[PATCH v7 0/6] Add driver for LTC2664 and LTC2672

[PATCH v7 0/6] Add driver for LTC2664 and LTC2672

[Kim Seer Paller]

Generalize the ABI documentation for DAC. The ABI defined for toggle mode
channels:

LTC2664:
  * out_voltageY_toggle_en
  * out_voltageY_raw0
  * out_voltageY_raw1
  * out_voltageY_symbol

LTC2672:
  * out_currentY_toggle_en
  * out_currentY_raw0
  * out_currentY_raw1
  * out_currentY_symbol

Default channels won't have any of the above ABIs. A channel is toggle capable
if the devicetree 'adi,toggle-mode' flag is set.

changes in v7:

Bindings:
  * Reverted DAC bindings to original conditional requirements.
  * Added Reviewed-by tag for dac.yaml.

changes in v6:

Bindings:
  * Added clarification description for output-range-microvolt property and
    modified conditional logic for output-range-microvolt for ltc2664 binding.
  * Simplified schema validation logic for DAC binding.
  * Added Reviewed-by tag for ltc2672 binding.

changes in v5:

ltc2664:
  * Removed return statement for error code in ltc2664_dac_code_read making it a
    void function.
  * Refactored voltage regulator error handling and logic setting for vref_mv.
  * Added Reviewed-by tag.

Bindings:
  * Added dac.yaml and generalized DAC common properties.
  * Modified ltc2664 binding adding constraints for the adi,manual-span-operation-config
    and output-range-microvolt properties.

changes in v4:

ltc2664:
  * Added comments for each field in the ltc2664_chan struct.
  * Changed global_toggle data type to bool and updated vref and rfsadj variables
    to include units.
  * Added 0,0 entry in ltc2672_span_helper to removed the id field from the
    ltc2664_chip_info struct.
  * Used mul_u64_u32_div helper function from linux/math64.h to avoid integer
    overflow during scale calculation.
  * Refactored code to use a single template for channel instead of separate
    channel arrays.
  * Used the devm_regulator_get_enable_read_voltage API for simplifying voltage
    retrieval.

ABI:
  sysfs-bus-iio:
    * Added commit message for the ABI changes.
  sysfs-bus-iio-dac:
    * Updated the description of toggle_en to clarify autonomous toggling.
    * Fixed inconsistent use of spacing and tabs.

Bindings:
  * Dropped Reviewed-by tag.
  * Updated the description for both bindings to include both 12-bit and 16-bit
    versions.

changes in v3:

ltc2664:
  * Added span sanity check for no match.
  * Initialized the variable 'span' to fix build warning.
  * Added Reported-by and Closes by tag.

ABI:
  * Modified descriptions to make it more generalize.
  * Removed MAINTAINERS file entry.

Bindings:
  * Changed clr-gpios to reset-gpios.
  * Added output range and reset code description for 'adi,manual-span-operation-config'
    property in ltc2664 binding.
  * Removed the $ref for 'adi,output-range-microamp' due to dt-schema warning
    in ltc2672 binding. Added Reported-by and Closes by tag.
  * Modified io-channels description and added maxItems constraint.

changes in v2:

ltc2664:
  * Updated struct ltc2664_chip_info to include device-specific data for scale,
    offset, measurement type, internal vref, manual span support, and rfsadj
    support.
  * Added a read-only extended info attribute powerdown_mode to indicate the
    state that the DAC output enters when the device is powered down.
  * Refactored code for setting the span into separate function and directly
    returning the span.
  * Adjusted memory allocation for st->iio_channels to include null terminator.
  * Spaces have been added after { and before }. Each pair of values is now
    placed on a separate line.

ABI:
  * Generalized the ABI documentation for DAC.
  * Added DAC 42kohm_to_gnd powerdown mode.

Bindings:
  * Created separate bindings for ltc2664 and ltc2672.
  * Added v-pos-supply and v-neg-supply regulator properties.
  * Renamed vref-supply to ref-supply based on the datasheet.
  * Added io-channels property and specifying the pin for multiplexer output.
  * Added vdd0-vdd4 supply properties for ltc2672, although they are not
    currently supported in the driver.
  * Changed clr-gpios description based on the datasheet.
  * Used 4 spaces for example indentation.

Kim Seer Paller (6):
  iio: ABI: Generalize ABI documentation for DAC
  iio: ABI: add DAC 42kohm_to_gnd powerdown mode
  dt-bindings: iio: dac: Generalize DAC common properties
  dt-bindings: iio: dac: Add adi,ltc2664.yaml
  dt-bindings: iio: dac: Add adi,ltc2672.yaml
  iio: dac: ltc2664: Add driver for LTC2664 and LTC2672

 Documentation/ABI/testing/sysfs-bus-iio       |   1 +
 Documentation/ABI/testing/sysfs-bus-iio-dac   |  61 ++
 .../ABI/testing/sysfs-bus-iio-dac-ltc2688     |  31 -
 .../bindings/iio/dac/adi,ltc2664.yaml         | 181 +++++
 .../bindings/iio/dac/adi,ltc2672.yaml         | 160 ++++
 .../devicetree/bindings/iio/dac/dac.yaml      |  50 ++
 MAINTAINERS                                   |  10 +
 drivers/iio/dac/Kconfig                       |  11 +
 drivers/iio/dac/Makefile                      |   1 +
 drivers/iio/dac/ltc2664.c                     | 735 ++++++++++++++++++
 10 files changed, 1210 insertions(+), 31 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac
 create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
 create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
 create mode 100644 Documentation/devicetree/bindings/iio/dac/dac.yaml
 create mode 100644 drivers/iio/dac/ltc2664.c


base-commit: 1ebab783647a9e3bf357002d5c4ff060c8474a0a
-- 
2.34.1

[PATCH v7 1/6] iio: ABI: Generalize ABI documentation for DAC

[Kim Seer Paller]

Introduces a more generalized ABI documentation for DAC. Instead of
having separate ABI files for each DAC, we now have a single ABI file
that covers the common sysfs interface for all DAC.

Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 Documentation/ABI/testing/sysfs-bus-iio-dac   | 61 +++++++++++++++++++
 .../ABI/testing/sysfs-bus-iio-dac-ltc2688     | 31 ----------
 2 files changed, 61 insertions(+), 31 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac b/Documentation/ABI/testing/sysfs-bus-iio-dac
new file mode 100644
index 000000000000..810eaac5533c
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-dac
@@ -0,0 +1,61 @@
+What:		/sys/bus/iio/devices/iio:deviceX/out_currentY_toggle_en
+KernelVersion:	5.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Toggle enable. Write 1 to enable toggle or 0 to disable it. This
+		is useful when one wants to change the DAC output codes. For
+		autonomous toggling, the way it should be done is:
+
+		- disable toggle operation;
+		- change out_currentY_rawN, where N is the integer value of the symbol;
+		- enable toggle operation.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_currentY_rawN
+KernelVersion:	5.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		This attribute has the same meaning as out_currentY_raw. It is
+		specific to toggle enabled channels and refers to the DAC output
+		code in INPUT_N (_rawN), where N is the integer value of the symbol.
+		The same scale and offset as in out_currentY_raw applies.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_currentY_symbol
+KernelVersion:	5.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Performs a SW switch to a predefined output symbol. This attribute
+		is specific to toggle enabled channels and allows switching between
+		multiple predefined symbols. Each symbol corresponds to a different
+		output, denoted as out_currentY_rawN, where N is the integer value
+		of the symbol. Writing an integer value N will select out_currentY_rawN.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_toggle_en
+KernelVersion:	5.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Toggle enable. Write 1 to enable toggle or 0 to disable it. This
+		is useful when one wants to change the DAC output codes. For
+		autonomous toggling, the way it should be done is:
+
+		- disable toggle operation;
+		- change out_voltageY_rawN, where N is the integer value of the symbol;
+		- enable toggle operation.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_rawN
+KernelVersion:	5.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		This attribute has the same meaning as out_currentY_raw. It is
+		specific to toggle enabled channels and refers to the DAC output
+		code in INPUT_N (_rawN), where N is the integer value of the symbol.
+		The same scale and offset as in out_currentY_raw applies.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_symbol
+KernelVersion:	5.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Performs a SW switch to a predefined output symbol. This attribute
+		is specific to toggle enabled channels and allows switching between
+		multiple predefined symbols. Each symbol corresponds to a different
+		output, denoted as out_voltageY_rawN, where N is the integer value
+		of the symbol. Writing an integer value N will select out_voltageY_rawN.
diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688 b/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688
index 1c35971277ba..ae95a5477382 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688
+++ b/Documentation/ABI/testing/sysfs-bus-iio-dac-ltc2688
@@ -53,34 +53,3 @@ KernelVersion:	5.18
 Contact:	linux-iio@vger.kernel.org
 Description:
 		Returns the available values for the dither phase.
-
-What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_toggle_en
-KernelVersion:	5.18
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Toggle enable. Write 1 to enable toggle or 0 to disable it. This is
-		useful when one wants to change the DAC output codes. The way it should
-		be done is:
-
-		- disable toggle operation;
-		- change out_voltageY_raw0 and out_voltageY_raw1;
-		- enable toggle operation.
-
-What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_raw0
-What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_raw1
-KernelVersion:	5.18
-Contact:	linux-iio@vger.kernel.org
-Description:
-		It has the same meaning as out_voltageY_raw. This attribute is
-		specific to toggle enabled channels and refers to the DAC output
-		code in INPUT_A (_raw0) and INPUT_B (_raw1). The same scale and offset
-		as in out_voltageY_raw applies.
-
-What:		/sys/bus/iio/devices/iio:deviceX/out_voltageY_symbol
-KernelVersion:	5.18
-Contact:	linux-iio@vger.kernel.org
-Description:
-		Performs a SW toggle. This attribute is specific to toggle
-		enabled channels and allows to toggle between out_voltageY_raw0
-		and out_voltageY_raw1 through software. Writing 0 will select
-		out_voltageY_raw0 while 1 selects out_voltageY_raw1.
-- 
2.34.1

[PATCH v7 2/6] iio: ABI: add DAC 42kohm_to_gnd powerdown mode

[Kim Seer Paller]

Add a new powerdown mode for DACs with 42kohm resistor to GND.

Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 Documentation/ABI/testing/sysfs-bus-iio | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 7cee78ad4108..6ee58f59065b 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -708,6 +708,7 @@ Description:
 		2.5kohm_to_gnd: connected to ground via a 2.5kOhm resistor,
 		6kohm_to_gnd: connected to ground via a 6kOhm resistor,
 		20kohm_to_gnd: connected to ground via a 20kOhm resistor,
+		42kohm_to_gnd: connected to ground via a 42kOhm resistor,
 		90kohm_to_gnd: connected to ground via a 90kOhm resistor,
 		100kohm_to_gnd: connected to ground via an 100kOhm resistor,
 		125kohm_to_gnd: connected to ground via an 125kOhm resistor,
-- 
2.34.1

[PATCH v7 3/6] dt-bindings: iio: dac: Generalize DAC common properties

[Kim Seer Paller]

Introduce a generalized DAC binding that can be used by DACs that have
similar properties adding output-range-microamp and output-range-microvolt.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 .../devicetree/bindings/iio/dac/dac.yaml      | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/dac.yaml

diff --git a/Documentation/devicetree/bindings/iio/dac/dac.yaml b/Documentation/devicetree/bindings/iio/dac/dac.yaml
new file mode 100644
index 000000000000..daa40724e1cf
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/dac.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/dac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: IIO Common Properties for DAC Channels
+
+maintainers:
+  - Jonathan Cameron <jic23@kernel.org>
+
+description:
+  A few properties are defined in a common way for DAC channels.
+
+properties:
+  $nodename:
+    pattern: "^channel(@[0-9a-f]+)?$"
+    description:
+      A channel index should match reg.
+
+  reg:
+    maxItems: 1
+
+  label:
+    description: Unique name to identify which channel this is.
+
+  output-range-microamp:
+    maxItems: 2
+    minItems: 2
+    description:
+      Specify the channel output full scale range in microamperes.
+
+  output-range-microvolt:
+    maxItems: 2
+    minItems: 2
+    description:
+      Specify the channel output full scale range in microvolts.
+
+anyOf:
+  - oneOf:
+      - required:
+          - reg
+          - output-range-microamp
+      - required:
+          - reg
+          - output-range-microvolt
+  - required:
+      - reg
+
+additionalProperties: true
-- 
2.34.1

[PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Kim Seer Paller]

Add documentation for ltc2664.

Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 .../bindings/iio/dac/adi,ltc2664.yaml         | 181 ++++++++++++++++++
 MAINTAINERS                                   |   8 +
 2 files changed, 189 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
new file mode 100644
index 000000000000..84488437b788
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
@@ -0,0 +1,181 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/adi,ltc2664.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LTC2664 DAC
+
+maintainers:
+  - Michael Hennerich <michael.hennerich@analog.com>
+  - Kim Seer Paller <kimseer.paller@analog.com>
+
+description: |
+  Analog Devices LTC2664 4 channel, 12-/16-Bit, +-10V DAC
+  https://www.analog.com/media/en/technical-documentation/data-sheets/2664fa.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ltc2664
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 50000000
+
+  vcc-supply:
+    description: Analog Supply Voltage Input.
+
+  v-pos-supply:
+    description: Positive Supply Voltage Input.
+
+  v-neg-supply:
+    description: Negative Supply Voltage Input.
+
+  iovcc-supply:
+    description: Digital Input/Output Supply Voltage.
+
+  ref-supply:
+    description:
+      Reference Input/Output. The voltage at the REF pin sets the full-scale
+      range of all channels. If not provided the internal reference is used and
+      also provided on the VREF pin.
+
+  reset-gpios:
+    description:
+      Active-low Asynchronous Clear Input. A logic low at this level-triggered
+      input clears the part to the reset code and range determined by the
+      hardwired option chosen using the MSPAN pins. The control registers are
+      cleared to zero.
+    maxItems: 1
+
+  adi,manual-span-operation-config:
+    description:
+      This property must mimic the MSPAN pin configurations. By tying the MSPAN
+      pins (MSP2, MSP1 and MSP0) to GND and/or VCC, any output range can be
+      hardware-configured with different mid-scale or zero-scale reset options.
+      The hardware configuration is latched during power on reset for proper
+      operation.
+        0 - MPS2=GND, MPS1=GND, MSP0=GND (+-10V, reset to 0V)
+        1 - MPS2=GND, MPS1=GND, MSP0=VCC (+-5V, reset to 0V)
+        2 - MPS2=GND, MPS1=VCC, MSP0=GND (+-2.5V, reset to 0V)
+        3 - MPS2=GND, MPS1=VCC, MSP0=VCC (0V to 10, reset to 0V)
+        4 - MPS2=VCC, MPS1=GND, MSP0=GND (0V to 10V, reset to 5V)
+        5 - MPS2=VCC, MPS1=GND, MSP0=VCC (0V to 5V, reset to 0V)
+        6 - MPS2=VCC, MPS1=VCC, MSP0=GND (0V to 5V, reset to 2.5V)
+        7 - MPS2=VCC, MPS1=VCC, MSP0=VCC (0V to 5V, reset to 0V, enables SoftSpan)
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1, 2, 3, 4, 5, 6, 7]
+    default: 7
+
+  io-channels:
+    description:
+      ADC channel to monitor voltages and temperature at the MUXOUT pin.
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  "^channel@[0-3]$":
+    $ref: dac.yaml
+    type: object
+    additionalProperties: false
+
+    properties:
+      reg:
+        description: The channel number representing the DAC output channel.
+        maximum: 3
+
+      adi,toggle-mode:
+        description:
+          Set the channel as a toggle enabled channel. Toggle operation enables
+          fast switching of a DAC output between two different DAC codes without
+          any SPI transaction.
+        type: boolean
+
+      output-range-microvolt:
+        description:
+          This property is only allowed when SoftSpan is enabled. If not present,
+          [0, 5000000] is the default output range.
+        oneOf:
+          - items:
+              - const: 0
+              - enum: [5000000, 10000000]
+          - items:
+              - const: -5000000
+              - const: 5000000
+          - items:
+              - const: -10000000
+              - const: 10000000
+          - items:
+              - const: -2500000
+              - const: 2500000
+
+    required:
+      - reg
+
+    allOf:
+      - if:
+          not:
+            properties:
+              adi,manual-span-operation-config:
+                const: 7
+        then:
+          patternProperties:
+            "^channel@[0-3]$":
+              properties:
+                output-range-microvolt: false
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+  - vcc-supply
+  - iovcc-supply
+  - v-pos-supply
+  - v-neg-supply
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        dac@0 {
+            compatible = "adi,ltc2664";
+            reg = <0>;
+            spi-max-frequency = <10000000>;
+
+            vcc-supply = <&vcc>;
+            iovcc-supply = <&vcc>;
+            ref-supply = <&vref>;
+            v-pos-supply = <&vpos>;
+            v-neg-supply = <&vneg>;
+
+            io-channels = <&adc 0>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+            channel@0 {
+                    reg = <0>;
+                    adi,toggle-mode;
+                    output-range-microvolt = <(-10000000) 10000000>;
+            };
+
+            channel@1 {
+                    reg = <1>;
+                    output-range-microvolt= <0 10000000>;
+            };
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 06ecfa64a39a..c25863321328 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13080,6 +13080,14 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/iio/dac/lltc,ltc1660.yaml
 F:	drivers/iio/dac/ltc1660.c
 
+LTC2664 IIO DAC DRIVER
+M:	Michael Hennerich <michael.hennerich@analog.com>
+M:	Kim Seer Paller <kimseer.paller@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
+
 LTC2688 IIO DAC DRIVER
 M:	Nuno Sá <nuno.sa@analog.com>
 L:	linux-iio@vger.kernel.org
-- 
2.34.1

[PATCH v7 5/6] dt-bindings: iio: dac: Add adi,ltc2672.yaml

[Kim Seer Paller]

Add documentation for ltc2672.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 .../bindings/iio/dac/adi,ltc2672.yaml         | 160 ++++++++++++++++++
 MAINTAINERS                                   |   1 +
 2 files changed, 161 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml

diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
new file mode 100644
index 000000000000..4c78e46c58d8
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
@@ -0,0 +1,160 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/adi,ltc2672.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LTC2672 DAC
+
+maintainers:
+  - Michael Hennerich <michael.hennerich@analog.com>
+  - Kim Seer Paller <kimseer.paller@analog.com>
+
+description: |
+  Analog Devices LTC2672 5 channel, 12-/16-Bit, 300mA DAC
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ltc2672.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ltc2672
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 50000000
+
+  vcc-supply:
+    description: Analog Supply Voltage Input.
+
+  v-neg-supply:
+    description: Negative Supply Voltage Input.
+
+  vdd0-supply:
+    description: Positive Supply Voltage Input for DAC OUT0.
+
+  vdd1-supply:
+    description: Positive Supply Voltage Input for DAC OUT1.
+
+  vdd2-supply:
+    description: Positive Supply Voltage Input for DAC OUT2.
+
+  vdd3-supply:
+    description: Positive Supply Voltage Input for DAC OUT3.
+
+  vdd4-supply:
+    description: Positive Supply Voltage Input for DAC OUT4.
+
+  iovcc-supply:
+    description: Digital Input/Output Supply Voltage.
+
+  ref-supply:
+    description:
+      Reference Input/Output. The voltage at the REF pin sets the full-scale
+      range of all channels. If not provided the internal reference is used and
+      also provided on the VREF pin.
+
+  reset-gpios:
+    description:
+      Active Low Asynchronous Clear Input. A logic low at this level triggered
+      input clears the device to the default reset code and output range, which
+      is zero-scale with the outputs off. The control registers are cleared to
+      zero.
+    maxItems: 1
+
+  adi,rfsadj-ohms:
+    description:
+      If FSADJ is tied to VCC, an internal RFSADJ (20 kΩ) is selected, which
+      results in nominal output ranges. When an external resistor of 19 kΩ to
+      41 kΩ can be used instead by connecting the resistor between FSADJ and GND
+      it controls the scaling of the ranges, and the internal resistor is
+      automatically disconnected.
+    minimum: 19000
+    maximum: 41000
+    default: 20000
+
+  io-channels:
+    description:
+      ADC channel to monitor voltages and currents at the MUX pin.
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  "^channel@[0-4]$":
+    $ref: dac.yaml
+    type: object
+    additionalProperties: false
+
+    properties:
+      reg:
+        description: The channel number representing the DAC output channel.
+        maximum: 4
+
+      adi,toggle-mode:
+        description:
+          Set the channel as a toggle enabled channel. Toggle operation enables
+          fast switching of a DAC output between two different DAC codes without
+          any SPI transaction.
+        type: boolean
+
+      output-range-microamp:
+        items:
+          - const: 0
+          - enum: [3125000, 6250000, 12500000, 25000000, 50000000, 100000000,
+                   200000000, 300000000]
+
+    required:
+      - reg
+      - output-range-microamp
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+  - vcc-supply
+  - iovcc-supply
+  - v-neg-supply
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        dac@0 {
+            compatible = "adi,ltc2672";
+            reg = <0>;
+            spi-max-frequency = <10000000>;
+
+            vcc-supply = <&vcc>;
+            iovcc-supply = <&vcc>;
+            ref-supply = <&vref>;
+            v-neg-supply = <&vneg>;
+
+            io-channels = <&adc 0>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+            channel@0 {
+                    reg = <0>;
+                    adi,toggle-mode;
+                    output-range-microamp = <0 3125000>;
+            };
+
+            channel@1 {
+                    reg = <1>;
+                    output-range-microamp = <0 6250000>;
+            };
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index c25863321328..d54b56aca1b2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13087,6 +13087,7 @@ L:	linux-iio@vger.kernel.org
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
+F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
 
