staging: iio: cdc: ad7746: add dt properties for capacitive channel setup

Add device tree binding documentation for AD7746 cdc in YAML format.

Signed-off-by Lucas Stankus <[email protected]>

---

A minor note about the adi,excitation-vdd-permille property. Jonathan suggested the name to be adi,excitation-vdd-milicent, but I was unsure of the milicent naming. With a quick search I found out that the common way to call a thousandth is 'per mille'[1], but I didn't find any use of it in the kernel documentation. Any thoughts about it?

[1] https://en.wikipedia.org/wiki/Per_mille

 .../bindings/iio/cdc/adi,ad7746.yaml          | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +30 -0

new file mode 100644
index 000000000000..a2a7eee674ba
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/cdc/adi,ad7746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+maintainers:
+  - Michael Hennerich <[email protected]>
+
+description: |
+  AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+  Specifications about the part can be found at:
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7291.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7745
+      - adi,ad7746
+      - adi,ad7747
+
+  reg:
+    maxItems: 1
+
+  adi,excitation-vdd-permille:
+    description: |
+      Set VDD per mille to be used as the excitation voltage.

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +33 -0

+
+  adi,excb-output-en:
+    description: Enables the EXCB pin as the excitation output.
+    type: boolean
+
+  adi,excb-output-invert:
+    description: Inverts the excitation output in the EXCB pin.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ad7746: cdc@48 {
+        compatible = "adi,ad7746";
+        reg = <0x48>;
+        adi,excitation-vdd-permille = <125>;
+
+        adi,exca-output-en;
+        adi,exca-output-invert;
+        adi,excb-output-en;
+        adi,excb-output-invert;
+      };
+    };
+...

Signature · 1 line

2.31.1

Quoted 10 lines · Lucas Stankus

Add device tree binding documentation for AD7746 cdc in YAML format.

Signed-off-by Lucas Stankus <[email protected]>

---

A minor note about the adi,excitation-vdd-permille property. Jonathan suggested the name to be adi,excitation-vdd-milicent, but I was unsure of the milicent naming. With a quick search I found out that the common way to call a thousandth is 'per mille'[1], but I didn't find any use of it in the kernel documentation. Any thoughts about it?

Seems okay to me.

Quoted 49 lines

[1] https://en.wikipedia.org/wiki/Per_mille

 .../bindings/iio/cdc/adi,ad7746.yaml          | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +37 -0

new file mode 100644
index 000000000000..a2a7eee674ba
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/cdc/adi,ad7746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+maintainers:
+  - Michael Hennerich <[email protected]>
+
+description: |
+  AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+  Specifications about the part can be found at:
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7291.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7745
+      - adi,ad7746
+      - adi,ad7747
+
+  reg:
+    maxItems: 1
+
+  adi,excitation-vdd-permille:
+    description: |
+      Set VDD per mille to be used as the excitation voltage.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [125, 250, 375, 500]
+
+  adi,exca-output-en:
+    description: Enables the EXCA pin as the excitation output.
+    type: boolean
+

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml line 40

Quoted 3 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +3 -0

+  adi,exca-output-invert:
+    description: Inverts the excitation output in the EXCA pin.
+    type: boolean

'invert' assumes I know what the non-inverted signal is. Sometimes that makes sense, but if you can define in terms of the inverse that would be better. For example, for a normally active low signal, name the property 'foo-active-high'.

Quoted 37 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +33 -1

+
+  adi,excb-output-en:
+    description: Enables the EXCB pin as the excitation output.
+    type: boolean
+
+  adi,excb-output-invert:
+    description: Inverts the excitation output in the EXCB pin.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ad7746: cdc@48 {
+        compatible = "adi,ad7746";
+        reg = <0x48>;
+        adi,excitation-vdd-permille = <125>;
+
+        adi,exca-output-en;
+        adi,exca-output-invert;
+        adi,excb-output-en;
+        adi,excb-output-invert;
+      };
+    };
+...
--

2.31.1

Quoted 61 lines · Rob Herring

Quoted 10 lines · Lucas Stankus

Add device tree binding documentation for AD7746 cdc in YAML format.

Signed-off-by Lucas Stankus <[email protected]>

---

A minor note about the adi,excitation-vdd-permille property. Jonathan suggested the name to be adi,excitation-vdd-milicent, but I was unsure of the milicent naming. With a quick search I found out that the common way to call a thousandth is 'per mille'[1], but I didn't find any use of it in the kernel documentation. Any thoughts about it?

