[PATCH v3 0/4] Support more parts in LTC2983

[PATCH v3 0/4] Support more parts in LTC2983

[Cosmin Tanislav]

Add support for the following parts:
 * LTC2984
 * LTC2986
 * LTM2985

The LTC2984 is a variant of the LTC2983 with EEPROM.
The LTC2986 is a variant of the LTC2983 with only 10 channels,
EEPROM and support for active analog temperature sensors.
The LTM2985 is software-compatible with the LTC2986.

Also, make bulk write buffer DMA-safe.

V1 -> V2:
 * add Fixes tag
 * add patch that fixes the regmap_bulk_write() call with stack allocated
   buffer
 * add patch that refines the binding in preperation for adding new
   parts support to it
 * do not use stack allocated buffer for writing the EEPROM key

V2 -> V3:
 * drop minItems if equal to maxItems
 * drop adi,single-ended conditions because of recent dtschema
   restrictions (even though they're valid in jsonschema and the last
   dtschema tag)
 * drop "allocate iio channels once" patch since it's been picked as a fix

Cosmin Tanislav (4):
  iio: temperature: ltc2983: make bulk write buffer DMA-safe
  dt-bindings: iio: temperature: ltc2983: refine
  dt-bindings: iio: temperature: ltc2983: support more parts
  iio: temperature: ltc2983: support more parts

 .../bindings/iio/temperature/adi,ltc2983.yaml | 329 +++++++++++-------
 drivers/iio/temperature/ltc2983.c             | 193 +++++++++-
 2 files changed, 380 insertions(+), 142 deletions(-)

-- 
2.38.1

[PATCH v3 1/4] iio: temperature: ltc2983: make bulk write buffer DMA-safe

[Cosmin Tanislav]

From: Cosmin Tanislav <cosmin.tanislav@analog.com>

regmap_bulk_write() does not guarantee implicit DMA-safety,
even though the current implementation duplicates the given
buffer. Do not rely on it.

Fixes: f110f3188e56 ("iio: temperature: Add support for LTC2983")
Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
---
 drivers/iio/temperature/ltc2983.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
index b652d2b39bcf..ca1bb5f48988 100644
--- a/drivers/iio/temperature/ltc2983.c
+++ b/drivers/iio/temperature/ltc2983.c
@@ -209,6 +209,7 @@ struct ltc2983_data {
 	 * Holds the converted temperature
 	 */
 	__be32 temp __aligned(IIO_DMA_MINALIGN);
+	__be32 chan_val;
 };
 
 struct ltc2983_sensor {
@@ -313,19 +314,18 @@ static int __ltc2983_fault_handler(const struct ltc2983_data *st,
 	return 0;
 }
 
-static int __ltc2983_chan_assign_common(const struct ltc2983_data *st,
+static int __ltc2983_chan_assign_common(struct ltc2983_data *st,
 					const struct ltc2983_sensor *sensor,
 					u32 chan_val)
 {
 	u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan);
-	__be32 __chan_val;
 
 	chan_val |= LTC2983_CHAN_TYPE(sensor->type);
 	dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg,
 		chan_val);
-	__chan_val = cpu_to_be32(chan_val);
-	return regmap_bulk_write(st->regmap, reg, &__chan_val,
-				 sizeof(__chan_val));
+	st->chan_val = cpu_to_be32(chan_val);
+	return regmap_bulk_write(st->regmap, reg, &st->chan_val,
+				 sizeof(st->chan_val));
 }
 
 static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st,
-- 
2.38.1

[PATCH v3 2/4] dt-bindings: iio: temperature: ltc2983: refine

[Cosmin Tanislav]

From: Cosmin Tanislav <cosmin.tanislav@analog.com>

 * make sure addresses are represented as hex
 * add note about wrong unit value for adi,mux-delay-config-us
 * simplify descriptions
 * add descriptions for the items of custom sensor tables
 * add default property values where applicable
 * use conditionals to extend minimum reg value
   for single ended sensors
 * remove " around phandle schema $ref
 * remove label from example and use generic temperature
   sensor name

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 270 ++++++++++--------
 1 file changed, 144 insertions(+), 126 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 722781aa4697..a878fd84636f 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -26,25 +26,25 @@ properties:
 
   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.
+      Extra delay prior to each conversion, in addition to the internal 1ms
+      delay, for the multiplexer to switch input configurations and
+      excitation values.
+
+      This property is supposed to be in microseconds, but to maintain
+      compatibility, this value will be multiplied by 100 before usage.
     maximum: 255
+    default: 0
 
   adi,filter-notch-freq:
     description:
-      Set's the default setting of the digital filter. The default is
-      simultaneous 50/60Hz rejection.
+      Notch frequency of the digital filter.
       0 - 50/60Hz rejection
       1 - 60Hz rejection
       2 - 50Hz rejection
     $ref: /schemas/types.yaml#/definitions/uint32
     minimum: 0
     maximum: 2
+    default: 0
 
   '#address-cells':
     const: 1
@@ -53,19 +53,19 @@ properties:
     const: 0
 
 patternProperties:
-  "@([1-9]|1[0-9]|20)$":
+  "@([0-9a-f]+)$":
     type: object
-
+    description: Sensor.
     properties:
       reg:
         description:
-          The channel number. It can be connected to one of the 20 channels of
-          the device.
+          Channel number. Connects the sensor to the channel with this number
+          of the device.
         minimum: 1
         maximum: 20
 
       adi,sensor-type:
-        description: Identifies the type of sensor connected to the device.
+        description: Type of sensor connected to the device.
         $ref: /schemas/types.yaml#/definitions/uint32
 
     required:
@@ -74,10 +74,7 @@ patternProperties:
 
   "^thermocouple@":
     type: object
-    description:
-      Represents a thermocouple sensor which is connected to one of the device
-      channels.
-
+    description: Thermocouple sensor.
     properties:
       adi,sensor-type:
         description: |
@@ -95,87 +92,86 @@ patternProperties:
         maximum: 9
 
       adi,single-ended:
-        description:
-          Boolean property which set's the thermocouple as single-ended.
+        description: Whether the sensor is single-ended.
         type: boolean
 
       adi,sensor-oc-current-microamp:
-        description:
-          This property set's the pulsed current value applied during
-          open-circuit detect.
+        description: Pulsed current value applied during open-circuit detect.
         enum: [10, 100, 500, 1000]
+        default: 10
 
       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"
+          Sensor 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.
-          Note should be signed, but dtc doesn't currently maintain the
-          sign.
+          Used for digitizing custom thermocouples.
+          See Page 59 of the datasheet.
         $ref: /schemas/types.yaml#/definitions/uint64-matrix
         minItems: 3
         maxItems: 64
         items:
-          minItems: 2
-          maxItems: 2
+          items:
+            - description: Voltage point in nV, signed.
+            - description: Temperature point in uK.
+
+    allOf:
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 9
+        then:
+          required:
+            - adi,custom-thermocouple
 
