1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/gpio/mcp23018.h b/drivers/gpio/mcp23018.h
new file mode 100644
index 0000000000..e7c2730dd1
--- /dev/null
+++ b/drivers/gpio/mcp23018.h
@@ -0,0 +1,65 @@
+// Copyright 2022 zvecr<git@zvecr.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * Port ID
+ */
+typedef enum {
+    mcp23018_PORTA,
+    mcp23018_PORTB,
+} mcp23018_port_t;
+
+/**
+ * Helpers for set_config
+ */
+enum {
+    ALL_OUTPUT = 0,
+    ALL_INPUT  = 0xFF,
+};
+
+/**
+ * Helpers for set_output
+ */
+enum {
+    ALL_LOW  = 0,
+    ALL_HIGH = 0xFF,
+};
+
+/**
+ * Init expander and any other dependent drivers
+ */
+void mcp23018_init(uint8_t slave_addr);
+
+/**
+ * Configure input/output to a given port
+ */
+bool mcp23018_set_config(uint8_t slave_addr, mcp23018_port_t port, uint8_t conf);
+
+/**
+ * Write high/low to a given port
+ */
+bool mcp23018_set_output(uint8_t slave_addr, mcp23018_port_t port, uint8_t conf);
+
+/**
+ * Write high/low to both ports sequentially
+ *
+ *  - slightly faster than multiple set_output
+ */
+bool mcp23018_set_output_all(uint8_t slave_addr, uint8_t confA, uint8_t confB);
+
+/**
+ * Read state of a given port
+ */
+bool mcp23018_readPins(uint8_t slave_addr, mcp23018_port_t port, uint8_t* ret);
+
+/**
+ * Read state of both ports sequentially
+ *
+ *  - slightly faster than multiple readPins
+ */
+bool mcp23018_readPins_all(uint8_t slave_addr, uint16_t* ret);