Seems okay to me.

Quoted 48 lines

[1] https://en.wikipedia.org/wiki/Per_mille

  .../bindings/iio/cdc/adi,ad7746.yaml          | 73 +++++++++++++++++++
  1 file changed, 73 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +36 -0

new file mode 100644
index 000000000000..a2a7eee674ba
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/cdc/adi,ad7746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+maintainers:
+  - Michael Hennerich <[email protected]>
+
+description: |
+  AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+  Specifications about the part can be found at:
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7291.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7745
+      - adi,ad7746
+      - adi,ad7747
+
+  reg:
+    maxItems: 1
+
+  adi,excitation-vdd-permille:
+    description: |
+      Set VDD per mille to be used as the excitation voltage.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [125, 250, 375, 500]
+
+  adi,exca-output-en:
+    description: Enables the EXCA pin as the excitation output.
+    type: boolean

Quoted 8 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml line 40

Quoted 4 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +4 -0

+
+  adi,exca-output-invert:
+    description: Inverts the excitation output in the EXCA pin.
+    type: boolean

'invert' assumes I know what the non-inverted signal is. Sometimes that makes sense, but if you can define in terms of the inverse that would be better. For example, for a normally active low signal, name the property 'foo-active-high'.

Thanks for the feedback!
From reading the data sheet I couldn't quite grasp what would be an inverted
excitation output, but I don't have a lot of experience with CDCs. Maybe someone with more experience could help out with a better suggestion.

Quoted 5 lines · Lucas Stankus

Add device tree binding documentation for AD7746 cdc in YAML format.

Signed-off-by Lucas Stankus <[email protected]>

---

Quoted 5 lines

A minor note about the adi,excitation-vdd-permille property. Jonathan suggested the name to be adi,excitation-vdd-milicent, but I was unsure of the milicent naming. With a quick search I found out that the common way to call a thousandth is 'per mille'[1], but I didn't find any use of it in the kernel documentation. Any thoughts about it?

Seems okay to me.

Quoted 43 lines

[1] https://en.wikipedia.org/wiki/Per_mille

 .../bindings/iio/cdc/adi,ad7746.yaml          | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +30 -0

new file mode 100644
index 000000000000..a2a7eee674ba
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/cdc/adi,ad7746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+maintainers:
+  - Michael Hennerich <[email protected]>
+
+description: |
+  AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+  Specifications about the part can be found at:
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7291.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7745
+      - adi,ad7746
+      - adi,ad7747
+
+  reg:
+    maxItems: 1
+
+  adi,excitation-vdd-permille:
+    description: |
+      Set VDD per mille to be used as the excitation voltage.

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml line 40

Quoted 10 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +10 -0

+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [125, 250, 375, 500]
+
+  adi,exca-output-en:
+    description: Enables the EXCA pin as the excitation output.
+    type: boolean
+
+  adi,exca-output-invert:
+    description: Inverts the excitation output in the EXCA pin.
+    type: boolean  

'invert' assumes I know what the non-inverted signal is. Sometimes that makes sense, but if you can define in terms of the inverse that would be better. For example, for a normally active low signal, name the property 'foo-active-high'.

Quoted 36 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +33 -0

+
+  adi,excb-output-en:
+    description: Enables the EXCB pin as the excitation output.
+    type: boolean
+
+  adi,excb-output-invert:
+    description: Inverts the excitation output in the EXCB pin.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ad7746: cdc@48 {
+        compatible = "adi,ad7746";
+        reg = <0x48>;
+        adi,excitation-vdd-permille = <125>;
+
+        adi,exca-output-en;
+        adi,exca-output-invert;
+        adi,excb-output-en;
+        adi,excb-output-invert;
+      };
+    };
+...

Signature · 1 line

2.31.1

Quoted 70 lines · Lucas Stankus

Quoted 61 lines · Rob Herring

Quoted 10 lines · Lucas Stankus

Add device tree binding documentation for AD7746 cdc in YAML format.

Signed-off-by Lucas Stankus <[email protected]>

---

A minor note about the adi,excitation-vdd-permille property. Jonathan suggested the name to be adi,excitation-vdd-milicent, but I was unsure of the milicent naming. With a quick search I found out that the common way to call a thousandth is 'per mille'[1], but I didn't find any use of it in the kernel documentation. Any thoughts about it?

