Kernel IMU API

Drivers/bmi270-module/include/drivers/bmi270.h

@@ -2,6 +2,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <tactility/drivers/imu.h>
 #include <tactility/error.h>
 
 struct Device;
@@ -15,18 +16,29 @@ struct Bmi270Config {
     uint8_t address;
 };
 
-struct Bmi270Data {
-    float ax, ay, az; // acceleration in g (±8g range)
-    float gx, gy, gz; // angular rate in °/s (±2000°/s range)
-};
+/**
+ * Read accelerometer data only.
+ * @param[in] device bmi270 device
+ * @param[out] data Pointer to ImuAccelData structure to store the data (±8g range)
+ * @return ERROR_NONE on success
+ */
+error_t bmi270_read_accel(struct Device* device, struct ImuAccelData* data);
+
+/**
+ * Read gyroscope data only.
+ * @param[in] device bmi270 device
+ * @param[out] data Pointer to ImuGyroData structure to store the data (±2000°/s range)
+ * @return ERROR_NONE on success
+ */
+error_t bmi270_read_gyro(struct Device* device, struct ImuGyroData* data);
 
 /**
- * Read accelerometer and gyroscope data.
+ * Read the chip's on-die temperature.
  * @param[in] device bmi270 device
- * @param[out] data Pointer to Bmi270Data structure to store the data
+ * @param[out] temperature_c Pointer to store the temperature, in °C
  * @return ERROR_NONE on success
  */
-error_t bmi270_read(struct Device* device, struct Bmi270Data* data);
+error_t bmi270_read_temperature(struct Device* device, float* temperature_c);
 
 #ifdef __cplusplus
 }

Drivers/bmi270-module/source/bmi270.cpp

@@ -11,6 +11,7 @@
 static constexpr uint8_t REG_CHIP_ID = 0x00; // read: expect 0x24
 static constexpr uint8_t REG_DATA_ACC = 0x0C; // 6 bytes: acc X/Y/Z LSB/MSB
 static constexpr uint8_t REG_DATA_GYR = 0x12; // 6 bytes: gyr X/Y/Z LSB/MSB
+static constexpr uint8_t REG_TEMPERATURE = 0x22; // 2 bytes: on-die temperature, 0x8000 = invalid
 static constexpr uint8_t REG_INTERNAL_ST = 0x21; // bit0: init done
 static constexpr uint8_t REG_ACC_CONF = 0x40; // ODR + BWP + filter_perf
 static constexpr uint8_t REG_ACC_RANGE = 0x41; // range selector
@@ -152,38 +153,73 @@ static error_t stop(Device* device) {
 
 extern "C" {
 
-error_t bmi270_read(Device* device, Bmi270Data* data) {
+error_t bmi270_read_accel(Device* device, ImuAccelData* data) {
     auto* i2c_controller = device_get_parent(device);
-
     auto address = GET_CONFIG(device)->address;
 
-    // Burst-read 12 bytes: acc X/Y/Z (6 bytes) + gyro X/Y/Z (6 bytes)
-    // Registers: 0x0C–0x17 are contiguous for acc+gyro in I2C mode (no dummy byte)
-    uint8_t buffer[12] = {};
+    uint8_t buffer[6] = {};
     error_t error = i2c_controller_read_register(i2c_controller, address, REG_DATA_ACC, buffer, sizeof(buffer), I2C_TIMEOUT_TICKS);
     if (error != ERROR_NONE) return error;
 
     auto toI16 = [](uint8_t lo, uint8_t hi) -> int16_t {
         return static_cast<int16_t>(static_cast<uint16_t>(hi) << 8 | lo);
     };
 
