[PATCH v4 00/13] Support more parts in LTC2983

[PATCH v4 00/13] 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.
Besides that, refine the binding.

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

V3 -> V4:
  * add pipe for 'adi,mux-delay-config-us' description
  * add pipe for 'adi,rtd-curve' description
  * keep newlines after descriptions
  * move 'adi,current-rotate' to conditional
  * put 'adi,custom-steinhart' in the original place
  * keep 'minItems' for 'adi,custom-steinhart'
  * override 'enum' to forbid auto-range in 'adi,excitation-current-nanoamp'
    when using custom thermistors
  * split refine patch into multiple patches
    - use generic node name in example
    - describe broken mux delay property
    - refine descriptions
    - change default excitation for custom thermistors
    - require 4 wire rtd for current rotate
    - require custom sensor tables
    - describe matrix items
    - remove qutations from phandle ref
    - use hex for sensor address
    - add default values

Cosmin Tanislav (13):
  iio: temperature: ltc2983: make bulk write buffer DMA-safe
  dt-bindings: iio: temperature: ltc2983: add default values
  dt-bindings: iio: temperature: ltc2983: use hex for sensor address
  dt-bindings: iio: temperature: ltc2983: remove qutations from phandle
    ref
  dt-bindings: iio: temperature: ltc2983: describe matrix items
  dt-bindings: iio: temperature: ltc2983: require custom sensor tables
  dt-bindings: iio: temperature: ltc2983: require 4 wire rtd for current
    rotate
  dt-bindings: iio: temperature: ltc2983: change default excitation for
    custom thermistors
  dt-bindings: iio: temperature: ltc2983: refine descriptions
  dt-bindings: iio: temperature: ltc2983: describe broken mux delay
    property
  dt-bindings: iio: temperature: ltc2983: use generic node name in
    example
  dt-bindings: iio: temperature: ltc2983: support more parts
  iio: temperature: ltc2983: support more parts

 .../bindings/iio/temperature/adi,ltc2983.yaml | 335 +++++++++++-------
 drivers/iio/temperature/ltc2983.c             | 193 +++++++++-
 2 files changed, 389 insertions(+), 139 deletions(-)

-- 
2.38.1

[PATCH v4 01/13] 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>
---
 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 v4 02/13] dt-bindings: iio: temperature: ltc2983: add default values

[Cosmin Tanislav]

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

Binding properties should have default values to let the reader
know if they should change it. Add them based on driver logic.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 722781aa4697..82667adc85b1 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -34,6 +34,7 @@ properties:
       cases. An extra delay can be configured using this property. The value is
       rounded to nearest 100us.
     maximum: 255
+    default: 0
 
   adi,filter-notch-freq:
     description:
@@ -45,6 +46,7 @@ properties:
     $ref: /schemas/types.yaml#/definitions/uint32
     minimum: 0
     maximum: 2
+    default: 0
 
   '#address-cells':
     const: 1
@@ -104,6 +106,7 @@ patternProperties:
           This property set's the pulsed current value applied during
           open-circuit detect.
         enum: [10, 100, 500, 1000]
+        default: 10
 
       adi,cold-junction-handle:
         description:
@@ -163,6 +166,7 @@ patternProperties:
           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]
+        default: 10
 
       adi,ideal-factor-value:
         description:
@@ -170,6 +174,7 @@ patternProperties:
           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
+        default: 0
 