   "^diode@":
     type: object
-    description:
-      Represents a diode sensor which is connected to one of the device
-      channels.
-
+    description: Diode sensor.
     properties:
       adi,sensor-type:
-        description: Identifies the sensor as a diode.
+        description: Sensor type for diodes.
         $ref: /schemas/types.yaml#/definitions/uint32
         const: 28
 
       adi,single-ended:
-        description: Boolean property which set's the diode as single-ended.
+        description: Whether the sensor is 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.
+          Whether to use three conversion cycles to remove parasitic
+          resistance between the device 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.
+          Whether to use a running average of the diode temperature
+          reading to reduce 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).
+          Magnitude of the 1l excitation current applied to the diode.
+          4l excitation current will be 4 times this value, and 8l
+          excitation current will be 8 times value.
         enum: [10, 20, 40, 80]
+        default: 10
 
       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.
+          Diode ideality factor.
+          Set this property to 1000000 times the real value.
         $ref: /schemas/types.yaml#/definitions/uint32
+        default: 0
 
   "^rtd@":
     type: object
-    description:
-      Represents a rtd sensor which is connected to one of the device channels.
-
+    description: RTD sensor.
     properties:
       reg:
         minimum: 2
@@ -197,56 +193,57 @@ patternProperties:
         maximum: 18
 
       adi,rsense-handle:
-        description:
-          Phandle pointing to a rsense object associated with this RTD.
-        $ref: "/schemas/types.yaml#/definitions/phandle"
+        description: Associated sense resistor sensor.
+        $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.
+          Number of wires used by the RTD.
+          5 means 4 wires with Kelvin sense resistor.
         $ref: /schemas/types.yaml#/definitions/uint32
         enum: [2, 3, 4, 5]
+        default: 2
 
       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.
+          Whether to enable sense resistor sharing, where one sense
+          resistor is used by multiple sensors.
         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.
+          Whether to enable excitation current rotation to automatically
+          remove parasitic thermocouple effects.
         type: boolean
 
       adi,excitation-current-microamp:
-        description:
-          This property controls the magnitude of the excitation current
-          applied to the RTD.
+        description: Excitation current applied to the RTD.
         enum: [5, 10, 25, 50, 100, 250, 500, 1000]
+        default: 5
 
       adi,rtd-curve:
         description:
-          This property set the RTD curve used and the corresponding
-          Callendar-VanDusen constants. Look at table 30 of the datasheet.
+          RTD curve and the corresponding Callendar-VanDusen constants.
+          0 - European
+          1 - American
+          2 - Japanese
+          3 - ITS-90
         $ref: /schemas/types.yaml#/definitions/uint32
         minimum: 0
         maximum: 3
+        default: 0
 
       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.
+          Used for digitizing custom RTDs.
+          See Page 62 of the datasheet.
         $ref: /schemas/types.yaml#/definitions/uint64-matrix
+        minItems: 3
+        maxItems: 64
         items:
-          minItems: 3
-          maxItems: 64
           items:
-            minItems: 2
-            maxItems: 2
+            - description: Resistance point in uOhms.
+            - description: Temperature point in uK.
 
     required:
       - adi,rsense-handle
@@ -254,12 +251,25 @@ patternProperties:
     dependencies:
       adi,current-rotate: [ "adi,rsense-share" ]
 
+    allOf:
+      - if:
+          properties:
+            adi,number-of-wires:
+              enum: [2, 3]
+        then:
+          properties:
+            adi,current-rotate: false
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 18
+        then:
+          required:
+            - adi,custom-rtd
+
   "^thermistor@":
     type: object
-    description:
-      Represents a thermistor sensor which is connected to one of the device
-      channels.
-
+    description: Thermistor sensor.
     properties:
       adi,sensor-type:
         description:
@@ -277,61 +287,53 @@ patternProperties:
         maximum: 27
 
       adi,rsense-handle:
-        description:
-          Phandle pointing to a rsense object associated with this
-          thermistor.
-        $ref: "/schemas/types.yaml#/definitions/phandle"
+        description: Associated sense resistor sensor.
+        $ref: /schemas/types.yaml#/definitions/phandle
 
       adi,single-ended:
-        description:
-          Boolean property which set's the thermistor as single-ended.
+        description: Whether the sensor is 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.
+          Whether to enable sense resistor sharing, where one sense
+          resistor is used by multiple sensors.
         type: boolean
 
       adi,current-rotate:
         description:
-          Boolean property which enables excitation current rotation to
-          automatically remove parasitic thermocouple effects.
+          Whether to enable 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.
+          Excitation current applied to the thermistor.
+          0 sets the sensor in auto-range mode.
         $ref: /schemas/types.yaml#/definitions/uint32
         enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000, 250000,
                500000, 1000000]
+        default: 0
+
+      adi,custom-steinhart:
+        description:
+          Steinhart-Hart coefficients in raw format, used for digitizing
+          custom thermistors.
+          See Page 68 of the datasheet.
+        $ref: /schemas/types.yaml#/definitions/uint32-array
+        maxItems: 6
 
       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.
+          Used for digitizing custom thermistors.
+          See Page 65 of the datasheet.
         $ref: /schemas/types.yaml#/definitions/uint64-matrix
         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.
-        $ref: /schemas/types.yaml#/definitions/uint32-array
-        items:
-          minItems: 6
-          maxItems: 6
+          items:
+            - description: Resistance point in uOhms.
+            - description: Temperature point in uK.
 
     required:
       - adi,rsense-handle
@@ -339,40 +341,56 @@ patternProperties:
     dependencies:
       adi,current-rotate: [ "adi,rsense-share" ]
 
+    allOf:
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 26
+        then:
+          properties:
+            adi,excitation-current-nanoamp:
+              default: 1000
+          required:
+            - adi,custom-steinhart
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 27
+        then:
+          properties:
+            adi,excitation-current-nanoamp:
+              default: 1000
+          required:
+            - adi,custom-thermistor
+
   "^adc@":
     type: object
-    description: Represents a channel which is being used as a direct adc.
-
+    description: Direct ADC sensor.
     properties:
       adi,sensor-type:
-        description: Identifies the sensor as a direct adc.
+        description: Sensor type for direct ADC sensors.
         $ref: /schemas/types.yaml#/definitions/uint32
         const: 30
 
       adi,single-ended:
-        description: Boolean property which set's the adc as single-ended.
+        description: Whether the sensor is 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.
-
+    description: Sense resistor sensor.
     properties:
       reg:
         minimum: 2
         maximum: 20
 
       adi,sensor-type:
-        description: Identifies the sensor as a rsense.
+        description: Sensor type sense resistor sensors.
         $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.
+        description: Value of the sense resistor.
 
     required:
       - adi,rsense-val-milli-ohms
@@ -391,7 +409,7 @@ examples:
         #address-cells = <1>;
         #size-cells = <0>;
 
-        sensor_ltc2983: ltc2983@0 {
+        temp@0 {
                 compatible = "adi,ltc2983";
                 reg = <0>;
 
-- 
2.38.1

Re: [PATCH v3 2/4] dt-bindings: iio: temperature: ltc2983: refine

[Rob Herring]

On Tue, Oct 25, 2022 at 11:18:40AM +0300, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>

'refine' is not a great subject. That's due to doing many things in 1 
patch. I'd at least split out all the 'description' changes from actual 
schema changes to separate patches.