Seems okay to me.

Quoted 48 lines

[1] https://en.wikipedia.org/wiki/Per_mille

  .../bindings/iio/cdc/adi,ad7746.yaml          | 73 +++++++++++++++++++
  1 file changed, 73 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +36 -0

new file mode 100644
index 000000000000..a2a7eee674ba
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/cdc/adi,ad7746.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+maintainers:
+  - Michael Hennerich <[email protected]>
+
+description: |
+  AD7746 24-Bit Capacitance-to-Digital Converter with Temperature Sensor
+
+  Specifications about the part can be found at:
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7291.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7745
+      - adi,ad7746
+      - adi,ad7747
+
+  reg:
+    maxItems: 1
+
+  adi,excitation-vdd-permille:
+    description: |
+      Set VDD per mille to be used as the excitation voltage.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [125, 250, 375, 500]
+
+  adi,exca-output-en:
+    description: Enables the EXCA pin as the excitation output.
+    type: boolean

Quoted 8 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml line 40

Quoted 4 lines

Documentation/devicetree/bindings/iio/cdc/adi,ad7746.yaml new file +4 -0

+
+  adi,exca-output-invert:
+    description: Inverts the excitation output in the EXCA pin.
+    type: boolean  

'invert' assumes I know what the non-inverted signal is. Sometimes that makes sense, but if you can define in terms of the inverse that would be better. For example, for a normally active low signal, name the property 'foo-active-high'.

Quoted 4 lines

Thanks for the feedback!
From reading the data sheet I couldn't quite grasp what would be an inverted
excitation output, but I don't have a lot of experience with CDCs. Maybe someone with more experience could help out with a better suggestion.

This is the only thing I could find
https://www.analog.com/media/en/technical-documentation/application-notes/AN-1585.pdf.

The datasheet also says that only at most one of them should be inverted. So maybe only a single property which selects which of the two is inverted.

Ditch platform_data fields in favor of device tree properties for configuring EXCA and EXCB output pins and setting the capacitive channel excitation level.

As this covers all current use cases for the platform_data struct, remove ad7746.h header file since it's no longer needed.

Signed-off-by Lucas Stankus <[email protected]>

---

Changes in v2:
Previously this change set was composed of two patches, but it lead to regressions between the two. Merging them avoids the unwanted behaviour without having to deal with the special cases.

 drivers/staging/iio/cdc/ad7746.c | 42 +++++++++++++++-----------------
 drivers/staging/iio/cdc/ad7746.h | 28 ---------------------
 2 files changed, 19 insertions(+), 51 deletions(-)
 delete mode 100644 drivers/staging/iio/cdc/ad7746.h

drivers/staging/iio/cdc/ad7746.c +0 -2

index dfd71e99e872..c0e84c1cf4f1 100644
@@ -18,8 +18,6 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
-#include "ad7746.h"
-
 /*
  * AD7746 Register Definition
  */

drivers/staging/iio/cdc/ad7746.c +18 -20

 /* Config Register Bit Designations (AD7746_REG_CFG) */
 #define AD7746_CONF_VTFS_SHIFT		6

@@ -676,10 +674,11 @@ static const struct iio_info ad7746_info = {
 static int ad7746_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
-	struct ad7746_platform_data *pdata = client->dev.platform_data;
+	struct device *dev = &client->dev;
 	struct ad7746_chip_info *chip;
 	struct iio_dev *indio_dev;
 	unsigned char regval = 0;
+	unsigned int vdd_permille;
 	int ret = 0;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));

@@ -703,28 +702,25 @@ static int ad7746_probe(struct i2c_client *client,
 	indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	if (pdata) {
-		if (pdata->exca_en) {
-			if (pdata->exca_inv_en)
-				regval |= AD7746_EXCSETUP_NEXCA;
-			else
-				regval |= AD7746_EXCSETUP_EXCA;
-		}
-
-		if (pdata->excb_en) {
-			if (pdata->excb_inv_en)
-				regval |= AD7746_EXCSETUP_NEXCB;
-			else
-				regval |= AD7746_EXCSETUP_EXCB;
-		}
+	if (device_property_read_bool(dev, "adi,exca-output-en")) {
+		if (device_property_read_bool(dev, "adi,exca-output-invert"))
+			regval |= AD7746_EXCSETUP_NEXCA;
+		else
+			regval |= AD7746_EXCSETUP_EXCA;
+	}
 
