RE: [PATCH v6 3/4] dt-bindings: iio: adc: Add Xilinx AMS binding documentation

From: Anand Ashok Dumbre
Date: Thu Jul 15 2021 - 02:59:06 EST


Hi Rob,

Thank you for reviewing the patch.

My responses in line.

> -----Original Message-----
> From: Rob Herring <robh@xxxxxxxxxx>
> Sent: Tuesday 13 July 2021 11:31 PM
> To: Anand Ashok Dumbre <ANANDASH@xxxxxxxxxx>
> Cc: jic23@xxxxxxxxxx; lars@xxxxxxxxxx; linux-iio@xxxxxxxxxxxxxxx; git-dev
> <git-dev@xxxxxxxxxx>; Michal Simek <michals@xxxxxxxxxx>;
> pmeerw@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v6 3/4] dt-bindings: iio: adc: Add Xilinx AMS binding
> documentation
>
> On Thu, Jun 24, 2021 at 07:29:38PM +0100, Anand Ashok Dumbre wrote:
> > Xilinx AMS have several ADC channels that can be used for measurement
> > of different voltages and temperatures. Document the same in the
> bindings.
> >
> > Signed-off-by: Anand Ashok Dumbre <anand.ashok.dumbre@xxxxxxxxxx>
> > ---
> > .../bindings/iio/adc/xlnx,zynqmp-ams.yaml | 228 ++++++++++++++++++
> > 1 file changed, 228 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/iio/adc/xlnx,zynqmp-ams.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/iio/adc/xlnx,zynqmp-ams.yaml
> > b/Documentation/devicetree/bindings/iio/adc/xlnx,zynqmp-ams.yaml
> > new file mode 100644
> > index 000000000000..a065ddd55d38
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/xlnx,zynqmp-ams.yaml
> > @@ -0,0 +1,228 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/adc/xlnx,zynqmp-ams.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Xilinx Zynq Ultrascale AMS controller
> > +
> > +maintainers:
> > + - Anand Ashok Dumbre <anand.ashok.dumbre@xxxxxxxxxx>
> > +
> > +description: |
> > + The AMS (Analog Monitoring System) includes an ADC as well as
> > +on-chip sensors
> > + that can be used to sample external voltages and monitor on-die
> > +operating
> > + conditions, such as temperature and supply voltage levels.
> > + The AMS has two SYSMON blocks which are PL (Programmable Logic)
> > +SYSMON and
> > + PS (Processing System) SYSMON.
> > + All designs should have AMS registers, but PS and PL are optional.
> > +The
> > + AMS controller can work with only PS, only PL and both PS and PL
> > + configurations. Please specify registers according to your design.
> > +Devicetree
> > + should always have AMS module property. Providing PS & PL module is
> optional.
> > +
> > + AMS Channel Details
> > + ```````````````````
> > + Sysmon Block |Channel| Details
> |Measurement
> > + |Number | |Type
> > + -----------------------------------------------------------------------------------------
> ----------------
> > + AMS CTRL |0 |System PLLs voltage measurement, VCC_PSPLL.
> |Voltage
> > + |1 |Battery voltage measurement, VCC_PSBATT.
> |Voltage
> > + |2 |PL Internal voltage measurement, VCCINT.
> |Voltage
> > + |3 |Block RAM voltage measurement, VCCBRAM.
> |Voltage
> > + |4 |PL Aux voltage measurement, VCCAUX.
> |Voltage
> > + |5 |Voltage measurement for six DDR I/O PLLs,
> VCC_PSDDR_PLL. |Voltage
> > + |6 |VCC_PSINTFP_DDR voltage measurement.
> |Voltage
> > + -----------------------------------------------------------------------------------------
> ----------------
> > + PS Sysmon |7 |LPD temperature measurement.
> |Temperature
> > + |8 |FPD temperature measurement (REMOTE).
> |Temperature
> > + |9 |VCC PS LPD voltage measurement (supply1).
> |Voltage
> > + |10 |VCC PS FPD voltage measurement (supply2).
> |Voltage
> > + |11 |PS Aux voltage reference (supply3). |Voltage
> > + |12 |DDR I/O VCC voltage measurement.
> |Voltage