-    data->ax = toI16(buffer[0],  buffer[1])  * ACCEL_SCALE;
-    data->ay = toI16(buffer[2],  buffer[3])  * ACCEL_SCALE;
-    data->az = toI16(buffer[4],  buffer[5])  * ACCEL_SCALE;
-    data->gx = toI16(buffer[6],  buffer[7])  * GYRO_SCALE;
-    data->gy = toI16(buffer[8],  buffer[9])  * GYRO_SCALE;
-    data->gz = toI16(buffer[10], buffer[11]) * GYRO_SCALE;
+    data->ax = toI16(buffer[0], buffer[1]) * ACCEL_SCALE;
+    data->ay = toI16(buffer[2], buffer[3]) * ACCEL_SCALE;
+    data->az = toI16(buffer[4], buffer[5]) * ACCEL_SCALE;
 
     return ERROR_NONE;
 }
 
+error_t bmi270_read_gyro(Device* device, ImuGyroData* data) {
+    auto* i2c_controller = device_get_parent(device);
+    auto address = GET_CONFIG(device)->address;
+
+    uint8_t buffer[6] = {};
+    error_t error = i2c_controller_read_register(i2c_controller, address, REG_DATA_GYR, buffer, sizeof(buffer), I2C_TIMEOUT_TICKS);
+    if (error != ERROR_NONE) return error;
+
+    auto toI16 = [](uint8_t lo, uint8_t hi) -> int16_t {
+        return static_cast<int16_t>(static_cast<uint16_t>(hi) << 8 | lo);
+    };
+
+    data->gx = toI16(buffer[0], buffer[1]) * GYRO_SCALE;
+    data->gy = toI16(buffer[2], buffer[3]) * GYRO_SCALE;
+    data->gz = toI16(buffer[4], buffer[5]) * GYRO_SCALE;
+
+    return ERROR_NONE;
+}
+
+error_t bmi270_read_temperature(Device* device, float* temperature_c) {
+    auto* i2c_controller = device_get_parent(device);
+    auto address = GET_CONFIG(device)->address;
+
+    uint8_t buffer[2] = {};
+    error_t error = i2c_controller_read_register(i2c_controller, address, REG_TEMPERATURE, buffer, sizeof(buffer), I2C_TIMEOUT_TICKS);
+    if (error != ERROR_NONE) return error;
+
+    uint16_t raw = static_cast<uint16_t>(buffer[1]) << 8 | buffer[0];
+    if (raw == 0x8000) return ERROR_NOT_FOUND; // sensor reports "invalid" (not enabled/not ready)
+
+    // Datasheet: temperature = raw / 512 + 23 (°C), raw is a signed 16-bit value
+    *temperature_c = static_cast<int16_t>(raw) / 512.0f + 23.0f;
+    return ERROR_NONE;
+}
+
+ImuApi bmi270_imu_api = {
+    .read_accel = bmi270_read_accel,
+    .read_gyro = bmi270_read_gyro,
+    .read_temperature = bmi270_read_temperature
+};
+
 Driver bmi270_driver = {
     .name = "bmi270",
     .compatible = (const char*[]) { "bosch,bmi270", nullptr},
     .start_device = start,
     .stop_device = stop,
-    .api = nullptr,
-    .device_type = nullptr,
+    .api = &bmi270_imu_api,
+    .device_type = &IMU_TYPE,
     .owner = &bmi270_module,
     .internal = nullptr
 };

Drivers/bmi270-module/source/module.cpp

@@ -11,12 +11,9 @@ static Driver* const bmi270_drivers[] = {
     nullptr
 };
 
-extern const ModuleSymbol bmi270_module_symbols[];
-
 Module bmi270_module = {
     .name = "bmi270",
-    .drivers = bmi270_drivers,
-    .symbols = bmi270_module_symbols
+    .drivers = bmi270_drivers
 };
 
 }

Drivers/mpu6886-module/include/drivers/mpu6886.h

@@ -2,6 +2,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <tactility/drivers/imu.h>
 #include <tactility/error.h>
 
 struct Device;
@@ -15,18 +16,29 @@ struct Mpu6886Config {
     uint8_t address;
 };
 
-struct Mpu6886Data {
-    float ax, ay, az; // acceleration in g (±8g range)
-    float gx, gy, gz; // angular rate in °/s (±2000°/s range)
-};
+/**
+ * Read accelerometer data only.
+ * @param[in]  device mpu6886 device
+ * @param[out] data   Pointer to ImuAccelData to populate (±8g range)
+ * @return ERROR_NONE on success
+ */
+error_t mpu6886_read_accel(struct Device* device, struct ImuAccelData* data);
+
+/**
+ * Read gyroscope data only.
+ * @param[in]  device mpu6886 device
+ * @param[out] data   Pointer to ImuGyroData to populate (±2000°/s range)
+ * @return ERROR_NONE on success
+ */
+error_t mpu6886_read_gyro(struct Device* device, struct ImuGyroData* data);
 
