dts: bindings: gpio: Adding Arduino MKR header
Add MKR header connector that is implemented by Arduino MKR series.
This allows hardware with compatible headers to define the related GPIOs.
Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@fujitsu.com>
diff --git a/dts/bindings/gpio/arduino-mkr-header.yaml b/dts/bindings/gpio/arduino-mkr-header.yaml
new file mode 100644
index 0000000..67e7360
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+++ b/dts/bindings/gpio/arduino-mkr-header.yaml
@@ -0,0 +1,39 @@
+# Copyright (c) 2022 TOKITA Hiroshi <tokita.hiroshi@fujitsu.com>
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+ GPIO pins exposing on Arduino MKR headers.
+
+ The Arduino MKR layout provides two headers on both edges of the board.
+
+ * One side of the 14-pin header is analog inputs and digital signals.
+ A1 to A6 is Analog input. The outside pin is AREF.
+ A0 that is next to AREF used as a DAC output pin too.
+ D0-D5 is a digital output.
+ * The other side 14-pin header is power supplies and peripheral interface.
+ There are 5V and VCC power supply, GND, and RESET pin. UART, I2C,
+ and SPI peripheral pins are also there. The end 2 pins are simple GPIO pins.
+
+ This binding provides a nexus mapping for 22 pins where parent pins 0
+ through 14 correspond to D0 through D21, and parent pins 15 through 21
+ correspond to A0 through A6, as depicted below.
+
+ - AREF 5V -
+ 15 A0/D15/DAC0 VIN -
+ 16 A1/D16 VCC -
+ 17 A2/D17 GND -
+ 18 A3/D18 RESET -
+ 19 A4/D19 D14/TX 14
+ 20 A5/D20 D13/RX 13
+ 21 A6/D21 D12/SCL 12
+ 0 D0 D11/SDA 11
+ 1 D1 D10/CPIO 10
+ 2 D2 D9/SCK 0
+ 3 D3 D8/COPI 8
+ 4 D4 D7 7
+ 5 D5 D6 6
+
+
+compatible: "arduino-mkr-header"
+
+include: [gpio-nexus.yaml, base.yaml]