-		regval |= AD7746_EXCSETUP_EXCLVL(pdata->exclvl);
-	} else {
-		dev_warn(&client->dev, "No platform data? using default\n");
-		regval = AD7746_EXCSETUP_EXCA | AD7746_EXCSETUP_EXCB |
-			AD7746_EXCSETUP_EXCLVL(3);
+	if (device_property_read_bool(dev, "adi,excb-output-en")) {
+		if (device_property_read_bool(dev, "adi,excb-output-invert"))
+			regval |= AD7746_EXCSETUP_NEXCB;
+		else
+			regval |= AD7746_EXCSETUP_EXCB;
 	}
 
+	ret = device_property_read_u32(dev, "adi,excitation-vdd-permille",
+				       &vdd_permille);
+	if (!ret)
+		regval |= AD7746_EXCSETUP_EXCLVL(vdd_permille);
+
 	ret = i2c_smbus_write_byte_data(chip->client,
 					AD7746_REG_EXC_SETUP, regval);
 	if (ret < 0)

drivers/staging/iio/cdc/ad7746.h deleted +0 -28

deleted file mode 100644
index 8bdbd732dbbd..000000000000
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
- *
- * Copyright 2011 Analog Devices Inc.
- */
-
-#ifndef IIO_CDC_AD7746_H_
-#define IIO_CDC_AD7746_H_
-
-/*
- * TODO: struct ad7746_platform_data needs to go into include/linux/iio
- */
-
-#define AD7466_EXCLVL_0		0 /* +-VDD/8 */
-#define AD7466_EXCLVL_1		1 /* +-VDD/4 */
-#define AD7466_EXCLVL_2		2 /* +-VDD * 3/8 */
-#define AD7466_EXCLVL_3		3 /* +-VDD/2 */
-
-struct ad7746_platform_data {
-	unsigned char exclvl;	/*Excitation Voltage Level */
-	bool exca_en;		/* enables EXCA pin as the excitation output */
-	bool exca_inv_en;	/* enables /EXCA pin as the excitation output */
-	bool excb_en;		/* enables EXCB pin as the excitation output */
-	bool excb_inv_en;	/* enables /EXCB pin as the excitation output */
-};
-
-#endif /* IIO_CDC_AD7746_H_ */

Quoted 8 lines · On Sun, 18 Apr 2021 19:50:10 -0300 Lucas Stankus <[email protected]>…

Ditch platform_data fields in favor of device tree properties for configuring EXCA and EXCB output pins and setting the capacitive channel excitation level.

As this covers all current use cases for the platform_data struct, remove ad7746.h header file since it's no longer needed.

Signed-off-by Lucas Stankus <[email protected]>

Hi Lucas,

Just one comment which is that the permille to register value is a bit opaque so I think I'd prefer a simple lookup table even though it is a bit more code.

Otherwise looks good to me.

Thanks,

Jonathan

Quoted 20 lines

---

Changes in v2:
Previously this change set was composed of two patches, but it lead to regressions between the two. Merging them avoids the unwanted behaviour without having to deal with the special cases.

 drivers/staging/iio/cdc/ad7746.c | 42 +++++++++++++++-----------------
 drivers/staging/iio/cdc/ad7746.h | 28 ---------------------
 2 files changed, 19 insertions(+), 51 deletions(-)
 delete mode 100644 drivers/staging/iio/cdc/ad7746.h

drivers/staging/iio/cdc/ad7746.c +0 -0

index dfd71e99e872..c0e84c1cf4f1 100644
@@ -18,8 +18,6 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 

drivers/staging/iio/cdc/ad7746.c line 67

Quoted 11 lines

drivers/staging/iio/cdc/ad7746.c +1 -3

-#include "ad7746.h"
-
 /*
  * AD7746 Register Definition
  */

@@ -66,7 +64,7 @@
 #define AD7746_EXCSETUP_NEXCB                BIT(4)
 #define AD7746_EXCSETUP_EXCA         BIT(3)
 #define AD7746_EXCSETUP_NEXCA                BIT(2)
-#define AD7746_EXCSETUP_EXCLVL(x)    (((x) & 0x3) << 0)
+#define AD7746_EXCSETUP_EXCLVL(x)    (((x) >> 7) & 0x3)