> > + |13 |PS IO Bank 503 voltage measurement (supply5).
> |Voltage
> > + |14 |PS IO Bank 500 voltage measurement (supply6).
> |Voltage
> > + |15 |VCCO_PSIO1 voltage measurement.
> |Voltage
> > + |16 |VCCO_PSIO2 voltage measurement.
> |Voltage
> > + |17 |VCC_PS_GTR voltage measurement (VPS_MGTRAVCC).
> |Voltage
> > + |18 |VTT_PS_GTR voltage measurement (VPS_MGTRAVTT).
> |Voltage
> > + |19 |VCC_PSADC voltage measurement.
> |Voltage
> > + -----------------------------------------------------------------------------------------
> ----------------
> > + PL Sysmon |20 |PL temperature measurement.
> |Temperature
> > + |21 |PL Internal voltage measurement, VCCINT.
> |Voltage
> > + |22 |PL Auxiliary voltage measurement, VCCAUX.
> |Voltage
> > + |23 |ADC Reference P+ voltage measurement.
> |Voltage
> > + |24 |ADC Reference N- voltage measurement.
> |Voltage
> > + |25 |PL Block RAM voltage measurement, VCCBRAM.
> |Voltage
> > + |26 |LPD Internal voltage measurement, VCC_PSINTLP
> (supply4). |Voltage
> > + |27 |FPD Internal voltage measurement, VCC_PSINTFP
> (supply5). |Voltage
> > + |28 |PS Auxiliary voltage measurement (supply6).
> |Voltage
> > + |29 |PL VCCADC voltage measurement (vccams).
> |Voltage
> > + |30 |Differential analog input signal voltage measurment.
> |Voltage
> > + |31 |VUser0 voltage measurement (supply7).
> |Voltage
> > + |32 |VUser1 voltage measurement (supply8).
> |Voltage
> > + |33 |VUser2 voltage measurement (supply9).
> |Voltage
> > + |34 |VUser3 voltage measurement (supply10).
> |Voltage
> > + |35 |Auxiliary ch 0 voltage measurement (VAux0).
> |Voltage
> > + |36 |Auxiliary ch 1 voltage measurement (VAux1).
> |Voltage
> > + |37 |Auxiliary ch 2 voltage measurement (VAux2).
> |Voltage
> > + |38 |Auxiliary ch 3 voltage measurement (VAux3).
> |Voltage
> > + |39 |Auxiliary ch 4 voltage measurement (VAux4).
> |Voltage
> > + |40 |Auxiliary ch 5 voltage measurement (VAux5).
> |Voltage
> > + |41 |Auxiliary ch 6 voltage measurement (VAux6).
> |Voltage
> > + |42 |Auxiliary ch 7 voltage measurement (VAux7).
> |Voltage
> > + |43 |Auxiliary ch 8 voltage measurement (VAux8).
> |Voltage
> > + |44 |Auxiliary ch 9 voltage measurement (VAux9).
> |Voltage
> > + |45 |Auxiliary ch 10 voltage measurement (VAux10).
> |Voltage
> > + |46 |Auxiliary ch 11 voltage measurement (VAux11).
> |Voltage
> > + |47 |Auxiliary ch 12 voltage measurement (VAux12).
> |Voltage
> > + |48 |Auxiliary ch 13 voltage measurement (VAux13).
> |Voltage
> > + |49 |Auxiliary ch 14 voltage measurement (VAux14).
> |Voltage
> > + |50 |Auxiliary ch 15 voltage measurement (VAux15).
> |Voltage
> > +
> > + --------------------------------------------------------------------
> > + ------------------------------------
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - xlnx,zynqmp-ams
> > +
> > + interrupts:
> > + maxItems: 1
> > +
> > + reg:
> > + description: AMS Controller register space
> > + maxItems: 1
> > +
> > + ranges:
> > + description:
> > + Maps the child address space for PS and/or PL.
> > + maxItems: 1
> > +
> > + '#address-cells':
> > + const: 1
> > +
> > + '#size-cells':
> > + const: 1
> > +
> > + '#io-channel-cells':
> > + const: 1
> > +
> > +patternProperties:
> > + "^ams-ps@0,400$":
>
> If your going to hardcode the unit-address, then it's a fixed string and should
> be under 'properties' instead.
Can you point me to an example?
When I tried putting it under just properties, I was not able to do so and was getting errors when I ran check_dt_bindings.
The only way I was not getting the error was by putting it under pattern properties.