 LTC2688 IIO DAC DRIVER
 M:	Nuno Sá <nuno.sa@analog.com>
-- 
2.34.1

[PATCH v7 6/6] iio: dac: ltc2664: Add driver for LTC2664 and LTC2672

[Kim Seer Paller]

LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC
LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
---
 MAINTAINERS               |   1 +
 drivers/iio/dac/Kconfig   |  11 +
 drivers/iio/dac/Makefile  |   1 +
 drivers/iio/dac/ltc2664.c | 735 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 748 insertions(+)
 create mode 100644 drivers/iio/dac/ltc2664.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d54b56aca1b2..cb67bf03d6b0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13088,6 +13088,7 @@ S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2664.yaml
 F:	Documentation/devicetree/bindings/iio/dac/adi,ltc2672.yaml
+F:	drivers/iio/dac/ltc2664.c
 
 LTC2688 IIO DAC DRIVER
 M:	Nuno Sá <nuno.sa@analog.com>
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index a2596c2d3de3..1cfd7e2a622f 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -371,6 +371,17 @@ config LTC2632
 	  To compile this driver as a module, choose M here: the
 	  module will be called ltc2632.
 
+config LTC2664
+	tristate "Analog Devices LTC2664 and LTC2672 DAC SPI driver"
+	depends on SPI
+	select REGMAP
+	help
+	  Say yes here to build support for Analog Devices
+	  LTC2664 and LTC2672 converters (DAC).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ltc2664.
+
 config M62332
 	tristate "Mitsubishi M62332 DAC driver"
 	depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 8432a81a19dc..2cf148f16306 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_DS4424) += ds4424.o
 obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
 obj-$(CONFIG_LTC1660) += ltc1660.o
 obj-$(CONFIG_LTC2632) += ltc2632.o
+obj-$(CONFIG_LTC2664) += ltc2664.o
 obj-$(CONFIG_LTC2688) += ltc2688.o
 obj-$(CONFIG_M62332) += m62332.o
 obj-$(CONFIG_MAX517) += max517.o
diff --git a/drivers/iio/dac/ltc2664.c b/drivers/iio/dac/ltc2664.c
new file mode 100644
index 000000000000..666ecdeb5f96
--- /dev/null
+++ b/drivers/iio/dac/ltc2664.c
@@ -0,0 +1,735 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC driver
+ * LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC driver
+ *
+ * Copyright 2024 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#define LTC2664_CMD_WRITE_N(n)		(0x00 + (n))
+#define LTC2664_CMD_UPDATE_N(n)		(0x10 + (n))
+#define LTC2664_CMD_WRITE_N_UPDATE_ALL	0x20
+#define LTC2664_CMD_WRITE_N_UPDATE_N(n)	(0x30 + (n))
+#define LTC2664_CMD_POWER_DOWN_N(n)	(0x40 + (n))
+#define LTC2664_CMD_POWER_DOWN_ALL	0x50
+#define LTC2664_CMD_SPAN_N(n)		(0x60 + (n))
+#define LTC2664_CMD_CONFIG		0x70
+#define LTC2664_CMD_MUX			0xB0
+#define LTC2664_CMD_TOGGLE_SEL		0xC0
+#define LTC2664_CMD_GLOBAL_TOGGLE	0xD0
+#define LTC2664_CMD_NO_OPERATION	0xF0
+#define LTC2664_REF_DISABLE		0x0001
+#define LTC2664_MSPAN_SOFTSPAN		7
+
+#define LTC2672_MAX_CHANNEL		5
+#define LTC2672_MAX_SPAN		7
+#define LTC2672_SCALE_MULTIPLIER(n)	(50 * BIT(n))
+
+enum {
+	LTC2664_SPAN_RANGE_0V_5V,
+	LTC2664_SPAN_RANGE_0V_10V,
+	LTC2664_SPAN_RANGE_M5V_5V,
+	LTC2664_SPAN_RANGE_M10V_10V,
+	LTC2664_SPAN_RANGE_M2V5_2V5,
+};
+
+enum {
+	LTC2664_INPUT_A,
+	LTC2664_INPUT_B,
+	LTC2664_INPUT_B_AVAIL,
+	LTC2664_POWERDOWN,
+	LTC2664_POWERDOWN_MODE,
+	LTC2664_TOGGLE_EN,
+	LTC2664_GLOBAL_TOGGLE,
+};
+
+static const u16 ltc2664_mspan_lut[8][2] = {
+	{ LTC2664_SPAN_RANGE_M10V_10V, 32768 }, /* MPS2=0, MPS1=0, MSP0=0 (0)*/
+	{ LTC2664_SPAN_RANGE_M5V_5V, 32768 }, /* MPS2=0, MPS1=0, MSP0=1 (1)*/
+	{ LTC2664_SPAN_RANGE_M2V5_2V5, 32768 }, /* MPS2=0, MPS1=1, MSP0=0 (2)*/
+	{ LTC2664_SPAN_RANGE_0V_10V, 0 }, /* MPS2=0, MPS1=1, MSP0=1 (3)*/
+	{ LTC2664_SPAN_RANGE_0V_10V, 32768 }, /* MPS2=1, MPS1=0, MSP0=0 (4)*/
+	{ LTC2664_SPAN_RANGE_0V_5V, 0 }, /* MPS2=1, MPS1=0, MSP0=1 (5)*/
+	{ LTC2664_SPAN_RANGE_0V_5V, 32768 }, /* MPS2=1, MPS1=1, MSP0=0 (6)*/
+	{ LTC2664_SPAN_RANGE_0V_5V, 0 } /* MPS2=1, MPS1=1, MSP0=1 (7)*/
+};
+
+struct ltc2664_state;
+
+struct ltc2664_chip_info {
+	const char *name;
+	int (*scale_get)(const struct ltc2664_state *st, int c);
+	int (*offset_get)(const struct ltc2664_state *st, int c);
+	int measurement_type;
+	unsigned int num_channels;
+	const int (*span_helper)[2];
+	unsigned int num_span;
+	unsigned int internal_vref_mv;
+	bool manual_span_support;
+	bool rfsadj_support;
+};
+
+struct ltc2664_chan {
+	/* indicates if the channel should be toggled */
+	bool toggle_chan;
+	/* indicates if the channel is in powered down state */
+	bool powerdown;
+	/* span code of the channel */
+	u8 span;
+	/* raw data of the current state of the chip registers (A/B) */
+	u16 raw[2];
+};
+
+struct ltc2664_state {
+	struct spi_device *spi;
+	struct regmap *regmap;
+	struct ltc2664_chan channels[LTC2672_MAX_CHANNEL];
+	/* lock to protect against multiple access to the device and shared data */
+	struct mutex lock;
+	const struct ltc2664_chip_info *chip_info;
+	struct iio_chan_spec *iio_channels;
+	int vref_mv;
+	u32 rfsadj_ohms;
+	u32 toggle_sel;
+	bool global_toggle;
+};
+
+static const int ltc2664_span_helper[][2] = {
+	{ 0, 5000 },
+	{ 0, 10000 },
+	{ -5000, 5000 },
+	{ -10000, 10000 },
+	{ -2500, 2500 },
+};
+
+static const int ltc2672_span_helper[][2] = {
+	{ 0, 0 },
+	{ 0, 3125 },
+	{ 0, 6250 },
+	{ 0, 12500 },
+	{ 0, 25000 },
+	{ 0, 50000 },
+	{ 0, 100000 },
+	{ 0, 200000 },
+	{ 0, 300000 },
+};
+
+static int ltc2664_scale_get(const struct ltc2664_state *st, int c)
+{
+	const struct ltc2664_chan *chan = &st->channels[c];
+	const int (*span_helper)[2] = st->chip_info->span_helper;
+	int span, fs;
+
+	span = chan->span;
+	if (span < 0)
+		return span;
+
+	fs = span_helper[span][1] - span_helper[span][0];
+
+	return fs * st->vref_mv / 2500;
+}
+
+static int ltc2672_scale_get(const struct ltc2664_state *st, int c)
+{
+	const struct ltc2664_chan *chan = &st->channels[c];
+	int span, fs;
+
+	span = chan->span - 1;
+	if (span < 0)
+		return span;
+
+	fs = 1000 * st->vref_mv;
+
+	if (span == LTC2672_MAX_SPAN)
+		return mul_u64_u32_div(4800, fs, st->rfsadj_ohms);
+
+	return mul_u64_u32_div(LTC2672_SCALE_MULTIPLIER(span), fs, st->rfsadj_ohms);
+}
+
+static int ltc2664_offset_get(const struct ltc2664_state *st, int c)
+{
+	const struct ltc2664_chan *chan = &st->channels[c];
+	int span;
+
+	span = chan->span;
+	if (span < 0)
+		return span;
+
+	if (st->chip_info->span_helper[span][0] < 0)
+		return -32768;
+
+	return 0;
+}
+
+static int ltc2664_dac_code_write(struct ltc2664_state *st, u32 chan, u32 input,
+				  u16 code)
+{
+	struct ltc2664_chan *c = &st->channels[chan];
+	int ret, reg;
+
+	guard(mutex)(&st->lock);
+	/* select the correct input register to write to */
+	if (c->toggle_chan) {
+		ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
+				   input << chan);
+		if (ret)
+			return ret;
+	}
+	/*
+	 * If in toggle mode the dac should be updated by an
+	 * external signal (or sw toggle) and not here.
+	 */
+	if (st->toggle_sel & BIT(chan))
+		reg = LTC2664_CMD_WRITE_N(chan);
+	else
