Re: [PATCH v4 2/2] dt-bindings: iio: Add ltc2983 documentation

Jonathan Cameron
2019-10-12T10:57:52Z

On Fri, 11 Oct 2019 10:40:38 +0200
Nuno Sá <nuno.sa@analog.com> wrote:

> Document the LTC2983 temperature sensor devicetree bindings.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>

I'm happy with this, but will be waiting for Rob to have a chance
for a final look before applying.

Thanks,

Jonathan

> ---
> Changes in v2:
> * Drop maxItems in non-array elements;
> * Set adi,mux-delay-config-us instead of adi,mux-delay-config;
> * Wrapped lines at 80 char;
> * Added comas to enum elements;
> * Use real units in adi,excitation-current;
> * Moved some enums to minimum and maximum;
> * Grouped patternProperties and moved reg property as a generic property.
>
> Changes in v3:
> * Add meaning to adi,sensor-type values which are not const;
> * Add meaning to adi,filter-notch-freq values;
> * Break up adi,sensor-config into human readable elements;
> * Set maxItems/minItems at the same identation as allOf in adi,custom-sensor;
> * Fixed the maximum value for adi,sensor-type for sensors with custom support;
> * Changed license to GPL-2.0-only as it should be for new bindings;
> * Changed spi0 to spi in the dts example;
> * Updated the dts example to the new properties.
>
> Changes in v4:
> * Set correct license for new bindings;
> * Drop $ref for standard unit suffixes;
> * Dropped adi,temperature-celcius;
> * Drop '.*' in the patternProperties regex;
> * Make min/man a single schema;
> * Have rsense in milli ohms;
> * Dropped '|' when no formatting is needed;
> * Add matrixes for adi,custom-sensors;
> * Rename adi,custom-sensor to a more appropriate and distinct name;
> * Add adi,custom-stenheirt for thermistors.
>
> .../bindings/iio/temperature/adi,ltc2983.yaml | 478 ++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 479 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
>
> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> new file mode 100644
> index 000000000000..b4946c6530c0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> @@ -0,0 +1,478 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$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,mux-delay-config-us:
> + 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 is
> + rounded to nearest 100us.
> + maximum: 255
> +
> + adi,filter-notch-freq:
> + description:
> + Set's the default setting of the digital filter. The default is
> + simultaneous 50/60Hz rejection.
> + 0 - 50/60Hz rejection
> + 1 - 60Hz rejection
> + 2 - 50Hz rejection
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + - minimum: 0
> + maximum: 2
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> +patternProperties:
> + "@([1-9]|1[0-9]|20)$":
> + type: object
> +
> + properties:
> + reg:
> + description:
> + The channel number. It can be connected to one of the 20 channels of
> + the device.
> + minimum: 1
> + maximum: 20
> +
> + adi,sensor-type:
> + description: Identifies the type of sensor connected to the device.
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> + required:
> + - reg
> + - adi,sensor-type
> +
> + "^thermocouple@":
> + type: object
> + description:
> + Represents a thermocouple sensor which is connected to one of the device
> + channels.
> +
> + properties:
> + adi,sensor-type:
> + description: |
> + 1 - Type J Thermocouple
> + 2 - Type K Thermocouple
> + 3 - Type E Thermocouple
> + 4 - Type N Thermocouple
> + 5 - Type R Thermocouple
> + 6 - Type S Thermocouple
> + 7 - Type T Thermocouple
> + 8 - Type B Thermocouple
> + 9 - Custom Thermocouple
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1
> + maximum: 9
> +
> + adi,single-ended:
> + description:
> + Boolean property which set's the thermocouple as single-ended.
> + type: boolean
> +
> + adi,sensor-oc-current-microamp:
> + description:
> + This property set's the pulsed current value applied during
> + open-circuit detect.
> + enum: [10, 100, 500, 1000]
> +
> + 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"
> +