My node looked something like this,

"ams-ps@0":
type:object
...
...

>
> The unit-address is also wrong. This is memory-mapped ranges, right? If so,
> this should just be '0' and the next one '400'.

I will fix this.
>
> > + type: object
> > + description: |
> > + PS (Processing System) SYSMON is memory mapped to PS. This block
> has
> > + built-in alarm generation logic that is used to interrupt the processor
> > + based on condition set.
> > +
> > + properties:
> > + compatible:
> > + enum:
> > + - xlnx,zynqmp-ams-ps
> > +
> > + reg:
> > + description: Register Space for PS-SYSMON
> > + maxItems: 1
> > +
> > + required:
> > + - compatible
> > + - reg
> > +
> > + additionalProperties: false
> > +
> > + "^ams-pl@400,400$":
> > + type: object
> > + description:
> > + PL-SYSMON is capable of monitoring off chip voltage and temperature.
> > + PL-SYSMON block has DRP, JTAG and I2C interface to enable
> monitoring
> > + from external master. Out of this interface currently only DRP is
> > + supported. This block has alarm generation logic that is used to
> > + interrupt the processor based on condition set.
> > +
> > + properties:
> > + compatible:
> > + items:
> > + - enum:
> > + - xlnx,zynqmp-ams-pl
> > +
> > + reg:
> > + description: Register Space for PL-SYSMON.
> > + maxItems: 1
> > +
> > + '#address-cells':
> > + const: 1
> > +
> > + '#size-cells':
> > + const: 0
> > +
> > + patternProperties:
> > + "^channel@([2-4][0-9]|50)$":
> > + type: object
> > + description:
> > + Describes the external channels connected.
> > +
> > + properties:
> > + reg:
> > + description:
> > + Pair of pins the channel is connected to. This value is
> > + same as Channel Number for a particular channel.
> > + minimum: 20
> > + maximum: 50
> > +
> > + xlnx,bipolar:
>
> Don't we have a common property for this now?
>
> > + $ref: /schemas/types.yaml#/definitions/flag
> > + type: boolean
> > + description:
> > + If the set channel is used in bipolar mode.
> > +
> > + required:
> > + - reg
> > +
> > + additionalProperties: false
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - ranges
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + bus {
> > + #address-cells = <2>;
> > + #size-cells = <2>;
> > +
> > + xilinx_ams: ams@ffa50000 {
> > + compatible = "xlnx,zynqmp-ams";
> > + interrupt-parent = <&gic>;
> > + interrupts = <0 56 4>;
> > + reg = <0x0 0xffa50000 0x0 0x800>;
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + #io-channel-cells = <1>;
> > + ranges = <0 0 0xffa50800 0x800>;
> > +
> > + ams_ps: ams-ps@0,400 {
> > + compatible = "xlnx,zynqmp-ams-ps";
> > + reg = <0 0x400>;
> > + };
> > +
> > + ams_pl: ams-pl@400,400 {
> > + compatible = "xlnx,zynqmp-ams-pl";
> > + reg = <0x400 0x400>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > + channel@30 {
> > + reg = <30>;
> > + xlnx,bipolar;
> > + };
> > + channel@31 {
> > + reg = <31>;
> > + };
> > + channel@38 {
> > + reg = <38>;
> > + xlnx,bipolar;
> > + };
> > + };
> > + };
> > + };
> > --
> > 2.17.1
> >
> >