+		reg = LTC2664_CMD_WRITE_N_UPDATE_N(chan);
+
+	ret = regmap_write(st->regmap, reg, code);
+	if (ret)
+		return ret;
+
+	c->raw[input] = code;
+
+	if (c->toggle_chan) {
+		ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
+				   st->toggle_sel);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void ltc2664_dac_code_read(struct ltc2664_state *st, u32 chan, u32 input,
+				  u32 *code)
+{
+	guard(mutex)(&st->lock);
+	*code = st->channels[chan].raw[input];
+}
+
+static const int ltc2664_raw_range[] = { 0, 1, U16_MAX };
+
+static int ltc2664_read_avail(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long info)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		*vals = ltc2664_raw_range;
+		*type = IIO_VAL_INT;
+
+		return IIO_AVAIL_RANGE;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltc2664_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long info)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		ltc2664_dac_code_read(st, chan->channel, LTC2664_INPUT_A, val);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = st->chip_info->offset_get(st, chan->channel);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->chip_info->scale_get(st, chan->channel);
+
+		*val2 = 16;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltc2664_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int val,
+			     int val2, long info)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		if (val > U16_MAX || val < 0)
+			return -EINVAL;
+
+		return ltc2664_dac_code_write(st, chan->channel,
+					      LTC2664_INPUT_A, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t ltc2664_reg_bool_get(struct iio_dev *indio_dev,
+				    uintptr_t private,
+				    const struct iio_chan_spec *chan,
+				    char *buf)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+	u32 val;
+
+	guard(mutex)(&st->lock);
+	switch (private) {
+	case LTC2664_POWERDOWN:
+		val = st->channels[chan->channel].powerdown;
+
+		return sysfs_emit(buf, "%u\n", val);
+	case LTC2664_POWERDOWN_MODE:
+		return sysfs_emit(buf, "42kohm_to_gnd\n");
+	case LTC2664_TOGGLE_EN:
+		val = !!(st->toggle_sel & BIT(chan->channel));
+
+		return sysfs_emit(buf, "%u\n", val);
+	case LTC2664_GLOBAL_TOGGLE:
+		val = st->global_toggle;
+
+		return sysfs_emit(buf, "%u\n", val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t ltc2664_reg_bool_set(struct iio_dev *indio_dev,
+				    uintptr_t private,
+				    const struct iio_chan_spec *chan,
+				    const char *buf, size_t len)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+	int ret;
+	bool en;
+
+	ret = kstrtobool(buf, &en);
+	if (ret)
+		return ret;
+
+	guard(mutex)(&st->lock);
+	switch (private) {
+	case LTC2664_POWERDOWN:
+		ret = regmap_write(st->regmap,
+				   en ? LTC2664_CMD_POWER_DOWN_N(chan->channel) :
+				   LTC2664_CMD_UPDATE_N(chan->channel), en);
+		if (ret)
+			return ret;
+
+		st->channels[chan->channel].powerdown = en;
+
+		return len;
+	case LTC2664_TOGGLE_EN:
+		if (en)
+			st->toggle_sel |= BIT(chan->channel);
+		else
+			st->toggle_sel &= ~BIT(chan->channel);
+
+		ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
+				   st->toggle_sel);
+		if (ret)
+			return ret;
+
+		return len;
+	case LTC2664_GLOBAL_TOGGLE:
+		ret = regmap_write(st->regmap, LTC2664_CMD_GLOBAL_TOGGLE, en);
+		if (ret)
+			return ret;
+
+		st->global_toggle = en;
+
+		return len;
+	default:
+		return -EINVAL;
+	}
+}
+
+static ssize_t ltc2664_dac_input_read(struct iio_dev *indio_dev,
+				      uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      char *buf)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+	u32 val;
+
+	if (private == LTC2664_INPUT_B_AVAIL)
+		return sysfs_emit(buf, "[%u %u %u]\n", ltc2664_raw_range[0],
+				  ltc2664_raw_range[1],
+				  ltc2664_raw_range[2] / 4);
+
+	ltc2664_dac_code_read(st, chan->channel, private, &val);
+
+	return sysfs_emit(buf, "%u\n", val);
+}
+
+static ssize_t ltc2664_dac_input_write(struct iio_dev *indio_dev,
+				       uintptr_t private,
+				       const struct iio_chan_spec *chan,
+				       const char *buf, size_t len)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+	int ret;
+	u16 val;
+
+	if (private == LTC2664_INPUT_B_AVAIL)
+		return -EINVAL;
+
+	ret = kstrtou16(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	ret = ltc2664_dac_code_write(st, chan->channel, private, val);
+	if (ret)
+		return ret;
+
+	return len;
+}
+
+static int ltc2664_reg_access(struct iio_dev *indio_dev,
+			      unsigned int reg,
+			      unsigned int writeval,
+			      unsigned int *readval)
+{
+	struct ltc2664_state *st = iio_priv(indio_dev);
+
+	if (readval)
+		return -EOPNOTSUPP;
+
+	return regmap_write(st->regmap, reg, writeval);
+}
+
+#define LTC2664_CHAN_EXT_INFO(_name, _what, _shared, _read, _write) {	\
+	.name = _name,							\
+	.read = (_read),						\
+	.write = (_write),						\
+	.private = (_what),						\
+	.shared = (_shared),						\
+}
+
+/*
+ * For toggle mode we only expose the symbol attr (sw_toggle) in case a TGPx is
+ * not provided in dts.
+ */
+static const struct iio_chan_spec_ext_info ltc2664_toggle_sym_ext_info[] = {
+	LTC2664_CHAN_EXT_INFO("raw0", LTC2664_INPUT_A, IIO_SEPARATE,
+			      ltc2664_dac_input_read, ltc2664_dac_input_write),
+	LTC2664_CHAN_EXT_INFO("raw1", LTC2664_INPUT_B, IIO_SEPARATE,
+			      ltc2664_dac_input_read, ltc2664_dac_input_write),
+	LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
+			      ltc2664_reg_bool_get, ltc2664_reg_bool_set),
+	LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
+			      IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
+	LTC2664_CHAN_EXT_INFO("symbol", LTC2664_GLOBAL_TOGGLE, IIO_SEPARATE,
+			      ltc2664_reg_bool_get, ltc2664_reg_bool_set),
+	LTC2664_CHAN_EXT_INFO("toggle_en", LTC2664_TOGGLE_EN,
+			      IIO_SEPARATE, ltc2664_reg_bool_get,
+			      ltc2664_reg_bool_set),
+	{ }
+};
+
+static const struct iio_chan_spec_ext_info ltc2664_ext_info[] = {
+	LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
+			      ltc2664_reg_bool_get, ltc2664_reg_bool_set),
+	LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
+			      IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
+	{ }
+};
+
+static const struct iio_chan_spec ltc2664_channel_template = {
+	.indexed = 1,
+	.output = 1,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) |
+			      BIT(IIO_CHAN_INFO_OFFSET) |
+			      BIT(IIO_CHAN_INFO_RAW),
+	.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+	.ext_info = ltc2664_ext_info,
+};
+
+static const struct ltc2664_chip_info ltc2664_chip = {
+	.name = "ltc2664",
+	.scale_get = ltc2664_scale_get,
+	.offset_get = ltc2664_offset_get,
+	.measurement_type = IIO_VOLTAGE,
+	.num_channels = 4,
+	.span_helper = ltc2664_span_helper,
+	.num_span = ARRAY_SIZE(ltc2664_span_helper),
+	.internal_vref_mv = 2500,
+	.manual_span_support = true,
+	.rfsadj_support = false,
+};
+
+static const struct ltc2664_chip_info ltc2672_chip = {
+	.name = "ltc2672",
+	.scale_get = ltc2672_scale_get,
+	.offset_get = ltc2664_offset_get,
