas,isl69254
> > +      - renesas,isl69255
> > +      - renesas,isl69256
> > +      - renesas,isl69259
> > +      - renesas,isl69260
> > +      - renesas,isl69268
> > +      - renesas,isl69269
> > +      - renesas,isl69298
> > +      - renesas,raa228000
> > +      - renesas,raa228004
> > +      - renesas,raa228006
> > +      - renesas,raa228228
> > +      - renesas,raa229001
> > +      - renesas,raa229004
> 
> Damn, that;s a list and a half, innit! Looking briefly at the driver
> change, the match data implies that quite a few of these actually would
> be suitable for fallback compatibles.

Yes, there are quite a few part numbers (and likely to be more in the
future). My intention was to make the driver more user friendly since the
variants listed in the driver do not map to something in any of the
datasheets. So using those instead would require users to inspect the
source of the driver instead of simply referencing their part number(s).

> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +patternProperties:
> > +  "^channel@([0-3])$":
> > +    type: object
> > +    description:
> > +      Container for properties specific to a particular channel (rail).
> > +
> > +    properties:
> > +      reg:
> > +        description: The channel (rail) index.
> > +        items:
> > +          minimum: 0
> > +          maximum: 3
> > +
> > +      renesas,vout-voltage-divider:
> 
> There's already a binding for voltage dividers: voltage-divider.yaml
> That said, I have no idea how that would work with an extant driver for
> the hardware like we have here. I'd imagine it would really have to be
> used with iio-hwmon? + Peter and Jonathan, since I don't know how the
> driver side of using the voltage divider works.

In his recent revier, Guenter requested using a standard voltage divider
schema as well. I see there is an implementation in maxim,maxim20730.yaml
but that differs from the one in voltage-divider.yaml. Should I opt to
match maxim,maxim20730.yaml?

> 
> > +        description:
> > +          Resistances of a voltage divider placed between Vout and the voltage
> > +          sense pin for the given channel (rail). It has two numbers
> > +          representing the resistances of the voltage divider provided as
> > +          <R1 R2> which yields an adjusted Vout as
> > +          Vout_adj = Vout * (R1 + R2) / R2 given the original Vout as reported
> > +          by the Vsense pin.
> > +        $ref: /schemas/types.yaml#/definitions/uint32-array
> > +        minItems: 2
> > +        maxItems: 2
> > +
> > +    required:
> > +      - reg
> > +
> > +    additionalProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    i2c {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      isl68239@60 {
> > +        compatible = "renesas,isl68239";
> > +        reg = <0x60>;
> > +      };
> > +    };
> 
> Without any channels, what does this actually do? If you've got no
> channels you cannot measure anything making this example invalid?
> 
> Thanks,
> Conor.
> 
> > + [...]

The channel structures are optional to allow users to arbitrarily define
voltage dividers for any particular rail. Omitting the channel definitions
still allow the device to be instantiated and probed as an I2C device
along with all related hwmon PMBus telemetry dictated by the part variant.

Thanks again,
Grant
Conor Dooley Oct. 31, 2024, 12:55 p.m. UTC | #3
On Thu, Oct 24, 2024 at 01:32:09PM -0500, Grant Peltier wrote:
> On Thu, Oct 24, 2024 at 06:01:11PM +0100, Conor Dooley wrote:
> > On Wed, Oct 23, 2024 at 03:53:51PM -0500, Grant Peltier wrote:
> > > + [...]
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - renesas,isl68220
> > > +      - renesas,isl68221
> > > +      - renesas,isl68222
> > > +      - renesas,isl68223
> > > +      - renesas,isl68224
> > > +      - renesas,isl68225
> > > +      - renesas,isl68226
> > > +      - renesas,isl68227
> > > +      - renesas,isl68229
> > > +      - renesas,isl68233
> > > +      - renesas,isl68239
> > > +      - renesas,isl69222
> > > +      - renesas,isl69223
> > > +      - renesas,isl69224
> > > +      - renesas,isl69225
> > > +      - renesas,isl69227
> > > +      - renesas,isl69228
> > > +      - renesas,isl69234
> > > +      - renesas,isl69236
> > > +      - renesas,isl69239
> > > +      - renesas,isl69242
> > > +      - renesas,isl69243
> > > +      - renesas,isl69247
> > > +      - renesas,isl69248
> > > +      - renesas,isl69254
> > > +      - renesas,isl69255
> > > +      - renesas,isl69256
> > > +      - renesas,isl69259
> > > +      - renesas,isl69260
> > > +      - renesas,isl69268
> > > +      - renesas,isl69269
> > > +      - renesas,isl69298
> > > +      - renesas,raa228000
> > > +      - renesas,raa228004
> > > +      - renesas,raa228006
> > > +      - renesas,raa228228
> > > +      - renesas,raa229001
> > > +      - renesas,raa229004
> > 
> > Damn, that;s a list and a half, innit! Looking briefly at the driver
> > change, the match data implies that quite a few of these actually would
> > be suitable for fallback compatibles.
> 
> Yes, there are quite a few part numbers (and likely to be more in the
> future). My intention was to make the driver more user friendly since the
> variants listed in the driver do not map to something in any of the
> datasheets. So using those instead would require users to inspect the
> source of the driver instead of simply referencing their part number(s).

