On Mon, 30 Sep 2019 12:42:47 +0200 Nuno Sá <nuno.sa@xxxxxxxxxx> wrote: > Document the LTC2983 temperature sensor devicetree bindings. > > Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx> Hi Nuno, A few comments inline. This is a complex one so I'll definitely be looking for a review from Rob or Mark, 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. > > .../bindings/iio/temperature/adi,ltc2983.yaml | 406 ++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 407 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..df68b8233e5e > --- /dev/null > +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml > @@ -0,0 +1,406 @@ > +# 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@xxxxxxxxxx> > + > +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 > + > + 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. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - maximum: 255 > + > + adi,filter-notch-freq: > + description: > + Set's the default setting of the digital filter. The default is > + simultaneous 50/60Hz rejection. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - minimum: 0 > + - maximum: 2 This one is an oddity and you should define what the 3 values mean. If the sensor had supported no notch rejection at all rather than just 50, 60, 50/60 I would have suggested two bools but as it stands I guess this will just need to be an enum. > + > + '#address-cells': > + const: 1 > + > + '#size-cells': > + const: 0 > + > +patternProperties: > + ".*@([1-9]|1[0-9]|20)$": > + 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 > + > + required: > + - reg > + > + patternProperties: > + "^thermocouple@.*": > + type: object > + description: | > + Represents a thermocouple sensor which is connected to one of the device > + channels. > + > + properties: > + adi,sensor-type: > + description: | > + Identifies the type of thermocouple connected to the device. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - minimum: 1 > + - maximum: 8 Meaning of values should be defined... > + > + 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 Hmm. Whilst there are quite a few things in here, it would be nice to break it up into human readable elements. It's only 3 things and there are a bunch of don't care states it seems. > + > + 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-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: > + - adi,sensor-type > + > + "^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. > + const: 28 > + > + 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 > + - minimum: 0 > + - maximum: 7 Another one I'd like to see broken up. > + > + 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). > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - 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. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + > + required: > + - adi,sensor-type > + > + "^rtd@.*": > + type: object > + description: | > + Represents a rtd sensor which is connected to one of the device channels. > + > + properties: > + reg: > + minimum: 2 > + > + adi,sensor-type: > + description: Identifies the type of RTD connected to the device. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - minimum: 10 > + - maximum: 17 > + > + adi,rsense-handle: > + description: | > + Phandle pointing to a rsense object associated with this RTD. > + $ref: "/schemas/types.yaml#/definitions/phandle" > + > + 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] Another one to break up into it's parts, which would also get rid of the enum with gaps element. > + > + adi,excitation-current-microamp: > + description: | > + This property controls the magnitude of the excitation current > + applied to the RTD. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - 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-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: > + - adi,sensor-type > + - adi,rsense-handle > + > + "^thermistor@.*": > + type: object > + description: | > + Represents a thermistor sensor which is connected to one of the device > + channels. > + > + properties: > + adi,sensor-type: > + description: | > + Identifies the type of thermistor connected to the > + device. > + allOf: > + - $ref: /schemas/types.yaml#/definitions/uint32 > + - minimum: 19 > + - maximum: 25 > + > + adi,rsense-handle: > + description: | > + Phandle pointing to a rsense object associated with this > + thermistor. > + $ref: "/schemas/types.yaml#/definitions/phandle" > + > + 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 > + - minimum: 0 > + - maximum: 4 Nasty as value 3 is reserved. So break this one up into it's parts as well. > + > + 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-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: > + - adi,sensor-type > + - adi,rsense-handle > + > + "^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. > + const: 30 > + > + adi,single-ended: > + description: Boolean property which set's the adc as single-ended. > + type: boolean > + > + required: > + - adi,sensor-type > + > + "^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 > + > + adi,sensor-type: > + description: Identifies the sensor as a rsense. > + const: 29 > + > + 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 > + > + required: > + - 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@xxxxxxxxxxxxxxx > 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@xxxxxxxxxxxx>
