dts: bindings: Add Pmod connector GPIO nexus

Add a GPIO nexus binding for Pmod interface connectors. This commit also includes a header file with macros that map signal names in the Pmod specification to the corresponding indices in the GPIO nexus, meant for use in devicetree files. Signed-off-by: Alexander Mihajlovic <alexander@eub.se>
2023-03-01 21:57:50 +01:00 · 2023-03-01 21:57:50 +01:00 · 9d50b143ae
commit 9d50b143ae
parent 1a132fabc0
2 changed files with 263 additions and 0 deletions
--- a/dts/bindings/gpio/digilent,pmod.yaml
+++ b/dts/bindings/gpio/digilent,pmod.yaml
@ -0,0 +1,36 @@
+# Copyright (c) 2023 Elektronikutvecklingsbyrån EUB AB
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+    GPIO pins exposed on a Digilent Pmod interface.
+
+    This binding provides a nexus mapping for 8 pins where parent pins 0
+    through 3 correspond to IO1 through IO4, and parent pins 4 through 7
+    correspond to IO5 through IO8, as depicted below for a 12-pin connector.
+
+    12-pin Pmod interface:
+
+        0 IO1                    IO5   4
+        1 IO2                    IO6   5
+        2 IO3                    IO7   6
+        3 IO4                    IO8   7
+        - GND                    GND   -
+        - VDD                    VDD   -
+
+    This binding can also be used with the 6-pin Pmod connector variant which
+    is a proper subset of the 12-pin connector. In that case parent pins 4
+    through 7 are omitted from the GPIO nexus node, resulting in a mapping
+    as depicted below.
+
+    6-pin Pmod interface:
+
+        0 IO1
+        1 IO2
+        2 IO3
+        3 IO4
+        - GND
+        - VDD
+
+compatible: "digilent,pmod"
+
+include: [gpio-nexus.yaml, base.yaml]
--- a/include/zephyr/dt-bindings/gpio/digilent-pmod.h
+++ b/include/zephyr/dt-bindings/gpio/digilent-pmod.h
@ -0,0 +1,227 @@
+/*
+ * Copyright (c) 2023 Elektronikutvecklingsbyrån EUB AB
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief Pmod GPIO nexus signal index definitions
+ *
+ * Defines meant to be used in conjunction with the "digilent,pmod"
+ * GPIO nexus mapping.
+ *
+ * Example usage:
+ *
+ * @code{.dts}
+ * &spi1 {
+ *         cs-gpios = <&pmod0 PMOD_SPI_CS GPIO_ACTIVE_LOW>;
+ *
+ *         example_device: example-dev@0 {
+ *                 compatible = "vnd,spi-device";
+ *                 reg = <0>;
+ *         };
+ * };
+ * @endcode
+ */
+
+#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_GPIO_DIGILENT_PMOD_H_
+#define ZEPHYR_INCLUDE_DT_BINDINGS_GPIO_DIGILENT_PMOD_H_
+
+/**
+ * For reference see the Pmod interface specification:
+ * https://digilent.com/reference/_media/reference/pmod/pmod-interface-specification-1_2_0.pdf
+ */
+
+/* GPIO */
+
+/**
+ * @brief IO[n] signal on a Pmod GPIO nexus node following
+ * Pmod Interface Type 1 or 1A (GPIO or expanded GPIO)
+ *
+ * The Pmod GPIO nexus maps pin indexes 0..7 to IO1..IO8.
+ */
+#define PMOD_IO(n) ((n) - 1)
+
+/* SPI */
+
+/**
+ * @brief SPI CS signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2 (SPI) peripherals.
+ */
+#define PMOD_SPI_CS	PMOD_IO(1)
+
+/**
+ * @brief SPI MOSI signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2 (SPI) peripherals.
+ */
+#define PMOD_SPI_MOSI	PMOD_IO(2)
+
+/**
+ * @brief SPI MISO signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2 (SPI) peripherals.
+ */
+#define PMOD_SPI_MISO	PMOD_IO(3)
+
+/**
+ * @brief SPI SCK signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2 (SPI) peripherals.