> 
>  * make sure addresses are represented as hex
>  * add note about wrong unit value for adi,mux-delay-config-us
>  * simplify descriptions
>  * add descriptions for the items of custom sensor tables
>  * add default property values where applicable
>  * use conditionals to extend minimum reg value
>    for single ended sensors
>  * remove " around phandle schema $ref
>  * remove label from example and use generic temperature
>    sensor name
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 270 ++++++++++--------
>  1 file changed, 144 insertions(+), 126 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> index 722781aa4697..a878fd84636f 100644
> --- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> @@ -26,25 +26,25 @@ properties:
>  
>    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.
> +      Extra delay prior to each conversion, in addition to the internal 1ms
> +      delay, for the multiplexer to switch input configurations and
> +      excitation values.
> +
> +      This property is supposed to be in microseconds, but to maintain
> +      compatibility, this value will be multiplied by 100 before usage.

You need '|' for the block if you want to retain formatting.

>      maximum: 255
> +    default: 0
>  
>    adi,filter-notch-freq:
>      description:
> -      Set's the default setting of the digital filter. The default is
> -      simultaneous 50/60Hz rejection.
> +      Notch frequency of the digital filter.
>        0 - 50/60Hz rejection
>        1 - 60Hz rejection
>        2 - 50Hz rejection
>      $ref: /schemas/types.yaml#/definitions/uint32
>      minimum: 0
>      maximum: 2
> +    default: 0
>  
>    '#address-cells':
>      const: 1
> @@ -53,19 +53,19 @@ properties:
>      const: 0
>  
>  patternProperties:
> -  "@([1-9]|1[0-9]|20)$":
> +  "@([0-9a-f]+)$":

Before 1-20 was supported which matched 'reg' and now there is no limit. 
However, you did fix that the unit address should be hex. So it should 
be:

"@([1-9a-f]|1[0-4])$"

>      type: object
> -
> +    description: Sensor.
>      properties:
>        reg:
>          description:
> -          The channel number. It can be connected to one of the 20 channels of
> -          the device.
> +          Channel number. Connects the sensor to the channel with this number
> +          of the device.
>          minimum: 1
>          maximum: 20
>  
>        adi,sensor-type:
> -        description: Identifies the type of sensor connected to the device.
> +        description: Type of sensor connected to the device.
>          $ref: /schemas/types.yaml#/definitions/uint32
>  
>      required:
> @@ -74,10 +74,7 @@ patternProperties:
>  
>    "^thermocouple@":
>      type: object
> -    description:
> -      Represents a thermocouple sensor which is connected to one of the device
> -      channels.
> -

Keep the blank line.

> +    description: Thermocouple sensor.
>      properties:
>        adi,sensor-type:
>          description: |
> @@ -95,87 +92,86 @@ patternProperties:
>          maximum: 9
>  
>        adi,single-ended:
> -        description:
> -          Boolean property which set's the thermocouple as single-ended.
> +        description: Whether the sensor is single-ended.
>          type: boolean
>  
>        adi,sensor-oc-current-microamp:
> -        description:
> -          This property set's the pulsed current value applied during
> -          open-circuit detect.
> +        description: Pulsed current value applied during open-circuit detect.
>          enum: [10, 100, 500, 1000]
> +        default: 10
>  
>        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"
> +          Sensor 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.
> -          Note should be signed, but dtc doesn't currently maintain the
> -          sign.
> +          Used for digitizing custom thermocouples.
> +          See Page 59 of the datasheet.
>          $ref: /schemas/types.yaml#/definitions/uint64-matrix
>          minItems: 3
>          maxItems: 64
>          items:
> -          minItems: 2
> -          maxItems: 2
> +          items:
> +            - description: Voltage point in nV, signed.
> +            - description: Temperature point in uK.
> +
> +    allOf:
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 9
> +        then:
> +          required:
> +            - adi,custom-thermocouple
>  
>    "^diode@":
>      type: object
> -    description:
> -      Represents a diode sensor which is connected to one of the device
> -      channels.
> -
> +    description: Diode sensor.
>      properties:
>        adi,sensor-type:
> -        description: Identifies the sensor as a diode.
> +        description: Sensor type for diodes.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          const: 28
>  
>        adi,single-ended:
> -        description: Boolean property which set's the diode as single-ended.
> +        description: Whether the sensor is 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.
> +          Whether to use three conversion cycles to remove parasitic
> +          resistance between the device 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.
> +          Whether to use a running average of the diode temperature
> +          reading to reduce 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).
> +          Magnitude of the 1l excitation current applied to the diode.
> +          4l excitation current will be 4 times this value, and 8l
> +          excitation current will be 8 times value.
>          enum: [10, 20, 40, 80]
> +        default: 10
>  
>        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.
> +          Diode ideality factor.
> +          Set this property to 1000000 times the real value.
>          $ref: /schemas/types.yaml#/definitions/uint32
> +        default: 0
>  
>    "^rtd@":
>      type: object
> -    description:
> -      Represents a rtd sensor which is connected to one of the device channels.
> -
> +    description: RTD sensor.

Keep the blank line. And any other case.

>      properties:
>        reg:
>          minimum: 2
> @@ -197,56 +193,57 @@ patternProperties:
>          maximum: 18
>  
>        adi,rsense-handle:
> -        description:
> -          Phandle pointing to a rsense object associated with this RTD.
> -        $ref: "/schemas/types.yaml#/definitions/phandle"
> +        description: Associated sense resistor sensor.
> +        $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.
> +          Number of wires used by the RTD.
> +          5 means 4 wires with Kelvin sense resistor.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          enum: [2, 3, 4, 5]
> +        default: 2
>  
>        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.
> +          Whether to enable sense resistor sharing, where one sense
> +          resistor is used by multiple sensors.
>          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.
> +          Whether to enable excitation current rotation to automatically
> +          remove parasitic thermocouple effects.
>          type: boolean
>  
>        adi,excitation-current-microamp:
> -        description:
> -          This property controls the magnitude of the excitation current
> -          applied to the RTD.
> +        description: Excitation current applied to the RTD.
>          enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> +        default: 5
>  
>        adi,rtd-curve:
>          description:
> -          This property set the RTD curve used and the corresponding
> -          Callendar-VanDusen constants. Look at table 30 of the datasheet.
> +          RTD curve and the corresponding Callendar-VanDusen constants.
> +          0 - European
> +          1 - American
> +          2 - Japanese
> +          3 - ITS-90
>          $ref: /schemas/types.yaml#/definitions/uint32
>          minimum: 0
>          maximum: 3
> +        default: 0
>  
>        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.
> +          Used for digitizing custom RTDs.
> +          See Page 62 of the datasheet.
>          $ref: /schemas/types.yaml#/definitions/uint64-matrix
> +        minItems: 3
> +        maxItems: 64
>          items:
> -          minItems: 3
> -          maxItems: 64
>            items:
> -            minItems: 2
> -            maxItems: 2
> +            - description: Resistance point in uOhms.
> +            - description: Temperature point in uK.
>  
>      required:
>        - adi,rsense-handle
> @@ -254,12 +251,25 @@ patternProperties:
>      dependencies:
>        adi,current-rotate: [ "adi,rsense-share" ]
>  
> +    allOf:
> +      - if:
> +          properties:
> +            adi,number-of-wires:
> +              enum: [2, 3]