   "^rtd@":
     type: object
@@ -207,6 +212,7 @@ patternProperties:
           property to 5 means 4 wires with Kelvin Rsense.
         $ref: /schemas/types.yaml#/definitions/uint32
         enum: [2, 3, 4, 5]
+        default: 2
 
       adi,rsense-share:
         description:
@@ -226,6 +232,7 @@ patternProperties:
           This property controls the magnitude of the excitation current
           applied to the RTD.
         enum: [5, 10, 25, 50, 100, 250, 500, 1000]
+        default: 5
 
       adi,rtd-curve:
         description:
@@ -234,6 +241,7 @@ patternProperties:
         $ref: /schemas/types.yaml#/definitions/uint32
         minimum: 0
         maximum: 3
+        default: 0
 
       adi,custom-rtd:
         description:
@@ -308,6 +316,7 @@ patternProperties:
         $ref: /schemas/types.yaml#/definitions/uint32
         enum: [0, 250, 500, 1000, 5000, 10000, 25000, 50000, 100000, 250000,
                500000, 1000000]
+        default: 0
 
       adi,custom-thermistor:
         description:
-- 
2.38.1

Re: [PATCH v4 02/13] dt-bindings: iio: temperature: ltc2983: add default values

[Rob Herring]

On Thu, 03 Nov 2022 15:00:30 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Binding properties should have default values to let the reader
> know if they should change it. Add them based on driver logic.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 

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

[PATCH v4 03/13] dt-bindings: iio: temperature: ltc2983: use hex for sensor address

[Cosmin Tanislav]

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

Addresses should be in hex, fix it.

Although the driver initially specified 1-20, it can be made free-range
since the address is supposed to match reg, onto which we can impose
restrictions based on the compatible property value.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 82667adc85b1..29f6fa5e2529 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -55,7 +55,7 @@ properties:
     const: 0
 
 patternProperties:
-  "@([1-9]|1[0-9]|20)$":
+  "@([0-9a-f]+)$":
     type: object
 
     properties:
-- 
2.38.1

Re: [PATCH v4 03/13] dt-bindings: iio: temperature: ltc2983: use hex for sensor address

[Rob Herring]

On Thu, 03 Nov 2022 15:00:31 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Addresses should be in hex, fix it.
> 
> Although the driver initially specified 1-20, it can be made free-range
> since the address is supposed to match reg, onto which we can impose
> restrictions based on the compatible property value.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml        | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

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

[PATCH v4 04/13] dt-bindings: iio: temperature: ltc2983: remove qutations from phandle ref

[Cosmin Tanislav]

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

Not needed, so why have them?

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml    | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 29f6fa5e2529..6b3a20448f78 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -112,7 +112,7 @@ patternProperties:
         description:
           Phandle which points to a sensor object responsible for measuring
           the thermocouple cold junction temperature.
-        $ref: "/schemas/types.yaml#/definitions/phandle"
+        $ref: /schemas/types.yaml#/definitions/phandle
 
       adi,custom-thermocouple:
         description:
@@ -204,7 +204,7 @@ patternProperties:
       adi,rsense-handle:
         description:
           Phandle pointing to a rsense object associated with this RTD.
-        $ref: "/schemas/types.yaml#/definitions/phandle"
+        $ref: /schemas/types.yaml#/definitions/phandle
 
       adi,number-of-wires:
         description:
@@ -288,7 +288,7 @@ patternProperties:
         description:
           Phandle pointing to a rsense object associated with this
           thermistor.
-        $ref: "/schemas/types.yaml#/definitions/phandle"
+        $ref: /schemas/types.yaml#/definitions/phandle
 
       adi,single-ended:
         description:
-- 
2.38.1

Re: [PATCH v4 04/13] dt-bindings: iio: temperature: ltc2983: remove qutations from phandle ref

[Rob Herring]

On Thu, 03 Nov 2022 15:00:32 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Not needed, so why have them?
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml    | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 

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

[PATCH v4 05/13] dt-bindings: iio: temperature: ltc2983: describe matrix items

[Cosmin Tanislav]

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

Give a little bit of information on what each item in the matrix is
supposed to be.

Also, some matrices put the 'minItems' and 'maxItems' keywords in the
wrong level. They should be on the same level as the 'items' keyword.
Fix it.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 23 ++++++++++---------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 6b3a20448f78..4f26b337c957 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -126,8 +126,9 @@ patternProperties:
         minItems: 3
         maxItems: 64
         items:
-          minItems: 2
-          maxItems: 2
+          items:
+            - description: Voltage point in nV, signed.
+            - description: Temperature point in uK.
 
