Re: [PATCH 2/2] dt-bindings: iio: Add ltc2983 documentation

Jonathan Cameron
2019-09-15T11:07:58Z

On Fri, 13 Sep 2019 15:36:21 +0100
Rob Herring <robh@kernel.org> wrote:

> On Mon, Sep 09, 2019 at 04:45:50PM +0200, Nuno Sá wrote:
> > Document the LTC2983 temperature sensor devicetree bindings.
> >
> > Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> > ---
> > .../bindings/iio/temperature/adi,ltc2983.yaml | 442 ++++++++++++++++++
> > MAINTAINERS | 1 +
> > 2 files changed, 443 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> > new file mode 100644
> > index 000000000000..2b468b3ed177
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> > @@ -0,0 +1,442 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/temperature/adi,ltc2983.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices LTC2983 Multi-sensor Temperature system
> > +
> > +maintainers:
> > + - Nuno Sá <nuno.sa@analog.com>
> > +
> > +description: |
> > + Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
> > + https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - adi,ltc2983
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + interrupts:
> > + maxItems: 1
> > +
> > + adi,temperature-celcius:
> > + description:
> > + If this property is present, the temperature is reported in Celsius.
> > + type: boolean
> > + maxItems: 1
>
> It's a boolean, not an array so 'maxItems' doesn't make sense.
>
> Running 'make dt_binding_check' should tell you this. You may need to
> update dt-schema install though.
>
> > +
> > + adi,mux-delay-config:
> > + description:
> > + The LTC2983 performs 2 or 3 internal conversion cycles per temperature result.
> > + Each conversion cycle is performed with different excitation and input multiplexer
> > + configurations. Prior to each conversion, these excitation circuits and input
> > + switch configurations are changed and an internal 1ms delay ensures settling prior
> > + to the conversion cycle in most cases. An extra delay can be configured using this
> > + property. The value written here is multiplied by 100us.

Make this adi,mux-delay-config-us and state it is rounded to nearest 100us.

> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - maximum: 255
> > + maxItems: 1
>
> Drop this.
>
> > +
> > + adi,filter-notch-freq:
> > + description:
> > + Set's the default setting of the digital filter. The default is simultaneous
> > + 50/60Hz rejection.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [0, 1, 2]
> > + maxItems: 1
>
> Drop this.
>
> > +
> > + '#address-cells':
> > + const: 1
> > +
> > + '#size-cells':
> > + const: 0
> > +
> > +patternProperties:
> > + "^thermocouple@([1-9]|1[0-9]|20)$":
> > + type: object
> > + description: Represents a thermocouple sensor which is connected to one of the device channels.
>
> Wrap lines at 80 char.
>
> > +
> > + properties:
> > + reg:
> > + description: |
> > + The channel number. It can be connected to one of the 20 channels of the device.
> > + Note that, for differential thermocouples, the minimum is 2.
> > + minimum: 1
> > + maximum: 20
> > + maxItems: 1
>
> Drop this and pretty much everywhere else that is never an array.
>
> > +
> > + adi,sensor-type:
> > + description: |
> > + Identifies the type of thermocouple connected to the device.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [1 2 3 4 5 6 7 8]
>
> Missing commas which may not even parse. Maybe be consistent with
> elsewhere and use minimum and maximum.
>
> > + maxItems: 1
> > +
> > + adi,sensor-config:
> > + description: |
> > + Raw value which set's the sensor configuration. Look at table 14 of the
> > + datasheet for how to set this value for thermocouples.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - minimum: 1
> > + - maximun: 15
> > + maxItems: 1
> > +
> > + adi,cold-junction-handle:
> > + description: |
> > + Phandle which points to a sensor object responsible for measuring the
> > + thermocouple cold junction temperature.
> > + $ref: "/schemas/types.yaml#/definitions/phandle"
> > + maxItems: 1
> > +
> > + adi,custom-sensor:
> > + description: |
> > + This is a table, where each entry should be a pair of voltage(mv)-temperature(K).
> > + The entries must be given in nv and uK so that, the original values must be
> > + multiplied by 1000000. For more details look at table 69 and 70.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/int64-array
> > + minItems: 6
> > + maxItems: 128
> > + required:
> > + - reg
> > + - adi,sensor-type
> > +
> > +patternProperties:
> > + "^diode@([1-9]|1[0-9]|20)$":
> > + type: object
> > + description: Represents a diode sensor which is connected to one of the device channels.
> > +
> > + properties:
> > + reg:
> > + description:
> > + The channel number. It can be connected to one of the 20 channels of the device.
> > + Note that, for differential diodes, the minimum is 2.
> > + minimum: 1
> > + maximum: 20
> > + maxItems: 1
> > +
> > + adi,sensor-type:
> > + description: |
> > + Identifies the sensor as a diode.
> > + const: 28
> > + maxItems: 1
> > +
> > + adi,sensor-config:
> > + description: |
> > + Raw value which set's the sensor configuration. Look at table 17 of the
> > + datasheet for how to set this value for diodes.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [0 1 2 3 4 5 6 7]
> > + maxItems: 1
> > +
> > + adi,excitation-current:
> > + description: |
> > + This property controls the magnitude of the excitation current applied
> > + to the diode. Look at table 19 of the datasheet for more info.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [0 1 2 3]
> > + maxItems: 1
> > +
> > + adi,ideal-factor-value:
> > + description: |
> > + This property sets the diode ideality factor. The real value must be
> > + multiplied by 1000000 to remove the fractional part. For more information
> > + look at table 20 of the datasheet.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + maxItems: 1
> > +
> > + required:
> > + - reg
> > + - adi,sensor-type
> > +
> > +patternProperties:
> > + "^rtd@([2-9]|1[0-9]|20)$":
> > + type: object
> > + description: Represents a rtd sensor which is connected to one of the device channels.
> > +
> > + properties:
> > + reg:
> > + description: |
> > + The channel number. It can be connected to one of the 20 channels of the device.
> > + minimum: 2
> > + maximum: 20
> > + maxItems: 1
>
> As this is pretty much the same for all child nodes, make a pattern that
> matches all child nodes and put this there rather than duplicating it.
> Then you only need 'minimum: 2' in the cases needing that.
>
> > +
> > + adi,sensor-type:
> > + description: |
> > + Identifies the type of RTD connected to the device.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [10 11 12 13 14 15 16 17]
> > + maxItems: 1
> > +
> > + adi,rsense-handle:
> > + description: |
> > + Phandle pointing to a rsense object associated with this RTD.
> > + $ref: "/schemas/types.yaml#/definitions/phandle"
> > + maxItems: 1
> > +
> > + adi,sensor-config:
> > + description: |
> > + Raw value which set's the sensor configuration. Look at table 28 of the
> > + datasheet for how to set this value for RTD's.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [0 1 4 5 8 9 10 12 13 14]
> > + maxItems: 1
> > +
> > + adi,excitation-current:
> > + description: |
> > + This property controls the magnitude of the excitation current applied
> > + to the RTD. Look at table 29 of the datasheet for more info.

