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-rw-r--r--drivers/gpio/mcp23018.c108
-rw-r--r--drivers/gpio/mcp23018.h65
2 files changed, 173 insertions, 0 deletions
diff --git a/drivers/gpio/mcp23018.c b/drivers/gpio/mcp23018.c
new file mode 100644
index 0000000000..dc8ab03c50
--- /dev/null
+++ b/drivers/gpio/mcp23018.c
@@ -0,0 +1,108 @@
+// Copyright 2022 zvecr<git@zvecr.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "mcp23018.h"
+#include "i2c_master.h"
+#include "wait.h"
+#include "debug.h"
+
+#define SLAVE_TO_ADDR(n) (n << 1)
+#define TIMEOUT 100
+
+enum {
+ CMD_IODIRA = 0x00, // i/o direction register
+ CMD_IODIRB = 0x01,
+ CMD_GPPUA = 0x0C, // GPIO pull-up resistor register
+ CMD_GPPUB = 0x0D,
+ CMD_GPIOA = 0x12, // general purpose i/o port register (write modifies OLAT)
+ CMD_GPIOB = 0x13,
+};
+
+void mcp23018_init(uint8_t addr) {
+ static uint8_t s_init = 0;
+ if (!s_init) {
+ i2c_init();
+ wait_ms(1000);
+
+ s_init = 1;
+ }
+}
+
+bool mcp23018_set_config(uint8_t slave_addr, mcp23018_port_t port, uint8_t conf) {
+ uint8_t addr = SLAVE_TO_ADDR(slave_addr);
+ uint8_t cmdDirection = port ? CMD_IODIRB : CMD_IODIRA;
+ uint8_t cmdPullup = port ? CMD_GPPUB : CMD_GPPUA;
+
+ i2c_status_t ret = i2c_writeReg(addr, cmdDirection, &conf, sizeof(conf), TIMEOUT);
+ if (ret != I2C_STATUS_SUCCESS) {
+ dprintf("mcp23018_set_config::directionFAILED::%u\n", ret);
+ return false;
+ }
+
+ ret = i2c_writeReg(addr, cmdPullup, &conf, sizeof(conf), TIMEOUT);
+ if (ret != I2C_STATUS_SUCCESS) {
+ dprintf("mcp23018_set_config::pullupFAILED::%u\n", ret);
+ return false;
+ }
+
+ return true;
+}
+
+bool mcp23018_set_output(uint8_t slave_addr, mcp23018_port_t port, uint8_t conf) {
+ uint8_t addr = SLAVE_TO_ADDR(slave_addr);
+ uint8_t cmd = port ? CMD_GPIOB : CMD_GPIOA;
+
+ i2c_status_t ret = i2c_writeReg(addr, cmd, &conf, sizeof(conf), TIMEOUT);
+ if (ret != I2C_STATUS_SUCCESS) {
+ dprintf("mcp23018_set_output::FAILED::%u\n", ret);
+ return false;
+ }
+
+ return true;
+}
+
+bool mcp23018_set_output_all(uint8_t slave_addr, uint8_t confA, uint8_t confB) {
+ uint8_t addr = SLAVE_TO_ADDR(slave_addr);
+ uint8_t conf[2] = {confA, confB};
+
+ i2c_status_t ret = i2c_writeReg(addr, CMD_GPIOA, &conf[0], sizeof(conf), TIMEOUT);
+ if (ret != I2C_STATUS_SUCCESS) {
+ dprintf("mcp23018_set_output::FAILED::%u\n", ret);
+ return false;
+ }
+
+ return true;
+}
+
+bool mcp23018_readPins(uint8_t slave_addr, mcp23018_port_t port, uint8_t* out) {
+ uint8_t addr = SLAVE_TO_ADDR(slave_addr);
+ uint8_t cmd = port ? CMD_GPIOB : CMD_GPIOA;
+
+ i2c_status_t ret = i2c_readReg(addr, cmd, out, sizeof(uint8_t), TIMEOUT);
+ if (ret != I2C_STATUS_SUCCESS) {
+ dprintf("mcp23018_readPins::FAILED::%u\n", ret);
+ return false;
+ }
+
+ return true;
+}
+
+bool mcp23018_readPins_all(uint8_t slave_addr, uint16_t* out) {
+ uint8_t addr = SLAVE_TO_ADDR(slave_addr);
+
+ typedef union {
+ uint8_t u8[2];
+ uint16_t u16;
+ } data16;
+
+ data16 data = {.u16 = 0};
+
+ i2c_status_t ret = i2c_readReg(addr, CMD_GPIOA, &data.u8[0], sizeof(data), TIMEOUT);
+ if (ret != I2C_STATUS_SUCCESS) {
+ dprintf("mcp23018_readPins::FAILED::%u\n", ret);
+ return false;
+ }
+
+ *out = data.u16;
+ return true;
+}
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);