+	.measurement_type = IIO_CURRENT,
+	.num_channels = 5,
+	.span_helper = ltc2672_span_helper,
+	.num_span = ARRAY_SIZE(ltc2672_span_helper),
+	.internal_vref_mv = 1250,
+	.manual_span_support = false,
+	.rfsadj_support = true,
+};
+
+static int ltc2664_set_span(const struct ltc2664_state *st, int min, int max,
+			    int chan)
+{
+	const struct ltc2664_chip_info *chip_info = st->chip_info;
+	const int (*span_helper)[2] = chip_info->span_helper;
+	int span, ret;
+
+	for (span = 0; span < chip_info->num_span; span++) {
+		if (min == span_helper[span][0] && max == span_helper[span][1])
+			break;
+	}
+
+	if (span == chip_info->num_span)
+		return -EINVAL;
+
+	ret = regmap_write(st->regmap, LTC2664_CMD_SPAN_N(chan), span);
+	if (ret)
+		return ret;
+
+	return span;
+}
+
+static int ltc2664_channel_config(struct ltc2664_state *st)
+{
+	const struct ltc2664_chip_info *chip_info = st->chip_info;
+	struct device *dev = &st->spi->dev;
+	u32 reg, tmp[2], mspan;
+	int ret, span = 0;
+
+	mspan = LTC2664_MSPAN_SOFTSPAN;
+	ret = device_property_read_u32(dev, "adi,manual-span-operation-config",
+				       &mspan);
+	if (!ret) {
+		if (!chip_info->manual_span_support)
+			return dev_err_probe(dev, -EINVAL,
+			       "adi,manual-span-operation-config not supported\n");
+
+		if (mspan > ARRAY_SIZE(ltc2664_mspan_lut))
+			return dev_err_probe(dev, -EINVAL,
+			       "adi,manual-span-operation-config not in range\n");
+	}
+
+	st->rfsadj_ohms = 20000;
+	ret = device_property_read_u32(dev, "adi,rfsadj-ohms", &st->rfsadj_ohms);
+	if (!ret) {
+		if (!chip_info->rfsadj_support)
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,rfsadj-ohms not supported\n");
+
+		if (st->rfsadj_ohms < 19000 || st->rfsadj_ohms > 41000)
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,rfsadj-ohms not in range\n");
+	}
+
+	device_for_each_child_node_scoped(dev, child) {
+		struct ltc2664_chan *chan;
+
+		ret = fwnode_property_read_u32(child, "reg", &reg);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to get reg property\n");
+
+		if (reg >= chip_info->num_channels)
+			return dev_err_probe(dev, -EINVAL,
+					     "reg bigger than: %d\n",
+					     chip_info->num_channels);
+
+		chan = &st->channels[reg];
+
+		if (fwnode_property_read_bool(child, "adi,toggle-mode")) {
+			chan->toggle_chan = true;
+			/* assume sw toggle ABI */
+			st->iio_channels[reg].ext_info = ltc2664_toggle_sym_ext_info;
+
+			/*
+			 * Clear IIO_CHAN_INFO_RAW bit as toggle channels expose
+			 * out_voltage/current_raw{0|1} files.
+			 */
+			__clear_bit(IIO_CHAN_INFO_RAW,
+				    &st->iio_channels[reg].info_mask_separate);
+		}
+
+		chan->raw[0] = ltc2664_mspan_lut[mspan][1];
+		chan->raw[1] = ltc2664_mspan_lut[mspan][1];
+
+		chan->span = ltc2664_mspan_lut[mspan][0];
+
+		ret = fwnode_property_read_u32_array(child, "output-range-microvolt",
+						     tmp, ARRAY_SIZE(tmp));
+		if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) {
+			chan->span = ltc2664_set_span(st, tmp[0] / 1000,
+						      tmp[1] / 1000, reg);
+			if (span < 0)
+				return dev_err_probe(dev, span,
+						     "Failed to set span\n");
+		}
+
+		ret = fwnode_property_read_u32_array(child, "output-range-microamp",
+						     tmp, ARRAY_SIZE(tmp));
+		if (!ret) {
+			chan->span = ltc2664_set_span(st, 0, tmp[1] / 1000, reg);
+			if (span < 0)
+				return dev_err_probe(dev, span,
+						     "Failed to set span\n");
+		}
+	}
+
+	return 0;
+}
+
+static int ltc2664_setup(struct ltc2664_state *st)
+{
+	const struct ltc2664_chip_info *chip_info = st->chip_info;
+	struct gpio_desc *gpio;
+	int ret, i;
+
+	/* If we have a clr/reset pin, use that to reset the chip. */
+	gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpio))
+		return dev_err_probe(&st->spi->dev, PTR_ERR(gpio),
+				     "Failed to get reset gpio");
+	if (gpio) {
+		fsleep(1000);
+		gpiod_set_value_cansleep(gpio, 0);
+	}
+
+	/*
+	 * Duplicate the default channel configuration as it can change during
+	 * @ltc2664_channel_config()
+	 */
+	st->iio_channels = devm_kcalloc(&st->spi->dev,
+					chip_info->num_channels,
+					sizeof(struct iio_chan_spec),
+					GFP_KERNEL);
+	if (!st->iio_channels)
+		return -ENOMEM;
+
+	for (i = 0; i < chip_info->num_channels; i++) {
+		st->iio_channels[i] = ltc2664_channel_template;
+		st->iio_channels[i].type = chip_info->measurement_type;
+		st->iio_channels[i].channel = i;
+	}
+
+	ret = ltc2664_channel_config(st);
+	if (ret)
+		return ret;
+
+	return regmap_set_bits(st->regmap, LTC2664_CMD_CONFIG, LTC2664_REF_DISABLE);
+}
+
+static const struct regmap_config ltc2664_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = LTC2664_CMD_NO_OPERATION,
+};
+
+static const struct iio_info ltc2664_info = {
+	.write_raw = ltc2664_write_raw,
+	.read_raw = ltc2664_read_raw,
+	.read_avail = ltc2664_read_avail,
+	.debugfs_reg_access = ltc2664_reg_access,
+};
+
+static int ltc2664_probe(struct spi_device *spi)
+{
+	static const char * const regulators[] = { "vcc", "iovcc", "v-neg" };
+	const struct ltc2664_chip_info *chip_info;
+	struct device *dev = &spi->dev;
+	struct iio_dev *indio_dev;
+	struct ltc2664_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+
+	chip_info = spi_get_device_match_data(spi);
+	if (!chip_info)
+		return -ENODEV;
+
+	st->chip_info = chip_info;
+
+	mutex_init(&st->lock);
+
+	st->regmap = devm_regmap_init_spi(spi, &ltc2664_regmap_config);
+	if (IS_ERR(st->regmap))
+		return dev_err_probe(dev, PTR_ERR(st->regmap),
+				     "Failed to init regmap");
+
+	ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators),
+					     regulators);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable regulators\n");
+
+	ret = devm_regulator_get_enable_read_voltage(dev, "ref");
+	if (ret < 0 && ret != -ENODEV)
+		return ret;
+
+	st->vref_mv = ret > 0 ? ret / 1000 :  chip_info->internal_vref_mv;
+
+	ret = ltc2664_setup(st);
+	if (ret)
+		return ret;
+
+	indio_dev->name = chip_info->name;
+	indio_dev->info = &ltc2664_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->iio_channels;
+	indio_dev->num_channels = chip_info->num_channels;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id ltc2664_id[] = {
+	{ "ltc2664", (kernel_ulong_t)&ltc2664_chip },
+	{ "ltc2672", (kernel_ulong_t)&ltc2672_chip },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ltc2664_id);
+
+static const struct of_device_id ltc2664_of_id[] = {
+	{ .compatible = "adi,ltc2664", .data = &ltc2664_chip },
+	{ .compatible = "adi,ltc2672", .data = &ltc2672_chip },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ltc2664_of_id);
+
+static struct spi_driver ltc2664_driver = {
+	.driver = {
+		.name = "ltc2664",
+		.of_match_table = ltc2664_of_id,
+	},
+	.probe = ltc2664_probe,
+	.id_table = ltc2664_id,
+};
+module_spi_driver(ltc2664_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_AUTHOR("Kim Seer Paller <kimseer.paller@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTC2664 and LTC2672 DAC");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Krzysztof Kozlowski]