I'd like a comment on this maths, or just use a lookup table instead so we don't have to think about it and also enforce exact matches. The rounding this results in is a bit odd

Quoted 96 lines

drivers/staging/iio/cdc/ad7746.c +18 -20

 /* Config Register Bit Designations (AD7746_REG_CFG) */
 #define AD7746_CONF_VTFS_SHIFT               6

@@ -676,10 +674,11 @@ static const struct iio_info ad7746_info = {
 static int ad7746_probe(struct i2c_client *client,
                      const struct i2c_device_id *id)
 {
-     struct ad7746_platform_data *pdata = client->dev.platform_data;
+     struct device *dev = &client->dev;
      struct ad7746_chip_info *chip;
      struct iio_dev *indio_dev;
      unsigned char regval = 0;
+     unsigned int vdd_permille;
      int ret = 0;
 
      indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));

@@ -703,28 +702,25 @@ static int ad7746_probe(struct i2c_client *client,
      indio_dev->num_channels = ARRAY_SIZE(ad7746_channels);
      indio_dev->modes = INDIO_DIRECT_MODE;
 
-     if (pdata) {
-             if (pdata->exca_en) {
-                     if (pdata->exca_inv_en)
-                             regval |= AD7746_EXCSETUP_NEXCA;
-                     else
-                             regval |= AD7746_EXCSETUP_EXCA;
-             }
-
-             if (pdata->excb_en) {
-                     if (pdata->excb_inv_en)
-                             regval |= AD7746_EXCSETUP_NEXCB;
-                     else
-                             regval |= AD7746_EXCSETUP_EXCB;
-             }
+     if (device_property_read_bool(dev, "adi,exca-output-en")) {
+             if (device_property_read_bool(dev, "adi,exca-output-invert"))
+                     regval |= AD7746_EXCSETUP_NEXCA;
+             else
+                     regval |= AD7746_EXCSETUP_EXCA;
+     }
 
-             regval |= AD7746_EXCSETUP_EXCLVL(pdata->exclvl);
-     } else {
-             dev_warn(&client->dev, "No platform data? using default\n");
-             regval = AD7746_EXCSETUP_EXCA | AD7746_EXCSETUP_EXCB |
-                     AD7746_EXCSETUP_EXCLVL(3);
+     if (device_property_read_bool(dev, "adi,excb-output-en")) {
+             if (device_property_read_bool(dev, "adi,excb-output-invert"))
+                     regval |= AD7746_EXCSETUP_NEXCB;
+             else
+                     regval |= AD7746_EXCSETUP_EXCB;
      }
 
+     ret = device_property_read_u32(dev, "adi,excitation-vdd-permille",
+                                    &vdd_permille);
+     if (!ret)
+             regval |= AD7746_EXCSETUP_EXCLVL(vdd_permille);
+
      ret = i2c_smbus_write_byte_data(chip->client,
                                      AD7746_REG_EXC_SETUP, regval);
      if (ret < 0)

drivers/staging/iio/cdc/ad7746.h deleted +0 -28

deleted file mode 100644
index 8bdbd732dbbd..000000000000
@@ -1,28 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * AD7746 capacitive sensor driver supporting AD7745, AD7746 and AD7747
- *
- * Copyright 2011 Analog Devices Inc.
- */
-
-#ifndef IIO_CDC_AD7746_H_
-#define IIO_CDC_AD7746_H_
-
-/*
- * TODO: struct ad7746_platform_data needs to go into include/linux/iio
- */
-
-#define AD7466_EXCLVL_0              0 /* +-VDD/8 */
-#define AD7466_EXCLVL_1              1 /* +-VDD/4 */
-#define AD7466_EXCLVL_2              2 /* +-VDD * 3/8 */
-#define AD7466_EXCLVL_3              3 /* +-VDD/2 */
-
-struct ad7746_platform_data {
-     unsigned char exclvl;   /*Excitation Voltage Level */
-     bool exca_en;           /* enables EXCA pin as the excitation output */
-     bool exca_inv_en;       /* enables /EXCA pin as the excitation output */
-     bool excb_en;           /* enables EXCB pin as the excitation output */
-     bool excb_inv_en;       /* enables /EXCB pin as the excitation output */
-};
-
-#endif /* IIO_CDC_AD7746_H_ */