   "^diode@":
     type: object
@@ -249,12 +250,12 @@ patternProperties:
           resistance(ohm)-temperature(K). The entries added here are in uohm
           and uK. For more details values look at table 74 and 75.
         $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
@@ -328,8 +329,9 @@ patternProperties:
         minItems: 3
         maxItems: 64
         items:
-          minItems: 2
-          maxItems: 2
+          items:
+            - description: Resistance point in uOhms.
+            - description: Temperature point in uK.
 
       adi,custom-steinhart:
         description:
@@ -338,9 +340,8 @@ patternProperties:
           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
+        minItems: 6
+        maxItems: 6
 
     required:
       - adi,rsense-handle
-- 
2.38.1

Re: [PATCH v4 05/13] dt-bindings: iio: temperature: ltc2983: describe matrix items

[Rob Herring]

On Thu, 03 Nov 2022 15:00:33 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Give a little bit of information on what each item in the matrix is
> supposed to be.
> 
> Also, some matrices put the 'minItems' and 'maxItems' keywords in the
> wrong level. They should be on the same level as the 'items' keyword.
> Fix it.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 23 ++++++++++---------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 

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

[PATCH v4 06/13] dt-bindings: iio: temperature: ltc2983: require custom sensor tables

[Cosmin Tanislav]

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

The driver will error out when a custom sensor type is used but a
custom sensor table is not provided. Require it in the binding too.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 4f26b337c957..bbac5f5cfbb3 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -130,6 +130,15 @@ patternProperties:
             - 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:
@@ -263,6 +272,15 @@ patternProperties:
     dependencies:
       adi,current-rotate: [ "adi,rsense-share" ]
 
+    allOf:
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 18
+        then:
+          required:
+            - adi,custom-rtd
+
   "^thermistor@":
     type: object
     description:
@@ -349,6 +367,22 @@ patternProperties:
     dependencies:
       adi,current-rotate: [ "adi,rsense-share" ]
 
+    allOf:
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 26
+        then:
+          required:
+            - adi,custom-steinhart
+      - if:
+          properties:
+            adi,sensor-type:
+              const: 27
+        then:
+          required:
+            - adi,custom-thermistor
+
   "^adc@":
     type: object
     description: Represents a channel which is being used as a direct adc.
-- 
2.38.1

Re: [PATCH v4 06/13] dt-bindings: iio: temperature: ltc2983: require custom sensor tables

[Rob Herring]

On Thu, 03 Nov 2022 15:00:34 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> The driver will error out when a custom sensor type is used but a
> custom sensor table is not provided. Require it in the binding too.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 34 +++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 

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

[PATCH v4 07/13] dt-bindings: iio: temperature: ltc2983: require 4 wire rtd for current rotate

[Cosmin Tanislav]

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

The driver will error out when current rotation is enabled but the RTD
is not 4-wire. Require it in the binding too.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 25 +++++++++++--------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index bbac5f5cfbb3..b603219fb0c9 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -230,13 +230,6 @@ patternProperties:
           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
@@ -269,10 +262,22 @@ patternProperties:
     required:
       - adi,rsense-handle
 
-    dependencies:
-      adi,current-rotate: [ "adi,rsense-share" ]
-
     allOf:
+      - if:
+          properties:
+            adi,number-of-wires:
+              const: 4
+        then:
+          properties:
+            adi,current-rotate:
+              description:
+                Whether to enable excitation current rotation to automatically
+                remove parasitic thermocouple effects.
+              type: boolean
+
+          dependencies:
+            adi,current-rotate: [ "adi,rsense-share" ]
+
       - if:
           properties:
             adi,sensor-type:
-- 
2.38.1