On 14/07/2024 15:29, Kim Seer Paller wrote:
> Add documentation for ltc2664.
> 
> Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>

...

> +
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            channel@0 {
> +                    reg = <0>;
> +                    adi,toggle-mode;
> +                    output-range-microvolt = <(-10000000) 10000000>;

Mixed indentation.

Best regards,
Krzysztof

Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Conor Dooley]

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On Sun, Jul 14, 2024 at 09:29:58PM +0800, Kim Seer Paller wrote:
> Add documentation for ltc2664.
> 
> Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>

IIRC I gave you a reviewed-by on v5, was there a particular reason you
didn't add it?

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RE: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Paller, Kim Seer]

> -----Original Message-----
> From: Conor Dooley <conor@kernel.org>
> Sent: Tuesday, July 16, 2024 12:18 AM
> To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> Cc: linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org;
> devicetree@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; David
> Lechner <dlechner@baylibre.com>; Lars-Peter Clausen <lars@metafoo.de>;
> Liam Girdwood <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>;
> Dimitri Fedrau <dima.fedrau@gmail.com>; Krzysztof Kozlowski
> <krzk+dt@kernel.org>; Rob Herring <robh@kernel.org>; Conor Dooley
> <conor+dt@kernel.org>; Hennerich, Michael
> <Michael.Hennerich@analog.com>; Nuno Sá <noname.nuno@gmail.com>
> Subject: Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml
> 
> [External]
> 
> On Sun, Jul 14, 2024 at 09:29:58PM +0800, Kim Seer Paller wrote:
> > Add documentation for ltc2664.
> >
> > Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
> > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> 
> IIRC I gave you a reviewed-by on v5, was there a particular reason you didn't
> add it?

I made changes to the 'output-range-microvolt' logic in v6, which I thought
might require a new review. If your 'Reviewed-by' tag still applies, please let me know.