I don't understand. How would a fallback materially change anything in
that regard? You still put the compatible corresponding to the device
you have in your dts. A fallback means having multiple compatible
strings in the property, not a single one corresponding to another
device.

> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  '#address-cells':
> > > +    const: 1
> > > +
> > > +  '#size-cells':
> > > +    const: 0
> > > +
> > > +patternProperties:
> > > +  "^channel@([0-3])$":
> > > +    type: object
> > > +    description:
> > > +      Container for properties specific to a particular channel (rail).
> > > +
> > > +    properties:
> > > +      reg:
> > > +        description: The channel (rail) index.
> > > +        items:
> > > +          minimum: 0
> > > +          maximum: 3
> > > +
> > > +      renesas,vout-voltage-divider:
> > 
> > There's already a binding for voltage dividers: voltage-divider.yaml
> > That said, I have no idea how that would work with an extant driver for
> > the hardware like we have here. I'd imagine it would really have to be
> > used with iio-hwmon? + Peter and Jonathan, since I don't know how the
> > driver side of using the voltage divider works.
> 
> In his recent revier, Guenter requested using a standard voltage divider
> schema as well. I see there is an implementation in maxim,maxim20730.yaml
> but that differs from the one in voltage-divider.yaml. Should I opt to
> match maxim,maxim20730.yaml?

I would rather the standard binding was used, but it would probably
involve having to hook up iio-rescale to hwmon? I don't know enough
about that, which is why I Cced Peter and Jonathan.

> > > +examples:
> > > +  - |
> > > +    i2c {
> > > +      #address-cells = <1>;
> > > +      #size-cells = <0>;
> > > +
> > > +      isl68239@60 {
> > > +        compatible = "renesas,isl68239";
> > > +        reg = <0x60>;
> > > +      };
> > > +    };
> > 
> > Without any channels, what does this actually do? If you've got no
> > channels you cannot measure anything making this example invalid?
> 
> The channel structures are optional to allow users to arbitrarily define
> voltage dividers for any particular rail. Omitting the channel definitions
> still allow the device to be instantiated and probed as an I2C device
> along with all related hwmon PMBus telemetry dictated by the part variant.

I dunno, either the channels are hooked up to something or they are not.
If they are, the channels should be populated in the devicetree.

Cheers,
Conor.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml
new file mode 100644
index 000000000000..af10c55d547f
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/renesas,isl68137.yaml
@@ -0,0 +1,131 @@ 
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/pmbus/renesas,isl68137.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas Digital Multiphase Voltage Regulators with PMBus
+
+maintainers:
+  - Grant Peltier <grant.peltier.jg@renesas.com>
+
+description: |
+  Renesas digital multiphase voltage regulators with PMBus.
+  https://www.renesas.com/en/products/power-management/multiphase-power/multiphase-dcdc-switching-controllers
+
+properties:
+  compatible:
+    enum:
+      - renesas,isl68220
+      - renesas,isl68221
+      - renesas,isl68222
+      - renesas,isl68223
+      - renesas,isl68224
+      - renesas,isl68225
+      - renesas,isl68226
+      - renesas,isl68227
+      - renesas,isl68229
+      - renesas,isl68233
+      - renesas,isl68239
+      - renesas,isl69222
+      - renesas,isl69223
+      - renesas,isl69224
+      - renesas,isl69225
+      - renesas,isl69227
+      - renesas,isl69228
+      - renesas,isl69234
+      - renesas,isl69236
+      - renesas,isl69239
+      - renesas,isl69242
+      - renesas,isl69243
+      - renesas,isl69247
+      - renesas,isl69248
+      - renesas,isl69254
+      - renesas,isl69255
+      - renesas,isl69256
+      - renesas,isl69259
+      - renesas,isl69260
+      - renesas,isl69268
+      - renesas,isl69269
+      - renesas,isl69298
+      - renesas,raa228000
+      - renesas,raa228004
+      - renesas,raa228006
+      - renesas,raa228228
+      - renesas,raa229001
+      - renesas,raa229004
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  "^channel@([0-3])$":
+    type: object
+    description:
+      Container for properties specific to a particular channel (rail).
+
+    properties:
+      reg:
+        description: The channel (rail) index.
+        items:
+          minimum: 0
+          maximum: 3
+
+      renesas,vout-voltage-divider:
+        description:
+          Resistances of a voltage divider placed between Vout and the voltage
+          sense pin for the given channel (rail). It has two numbers
+          representing the resistances of the voltage divider provided as
+          <R1 R2> which yields an adjusted Vout as
+          Vout_adj = Vout * (R1 + R2) / R2 given the original Vout as reported
+          by the Vsense pin.
+        $ref: /schemas/types.yaml#/definitions/uint32-array
+        minItems: 2
+        maxItems: 2
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      isl68239@60 {
+        compatible = "renesas,isl68239";
+        reg = <0x60>;
+      };
+    };
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      isl68239@60 {
+        compatible = "renesas,isl68239";
+        reg = <0x60>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        channel@0 {
+          reg = <0>;
+          renesas,vout-voltage-divider = <1000 1000>;  // Reported Vout/Pout would be scaled by 2
+        };
+      };
+    };