Any way we can make this real units? Can list valid value here.

> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [1 2 3 4 5 6 7 8]
> > + maxItems: 1
> > +
> > + adi,rtd-curve:
> > + description: |
> > + This property set the RTD curve used and the corresponding Callendar-Van
> > + Dusen constants. Look at table 30 of the datasheet.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [0 1 2 3]
> > + maxItems: 1
> > +
> > + adi,custom-sensor:
> > + description: |
> > + This is a table, where each entry should be a pair of resistance(ohm)-temperature(K).
> > + The entries added here are in uohm and uK. For more details values look at table 74 and 75.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint64-array
> > + minItems: 6
> > + maxItems: 128
> > + required:
> > + - reg
> > + - adi,sensor-type
> > + - adi,rsense-handle
> > +
> > +patternProperties:
> > + "^thermistor@([1-9]|1[0-9]|20)$":
> > + type: object
> > + description: Represents a thermistor sensor which is connected to one of the device channels.
> > +
> > + properties:
> > + reg:
> > + description: |
> > + The channel number. It can be connected to one of the 20 channels of the device.
> > + Note that, for differential thermistors, the minimum is 2.
> > + minimum: 1
> > + maximum: 20
> > + maxItems: 1
> > +
> > + adi,sensor-type:
> > + description: |
> > + Identifies the type of thermistor connected to the device.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [19 20 21 22 23 24 25]
> > + maxItems: 1
> > +
> > + adi,rsense-handle:
> > + description: |
> > + Phandle pointing to a rsense object associated with this thermistor.
> > + $ref: "/schemas/types.yaml#/definitions/phandle"
> > + maxItems: 1
> > +
> > + adi,sensor-config:
> > + description: |
> > + Raw value which set's the sensor configuration. Look at table 52 of the
> > + datasheet for how to set this value for thermistors.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32
> > + - enum: [0 1 2 4]
> > + maxItems: 1
> > +
> > + adi,excitation-current:
> > + description: |
> > + This property controls the magnitude of the excitation current applied
> > + to the thermistor. Look at table 53 of the datasheet for more info.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint32-array
> > + - enum: [1 2 3 4 5 6 7 8 9 10 11 12]
> > + maxItems: 1
> > +
> > + adi,custom-sensor:
> > + description: |
> > + This is a table, where each entry should be a pair of resistance(ohm)-temperature(K).
> > + The entries added here are in uohm and uK only for custom thermistors.
> > + For more details look at table 78 and 79.
> > + Steinhart-Hart coefficients are also supported and can be programmed into the
> > + device memory using this property. For Steinhart sensors, this table has a constant
> > + size of 6 entries (defining the coefficients) and the values are given in the raw format.
> > + Look at table 82 for more information.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint64-array
> > + minItems: 6
> > + maxItems: 128
> > + required:
> > + - reg
> > + - adi,sensor-type
> > + - adi,rsense-handle
> > +
> > +patternProperties:
> > + "^adc@([1-9]|1[0-9]|20)$":
> > + type: object
> > + description: Represents a channel which is being used as a direct adc.
> > +
> > + properties:
> > + reg:
> > + description: |
> > + The channel number. It can be connected to one of the 20 channels of the device.
> > + Note that, for differential adc's, the minimum is 2.
> > + minimum: 1
> > + maximum: 20
> > + maxItems: 1
> > +
> > + adi,sensor-type:
> > + description: |
> > + Identifies the sensor as a direct adc.