> + adi,custom-thermocouple:
> + 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-matrix
> + items:
> + minItems: 3
> + maxItems: 64
> + items:
> + minItems: 2
> + maxItems: 2
> +
> + "^diode@":
> + type: object
> + description:
> + Represents a diode sensor which is connected to one of the device
> + channels.
> +
> + properties:
> + adi,sensor-type:
> + description: Identifies the sensor as a diode.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + const: 28
> +
> + adi,single-ended:
> + description: Boolean property which set's the diode as single-ended.
> + type: boolean
> +
> + adi,three-conversion-cycles:
> + description:
> + Boolean property which set's three conversion cycles removing
> + parasitic resistance effects between the LTC2983 and the diode.
> + type: boolean
> +
> + adi,average-on:
> + description:
> + Boolean property which enables a running average of the diode
> + temperature reading. This reduces the noise when the diode is used
> + as a cold junction temperature element on an isothermal block
> + where temperatures change slowly.
> + type: boolean
> +
> + adi,excitation-current-microamp:
> + description:
> + This property controls the magnitude of the excitation current
> + applied to the diode. Depending on the number of conversions
> + cycles, this property will assume different predefined values on
> + each cycle. Just set the value of the first cycle (1l).
> + enum: [10, 20, 40, 80]
> +
> + 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.
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> + "^rtd@":
> + type: object
> + description:
> + Represents a rtd sensor which is connected to one of the device channels.
> +
> + properties:
> + reg:
> + minimum: 2
> + maximum: 20
> +
> + adi,sensor-type:
> + description: |
> + 10 - RTD PT-10
> + 11 - RTD PT-50
> + 12 - RTD PT-100
> + 13 - RTD PT-200
> + 14 - RTD PT-500
> + 15 - RTD PT-1000
> + 16 - RTD PT-1000 (0.00375)
> + 17 - RTD NI-120
> + 18 - RTD Custom
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 10
> + maximum: 18
> +
> + adi,rsense-handle:
> + description:
> + Phandle pointing to a rsense object associated with this RTD.
> + $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> + adi,number-of-wires:
> + description:
> + Identifies the number of wires used by the RTD. Setting this
> + property to 5 means 4 wires with Kelvin Rsense.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + - enum: [2, 3, 4, 5]
> +
> + adi,rsense-share:
> + description:
> + Boolean property which enables Rsense sharing, where one sense
> + resistor is used for multiple 2-, 3-, and/or 4-wire RTDs.
> + type: boolean
> +
> + adi,current-rotate:
> + description:
> + Boolean property which enables excitation current rotation to
> + automatically remove parasitic thermocouple effects. Note that
> + this property is not allowed for 2- and 3-wire RTDs.
> + type: boolean
> +
> + adi,excitation-current-microamp:
> + description:
> + This property controls the magnitude of the excitation current
> + applied to the RTD.
> + enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> +
> + adi,rtd-curve:
> + description:
> + This property set the RTD curve used and the corresponding
> + Callendar-VanDusen constants. Look at table 30 of the datasheet.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + - minimum: 0
> + maximum: 3
> +
> + adi,custom-rtd:
> + 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-matrix
> + items:
> + minItems: 3
> + maxItems: 64
> + items:
> + minItems: 2
> + maxItems: 2
> +
> + required:
> + - adi,rsense-handle
> +
> + dependencies:
> + adi,current-rotate: [ adi,rsense-share ]
> +
> + "^thermistor@":
> + type: object
> + description:
> + Represents a thermistor sensor which is connected to one of the device
> + channels.
> +
> + properties:
> + adi,sensor-type:
> + description:
> + 19 - Thermistor 44004/44033 2.252kohm at 25°C
> + 20 - Thermistor 44005/44030 3kohm at 25°C
> + 21 - Thermistor 44007/44034 5kohm at 25°C
> + 22 - Thermistor 44006/44031 10kohm at 25°C