Re: [PATCH v4 07/13] dt-bindings: iio: temperature: ltc2983: require 4 wire rtd for current rotate

[Rob Herring]

On Thu, 03 Nov 2022 15:00:35 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> The driver will error out when current rotation is enabled but the RTD
> is not 4-wire. Require it in the binding too.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 25 +++++++++++--------
>  1 file changed, 15 insertions(+), 10 deletions(-)
> 

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

[PATCH v4 08/13] dt-bindings: iio: temperature: ltc2983: change default excitation for custom thermistors

[Cosmin Tanislav]

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

Excitation cannot be set to auto-range when using a custom thermistor
or Steinhart sensor type. Default it to 1000nA to match the driver
and remove the auto-range value from the enum.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml          | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index b603219fb0c9..1b6a11f2aa9d 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -378,6 +378,11 @@ patternProperties:
             adi,sensor-type:
               const: 26
         then:
+          properties:
+            adi,excitation-current-nanoamp:
+              enum: [250, 500, 1000, 5000, 10000, 25000, 50000, 100000,
+                     250000, 500000, 1000000]
+              default: 1000
           required:
             - adi,custom-steinhart
       - if:
@@ -385,6 +390,11 @@ patternProperties:
             adi,sensor-type:
               const: 27
         then:
+          properties:
+            adi,excitation-current-nanoamp:
+              enum: [250, 500, 1000, 5000, 10000, 25000, 50000, 100000,
+                     250000, 500000, 1000000]
+              default: 1000
           required:
             - adi,custom-thermistor
 
-- 
2.38.1

Re: [PATCH v4 08/13] dt-bindings: iio: temperature: ltc2983: change default excitation for custom thermistors

[Rob Herring]

On Thu, 03 Nov 2022 15:00:36 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Excitation cannot be set to auto-range when using a custom thermistor
> or Steinhart sensor type. Default it to 1000nA to match the driver
> and remove the auto-range value from the enum.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml          | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 

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

[PATCH v4 09/13] dt-bindings: iio: temperature: ltc2983: refine descriptions

[Cosmin Tanislav]

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

Some descriptions are too verbose, while others are too succint.
Rewrite them all.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 163 +++++++-----------
 1 file changed, 65 insertions(+), 98 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 1b6a11f2aa9d..676801b036cf 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -25,21 +25,16 @@ properties:
     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.
+    description: |
+      Extra delay prior to each conversion, in addition to the internal 1ms
+      delay, for the multiplexer to switch input configurations and
+      excitation values.
     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
@@ -57,17 +52,18 @@ properties:
 patternProperties:
   "@([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:
@@ -76,9 +72,7 @@ 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:
@@ -97,31 +91,24 @@ 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.
+          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
@@ -141,55 +128,50 @@ patternProperties:
 
   "^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:
@@ -212,35 +194,35 @@ patternProperties:
         maximum: 18
 
       adi,rsense-handle:
-        description:
-          Phandle pointing to a rsense object associated with this RTD.
+        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,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.
+        description: |
+          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
@@ -248,9 +230,8 @@ patternProperties:
 
       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
@@ -288,9 +269,7 @@ patternProperties:
 
   "^thermistor@":
     type: object
-    description:
-      Represents a thermistor sensor which is connected to one of the device
-      channels.
+    description: Thermistor sensor.
 
     properties:
       adi,sensor-type:
@@ -309,34 +288,29 @@ patternProperties:
         maximum: 27
 
       adi,rsense-handle:
-        description:
-          Phandle pointing to a rsense object associated with this
-          thermistor.
+        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]
@@ -344,10 +318,8 @@ patternProperties:
 
       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
@@ -358,10 +330,9 @@ patternProperties:
 
       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.
+          Steinhart-Hart coefficients in raw format, used for digitizing
+          custom thermistors.
+          See Page 68 of the datasheet.
         $ref: /schemas/types.yaml#/definitions/uint32-array
         minItems: 6
         maxItems: 6
@@ -400,23 +371,21 @@ patternProperties:
 