This is also true if adi,number-of-wires is not present. You need 
'required' if that's not ensured already. (Unless this was intentional)

> +        then:
> +          properties:
> +            adi,current-rotate: false
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 18
> +        then:
> +          required:
> +            - adi,custom-rtd
> +
>    "^thermistor@":
>      type: object
> -    description:
> -      Represents a thermistor sensor which is connected to one of the device
> -      channels.
> -
> +    description: Thermistor sensor.
>      properties:
>        adi,sensor-type:
>          description:
> @@ -277,61 +287,53 @@ patternProperties:
>          maximum: 27
>  
>        adi,rsense-handle:
> -        description:
> -          Phandle pointing to a rsense object associated with this
> -          thermistor.
> -        $ref: "/schemas/types.yaml#/definitions/phandle"
> +        description: Associated sense resistor sensor.
> +        $ref: /schemas/types.yaml#/definitions/phandle
>  
>        adi,single-ended:
> -        description:
> -          Boolean property which set's the thermistor as single-ended.
> +        description: Whether the sensor is 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.
> +          Whether to enable sense resistor sharing, where one sense
> +          resistor is used by multiple sensors.
>          type: boolean
>  
>        adi,current-rotate:
>          description:
> -          Boolean property which enables excitation current rotation to
> -          automatically remove parasitic thermocouple effects.
> +          Whether to enable 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.
> +          Excitation current applied to the thermistor.
> +          0 sets the sensor in auto-range mode.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000, 250000,
>                 500000, 1000000]
> +        default: 0
> +
> +      adi,custom-steinhart:
> +        description:
> +          Steinhart-Hart coefficients in raw format, used for digitizing
> +          custom thermistors.
> +          See Page 68 of the datasheet.
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        maxItems: 6
>  
>        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.
> +          Used for digitizing custom thermistors.
> +          See Page 65 of the datasheet.
>          $ref: /schemas/types.yaml#/definitions/uint64-matrix
>          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.
> -        $ref: /schemas/types.yaml#/definitions/uint32-array
> -        items:
> -          minItems: 6
> -          maxItems: 6
> +          items:
> +            - description: Resistance point in uOhms.
> +            - description: Temperature point in uK.
>  
>      required:
>        - adi,rsense-handle
> @@ -339,40 +341,56 @@ patternProperties:
>      dependencies:
>        adi,current-rotate: [ "adi,rsense-share" ]
>  
> +    allOf:
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 26
> +        then:
> +          properties:
> +            adi,excitation-current-nanoamp:
> +              default: 1000
> +          required:
> +            - adi,custom-steinhart
> +      - if:
> +          properties:
> +            adi,sensor-type:
> +              const: 27
> +        then:
> +          properties:
> +            adi,excitation-current-nanoamp:
> +              default: 1000
> +          required:
> +            - adi,custom-thermistor
> +
>    "^adc@":
>      type: object
> -    description: Represents a channel which is being used as a direct adc.
> -
> +    description: Direct ADC sensor.
>      properties:
>        adi,sensor-type:
> -        description: Identifies the sensor as a direct adc.
> +        description: Sensor type for direct ADC sensors.
>          $ref: /schemas/types.yaml#/definitions/uint32
>          const: 30
>  
>        adi,single-ended:
> -        description: Boolean property which set's the adc as single-ended.
> +        description: Whether the sensor is 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.
> -
> +    description: Sense resistor sensor.
>      properties:
>        reg:
>          minimum: 2
>          maximum: 20
>  
>        adi,sensor-type:
> -        description: Identifies the sensor as a rsense.
> +        description: Sensor type sense resistor sensors.
>          $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.
> +        description: Value of the sense resistor.
>  
>      required:
>        - adi,rsense-val-milli-ohms
> @@ -391,7 +409,7 @@ examples:
>          #address-cells = <1>;
>          #size-cells = <0>;
>  
> -        sensor_ltc2983: ltc2983@0 {
> +        temp@0 {
>                  compatible = "adi,ltc2983";
>                  reg = <0>;
>  
> -- 
> 2.38.1
> 
> 

Re: [PATCH v3 2/4] dt-bindings: iio: temperature: ltc2983: refine

[Cosmin Tanislav]

On Wed, 2022-10-26 at 15:03 -0500, Rob Herring wrote:
> On Tue, Oct 25, 2022 at 11:18:40AM +0300, Cosmin Tanislav wrote:
> > From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> 'refine' is not a great subject. That's due to doing many things in 1
> patch. I'd at least split out all the 'description' changes from
> actual 
> schema changes to separate patches.
> 
> > 
> >  * make sure addresses are represented as hex
> >  * add note about wrong unit value for adi,mux-delay-config-us
> >  * simplify descriptions
> >  * add descriptions for the items of custom sensor tables
> >  * add default property values where applicable
> >  * use conditionals to extend minimum reg value
> >    for single ended sensors
> >  * remove " around phandle schema $ref
> >  * remove label from example and use generic temperature
> >    sensor name
> > 
> > Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> > ---
> >  .../bindings/iio/temperature/adi,ltc2983.yaml | 270 ++++++++++----
> > ----
> >  1 file changed, 144 insertions(+), 126 deletions(-)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > index 722781aa4697..a878fd84636f 100644
> > ---
> > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > +++
> > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > @@ -26,25 +26,25 @@ properties:
> >  
> >    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.
> > +      Extra delay prior to each conversion, in addition to the
> > internal 1ms
> > +      delay, for the multiplexer to switch input configurations
> > and
> > +      excitation values.
> > +
> > +      This property is supposed to be in microseconds, but to
> > maintain
> > +      compatibility, this value will be multiplied by 100 before
> > usage.
> 
> You need '|' for the block if you want to retain formatting.
> 
> >      maximum: 255
> > +    default: 0
> >  
> >    adi,filter-notch-freq:
> >      description:
> > -      Set's the default setting of the digital filter. The default
> > is
> > -      simultaneous 50/60Hz rejection.
> > +      Notch frequency of the digital filter.
> >        0 - 50/60Hz rejection
> >        1 - 60Hz rejection
> >        2 - 50Hz rejection
> >      $ref: /schemas/types.yaml#/definitions/uint32
> >      minimum: 0
> >      maximum: 2
> > +    default: 0
> >  
> >    '#address-cells':
> >      const: 1
> > @@ -53,19 +53,19 @@ properties:
> >      const: 0
> >  
> >  patternProperties:
> > -  "@([1-9]|1[0-9]|20)$":
> > +  "@([0-9a-f]+)$":
> 
> Before 1-20 was supported which matched 'reg' and now there is no
> limit. 
> However, you did fix that the unit address should be hex. So it
> should 
> be:
> 
> "@([1-9a-f]|1[0-4])$"
> 

The address is supposed to match reg, isn't it?
I made it unlimited because there's no way to modify the node name of
the patternProperty conditionally, so parts with 10 channels will be
invalid anyway.