+ */
+#define PMOD_SPI_SCK	PMOD_IO(4)
+
+/* Expanded SPI */
+
+/**
+ * @brief SPI CS signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_CS		PMOD_IO(1)
+
+/**
+ * @brief SPI MOSI signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_MOSI	PMOD_IO(2)
+
+/**
+ * @brief SPI MISO signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_MISO	PMOD_IO(3)
+
+/**
+ * @brief SPI SCK signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_SCK	PMOD_IO(4)
+
+/**
+ * @brief INT alternate signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_INT	PMOD_IO(5)
+
+/**
+ * @brief RESET alternate signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_RESET	PMOD_IO(6)
+
+/**
+ * @brief SPI CS2 alternate signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_CS2	PMOD_IO(7)
+
+/**
+ * @brief SPI CS3 alternate signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 2A (expanded SPI) peripherals.
+ */
+#define PMOD_EXP_SPI_CS3	PMOD_IO(8)
+
+/* Expanded UART */
+
+/**
+ * @brief INT alternate signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 3A (expanded UART) peripherals.
+ */
+#define PMOD_EXP_UART_INT	PMOD_IO(5)
+
+/**
+ * @brief RESET alternate signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 3A (expanded UART) peripherals.
+ */
+#define PMOD_EXP_UART_RESET	PMOD_IO(6)
+
+/* H-bridge */
+
+/**
+ * @brief DIR signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 4 (H-bridge) peripherals.
+ */
+#define PMOD_HBRIDGE_DIR	PMOD_IO(1)
+
+/**
+ * @brief EN signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 4 (H-bridge) peripherals.
+ */
+#define PMOD_HBRIDGE_EN		PMOD_IO(2)
+
+/* Dual H-bridge */
+
+/**
+ * @brief DIR1 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5 (dual H-bridge) peripherals.
+ */
+#define PMOD_DUAL_HBRIDGE_DIR1	PMOD_IO(1)
+
+/**
+ * @brief EN1 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5 (dual H-bridge) peripherals.
+ */
+#define PMOD_DUAL_HBRIDGE_EN1	PMOD_IO(2)
+
+/**
+ * @brief DIR2 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5 (dual H-bridge) peripherals.
+ */
+#define PMOD_DUAL_HBRIDGE_DIR2	PMOD_IO(3)
+
+/**
+ * @brief EN2 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5 (dual H-bridge) peripherals.
+ */
+#define PMOD_DUAL_HBRIDGE_EN2	PMOD_IO(4)
+
+/* Expanded dual H-bridge */
+
+/**
+ * @brief DIR1 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5A (expanded dual H-bridge) peripherals.
+ */
+#define PMOD_EXP_DUAL_HBRIDGE_DIR1	PMOD_IO(1)
+
+/**
+ * @brief EN1 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5A (expanded dual H-bridge) peripherals.
+ */
+#define PMOD_EXP_DUAL_HBRIDGE_EN1	PMOD_IO(2)
+
+/**
+ * @brief DIR2 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5A (expanded dual H-bridge) peripherals.
+ */
+#define PMOD_EXP_DUAL_HBRIDGE_DIR2	PMOD_IO(5)
+
+/**
+ * @brief EN2 signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 5A (expanded dual H-bridge) peripherals.
+ */
+#define PMOD_EXP_DUAL_HBRIDGE_EN2	PMOD_IO(6)
+
+/* I2C */
+
+/**
+ * @brief INT signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 6 (I2C) peripherals.
+ */
+#define PMOD_I2C_INT	PMOD_IO(1)
+
+/**
+ * @brief RESET signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 6 (I2C) peripherals.
+ */
+#define PMOD_I2C_RESET	PMOD_IO(2)
+
+/**
+ * @brief SCL signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 6 (I2C) peripherals.
+ */
+#define PMOD_I2C_SCL	PMOD_IO(3)
+
+/**
+ * @brief SDA signal index on a Pmod GPIO nexus node.
+ * Used with Pmod Interface Type 6 (I2C) peripherals.
+ */
+#define PMOD_I2C_SDA	PMOD_IO(4)
+
+#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_GPIO_DIGILENT_PMOD_H_ */