   "^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:
@@ -424,14 +393,12 @@ patternProperties:
         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
-- 
2.38.1

Re: [PATCH v4 09/13] dt-bindings: iio: temperature: ltc2983: refine descriptions

[Rob Herring]

On Thu, 03 Nov 2022 15:00:37 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Some descriptions are too verbose, while others are too succint.
> Rewrite them all.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 163 +++++++-----------
>  1 file changed, 65 insertions(+), 98 deletions(-)
> 

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

[PATCH v4 10/13] dt-bindings: iio: temperature: ltc2983: describe broken mux delay property

[Cosmin Tanislav]

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

The 'adi,mux-delay-config-us' property is broken. It was supposed to
be in us, but the value is actually written directly to the register.
Describe the fact that it is broken and how it actually works.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml       | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 676801b036cf..467e165e9b0b 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -29,6 +29,9 @@ properties:
       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
 
-- 
2.38.1

Re: [PATCH v4 10/13] dt-bindings: iio: temperature: ltc2983: describe broken mux delay property

[Rob Herring]

On Thu, 03 Nov 2022 15:00:38 +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> The 'adi,mux-delay-config-us' property is broken. It was supposed to
> be in us, but the value is actually written directly to the register.
> Describe the fact that it is broken and how it actually works.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml       | 3 +++
>  1 file changed, 3 insertions(+)
> 

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

[PATCH v4 11/13] dt-bindings: iio: temperature: ltc2983: use generic node name in example

[Cosmin Tanislav]

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

Examples should use the generic IIO node name. Fix it.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index 467e165e9b0b..bd357ff28e65 100644
--- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
+++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
@@ -420,7 +420,7 @@ examples:
         #address-cells = <1>;
         #size-cells = <0>;
 
-        sensor_ltc2983: ltc2983@0 {
+        temp@0 {
                 compatible = "adi,ltc2983";
                 reg = <0>;
 
-- 
2.38.1

Re: [PATCH v4 11/13] dt-bindings: iio: temperature: ltc2983: use generic node name in example

[Rob Herring]

On Thu, Nov 03, 2022 at 03:00:39PM +0200, Cosmin Tanislav wrote:
> From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> 
> Examples should use the generic IIO node name. Fix it.
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> ---
>  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml        | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> index 467e165e9b0b..bd357ff28e65 100644
> --- a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> +++ b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
> @@ -420,7 +420,7 @@ examples:
>          #address-cells = <1>;
>          #size-cells = <0>;
>  
> -        sensor_ltc2983: ltc2983@0 {
> +        temp@0 {

The DT spec defines 'temperature-sensor'.

>                  compatible = "adi,ltc2983";
>                  reg = <0>;
>  
> -- 
> 2.38.1
> 
> 

Re: [PATCH v4 11/13] dt-bindings: iio: temperature: ltc2983: use generic node name in example

[Cosmin Tanislav]

On Mon, 2022-11-07 at 12:13 -0600, Rob Herring wrote:
> On Thu, Nov 03, 2022 at 03:00:39PM +0200, Cosmin Tanislav wrote:
> > From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> > 
> > Examples should use the generic IIO node name. Fix it.
> > 
> > Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> > ---
> >  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml        |
> > 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > index 467e165e9b0b..bd357ff28e65 100644
> > ---
> > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > +++
> > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > l
> > @@ -420,7 +420,7 @@ examples:
> >          #address-cells = <1>;
> >          #size-cells = <0>;
> >  
> > -        sensor_ltc2983: ltc2983@0 {
> > +        temp@0 {
> 
> The DT spec defines 'temperature-sensor'.

Jonathan, could you maybe fix this (replace 'temp' with
'temperature-sensor') while picking it up? Thanks.

