Added WIP LSM6DSL.

Signed-off-by: Yilin Sun <imi415@imi.moe>

CMakeLists.txt

@@ -8,12 +8,14 @@ set(IMSENSORS_SRCS
     "src/als/als_ltr_303als.c"
     "src/dht/dht_aht10.c"
     "src/dht/dht_bme280.c"
+    "src/imu/imu_lsm6dsl.c"
 )
 
 set(IMSENSORS_INCS
     "include/imsensors/common"
     "include/imsensors/als"
     "include/imsensors/dht"
+    "include/imsensors/imu"
 )
 
 set(IMSENSORS_INTF_INCS

include/imsensors/common/sensors_common.h

@@ -4,6 +4,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <string.h>
 
 typedef enum {
     IMS_SUCCESS,

include/imsensors/dht/dht_bme280.h

@@ -70,11 +70,10 @@ typedef struct {
     double humidity;
 } ims_bme280_result_t;
 #else
-/* Result is multiplied by 10000. */
 typedef struct {
-    int32_t  temperature;
-    uint32_t pressure;
-    int32_t  humidity;
+    int32_t  temperature; /* Temperature (C), multiplied by 100. */
+    uint32_t pressure;    /* Humidity (%), multiplied by 1024. */
+    int32_t  humidity;    /* Pressure (Pa) multiplied by 256. */
 } ims_bme280_result_t;
 #endif
 

include/imsensors/imu/imu_lsm6dsl.h

@@ -0,0 +1,19 @@
+#ifndef IMS_IMU_LSM6DSL_H
+#define IMS_IMU_LSM6DSL_H
+
+#include "imsensors/common/sensors_common.h"
+
+typedef struct {
+    ims_i2c_xfer_t i2c_xfer;
+    ims_delay_t    delay;
+} ims_lsm6dsl_cb_t;
+
+typedef struct {
+    void            *pdev;
+    ims_lsm6dsl_cb_t cb;
+} ims_lsm6dsl_t;
+
+ims_ret_t ims_lsm6dsl_init(ims_lsm6dsl_t *imu);
+ims_ret_t ims_lsm6dsl_read_temperature(ims_lsm6dsl_t *imu, int16_t *temp);
+
+#endif  // IMS_IMU_LSM6DSL_H

src/imu/imu_lsm6dsl.c

@@ -0,0 +1,98 @@
+#include "imu_lsm6dsl.h"
+
+#define LSM6DSL_REG_WHOAMI     0x0FU
+#define LSM6DSL_REG_CTRL1_XL   0x10U
+#define LSM6DSL_REG_OUT_TEMP_L 0x20U
+#define LSM6DSL_REG_OUT_TEMP_H 0x21U
+
+#define LSM6DSL_CONST_WHOAMI 0x6AU
+
+#define LSM6DSL_MAXIMUM_MULTI_WRITE_SIZE 32
+
+static ims_ret_t ims_lsm6dsl_whoami(ims_lsm6dsl_t *imu, uint8_t *whoami);
+
+static ims_ret_t ims_lsm6dsl_read_register(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t *data);
+static ims_ret_t ims_lsm6dsl_read_registers(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t *data, uint16_t len);
+static ims_ret_t ims_lsm6dsl_write_register(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t data);
+static ims_ret_t ims_lsm6dsl_write_registers(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t *data, uint16_t len);
+
+ims_ret_t ims_lsm6dsl_init(ims_lsm6dsl_t *imu) {
+    ims_ret_t ret;
+
+    uint8_t who_am_i;
+
+    ret = ims_lsm6dsl_whoami(imu, &who_am_i);
+    if (ret != IMS_SUCCESS) {
+        return ret;
+    }
+
+    if (who_am_i != LSM6DSL_CONST_WHOAMI) {
+        return IMS_FAIL;
+    }
+
+    ret = ims_lsm6dsl_write_register(imu, LSM6DSL_REG_CTRL1_XL, 0xB0);
+    if (ret != IMS_SUCCESS) {
+        return IMS_FAIL;
+    }
+
+    return IMS_SUCCESS;
+}
+
+ims_ret_t ims_lsm6dsl_read_temperature(ims_lsm6dsl_t *imu, int16_t *temp) {
+    ims_ret_t ret;
+
+    uint8_t rx_temp[2];
+
+    ret = ims_lsm6dsl_read_registers(imu, LSM6DSL_REG_OUT_TEMP_L, rx_temp, 2);
+    if (ret != IMS_SUCCESS) {
+        return ret;
+    }
+
+    *temp = (int16_t)(uint16_t)((rx_temp[1] << 8U) | rx_temp[0]);
+
+    return IMS_SUCCESS;
+}
+
+static ims_ret_t ims_lsm6dsl_whoami(ims_lsm6dsl_t *imu, uint8_t *whoami) {
+    return ims_lsm6dsl_read_register(imu, LSM6DSL_REG_WHOAMI, whoami);
+}
+
+static ims_ret_t ims_lsm6dsl_read_register(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t *data) {
+    return ims_lsm6dsl_read_registers(imu, addr, data, 1U);
+}
+
+static ims_ret_t ims_lsm6dsl_read_registers(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t *data, uint16_t len) {
+    ims_i2c_xfer_desc_t xfer = {
+        .tx_size = 1U,
+        .tx_data = &addr,
+        .rx_size = len,
+        .rx_data = data,
+    };
+
+    return imu->cb.i2c_xfer(imu->pdev, &xfer);
+}
+
+static ims_ret_t ims_lsm6dsl_write_register(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t data) {
+    return ims_lsm6dsl_write_registers(imu, addr, &data, 1U);
+}
+
+static ims_ret_t ims_lsm6dsl_write_registers(ims_lsm6dsl_t *imu, uint8_t addr, uint8_t *data, uint16_t len) {
+    if (len > LSM6DSL_MAXIMUM_MULTI_WRITE_SIZE) {
+        return IMS_FAIL;
+    }
+
+    uint8_t tx_buf[LSM6DSL_MAXIMUM_MULTI_WRITE_SIZE + 1];
+
+    tx_buf[0] = addr;
+
+    memcpy(&tx_buf[1], data, len);
+
+    ims_i2c_xfer_desc_t xfer = {
+        .tx_size = len + 1,
+        .tx_data = tx_buf,
+        .rx_size = 0U,
+        .rx_data = NULL,
+    };
+
+    return imu->cb.i2c_xfer(imu->pdev, &xfer);
+}