Thanks,
Kim

Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1666 bytes --]

On Tue, Jul 16, 2024 at 01:50:23AM +0000, Paller, Kim Seer wrote:
> 
> 
> > -----Original Message-----
> > From: Conor Dooley <conor@kernel.org>
> > Sent: Tuesday, July 16, 2024 12:18 AM
> > To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> > Cc: linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org;
> > devicetree@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; David
> > Lechner <dlechner@baylibre.com>; Lars-Peter Clausen <lars@metafoo.de>;
> > Liam Girdwood <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>;
> > Dimitri Fedrau <dima.fedrau@gmail.com>; Krzysztof Kozlowski
> > <krzk+dt@kernel.org>; Rob Herring <robh@kernel.org>; Conor Dooley
> > <conor+dt@kernel.org>; Hennerich, Michael
> > <Michael.Hennerich@analog.com>; Nuno Sá <noname.nuno@gmail.com>
> > Subject: Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml
> > 
> > [External]
> > 
> > On Sun, Jul 14, 2024 at 09:29:58PM +0800, Kim Seer Paller wrote:
> > > Add documentation for ltc2664.
> > >
> > > Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
> > > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > > Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> > 
> > IIRC I gave you a reviewed-by on v5, was there a particular reason you didn't
> > add it?
> 
> I made changes to the 'output-range-microvolt' logic in v6, which I thought
> might require a new review. If your 'Reviewed-by' tag still applies, please let me know.

IIRC what I said was along the lines of "with the logic from the
previous version, Reviewed-by: Conor Dooley <conor.dooley@microchip.com>".
Is that what you did?

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RE: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Paller, Kim Seer]

> -----Original Message-----
> From: Conor Dooley <conor@kernel.org>
> Sent: Tuesday, July 16, 2024 11:58 PM
> To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> Cc: linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org;
> devicetree@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; David
> Lechner <dlechner@baylibre.com>; Lars-Peter Clausen <lars@metafoo.de>;
> Liam Girdwood <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>;
> Dimitri Fedrau <dima.fedrau@gmail.com>; Krzysztof Kozlowski
> <krzk+dt@kernel.org>; Rob Herring <robh@kernel.org>; Conor Dooley
> <conor+dt@kernel.org>; Hennerich, Michael
> <Michael.Hennerich@analog.com>; Nuno Sá <noname.nuno@gmail.com>
> Subject: Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml
> 
> [External]
> 
> On Tue, Jul 16, 2024 at 01:50:23AM +0000, Paller, Kim Seer wrote:
> >
> >
> > > -----Original Message-----
> > > From: Conor Dooley <conor@kernel.org>
> > > Sent: Tuesday, July 16, 2024 12:18 AM
> > > To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> > > Cc: linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org;
> > > devicetree@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; David
> > > Lechner <dlechner@baylibre.com>; Lars-Peter Clausen <lars@metafoo.de>;
> > > Liam Girdwood <lgirdwood@gmail.com>; Mark Brown
> <broonie@kernel.org>;
> > > Dimitri Fedrau <dima.fedrau@gmail.com>; Krzysztof Kozlowski
> > > <krzk+dt@kernel.org>; Rob Herring <robh@kernel.org>; Conor Dooley
> > > <conor+dt@kernel.org>; Hennerich, Michael
> > > <Michael.Hennerich@analog.com>; Nuno Sá <noname.nuno@gmail.com>
> > > Subject: Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml
> > >
> > > [External]
> > >
> > > On Sun, Jul 14, 2024 at 09:29:58PM +0800, Kim Seer Paller wrote:
> > > > Add documentation for ltc2664.
> > > >
> > > > Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
> > > > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > > > Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> > >
> > > IIRC I gave you a reviewed-by on v5, was there a particular reason you
> didn't
> > > add it?
> >
> > I made changes to the 'output-range-microvolt' logic in v6, which I thought
> > might require a new review. If your 'Reviewed-by' tag still applies, please let
> me know.
> 
> IIRC what I said was along the lines of "with the logic from the
> previous version, Reviewed-by: Conor Dooley <conor.dooley@microchip.com>".
> Is that what you did?

Yes. Additionally, considering Krzysztof's recent comment about the mixed 
indentation in the example section, should I send a new patch version that
includes this indentation fix along with adding your Reviewed-by tag?

Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2980 bytes --]

On Wed, Jul 17, 2024 at 01:07:31AM +0000, Paller, Kim Seer wrote:
> 
> 
> > -----Original Message-----
> > From: Conor Dooley <conor@kernel.org>
> > Sent: Tuesday, July 16, 2024 11:58 PM
> > To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> > Cc: linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org;
> > devicetree@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; David
> > Lechner <dlechner@baylibre.com>; Lars-Peter Clausen <lars@metafoo.de>;
> > Liam Girdwood <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>;
> > Dimitri Fedrau <dima.fedrau@gmail.com>; Krzysztof Kozlowski
> > <krzk+dt@kernel.org>; Rob Herring <robh@kernel.org>; Conor Dooley
> > <conor+dt@kernel.org>; Hennerich, Michael
> > <Michael.Hennerich@analog.com>; Nuno Sá <noname.nuno@gmail.com>
> > Subject: Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml
> > 
> > [External]
> > 
> > On Tue, Jul 16, 2024 at 01:50:23AM +0000, Paller, Kim Seer wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Conor Dooley <conor@kernel.org>
> > > > Sent: Tuesday, July 16, 2024 12:18 AM
> > > > To: Paller, Kim Seer <KimSeer.Paller@analog.com>
> > > > Cc: linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org;
> > > > devicetree@vger.kernel.org; Jonathan Cameron <jic23@kernel.org>; David
> > > > Lechner <dlechner@baylibre.com>; Lars-Peter Clausen <lars@metafoo.de>;
> > > > Liam Girdwood <lgirdwood@gmail.com>; Mark Brown
> > <broonie@kernel.org>;
> > > > Dimitri Fedrau <dima.fedrau@gmail.com>; Krzysztof Kozlowski
> > > > <krzk+dt@kernel.org>; Rob Herring <robh@kernel.org>; Conor Dooley
> > > > <conor+dt@kernel.org>; Hennerich, Michael
> > > > <Michael.Hennerich@analog.com>; Nuno Sá <noname.nuno@gmail.com>
> > > > Subject: Re: [PATCH v7 4/6] dt-bindings: iio: dac: Add adi,ltc2664.yaml
> > > >
> > > > [External]
> > > >
> > > > On Sun, Jul 14, 2024 at 09:29:58PM +0800, Kim Seer Paller wrote:
> > > > > Add documentation for ltc2664.
> > > > >
> > > > > Co-developed-by: Michael Hennerich <michael.hennerich@analog.com>
> > > > > Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
> > > > > Signed-off-by: Kim Seer Paller <kimseer.paller@analog.com>
> > > >
> > > > IIRC I gave you a reviewed-by on v5, was there a particular reason you
> > didn't
> > > > add it?
> > >
> > > I made changes to the 'output-range-microvolt' logic in v6, which I thought
> > > might require a new review. If your 'Reviewed-by' tag still applies, please let
> > me know.
> > 
> > IIRC what I said was along the lines of "with the logic from the
> > previous version, Reviewed-by: Conor Dooley <conor.dooley@microchip.com>".
> > Is that what you did?
> 
> Yes. Additionally, considering Krzysztof's recent comment about the mixed 
> indentation in the example section, should I send a new patch version that
> includes this indentation fix along with adding your Reviewed-by tag?

Seems reasonable to me, thanks.

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