> 
> >                  compatible = "adi,ltc2983";
> >                  reg = <0>;
> >  
> > -- 
> > 2.38.1
> > 
> > 

Re: [PATCH v4 11/13] dt-bindings: iio: temperature: ltc2983: use generic node name in example

[Jonathan Cameron]

On Tue, 08 Nov 2022 10:37:23 +0200
Cosmin Tanislav <demonsingur@gmail.com> wrote:

> On Mon, 2022-11-07 at 12:13 -0600, Rob Herring wrote:
> > On Thu, Nov 03, 2022 at 03:00:39PM +0200, Cosmin Tanislav wrote:  
> > > From: Cosmin Tanislav <cosmin.tanislav@analog.com>
> > > 
> > > Examples should use the generic IIO node name. Fix it.
> > > 
> > > Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
> > > ---
> > >  .../devicetree/bindings/iio/temperature/adi,ltc2983.yaml        |
> > > 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git
> > > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > index 467e165e9b0b..bd357ff28e65 100644
> > > ---
> > > a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > +++
> > > b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yam
> > > l
> > > @@ -420,7 +420,7 @@ examples:
> > >          #address-cells = <1>;
> > >          #size-cells = <0>;
> > >  
> > > -        sensor_ltc2983: ltc2983@0 {
> > > +        temp@0 {  
> > 
> > The DT spec defines 'temperature-sensor'.  
> 
> Jonathan, could you maybe fix this (replace 'temp' with
> 'temperature-sensor') while picking it up? Thanks.

Done.
> 
> >   
> > >                  compatible = "adi,ltc2983";
> > >                  reg = <0>;
> > >  
> > > -- 
> > > 2.38.1
> > > 
> > >   
> 

[PATCH v4 12/13] 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>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/iio/temperature/adi,ltc2983.yaml | 60 +++++++++++++++++--
 1 file changed, 56 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml b/Documentation/devicetree/bindings/iio/temperature/adi,ltc2983.yaml
index bd357ff28e65..ccab94b20b24 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
@@ -386,6 +397,35 @@ 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.
@@ -413,6 +453,18 @@ 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

[PATCH v4 13/13] 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>
---
 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

Re: [PATCH v4 00/13] Support more parts in LTC2983

[Jonathan Cameron]

On Thu,  3 Nov 2022 15:00:28 +0200
Cosmin Tanislav <demonsingur@gmail.com> wrote:

> 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.
> Besides that, refine the binding.
Replying at least partly so I can see I already looked at this...

Looks good to me.  Will pick up once DT bindings maintainers are
happy.

Thanks,

Jonathan

> 
> 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
> 
> V3 -> V4:
>   * add pipe for 'adi,mux-delay-config-us' description
>   * add pipe for 'adi,rtd-curve' description
>   * keep newlines after descriptions
>   * move 'adi,current-rotate' to conditional
>   * put 'adi,custom-steinhart' in the original place
>   * keep 'minItems' for 'adi,custom-steinhart'
>   * override 'enum' to forbid auto-range in 'adi,excitation-current-nanoamp'
>     when using custom thermistors
>   * split refine patch into multiple patches
>     - use generic node name in example
>     - describe broken mux delay property
>     - refine descriptions
>     - change default excitation for custom thermistors
>     - require 4 wire rtd for current rotate
>     - require custom sensor tables
>     - describe matrix items
>     - remove qutations from phandle ref
>     - use hex for sensor address
>     - add default values
> 
> Cosmin Tanislav (13):
>   iio: temperature: ltc2983: make bulk write buffer DMA-safe
>   dt-bindings: iio: temperature: ltc2983: add default values
>   dt-bindings: iio: temperature: ltc2983: use hex for sensor address
>   dt-bindings: iio: temperature: ltc2983: remove qutations from phandle
>     ref
>   dt-bindings: iio: temperature: ltc2983: describe matrix items
>   dt-bindings: iio: temperature: ltc2983: require custom sensor tables
>   dt-bindings: iio: temperature: ltc2983: require 4 wire rtd for current
>     rotate
>   dt-bindings: iio: temperature: ltc2983: change default excitation for
>     custom thermistors
>   dt-bindings: iio: temperature: ltc2983: refine descriptions
>   dt-bindings: iio: temperature: ltc2983: describe broken mux delay
>     property
>   dt-bindings: iio: temperature: ltc2983: use generic node name in
>     example
>   dt-bindings: iio: temperature: ltc2983: support more parts
>   iio: temperature: ltc2983: support more parts
> 
>  .../bindings/iio/temperature/adi,ltc2983.yaml | 335 +++++++++++-------
>  drivers/iio/temperature/ltc2983.c             | 193 +++++++++-
>  2 files changed, 389 insertions(+), 139 deletions(-)
> 

