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

Rob Herring
2019-09-13T14:36:49Z

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.
> + 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.
> + 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
>