Thread (9 messages) 9 messages, 3 authors, 2021-05-22

Re: [PATCH v2 2/2] dt-bindings: iio: adc: devicetree bindings for texas instruments ads7142

From: Jonathan Cameron <jic23@kernel.org>
Date: 2021-05-16 09:56:19
Also in: linux-iio, lkml

On Sun, 16 May 2021 07:31:05 +0000
Jozsef Horvath [off-list ref] wrote:
This is a device tree schema for iio driver for
 Texas Instruments ADS7142 dual-channel, programmable sensor monitor.

Datasheet: https://www.ti.com/lit/ds/symlink/ads7142.pdf

Signed-off-by: Jozsef Horvath <redacted>
Hi József,

A few comments inline.

thanks,

Jonathan
quoted hunk ↗ jump to hunk
---

changes v1
  - Redundant parameters (ti,threshold-rising, etc.)
    are removed
  - Supply name changed(vref -> avdd)
  - Added dvdd supply
  - All the properties are removed with prefix "ti,"
changes v2
  - "ti,prealert-count" parameter added, just for completeness.
---
 .../bindings/iio/adc/ti,ads7142.yaml          | 110 ++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml
new file mode 100644
index 000000000000..6e52079c68f7
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti,ads7142.yaml
@@ -0,0 +1,110 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/iio/adc/ti,ads7142.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Texas Instruments ADS7142 adc driver device tree bindings
ADC
+
+maintainers:
+  - József Horváth [off-list ref]
+
+description: |
+  This document is for describing the required device tree parameters
+   for ads7142 adc
ADC
+  The required parameters for proper operation are described below.
+
+  Datasheet: https://www.ti.com/lit/ds/symlink/ads7142.pdf
+
+properties:
+  compatible:
+    const: ti,ads7142
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    description: |
+      The BUSY/PDY pin is used as interrupt line
RDY ?
+       in autonomous monitoring mode.
+    maxItems: 1
+
+  avdd-supply:
+    description: Regulator for the reference voltage
+
+  dvdd-supply: true
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  "#io-channel-cells":
+    const: 1
+
+  ti,prealert-count:
+    description: |
+      Sets the Pre-Alert Event Count for both,
+       high and low comparators, for both the channels.
Interesting.  Why is this a device tree property rather than something
we want to configure from userspace?  Looks like it would map to _period
after scaling by the sampling frequency.

https://elixir.bootlin.com/linux/latest/source/Documentation/ABI/testing/sysfs-bus-iio#L1003

+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 15
+    minimum: 0
+
+patternProperties:
+  "^channel@[0-1]$":
+    $ref: "adc.yaml"
+    type: object
+    description: |
+      Represents the external channels which are connected to the ADC.
+    properties:
+      reg:
+        description: |
+          The channel number.
+        items:
+          minimum: 0
+          maximum: 1
enum: [0 1]
is a more compact way of putting this IIRC.
 
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - "#io-channel-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      adc@1f {
+        compatible = "ti,ads7142";
+        reg = <0x1f>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        #io-channel-cells = <1>;
+
+        avdd-supply = <&vdd_3v3_reg>;
+        dvdd-supply = <&vdd_1v8_reg>;
+
+        interrupt-parent = <&gpio>;
+        interrupts = <7 2>;
+
+        ti,prealert-count = <4>;
+
+        channel@0 {
+          reg = <0>;
+        };
+
+        channel@1 {
+          reg = <1>;
+        };
+      };
+    };
+...
+
  
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