 /**
- * Read accelerometer and gyroscope data.
+ * Read the chip's on-die temperature.
  * @param[in]  device mpu6886 device
- * @param[out] data   Pointer to Mpu6886Data to populate
+ * @param[out] temperature_c Pointer to store the temperature, in °C
  * @return ERROR_NONE on success
  */
-error_t mpu6886_read(struct Device* device, struct Mpu6886Data* data);
+error_t mpu6886_read_temperature(struct Device* device, float* temperature_c);
 
 #ifdef __cplusplus
 }

Drivers/mpu6886-module/source/module.cpp

@@ -11,12 +11,9 @@ static Driver* const mpu6886_drivers[] = {
     nullptr
 };
 
-extern const ModuleSymbol mpu6886_module_symbols[];
-
 Module mpu6886_module = {
     .name = "mpu6886",
-    .drivers = mpu6886_drivers,
-    .symbols = mpu6886_module_symbols,
+    .drivers = mpu6886_drivers
 };
 
 } // extern "C"

Drivers/mpu6886-module/source/mpu6886.cpp

@@ -16,6 +16,7 @@ static constexpr uint8_t REG_ACCEL_CONFIG2 = 0x1D; // accel low-pass filter
 static constexpr uint8_t REG_INT_PIN_CFG   = 0x37; // interrupt pin config
 static constexpr uint8_t REG_INT_ENABLE    = 0x38; // interrupt enable
 static constexpr uint8_t REG_ACCEL_XOUT_H  = 0x3B; // first accel output register
+static constexpr uint8_t REG_TEMP_OUT_H    = 0x41; // temperature output register
 static constexpr uint8_t REG_GYRO_XOUT_H   = 0x43; // first gyro output register
 static constexpr uint8_t REG_USER_CTRL     = 0x6A; // user control (DMP, FIFO, I2C)
 static constexpr uint8_t REG_PWR_MGMT_1    = 0x6B; // power management 1
@@ -126,38 +127,72 @@ static error_t stop(Device* device) {
 
 extern "C" {
 
-error_t mpu6886_read(Device* device, Mpu6886Data* data) {
+error_t mpu6886_read_accel(Device* device, ImuAccelData* data) {
     auto* i2c_controller = device_get_parent(device);
     auto address = GET_CONFIG(device)->address;
 
-    // MPU6886 is big-endian (MSB first), unlike BMI270
     auto toI16 = [](uint8_t hi, uint8_t lo) -> int16_t {
         return static_cast<int16_t>(static_cast<uint16_t>(hi) << 8 | lo);
     };
 
-    // Burst read: accel (6) + temp (2) + gyro (6) = 14 bytes at 0x3B
-    uint8_t buf[14] = {};
+    uint8_t buf[6] = {};
     error_t error = i2c_controller_read_register(i2c_controller, address, REG_ACCEL_XOUT_H, buf, sizeof(buf), I2C_TIMEOUT_TICKS);
     if (error != ERROR_NONE) return error;
 
     data->ax = toI16(buf[0], buf[1]) * ACCEL_SCALE;
     data->ay = toI16(buf[2], buf[3]) * ACCEL_SCALE;
     data->az = toI16(buf[4], buf[5]) * ACCEL_SCALE;
-    // buf[6..7] = temperature (skipped)
-    data->gx = toI16(buf[8], buf[9]) * GYRO_SCALE;
-    data->gy = toI16(buf[10], buf[11]) * GYRO_SCALE;
-    data->gz = toI16(buf[12], buf[13]) * GYRO_SCALE;
 