> >      type: object
> > -
> > +    description: Sensor.
> >      properties:
> >        reg:
> >          description:
> > -          The channel number. It can be connected to one of the 20
> > channels of
> > -          the device.
> > +          Channel number. Connects the sensor to the channel with
> > this number
> > +          of the device.
> >          minimum: 1
> >          maximum: 20
> >  
> >        adi,sensor-type:
> > -        description: Identifies the type of sensor connected to
> > the device.
> > +        description: Type of sensor connected to the device.
> >          $ref: /schemas/types.yaml#/definitions/uint32
> >  
> >      required:
> > @@ -74,10 +74,7 @@ patternProperties:
> >  
> >    "^thermocouple@":
> >      type: object
> > -    description:
> > -      Represents a thermocouple sensor which is connected to one
> > of the device
> > -      channels.
> > -
> 
> Keep the blank line.
> 
> > +    description: Thermocouple sensor.
> >      properties:
> >        adi,sensor-type:
> >          description: |
> > @@ -95,87 +92,86 @@ patternProperties:
> >          maximum: 9
> >  
> >        adi,single-ended:
> > -        description:
> > -          Boolean property which set's the thermocouple as single-
> > ended.
> > +        description: Whether the sensor is single-ended.
> >          type: boolean
> >  
> >        adi,sensor-oc-current-microamp:
> > -        description:
> > -          This property set's the pulsed current value applied
> > during
> > -          open-circuit detect.
> > +        description: Pulsed current value applied during open-
> > circuit detect.
> >          enum: [10, 100, 500, 1000]
> > +        default: 10
> >  
> >        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"
> > +          Sensor 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.
> > -          Note should be signed, but dtc doesn't currently
> > maintain the
> > -          sign.
> > +          Used for digitizing custom thermocouples.
> > +          See Page 59 of the datasheet.
> >          $ref: /schemas/types.yaml#/definitions/uint64-matrix
> >          minItems: 3
> >          maxItems: 64
> >          items:
> > -          minItems: 2
> > -          maxItems: 2
> > +          items:
> > +            - description: Voltage point in nV, signed.
> > +            - description: Temperature point in uK.
> > +
> > +    allOf:
> > +      - if:
> > +          properties:
> > +            adi,sensor-type:
> > +              const: 9
> > +        then:
> > +          required:
> > +            - adi,custom-thermocouple
> >  
> >    "^diode@":
> >      type: object
> > -    description:
> > -      Represents a diode sensor which is connected to one of the
> > device
> > -      channels.
> > -
> > +    description: Diode sensor.
> >      properties:
> >        adi,sensor-type:
> > -        description: Identifies the sensor as a diode.
> > +        description: Sensor type for diodes.
> >          $ref: /schemas/types.yaml#/definitions/uint32
> >          const: 28
> >  
> >        adi,single-ended:
> > -        description: Boolean property which set's the diode as
> > single-ended.
> > +        description: Whether the sensor is 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.
> > +          Whether to use three conversion cycles to remove
> > parasitic
> > +          resistance between the device 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.
> > +          Whether to use a running average of the diode
> > temperature
> > +          reading to reduce 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).
> > +          Magnitude of the 1l excitation current applied to the
> > diode.
> > +          4l excitation current will be 4 times this value, and 8l
> > +          excitation current will be 8 times value.
> >          enum: [10, 20, 40, 80]
> > +        default: 10
> >  
> >        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.
> > +          Diode ideality factor.
> > +          Set this property to 1000000 times the real value.
> >          $ref: /schemas/types.yaml#/definitions/uint32
> > +        default: 0
> >  
> >    "^rtd@":
> >      type: object
> > -    description:
> > -      Represents a rtd sensor which is connected to one of the
> > device channels.
> > -
> > +    description: RTD sensor.
> 
> Keep the blank line. And any other case.
> 
> >      properties:
> >        reg:
> >          minimum: 2
> > @@ -197,56 +193,57 @@ patternProperties:
> >          maximum: 18
> >  
> >        adi,rsense-handle:
> > -        description:
> > -          Phandle pointing to a rsense object associated with this
> > RTD.
> > -        $ref: "/schemas/types.yaml#/definitions/phandle"
> > +        description: Associated sense resistor sensor.
> > +        $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.
> > +          Number of wires used by the RTD.
> > +          5 means 4 wires with Kelvin sense resistor.
> >          $ref: /schemas/types.yaml#/definitions/uint32
> >          enum: [2, 3, 4, 5]
> > +        default: 2
> >  
> >        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.
> > +          Whether to enable sense resistor sharing, where one
> > sense
> > +          resistor is used by multiple sensors.
> >          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.
> > +          Whether to enable excitation current rotation to
> > automatically
> > +          remove parasitic thermocouple effects.
> >          type: boolean
> >  
> >        adi,excitation-current-microamp:
> > -        description:
> > -          This property controls the magnitude of the excitation
> > current
> > -          applied to the RTD.
> > +        description: Excitation current applied to the RTD.
> >          enum: [5, 10, 25, 50, 100, 250, 500, 1000]
> > +        default: 5
> >  
> >        adi,rtd-curve:
> >          description:
> > -          This property set the RTD curve used and the
> > corresponding
> > -          Callendar-VanDusen constants. Look at table 30 of the
> > datasheet.
> > +          RTD curve and the corresponding Callendar-VanDusen
> > constants.
> > +          0 - European
> > +          1 - American
> > +          2 - Japanese
> > +          3 - ITS-90
> >          $ref: /schemas/types.yaml#/definitions/uint32
> >          minimum: 0
> >          maximum: 3
> > +        default: 0
> >  
> >        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.
> > +          Used for digitizing custom RTDs.
> > +          See Page 62 of the datasheet.
> >          $ref: /schemas/types.yaml#/definitions/uint64-matrix
> > +        minItems: 3
> > +        maxItems: 64
> >          items:
> > -          minItems: 3
> > -          maxItems: 64
> >            items:
> > -            minItems: 2
> > -            maxItems: 2
> > +            - description: Resistance point in uOhms.
> > +            - description: Temperature point in uK.
> >  
> >      required:
> >        - adi,rsense-handle
> > @@ -254,12 +251,25 @@ patternProperties:
> >      dependencies:
> >        adi,current-rotate: [ "adi,rsense-share" ]
> >  
> > +    allOf:
> > +      - if:
> > +          properties:
> > +            adi,number-of-wires:
> > +              enum: [2, 3]
> 
> This is also true if adi,number-of-wires is not present. You need 
> 'required' if that's not ensured already. (Unless this was
> intentional)
> 
> > +        then:
> > +          properties:
> > +            adi,current-rotate: false
> > +      - if:
> > +          properties:
> > +            adi,sensor-type:
> > +              const: 18
> > +        then:
> > +          required:
> > +            - adi,custom-rtd
> > +
> >    "^thermistor@":
> >      type: object
> > -    description:
> > -      Represents a thermistor sensor which is connected to one of
> > the device
> > -      channels.
> > -
> > +    description: Thermistor sensor.
> >      properties:
> >        adi,sensor-type:
> >          description:
> > @@ -277,61 +287,53 @@ patternProperties:
> >          maximum: 27
> >  
> >        adi,rsense-handle:
> > -        description:
> > -          Phandle pointing to a rsense object associated with this
> > -          thermistor.
> > -        $ref: "/schemas/types.yaml#/definitions/phandle"
> > +        description: Associated sense resistor sensor.
> > +        $ref: /schemas/types.yaml#/definitions/phandle
> >  
> >        adi,single-ended:
> > -        description:
> > -          Boolean property which set's the thermistor as single-
> > ended.
> > +        description: Whether the sensor is 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.
> > +          Whether to enable sense resistor sharing, where one
> > sense
> > +          resistor is used by multiple sensors.
> >          type: boolean
> >  
> >        adi,current-rotate:
> >          description:
> > -          Boolean property which enables excitation current
> > rotation to
> > -          automatically remove parasitic thermocouple effects.
> > +          Whether to enable 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.
> > +          Excitation current applied to the thermistor.
> > +          0 sets the sensor in auto-range mode.
> >          $ref: /schemas/types.yaml#/definitions/uint32
> >          enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000,
> > 100000, 250000,
> >                 500000, 1000000]
> > +        default: 0
> > +
> > +      adi,custom-steinhart:
> > +        description:
> > +          Steinhart-Hart coefficients in raw format, used for
> > digitizing
> > +          custom thermistors.
> > +          See Page 68 of the datasheet.
> > +        $ref: /schemas/types.yaml#/definitions/uint32-array
> > +        maxItems: 6
> >  
> >        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.
> > +          Used for digitizing custom thermistors.
> > +          See Page 65 of the datasheet.
> >          $ref: /schemas/types.yaml#/definitions/uint64-matrix
> >          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.
> > -        $ref: /schemas/types.yaml#/definitions/uint32-array
> > -        items:
> > -          minItems: 6
> > -          maxItems: 6
> > +          items:
> > +            - description: Resistance point in uOhms.
> > +            - description: Temperature point in uK.
> >  
> >      required:
> >        - adi,rsense-handle
> > @@ -339,40 +341,56 @@ patternProperties:
> >      dependencies:
> >        adi,current-rotate: [ "adi,rsense-share" ]
> >  
> > +    allOf:
> > +      - if:
> > +          properties:
> > +            adi,sensor-type:
> > +              const: 26
> > +        then:
> > +          properties:
> > +            adi,excitation-current-nanoamp:
> > +              default: 1000
> > +          required:
> > +            - adi,custom-steinhart
> > +      - if:
> > +          properties:
> > +            adi,sensor-type:
> > +              const: 27
> > +        then:
> > +          properties:
> > +            adi,excitation-current-nanoamp:
> > +              default: 1000
> > +          required:
> > +            - adi,custom-thermistor
> > +
> >    "^adc@":
> >      type: object
> > -    description: Represents a channel which is being used as a
> > direct adc.
> > -
> > +    description: Direct ADC sensor.
> >      properties:
> >        adi,sensor-type:
> > -        description: Identifies the sensor as a direct adc.
> > +        description: Sensor type for direct ADC sensors.
> >          $ref: /schemas/types.yaml#/definitions/uint32
> >          const: 30
> >  
> >        adi,single-ended:
> > -        description: Boolean property which set's the adc as
> > single-ended.
> > +        description: Whether the sensor is 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.
> > -
> > +    description: Sense resistor sensor.
> >      properties:
> >        reg:
> >          minimum: 2
> >          maximum: 20
> >  
> >        adi,sensor-type:
> > -        description: Identifies the sensor as a rsense.
> > +        description: Sensor type sense resistor sensors.
> >          $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.
> > +        description: Value of the sense resistor.
> >  
> >      required:
> >        - adi,rsense-val-milli-ohms
> > @@ -391,7 +409,7 @@ examples:
> >          #address-cells = <1>;
> >          #size-cells = <0>;
> >  
> > -        sensor_ltc2983: ltc2983@0 {
> > +        temp@0 {
> >                  compatible = "adi,ltc2983";
> >                  reg = <0>;
> >  
> > -- 
> > 2.38.1
> > 
> > 

