dt-bindings:iio:potentiometer: give microchip,mcp4531 its own binding

We use this part in an example for the envelope detector. That showed
that we need to allow for the #io-channel-cells property which
trivial-devices.yaml does not.

It doesn't make sense to add that property to trivial-devices as
it only applies for those devices that can provide some sort of
DAC or ADC service to another device driver.  Hence solution will
be to pull some IIO devices out to have their own file on a case
by case basis.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20201031181242.742301-4-jic23@kernel.org

1 files changed, 116 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/iio/potentiometer/microchip,mcp4531.yaml b/Documentation/devicetree/bindings/iio/potentiometer/microchip,mcp4531.yaml
new file mode 100644
index 000000000000..5c4b9b9181ae
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/potentiometer/microchip,mcp4531.yaml
@@ -0,0 +1,116 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/potentiometer/microchip,mcp4531.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip mcp4531 and similar potentiometers.
+
+maintainers:
+  - Peter Rosin <peda@axentia.se>
+
+description: |
+  Family of I2C digital potentiometer
+  Datasheets at:
+  * volatile https://ww1.microchip.com/downloads/en/DeviceDoc/22096b.pdf
+  * non-volatile https://ww1.microchip.com/downloads/en/DeviceDoc/22107B.pdf
+  Part numbers as follows: mcp4ABC-XXX where
+  A =   5 (1 wiper), 6 (2 wipers)
+  B =   3 (7-bit, volatile), 4 (7-bit, non-volatile),
+        5 (8-bit, volatile), 6 (8-bit, non-volatile),
+  C:    1 (potentiometer), 2 (rheostat)
+  XXX = 502 (5 kOhms), 103 (10 kOhms), 503 (50 kOhms), 104 (100 kOhms)
+
+properties:
+  compatible:
+    enum:
+        # Ordering reflects part number + range, so 502 < 103 etc
+      - microchip,mcp4531-502
+      - microchip,mcp4531-103
+      - microchip,mcp4531-503
+      - microchip,mcp4531-104
+      - microchip,mcp4532-502
+      - microchip,mcp4532-103
+      - microchip,mcp4532-503
+      - microchip,mcp4532-104
+      - microchip,mcp4541-502
+      - microchip,mcp4541-103
+      - microchip,mcp4541-503
+      - microchip,mcp4541-104
+      - microchip,mcp4542-502
+      - microchip,mcp4542-103
+      - microchip,mcp4542-503
+      - microchip,mcp4542-104
+      - microchip,mcp4551-502
+      - microchip,mcp4551-103
+      - microchip,mcp4551-503
+      - microchip,mcp4551-104
+      - microchip,mcp4552-502
+      - microchip,mcp4552-103
+      - microchip,mcp4552-503
+      - microchip,mcp4552-104
+      - microchip,mcp4561-502
+      - microchip,mcp4561-103
+      - microchip,mcp4561-503
+      - microchip,mcp4561-104
+      - microchip,mcp4562-502
+      - microchip,mcp4562-103
+      - microchip,mcp4562-503
+      - microchip,mcp4562-104
+      - microchip,mcp4631-502
+      - microchip,mcp4631-103
+      - microchip,mcp4631-503
+      - microchip,mcp4631-104
+      - microchip,mcp4632-502
+      - microchip,mcp4632-103
+      - microchip,mcp4632-503
+      - microchip,mcp4632-104
+      - microchip,mcp4641-502
+      - microchip,mcp4641-103
+      - microchip,mcp4641-503
+      - microchip,mcp4641-104
+      - microchip,mcp4642-502
+      - microchip,mcp4642-103
+      - microchip,mcp4642-503
+      - microchip,mcp4642-104
+      - microchip,mcp4651-502
+      - microchip,mcp4651-103
+      - microchip,mcp4651-503
+      - microchip,mcp4651-104
+      - microchip,mcp4652-502
+      - microchip,mcp4652-103
+      - microchip,mcp4652-503
+      - microchip,mcp4652-104
+      - microchip,mcp4661-502
+      - microchip,mcp4661-103
+      - microchip,mcp4661-503
+      - microchip,mcp4661-104
+      - microchip,mcp4662-502
+      - microchip,mcp4662-103
+      - microchip,mcp4662-503
+      - microchip,mcp4662-104
+
+  reg:
+    maxItems: 1
+
+  "#io-channel-cells":
+    const: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        dpot: dpot@28 {
+            compatible = "microchip,mcp4651-104";
+            reg = <0x28>;
+            #io-channel-cells = <1>;
+        };
+    };
+...