> + 23 - Thermistor 44008/44032 30kohm at 25°C
> + 24 - Thermistor YSI 400 2.252kohm at 25°C
> + 25 - Thermistor Spectrum 1003k 1kohm
> + 26 - Thermistor Custom Steinhart-Hart
> + 27 - Custom Thermistor
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 19
> + maximum: 27
> +
> + adi,rsense-handle:
> + description:
> + Phandle pointing to a rsense object associated with this
> + thermistor.
> + $ref: "/schemas/types.yaml#/definitions/phandle"
> +
> + adi,single-ended:
> + description:
> + Boolean property which set's the thermistor as single-ended.
> + type: boolean
> +
> + adi,rsense-share:
> + description:
> + Boolean property which enables Rsense sharing, where one sense
> + resistor is used for multiple thermistors. Note that this property
> + is ignored if adi,single-ended is set.
> + type: boolean
> +
> + adi,current-rotate:
> + description:
> + Boolean property which enables excitation current rotation to
> + automatically remove parasitic thermocouple effects.
> + type: boolean
> +
> + adi,excitation-current-nanoamp:
> + description:
> + This property controls the magnitude of the excitation current
> + applied to the thermistor. Value 0 set's the sensor in auto-range
> + mode.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + - enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000,
> + 250000, 500000, 1000000]
> +
> + adi,custom-thermistor:
> + 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.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint64-matrix
> + items:
> + minItems: 3
> + maxItems: 64
> + items:
> + minItems: 2
> + maxItems: 2
> +
> + adi,custom-steinhart:
> + description:
> + Steinhart-Hart coefficients are also supported and can
> + be programmed into the device memory using this property. For
> + Steinhart sensors the coefficients are given in the raw
> + format. Look at table 82 for more information.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32-array
> + items:
> + minItems: 6
> + maxItems: 6
> +
> + required:
> + - adi,rsense-handle
> +
> + dependencies:
> + adi,current-rotate: [ adi,rsense-share ]
> +
> + "^adc@":
> + type: object
> + description: Represents a channel which is being used as a direct adc.
> +
> + properties:
> + adi,sensor-type:
> + description: Identifies the sensor as a direct adc.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + const: 30
> +
> + adi,single-ended:
> + description: Boolean property which set's the adc as single-ended.
> + type: boolean
> +
> + "^rsense@":
> + 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:
> + minimum: 2
> + maximum: 20
> +
> + adi,sensor-type:
> + description: Identifies the sensor as a rsense.
> + allOf:
> + - $ref: /schemas/types.yaml#/definitions/uint32
> + const: 29
> +
> + adi,rsense-val-milli-ohms:
> + description:
> + Sets the value of the sense resistor. Look at table 20 of the
> + datasheet for information.
> +
> + required:
> + - adi,rsense-val-milli-ohms
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/irq.h>
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + sensor_ltc2983: ltc2983@0 {
> + compatible = "adi,ltc2983";
> + reg = <0>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + interrupts = <20 IRQ_TYPE_EDGE_RISING>;
> + interrupt-parent = <&gpio>;
> +
> + thermocouple@18 {
> + reg = <18>;
> + adi,sensor-type = <8>; //Type B
> + adi,sensor-oc-current-microamp = <10>;
> + 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-milli-ohms = <1200000>; //1.2Kohms
> + };
> +
> + rtd@14 {
> + reg = <14>;
> + adi,sensor-type = <15>; //PT1000
> + /*2-wire, internal gnd, no current rotation*/
> + adi,number-of-wires = <2>;
> + adi,rsense-share;
> + adi,excitation-current-microamp = <500>;
> + 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-steinhart = <0x00F371EC 0x12345678
> + 0x2C0F8733 0x10018C66 0xA0FEACCD
> + 0x90021D99>; //6 entries
> + };
> +
> + thermocouple@20 {
> + reg = <20>;
> + adi,sensor-type = <9>; //custom thermocouple
> + adi,single-ended;
> + adi,custom-thermocouple = /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>