Re: [PATCH v4 00/13] Support more parts in LTC2983

[Jonathan Cameron]

On Sun, 6 Nov 2022 17:14:58 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> On Thu,  3 Nov 2022 15:00:28 +0200
> Cosmin Tanislav <demonsingur@gmail.com> wrote:
> 
> > 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.
> > Besides that, refine the binding.  
> Replying at least partly so I can see I already looked at this...
> 
> Looks good to me.  Will pick up once DT bindings maintainers are
> happy.

Series applied to the togreg branch of iio.git and initially pushed out
as testing.  I tweaked patch 11 as requested whilst applying.

Thanks,

Jonathan
> 
> Thanks,
> 
> Jonathan
> 
> > 
> > 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
> > 
> > V3 -> V4:
> >   * add pipe for 'adi,mux-delay-config-us' description
> >   * add pipe for 'adi,rtd-curve' description
> >   * keep newlines after descriptions
> >   * move 'adi,current-rotate' to conditional
> >   * put 'adi,custom-steinhart' in the original place
> >   * keep 'minItems' for 'adi,custom-steinhart'
> >   * override 'enum' to forbid auto-range in 'adi,excitation-current-nanoamp'
> >     when using custom thermistors
> >   * split refine patch into multiple patches
> >     - use generic node name in example
> >     - describe broken mux delay property
> >     - refine descriptions
> >     - change default excitation for custom thermistors
> >     - require 4 wire rtd for current rotate
> >     - require custom sensor tables
> >     - describe matrix items
> >     - remove qutations from phandle ref
> >     - use hex for sensor address
> >     - add default values
> > 
> > Cosmin Tanislav (13):
> >   iio: temperature: ltc2983: make bulk write buffer DMA-safe
> >   dt-bindings: iio: temperature: ltc2983: add default values
> >   dt-bindings: iio: temperature: ltc2983: use hex for sensor address
> >   dt-bindings: iio: temperature: ltc2983: remove qutations from phandle
> >     ref
> >   dt-bindings: iio: temperature: ltc2983: describe matrix items
> >   dt-bindings: iio: temperature: ltc2983: require custom sensor tables
> >   dt-bindings: iio: temperature: ltc2983: require 4 wire rtd for current
> >     rotate
> >   dt-bindings: iio: temperature: ltc2983: change default excitation for
> >     custom thermistors
> >   dt-bindings: iio: temperature: ltc2983: refine descriptions
> >   dt-bindings: iio: temperature: ltc2983: describe broken mux delay
> >     property
> >   dt-bindings: iio: temperature: ltc2983: use generic node name in
> >     example
> >   dt-bindings: iio: temperature: ltc2983: support more parts
> >   iio: temperature: ltc2983: support more parts
> > 
> >  .../bindings/iio/temperature/adi,ltc2983.yaml | 335 +++++++++++-------
> >  drivers/iio/temperature/ltc2983.c             | 193 +++++++++-
> >  2 files changed, 389 insertions(+), 139 deletions(-)
> >   
>