[PATCH v3 3/4] dt-bindings: iio: temperature: ltc2983: support more parts

[Cosmin Tanislav]

From: Cosmin Tanislav <cosmin.tanislav@analog.com>

Add support for the following parts:
 * LTC2984
 * LTC2986
 * LTM2985

The LTC2984 is a variant of the LTC2983 with EEPROM.
The LTC2986 is a variant of the LTC2983 with only 10 channels,
EEPROM and support for active analog temperature sensors.
The LTM2985 is software-compatible with the LTC2986.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 59 +++++++++++++++++--
 1 file changed, 55 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index a878fd84636f..5380a3b4e508 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -4,19 +4,30 @@
 $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
+title: Analog Devices LTC2983, LTC2986, LTM2985 Multi-sensor Temperature system
 
 maintainers:
   - Nuno Sá <nuno.sa@analog.com>
 
 description: |
-  Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
+  Analog Devices LTC2983, LTC2984, LTC2986, LTM2985 Multi-Sensor Digital
+  Temperature Measurement Systems
+
   https://www.analog.com/media/en/technical-documentation/data-sheets/2983fc.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/2984fb.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/29861fa.pdf
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ltm2985.pdf
 
 properties:
   compatible:
-    enum:
-      - adi,ltc2983
+    oneOf:
+      - enum:
+          - adi,ltc2983
+          - adi,ltc2986
+          - adi,ltm2985
+      - items:
+          - const: adi,ltc2984
+          - const: adi,ltc2983
 
   reg:
     maxItems: 1
@@ -376,6 +387,34 @@ patternProperties:
         description: Whether the sensor is single-ended.
         type: boolean
 
+  "^temp@":
+    type: object
+    description: Active analog temperature sensor.
+    properties:
+      adi,sensor-type:
+        description: Sensor type for active analog temperature sensors.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        const: 31
+
+      adi,single-ended:
+        description: Whether the sensor is single-ended.
+        type: boolean
+
+      adi,custom-temp:
+        description:
+          Used for digitizing active analog temperature sensors.
+          See Page 67 of the LTM2985 datasheet.
+        $ref: /schemas/types.yaml#/definitions/uint64-matrix
+        minItems: 3
+        maxItems: 64
+        items:
+          items:
+            - description: Voltage point in nV, signed.
+            - description: Temperature point in uK.
+
+    required:
+      - adi,custom-temp
+
   "^rsense@":
     type: object
     description: Sense resistor sensor.
@@ -402,6 +441,18 @@ required:
 
 additionalProperties: false
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - adi,ltc2983
+              - adi,ltc2984
+    then:
+      patternProperties:
+        "^temp@": false
+
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>
-- 
2.38.1

Re: [PATCH v3 3/4] dt-bindings: iio: temperature: ltc2983: support more parts

[Rob Herring]

On Tue, 25 Oct 2022 11:18:41 +0300, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Add support for the following parts:
>  * LTC2984
>  * LTC2986
>  * LTM2985
> 
> The LTC2984 is a variant of the LTC2983 with EEPROM.
> The LTC2986 is a variant of the LTC2983 with only 10 channels,
> EEPROM and support for active analog temperature sensors.
> The LTM2985 is software-compatible with the LTC2986.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 59 +++++++++++++++++--
>  1 file changed, 55 insertions(+), 4 deletions(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v3 4/4] iio: temperature: ltc2983: support more parts

