drivers: sensor: mb7040: add support for MaxBotix MB7040 ultrasonic sensor

drivers/sensor/CMakeLists.txt

@@ -71,6 +71,7 @@ add_subdirectory_ifdef(CONFIG_VEAA_X_3 veaa_x_3)
 add_subdirectory_ifdef(CONFIG_VOLTAGE_DIVIDER voltage_divider)
 add_subdirectory_ifdef(CONFIG_XBR818 xbr818)
 add_subdirectory_ifdef(CONFIG_TACH_ENE_KB1200 ene_tach_kb1200)
+add_subdirectory_ifdef(CONFIG_MB7040 mb7040)
 
 zephyr_syscall_header(${ZEPHYR_BASE}/include/zephyr/drivers/sensor.h)
 

drivers/sensor/Kconfig

@@ -143,6 +143,7 @@ source "drivers/sensor/ist8310/Kconfig"
 source "drivers/sensor/lm35/Kconfig"
 source "drivers/sensor/lm75/Kconfig"
 source "drivers/sensor/lm77/Kconfig"
+source "drivers/sensor/mb7040/Kconfig"
 source "drivers/sensor/mhz19b/Kconfig"
 source "drivers/sensor/nct75/Kconfig"
 source "drivers/sensor/ntc_thermistor/Kconfig"

drivers/sensor/mb7040/CMakeLists.txt

@@ -0,0 +1,5 @@
+#SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+
+zephyr_library_sources(mb7040.c)

drivers/sensor/mb7040/Kconfig

@@ -0,0 +1,19 @@
+#MB7040 ultrasonic sensor config
+
+#Copyright 2025 Sabrina Simkhovich <sabrinasimkhovich @gmail.com>
+#SPDX-License-Identifier: Apache-2.0
+
+config MB7040
+	bool "MB7040 ultrasonic distance sensor"
+	default y
+	depends on DT_HAS_MAXBOTIX_MB7040_ENABLED
+	select I2C
+	help
+	  Enable driver for MB7040 distance sensor.
+
+config MB7040_DELAY_MS
+	int "Delay in milliseconds to wait for distance measurements"
+	default 100
+	depends on MB7040
+	help
+	  Timeout for sample fetch.