> > + const: 30
> > + maxItems: 1
> > +
> > + adi,single-ended:
> > + description: |
> > + Boolean property which set's the adc as single-ended.
> > + type: boolean
> > +
> > + required:
> > + - reg
> > + - adi,sensor-type
> > +
> > +patternProperties:
> > + "^rsense@([2-9]|1[0-9]|20)$":
> > + type: object
> > + description: |
> > + Represents a rsense which is connected to one of the device channels.
> > + Rsense are used by thermistors and RTD's.
> > +
> > + properties:
> > + reg:
> > + description: |
> > + The channel number. It can be connected to one of the 20 channels of the device.
> > + minimum: 2
> > + maximum: 20
> > + maxItems: 1
> > +
> > + adi,sensor-type:
> > + description: |
> > + Identifies the sensor as a rsense.
> > + const: 29
> > + maxItems: 1
> > +
> > + adi,rsense-val-micro-ohms:
> > + description: |
> > + Sets the value of the sense resistor. Look at table 20 of the datasheet
> > + for information.
> > + allOf:
> > + - $ref: /schemas/types.yaml#/definitions/uint64
> > + maxItems: 1
> > +
> > + required:
> > + - reg
> > + - adi,sensor-type
> > + - adi, rsense-val
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - interrupts
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/interrupt-controller/irq.h>
> > + spi0 {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + sensor_ltc2983: ltc2983@0 {
> > + compatible = "adi,ltc2983";
> > + reg = <0>;
> > +
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + adi,temperature-celcius;
> > + interrupts = <20 IRQ_TYPE_EDGE_RISING>;
> > + interrupt-parent = <&gpio>;
> > +
> > + thermocouple@18 {
> > + reg = <18>;
> > + adi,sensor-type = <8>; //Type B
> > + adi,sensor-config = <1>; //Differential, open-circuit current
> > + adi,cold-junction-handle = <&diode5>;
> > + };
> > +
> > + diode5: diode@5 {
> > + reg = <5>;
> > + adi,sensor-type = <28>;
> > + };
> > +
> > + rsense2: rsense@2 {
> > + reg = <2>;
> > + adi,sensor-type = <29>;
> > + adi,rsense-val-micro-ohms = /bits/ 64 <1200000000>; //1.2Kohms
> > + };
> > +
> > + rtd@14 {
> > + reg = <14>;
> > + adi,sensor-type = <15>; //PT1000
> > + /*2-wire, internal gnd, no current rotation*/
> > + adi,sensor-config = <1>;
> > + adi,excitation-current = <7>; //500uA
> > + adi,rsense-handle = <&rsense2>;
> > + };
> > +
> > + adc@10 {
> > + reg = <10>;
> > + adi,sensor-type = <30>;
> > + adi,single-ended;
> > + };
> > +
> > + thermistor@12 {
> > + reg = <12>;
> > + adi,sensor-type = <26>; //Steinhart
> > + adi,rsense-handle = <&rsense2>;
> > + adi,custom-sensor = /bits/ 64 <0x00F371EC 0x12345678
> > + 0x2C0F8733 0x10018C66 0xA0FEACCD
> > + 0x90021D99>; //6 entries
> > + };
> > +
> > + thermocouple@20 {
> > + reg = <20>;
> > + adi,sensor-type = <9>; //custom thermocouple
> > + adi,sensor-config = <8>; //single-ended
> > + adi,custom-sensor = /bits/ 64
> > + <(-50220000) 0
> > + (-30200000) 99100000
> > + (-5300000) 135400000
> > + 0 273150000
> > + 40200000 361200000
> > + 55300000 522100000
> > + 88300000 720300000
> > + 132200000 811200000
> > + 188700000 922500000
> > + 460400000 1000000000>; //10 pairs
> > + };
> > +
> > + };
> > + };
> > +...
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 14a256e785ca..f747a9dc27f5 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -9497,6 +9497,7 @@ W: http://ez.analog.com/community/linux-device-drivers
> > L: linux-iio@vger.kernel.org
> > S: Supported
> > F: drivers/iio/temperature/ltc2983.c
> > +F: Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> >
> > LTC4261 HARDWARE MONITOR DRIVER
> > M: Guenter Roeck <linux@roeck-us.net>
> > --
> > 2.23.0
> >
>