[Cosmin Tanislav]

From: Cosmin Tanislav <cosmin.tanislav@analog.com>

Add support for the following parts:
 * LTC2984
 * LTC2986
 * LTM2985

The LTC2984 is a variant of the LTC2983 with EEPROM.
The LTC2986 is a variant of the LTC2983 with only 10 channels,
EEPROM and support for active analog temperature sensors.
The LTM2985 is software-compatible with the LTC2986.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
---
 drivers/iio/temperature/ltc2983.c | 183 ++++++++++++++++++++++++++++--
 1 file changed, 176 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/temperature/ltc2983.c b/drivers/iio/temperature/ltc2983.c
index ca1bb5f48988..72c052e4c7bc 100644
--- a/drivers/iio/temperature/ltc2983.c
+++ b/drivers/iio/temperature/ltc2983.c
@@ -25,9 +25,12 @@
 #define LTC2983_STATUS_REG			0x0000
 #define LTC2983_TEMP_RES_START_REG		0x0010
 #define LTC2983_TEMP_RES_END_REG		0x005F
+#define LTC2983_EEPROM_KEY_REG			0x00B0
+#define LTC2983_EEPROM_READ_STATUS_REG		0x00D0
 #define LTC2983_GLOBAL_CONFIG_REG		0x00F0
 #define LTC2983_MULT_CHANNEL_START_REG		0x00F4
 #define LTC2983_MULT_CHANNEL_END_REG		0x00F7
+#define LTC2986_EEPROM_STATUS_REG		0x00F9
 #define LTC2983_MUX_CONFIG_REG			0x00FF
 #define LTC2983_CHAN_ASSIGN_START_REG		0x0200
 #define LTC2983_CHAN_ASSIGN_END_REG		0x024F
@@ -35,13 +38,21 @@
 #define LTC2983_CUST_SENS_TBL_END_REG		0x03CF
 
 #define LTC2983_DIFFERENTIAL_CHAN_MIN		2
-#define LTC2983_MAX_CHANNELS_NR			20
 #define LTC2983_MIN_CHANNELS_NR			1
 #define LTC2983_SLEEP				0x97
 #define LTC2983_CUSTOM_STEINHART_SIZE		24
 #define LTC2983_CUSTOM_SENSOR_ENTRY_SZ		6
 #define LTC2983_CUSTOM_STEINHART_ENTRY_SZ	4
 
+#define LTC2983_EEPROM_KEY			0xA53C0F5A
+#define LTC2983_EEPROM_WRITE_CMD		0x15
+#define LTC2983_EEPROM_READ_CMD			0x16
+#define LTC2983_EEPROM_STATUS_FAILURE_MASK	GENMASK(3, 1)
+#define LTC2983_EEPROM_READ_FAILURE_MASK	GENMASK(7, 0)
+
+#define LTC2983_EEPROM_WRITE_TIME_MS		2600
+#define LTC2983_EEPROM_READ_TIME_MS		20
+
 #define LTC2983_CHAN_START_ADDR(chan) \
 			(((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)
 #define LTC2983_CHAN_RES_ADDR(chan) \
@@ -171,6 +182,7 @@ enum {
 	LTC2983_SENSOR_DIODE = 28,
 	LTC2983_SENSOR_SENSE_RESISTOR = 29,
 	LTC2983_SENSOR_DIRECT_ADC = 30,
+	LTC2983_SENSOR_ACTIVE_TEMP = 31,
 };
 
 #define to_thermocouple(_sensor) \
@@ -191,7 +203,17 @@ enum {
 #define to_adc(_sensor) \
 		container_of(_sensor, struct ltc2983_adc, sensor)
 
+#define to_temp(_sensor) \
+		container_of(_sensor, struct ltc2983_temp, sensor)
+
+struct ltc2983_chip_info {
+	unsigned int max_channels_nr;
+	bool has_temp;
+	bool has_eeprom;
+};
+
 struct ltc2983_data {
+	const struct ltc2983_chip_info *info;
 	struct regmap *regmap;
 	struct spi_device *spi;
 	struct mutex lock;
@@ -210,6 +232,7 @@ struct ltc2983_data {
 	 */
 	__be32 temp __aligned(IIO_DMA_MINALIGN);
 	__be32 chan_val;
+	__be32 eeprom_key;
 };
 
 struct ltc2983_sensor {
@@ -272,6 +295,12 @@ struct ltc2983_adc {
 	bool single_ended;
 };
 
+struct ltc2983_temp {
+	struct ltc2983_sensor sensor;
+	struct ltc2983_custom_sensor *custom;
+	bool single_ended;
+};
+
 /*
  * Convert to Q format numbers. These number's are integers where
  * the number of integer and fractional bits are specified. The resolution
@@ -606,6 +635,22 @@ static int ltc2983_adc_assign_chan(struct ltc2983_data *st,
 	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 }
 
+static int ltc2983_temp_assign_chan(struct ltc2983_data *st,
+				    const struct ltc2983_sensor *sensor)
+{
+	struct ltc2983_temp *temp = to_temp(sensor);
+	u32 chan_val;
+	int ret;
+
+	chan_val = LTC2983_ADC_SINGLE_ENDED(temp->single_ended);
+
+	ret = __ltc2983_chan_custom_sensor_assign(st, temp->custom, &chan_val);
+	if (ret)
+		return ret;
+
+	return __ltc2983_chan_assign_common(st, sensor, chan_val);
+}
+
 static struct ltc2983_sensor *
 ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 			 const struct ltc2983_sensor *sensor)
@@ -771,10 +816,10 @@ ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 	if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {
 		/* 4-wire */
 		u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,
-			max = LTC2983_MAX_CHANNELS_NR;
+			max = st->info->max_channels_nr;
 
 		if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)
-			max = LTC2983_MAX_CHANNELS_NR - 1;
+			max = st->info->max_channels_nr - 1;
 
 		if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
 		     == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
@@ -1143,6 +1188,38 @@ static struct ltc2983_sensor *ltc2983_adc_new(struct fwnode_handle *child,
 	return &adc->sensor;
 }
 
+static struct ltc2983_sensor *ltc2983_temp_new(struct fwnode_handle *child,
+					       struct ltc2983_data *st,
+					       const struct ltc2983_sensor *sensor)
+{
+	struct ltc2983_temp *temp;
+
+	temp = devm_kzalloc(&st->spi->dev, sizeof(*temp), GFP_KERNEL);
+	if (!temp)
+		return ERR_PTR(-ENOMEM);
+
+	if (fwnode_property_read_bool(child, "adi,single-ended"))
+		temp->single_ended = true;
+
+	if (!temp->single_ended &&
+	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
+		dev_err(&st->spi->dev, "Invalid chan:%d for differential temp\n",
+			sensor->chan);
+		return ERR_PTR(-EINVAL);
+	}
+
+	temp->custom = __ltc2983_custom_sensor_new(st, child, "adi,custom-temp",
+						   false, 4096, true);
+	if (IS_ERR(temp->custom))
+		return ERR_CAST(temp->custom);
+
+	/* set common parameters */
+	temp->sensor.assign_chan = ltc2983_temp_assign_chan;
+	temp->sensor.fault_handler = ltc2983_common_fault_handler;
+
+	return &temp->sensor;
+}
+
 static int ltc2983_chan_read(struct ltc2983_data *st,
 			const struct ltc2983_sensor *sensor, int *val)
 {
@@ -1302,10 +1379,10 @@ static int ltc2983_parse_dt(struct ltc2983_data *st)
 