     return ERROR_NONE;
 }
 
+error_t mpu6886_read_gyro(Device* device, ImuGyroData* data) {
+    auto* i2c_controller = device_get_parent(device);
+    auto address = GET_CONFIG(device)->address;
+
+    auto toI16 = [](uint8_t hi, uint8_t lo) -> int16_t {
+        return static_cast<int16_t>(static_cast<uint16_t>(hi) << 8 | lo);
+    };
+
+    uint8_t buf[6] = {};
+    error_t error = i2c_controller_read_register(i2c_controller, address, REG_GYRO_XOUT_H, buf, sizeof(buf), I2C_TIMEOUT_TICKS);
+    if (error != ERROR_NONE) return error;
+
+    data->gx = toI16(buf[0], buf[1]) * GYRO_SCALE;
+    data->gy = toI16(buf[2], buf[3]) * GYRO_SCALE;
+    data->gz = toI16(buf[4], buf[5]) * GYRO_SCALE;
+
+    return ERROR_NONE;
+}
+
+error_t mpu6886_read_temperature(Device* device, float* temperature_c) {
+    auto* i2c_controller = device_get_parent(device);
+    auto address = GET_CONFIG(device)->address;
+
+    uint8_t buf[2] = {};
+    error_t error = i2c_controller_read_register(i2c_controller, address, REG_TEMP_OUT_H, buf, sizeof(buf), I2C_TIMEOUT_TICKS);
+    if (error != ERROR_NONE) return error;
+
+    auto raw = static_cast<int16_t>(static_cast<uint16_t>(buf[0]) << 8 | buf[1]);
+
+    // Datasheet: temperature = raw / 326.8 + 25 (°C)
+    *temperature_c = static_cast<float>(raw) / 326.8f + 25.0f;
+    return ERROR_NONE;
+}
+
+ImuApi mpu6886_imu_api = {
+    .read_accel = mpu6886_read_accel,
+    .read_gyro = mpu6886_read_gyro,
+    .read_temperature = mpu6886_read_temperature
+};
+
 Driver mpu6886_driver = {
     .name = "mpu6886",
     .compatible = (const char*[]) { "invensense,mpu6886", nullptr },
     .start_device = start,
     .stop_device = stop,
-    .api = nullptr,
-    .device_type = nullptr,
+    .api = &mpu6886_imu_api,
+    .device_type = &IMU_TYPE,
     .owner = &mpu6886_module,
     .internal = nullptr
 };

Drivers/qmi8658-module/include/drivers/qmi8658.h

@@ -2,6 +2,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <tactility/drivers/imu.h>
 #include <tactility/error.h>
 
 struct Device;
@@ -15,18 +16,29 @@ struct Qmi8658Config {
     uint8_t address;
 };
 
-struct Qmi8658Data {
-    float ax, ay, az; // acceleration in g (±8g range)
-    float gx, gy, gz; // angular rate in °/s (±2048°/s range)
-};
+/**
+ * Read accelerometer data only.
+ * @param[in]  device qmi8658 device
+ * @param[out] data   Pointer to ImuAccelData to populate (±8g range)
+ * @return ERROR_NONE on success
+ */
+error_t qmi8658_read_accel(struct Device* device, struct ImuAccelData* data);
+
+/**
+ * Read gyroscope data only.
+ * @param[in]  device qmi8658 device
+ * @param[out] data   Pointer to ImuGyroData to populate (±2048°/s range)
+ * @return ERROR_NONE on success
+ */
+error_t qmi8658_read_gyro(struct Device* device, struct ImuGyroData* data);
 
 /**
- * Read accelerometer and gyroscope data.
+ * Read the chip's on-die temperature.
  * @param[in]  device qmi8658 device
- * @param[out] data   Pointer to Qmi8658Data to populate
+ * @param[out] temperature_c Pointer to store the temperature, in °C
  * @return ERROR_NONE on success
  */
-error_t qmi8658_read(struct Device* device, struct Qmi8658Data* data);
+error_t qmi8658_read_temperature(struct Device* device, float* temperature_c);
 
 #ifdef __cplusplus
 }

Drivers/qmi8658-module/source/module.cpp

@@ -11,12 +11,9 @@ static Driver* const qmi8658_drivers[] = {
     nullptr
 };
 
-extern const ModuleSymbol qmi8658_module_symbols[];
-
 Module qmi8658_module = {
     .name = "qmi8658",
-    .drivers = qmi8658_drivers,
-    .symbols = qmi8658_module_symbols,
+    .drivers = qmi8658_drivers
 };
 
 } // extern "C"