drivers/sensor/mb7040/mb7040.c

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2025 Sabrina Simkhovich <sabrinasimkhovich@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT maxbotix_mb7040
+
+#include <zephyr/kernel.h>
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/device.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/drivers/gpio.h>
+
+#define RANGE_CMD 0x51
+
+#define MB7040_HAS_STATUS_GPIO DT_ANY_INST_HAS_PROP_STATUS_OKAY(status_gpios)
+
+LOG_MODULE_REGISTER(mb7040, CONFIG_SENSOR_LOG_LEVEL);
+
+struct mb7040_data {
+	uint16_t distance_cm;
+	struct k_sem read_sem;
+#if MB7040_HAS_STATUS_GPIO
+	struct gpio_callback gpio_cb;
+#endif
+};
+
+struct mb7040_config {
+	struct i2c_dt_spec i2c;
+	uint8_t i2c_addr;
+#if MB7040_HAS_STATUS_GPIO
+	struct gpio_dt_spec status_gpio;
+#endif
+};
+
+#if MB7040_HAS_STATUS_GPIO
+static void status_gpio_callback(const struct device *dev, struct gpio_callback *cb, uint32_t pins)
+{
+	struct mb7040_data *data = CONTAINER_OF(cb, struct mb7040_data, gpio_cb);
+
+	k_sem_give(&data->read_sem);
+}
+#endif
+
+static int mb7040_sample_fetch(const struct device *dev, enum sensor_channel chan)
+{
+	const struct mb7040_config *cfg = (struct mb7040_config *)dev->config;
+	struct mb7040_data *data = (struct mb7040_data *)dev->data;
+	uint8_t cmd = RANGE_CMD;
+	int ret;
+	uint8_t read_data[2];
+
+	if (chan != SENSOR_CHAN_DISTANCE && chan != SENSOR_CHAN_ALL) {
+		LOG_ERR("Sensor only supports distance");
+		return -EINVAL;
+	}
+
+	k_sem_reset(&data->read_sem);
+
+#if MB7040_HAS_STATUS_GPIO
+	/* Check if status_gpio port is present */
+	if (cfg->status_gpio.port != NULL) {
+		/* Enable interrupt before writing */
+		ret = gpio_pin_interrupt_configure_dt(&cfg->status_gpio, GPIO_INT_EDGE_FALLING);
+		if (ret != 0) {
+			LOG_ERR("Failed to configure interrupt: %d", ret);
+			return ret;
+		}
+	}
+#endif
+
+	/* Write range command to sensor */
+	ret = i2c_reg_write_byte_dt(&cfg->i2c, cfg->i2c_addr, cmd);
+
+	if (ret != 0) {
+		LOG_ERR("I2C write failed with error %d", ret);
+#if MB7040_HAS_STATUS_GPIO
+		/* Disable interrupt before returning error*/
+		if (cfg->status_gpio.port != NULL) {
+			gpio_pin_interrupt_configure_dt(&cfg->status_gpio, GPIO_INT_DISABLE);
+		}
+#endif
+		return ret;
+	}
+
+	ret = k_sem_take(&data->read_sem, K_MSEC(CONFIG_MB7040_DELAY_MS));
+
+#if MB7040_HAS_STATUS_GPIO
+	/* Check if status_gpio port is present */
+	if (cfg->status_gpio.port != NULL) {
+		gpio_pin_interrupt_configure_dt(&cfg->status_gpio, GPIO_INT_DISABLE);
+		if (ret != 0) {
+			/* Success: interrupt fired and semaphore taken */
+			return ret;
+		}
+	} else {
+		if (ret != -EAGAIN) {
+			/* Should not happen: semaphore only given by GPIO interrupt */
+			return ret;
+		}
+	}
+#else
+	if (ret != -EAGAIN) {
+		/* Should not happen: semaphore only given by GPIO interrupt */
+		return ret;
+	}
+#endif
+	/*
+	 * Small wait due to device specific internal i2c timings. 10ms is a common
+	 * wait to time to ensure ultrasonic sensors achieve stability and accuracy.
+	 */
+	k_msleep(10);
+
+	ret = i2c_read_dt(&cfg->i2c, read_data, 2);
+
+	if (ret != 0) {
+		LOG_ERR("I2C read failed with error %d", ret);
+#if MB7040_HAS_STATUS_GPIO
+		if (cfg->status_gpio.port != NULL) {
+			gpio_pin_interrupt_configure_dt(&cfg->status_gpio, GPIO_INT_DISABLE);
+		}
+#endif
+		return ret;
+	}
+
+	/* Convert MSB/LSB to distance in cm */
+	data->distance_cm = (read_data[0] << 8) | read_data[1];
+	return 0;
+}
+
+static int mb7040_channel_get(const struct device *dev, enum sensor_channel chan,
+			      struct sensor_value *val)
+{
+	struct mb7040_data *data = (struct mb7040_data *)dev->data;
+
+	if (chan != SENSOR_CHAN_DISTANCE) {
+		LOG_ERR("Sensor only supports distance");
+		return -ENOTSUP;
+	}
+
+	/* Meters */
+	val->val1 = data->distance_cm / 100;
+	/* Micrometers */
+	val->val2 = (data->distance_cm % 100) * 10000;
+
+	return 0;
+}
+
+static DEVICE_API(sensor, mb7040_api) = {
+	.sample_fetch = mb7040_sample_fetch,
+	.channel_get = mb7040_channel_get,
+};
+
+static int mb7040_init(const struct device *dev)
+{
+	const struct mb7040_config *cfg = (struct mb7040_config *)dev->config;
+	struct mb7040_data *data = (struct mb7040_data *)dev->data;
+
+	k_sem_init(&data->read_sem, 0, 1);
+
+	if (!i2c_is_ready_dt(&cfg->i2c)) {
+		LOG_ERR("I2C not ready!");
+		return -ENODEV;
+	}
+	/* Initialize status GPIO if present */
+#if MB7040_HAS_STATUS_GPIO
+	if (cfg->status_gpio.port != NULL) {
+		if (!gpio_is_ready_dt(&cfg->status_gpio)) {
+			LOG_ERR("Status GPIO not ready");
+			return -ENODEV;
+		}
+
+		int ret = gpio_pin_configure_dt(&cfg->status_gpio, GPIO_INPUT);
+
+		if (ret < 0) {
+			LOG_ERR("Failed to configure status GPIO: %d", ret);
+			return ret;
+		}
+
+		gpio_init_callback(&data->gpio_cb, status_gpio_callback, BIT(cfg->status_gpio.pin));
+		ret = gpio_add_callback(cfg->status_gpio.port, &data->gpio_cb);
+		if (ret < 0) {
+			LOG_ERR("Failed to add GPIO callback: %d", ret);
+			return ret;
+		}
+		LOG_INF("MB7040 initialized with status GPIO");
+	}
+#else
+	LOG_INF("MB7040 initialized");
+#endif
+	return 0;
+}
+
+#define MB7040_DEFINE(inst)                                                                        \
+	static struct mb7040_data mb7040_data_##inst = {                                           \
+		.distance_cm = 0,                                                                  \
+	};                                                                                         \
+	static const struct mb7040_config mb7040_config_##inst = {                                 \
+		.i2c = I2C_DT_SPEC_INST_GET(inst),                                                 \
+		.i2c_addr = DT_INST_REG_ADDR(inst),                                                \
+		IF_ENABLED(DT_INST_NODE_HAS_PROP(inst, status_gpios),                              \
+		(.status_gpio = GPIO_DT_SPEC_INST_GET(inst, status_gpios),)) };                    \
+	SENSOR_DEVICE_DT_INST_DEFINE(inst, mb7040_init, NULL, &mb7040_data_##inst,                 \
+				     &mb7040_config_##inst, POST_KERNEL,                           \
+				     CONFIG_SENSOR_INIT_PRIORITY, &mb7040_api);
+
+DT_INST_FOREACH_STATUS_OKAY(MB7040_DEFINE)

dts/bindings/sensor/maxbotix,mb7040.yaml

@@ -0,0 +1,12 @@
+description: MB7040 ultrasonic distance sensor
+
+compatible: "maxbotix,mb7040"
+
+include: [sensor-device.yaml, i2c-device.yaml]
+
+properties:
+  status-gpios:
+    type: phandle-array
+    description: |
+      GPIO pin connected to Pin 2 (Address Announce/Status) to monitor sensor
+      state. Pin is high during range reading and low when ready for I2C communication.

tests/drivers/build_all/sensor/i2c.dtsi

@@ -1382,3 +1382,9 @@ test_i2c_lsm9ds1_mag: lsm9ds1_mag@b9 {
 	compatible = "st,lsm9ds1_mag";
 	reg = <0xb9>;
 };
+
+test_i2c_mb7040: mb7040@ba {
+	compatible = "maxbotix,mb7040";
+	reg = <0xba>;
+	status-gpios = <&test_gpio 0 0>;
+};