 		/* check if we have a valid channel */
 		if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
-		    sensor.chan > LTC2983_MAX_CHANNELS_NR) {
+		    sensor.chan > st->info->max_channels_nr) {
 			ret = -EINVAL;
 			dev_err(dev, "chan:%d must be from %u to %u\n", sensor.chan,
-				LTC2983_MIN_CHANNELS_NR, LTC2983_MAX_CHANNELS_NR);
+				LTC2983_MIN_CHANNELS_NR, st->info->max_channels_nr);
 			goto put_child;
 		} else if (channel_avail_mask & BIT(sensor.chan)) {
 			ret = -EINVAL;
@@ -1345,6 +1422,9 @@ static int ltc2983_parse_dt(struct ltc2983_data *st)
 			st->iio_channels--;
 		} else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {
 			st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);
+		} else if (st->info->has_temp &&
+			   sensor.type == LTC2983_SENSOR_ACTIVE_TEMP) {
+			st->sensors[chan] = ltc2983_temp_new(child, st, &sensor);
 		} else {
 			dev_err(dev, "Unknown sensor type %d\n", sensor.type);
 			ret = -EINVAL;
@@ -1371,6 +1451,45 @@ static int ltc2983_parse_dt(struct ltc2983_data *st)
 	return ret;
 }
 
+static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
+			      unsigned int wait_time, unsigned int status_reg,
+			      unsigned long status_fail_mask)
+{
+	unsigned long time;
+	unsigned int val;
+	int ret;
+
+	ret = regmap_bulk_write(st->regmap, LTC2983_EEPROM_KEY_REG,
+				&st->eeprom_key, sizeof(st->eeprom_key));
+	if (ret)
+		return ret;
+
+	reinit_completion(&st->completion);
+
+	ret = regmap_write(st->regmap, LTC2983_STATUS_REG,
+			   LTC2983_STATUS_START(true) | cmd);
+	if (ret)
+		return ret;
+
+	time = wait_for_completion_timeout(&st->completion,
+					   msecs_to_jiffies(wait_time));
+	if (!time) {
+		dev_err(&st->spi->dev, "EEPROM command timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	ret = regmap_read(st->regmap, status_reg, &val);
+	if (ret)
+		return ret;
+
+	if (val & status_fail_mask) {
+		dev_err(&st->spi->dev, "EEPROM command failed: 0x%02X\n", val);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
 {
 	u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status;
@@ -1403,6 +1522,15 @@ static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
 	if (ret)
 		return ret;
 
+	if (st->info->has_eeprom && !assign_iio) {
+		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_READ_CMD,
+					 LTC2983_EEPROM_READ_TIME_MS,
+					 LTC2983_EEPROM_READ_STATUS_REG,
+					 LTC2983_EEPROM_READ_FAILURE_MASK);
+		if (!ret)
+			return 0;
+	}
+
 	for (chan = 0; chan < st->num_channels; chan++) {
 		u32 chan_type = 0, *iio_chan;
 
@@ -1442,9 +1570,13 @@ static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
 static const struct regmap_range ltc2983_reg_ranges[] = {
 	regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG),
 	regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG),
+	regmap_reg_range(LTC2983_EEPROM_KEY_REG, LTC2983_EEPROM_KEY_REG),
+	regmap_reg_range(LTC2983_EEPROM_READ_STATUS_REG,
+			 LTC2983_EEPROM_READ_STATUS_REG),
 	regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG),
 	regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG,
 			 LTC2983_MULT_CHANNEL_END_REG),
+	regmap_reg_range(LTC2986_EEPROM_STATUS_REG, LTC2986_EEPROM_STATUS_REG),
 	regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG),
 	regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG,
 			 LTC2983_CHAN_ASSIGN_END_REG),
@@ -1489,6 +1621,12 @@ static int ltc2983_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
+	st->info = device_get_match_data(&spi->dev);
+	if (!st->info)
+		st->info = (void *)spi_get_device_id(spi)->driver_data;
+	if (!st->info)
+		return -ENODEV;
+
 	st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
 	if (IS_ERR(st->regmap)) {
 		dev_err(&spi->dev, "Failed to initialize regmap\n");
@@ -1498,6 +1636,7 @@ static int ltc2983_probe(struct spi_device *spi)
 	mutex_init(&st->lock);
 	init_completion(&st->completion);
 	st->spi = spi;
+	st->eeprom_key = cpu_to_be32(LTC2983_EEPROM_KEY);
 	spi_set_drvdata(spi, st);
 
 	ret = ltc2983_parse_dt(st);
@@ -1525,6 +1664,15 @@ static int ltc2983_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	if (st->info->has_eeprom) {
+		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_WRITE_CMD,
+					 LTC2983_EEPROM_WRITE_TIME_MS,
+					 LTC2986_EEPROM_STATUS_REG,
+					 LTC2983_EEPROM_STATUS_FAILURE_MASK);
+		if (ret)
+			return ret;
+	}
+
 	indio_dev->name = name;
 	indio_dev->num_channels = st->iio_channels;
 	indio_dev->channels = st->iio_chan;
@@ -1555,14 +1703,35 @@ static int ltc2983_suspend(struct device *dev)
 static DEFINE_SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend,
 				ltc2983_resume);
 
+static const struct ltc2983_chip_info ltc2983_chip_info_data = {
+	.max_channels_nr = 20,
+};
+
+static const struct ltc2983_chip_info ltc2984_chip_info_data = {
+	.max_channels_nr = 20,
+	.has_eeprom = true,
+};
+
+static const struct ltc2983_chip_info ltc2986_chip_info_data = {
+	.max_channels_nr = 10,
+	.has_temp = true,
+	.has_eeprom = true,
+};
+
 static const struct spi_device_id ltc2983_id_table[] = {
-	{ "ltc2983" },
+	{ "ltc2983", (kernel_ulong_t)&ltc2983_chip_info_data },
+	{ "ltc2984", (kernel_ulong_t)&ltc2984_chip_info_data },
+	{ "ltc2986", (kernel_ulong_t)&ltc2986_chip_info_data },
+	{ "ltm2985", (kernel_ulong_t)&ltc2986_chip_info_data },
 	{},
 };
 MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
 
 static const struct of_device_id ltc2983_of_match[] = {
-	{ .compatible = "adi,ltc2983" },
+	{ .compatible = "adi,ltc2983", .data = &ltc2983_chip_info_data },
+	{ .compatible = "adi,ltc2984", .data = &ltc2984_chip_info_data },
+	{ .compatible = "adi,ltc2986", .data = &ltc2986_chip_info_data },
+	{ .compatible = "adi,ltm2985", .data = &ltc2986_chip_info_data },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ltc2983_of_match);
-- 
2.38.1