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From: Christoph Winklhofer via B4 Relay
 <devnull+cj.winklhofer.gmail.com@kernel.org>
Date: Sat, 06 Jan 2024 17:02:24 +0100
Subject: [PATCH v4 1/3] dt-bindings: w1: UART 1-Wire bus
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References: <20240106-w1-uart-v4-0-7fe1378a8b3e@gmail.com>
In-Reply-To: <20240106-w1-uart-v4-0-7fe1378a8b3e@gmail.com>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>, 
 Rob Herring <robh+dt@kernel.org>, Conor Dooley <conor+dt@kernel.org>, 
 Christoph Winklhofer <cj.winklhofer@gmail.com>, 
 Rob Herring <robh@kernel.org>, 
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>, 
 Jiri Slaby <jirislaby@kernel.org>, 
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, 
 Jonathan Corbet <corbet@lwn.net>
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, 
 linux-serial@vger.kernel.org, linux-doc@vger.kernel.org
Reply-To: <cj.winklhofer@gmail.com>

From: Christoph Winklhofer <cj.winklhofer@gmail.com>

Add device tree binding for UART 1-Wire bus.

Signed-off-by: Christoph Winklhofer <cj.winklhofer@gmail.com>
---
 Documentation/devicetree/bindings/w1/w1-uart.yaml | 62 +++++++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml
new file mode 100644
index 000000000000..6b90693b2ca0
--- /dev/null
+++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/w1/w1-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: UART 1-Wire Bus
+
+maintainers:
+  - Christoph Winklhofer <cj.winklhofer@gmail.com>
+
+description: |
+  UART 1-wire bus. Utilizes the UART interface via the Serial Device Bus
+  to create the 1-Wire timing patterns.
+
+  The UART peripheral must support full-duplex and operate in open-drain
+  mode. The timing patterns are generated by a specific combination of
+  baud-rate and transmitted byte, which corresponds to a 1-Wire read bit,
+  write bit or reset pulse.
+
+  The default baud-rate for reset and presence detection is 9600 and for
+  a 1-Wire read or write operation 115200. In case the actual baud-rate
+  is different from the requested one, the transmitted byte is adapted
+  to generate the 1-Wire timing patterns.
+
+  https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html
+
+
+properties:
+  compatible:
+    const: w1-uart
+
+  reset-speed:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 9600
+    description: |
+      The baud rate for the 1-Wire reset and presence detect.
+
+  touch_0-speed:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 115200
+    description: |
+      The baud rate for the 1-Wire write-0 cycle (touch bit 0).
+
+  touch_1-speed:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 115200
+    description: |
+      The baud rate for the 1-Wire write-1 and read cycle (touch bit 1).
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    serial {
+      onewire {
+        compatible = "w1-uart";
+      };
+    };

-- 
2.43.0