1 files changed, 63 insertions, 0 deletions
diff --git a/keyboards/torn/mcp23018.c b/keyboards/torn/mcp23018.c
new file mode 100644
index 0000000000..c180f1dae5
--- /dev/null
+++ b/keyboards/torn/mcp23018.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2020 Richard Titmuss (richard.titmuss@gmail.com)
+ * Copyright 2012-2018 Jun Wako, Jack Humbert, Yiancar
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include QMK_KEYBOARD_H
+#include "i2c_master.h"
+#include "mcp23018.h"
+
+#define MCP23018_ADDR 0b0100000
+
+#define MCP23018_TIMEOUT 100
+
+static i2c_status_t mcp23018_status = I2C_STATUS_ERROR;
+
+void msp23018_init(void) {
+    mcp23018_status = I2C_STATUS_SUCCESS;
+
+    // Set pin direction
+    uint8_t iodir[] = {0b00001111, 0b11111111};
+    mcp23018_writeReg(IODIRA, iodir, 2);
+
+    // Set pull-up
+    uint8_t gppu[] = {0b00001111, 0b11111000};
+    mcp23018_writeReg(GPPUA, gppu, 2);
+
+    // LEDs output high
+    uint8_t gpio[] = {0b00000000, 0b00000111};
+    mcp23018_writeReg(GPIOA, gpio, 2);
+}
+
+bool mcp23018_reset_required(void) { return mcp23018_status != I2C_STATUS_SUCCESS; }
+
+i2c_status_t mcp23018_writeReg(uint8_t regaddr, const uint8_t* data, uint16_t length) {
+    if (mcp23018_status) {
+        return mcp23018_status;
+    }
+
+    mcp23018_status = i2c_writeReg((MCP23018_ADDR << 1), regaddr, data, length, MCP23018_TIMEOUT);
+    return mcp23018_status;
+}
+
+i2c_status_t mcp23018_readReg(uint8_t regaddr, uint8_t* data, uint16_t length) {
+    if (mcp23018_status) {
+        return mcp23018_status;
+    }
+
+    mcp23018_status = i2c_readReg((MCP23018_ADDR << 1), regaddr, data, length, MCP23018_TIMEOUT);
+    return mcp23018_status;
+}