drivers/lis2dh12: add support for temperature sensor

drivers/include/lis2dh12.h

@@ -244,8 +244,11 @@ typedef struct {
 
 /**
  * @brief   Export the SAUL interface for this driver
+ * @{
  */
 extern const saul_driver_t lis2dh12_saul_driver;
+extern const saul_driver_t lis2dh12_saul_temp_driver;
+/** @} */
 
 #if MODULE_LIS2DH12_INT || DOXYGEN
 /**
@@ -370,6 +373,21 @@ int lis2dh12_init(lis2dh12_t *dev, const lis2dh12_params_t *params);
  */
 int lis2dh12_read(const lis2dh12_t *dev, lis2dh12_fifo_data_t *data);
 
+/**
+ * @brief   Read temperature data from the given device
+ *
+ * @note    The temperature sensor is not calibrated.
+ *          Temperature values are only relative to a device specific
+ *          reference.
+ *
+ * @param[in]  dev      device descriptor
+ * @param[out] temp     temperature data in centi-°C
+ *
+ * @return  LIS2DH12_OK on success
+ * @return  LIS2DH12_NOBUS on bus error
+ */
+int lis2dh12_read_temperature(const lis2dh12_t *dev, int16_t *temp);
+
 /**
  * @brief   Clear the LIS2DH12 memory, clears all sampled data
  *

drivers/lis2dh12/include/lis2dh12_registers.h

@@ -33,6 +33,14 @@ enum {
     LIS2DH12_STATUS_REG_AUX_TOR = 0x40,   /**< Temperature data overrun */
 };
 
+/**
+ * @brief   STATUS_REG_TEMP definitions
+ */
+enum {
+    LIS2DH12_TEMP_CFG_REG_DISABLE = 0x00, /**< Temperature sensor disable */
+    LIS2DH12_TEMP_CFG_REG_ENABLE  = 0xC0, /**< Temperature sensor enable  */
+};
+
 /**
  * @brief   STATUS_REG definitions
  */

drivers/lis2dh12/lis2dh12.c

@@ -23,6 +23,7 @@
 #include "byteorder.h"
 #include "mutex.h"
 #include "timex.h"
+#include "xtimer.h"
 
 #include "lis2dh12.h"
 #include "lis2dh12_internal.h"
@@ -188,6 +189,9 @@ int lis2dh12_init(lis2dh12_t *dev, const lis2dh12_params_t *params)
 
     _write(dev, REG_CTRL_REG1, reg1.reg);
 
+    /* enable block data update */
+    _write(dev, REG_CTRL_REG4, 0x80);
+
     _release(dev);
 
     DEBUG("[lis2dh12] initialization successful\n");
@@ -579,6 +583,30 @@ int lis2dh12_clear_data(const lis2dh12_t *dev)
     return LIS2DH12_OK;
 }
 
+int lis2dh12_read_temperature(const lis2dh12_t *dev, int16_t *temp)
+{
+    uint8_t bytes[2];
+
+    _acquire(dev);
+
+    /* enable temperature sensor */
+    if (!_read(dev, REG_TEMP_CFG_REG)) {
+        uint8_t odr = _read(dev, REG_CTRL_REG1) >> 4;
+        _write(dev, REG_TEMP_CFG_REG, LIS2DH12_TEMP_CFG_REG_ENABLE);
+        if (IS_USED(MODULE_XTIMER)) {
+            xtimer_msleep(MS_PER_SEC / hz_per_dr[odr]);
+        }
+    }
+
+    _read_burst(dev, REG_OUT_TEMP_L, bytes, sizeof(bytes));
+    _release(dev);
+
+    *temp =  100 * (int8_t)bytes[1];
+    *temp += (100 * bytes[0]) >> 8;
+
+    return 0;
+}
+
 int lis2dh12_set_reference(const lis2dh12_t *dev, uint8_t reference)
 {
 
@@ -777,5 +805,10 @@ int lis2dh12_poweroff(const lis2dh12_t *dev)
     /* set datarate to zero */
     lis2dh12_set_datarate(dev, 0);
 
+    /* disable temperature sensor */
+    _acquire(dev);
+    _write(dev, REG_TEMP_CFG_REG, LIS2DH12_TEMP_CFG_REG_DISABLE);
+    _release(dev);
+
     return LIS2DH12_OK;
 }

drivers/lis2dh12/lis2dh12_saul.c

@@ -31,8 +31,25 @@ static int read_accelerometer(const void *dev, phydat_t *res)
     return 3;
 }
 
+static int read_temperature(const void *dev, phydat_t *res)
+{
+    if (lis2dh12_read_temperature(dev, &res->val[0])) {
+        return -ECANCELED;
+    }
+    res->unit = UNIT_TEMP_C;
+    res->scale = -2;
+
+    return 1;
+}
+
 const saul_driver_t lis2dh12_saul_driver = {
     .read = read_accelerometer,
     .write = saul_notsup,
-    .type = SAUL_SENSE_ACCEL
+    .type = SAUL_SENSE_ACCEL,
+};
+
+const saul_driver_t lis2dh12_saul_temp_driver = {
+    .read = read_temperature,
+    .write = saul_notsup,
+    .type = SAUL_SENSE_TEMP,
 };

drivers/saul/init_devs/auto_init_lis2dh12.c

@@ -30,7 +30,6 @@
  */
 #define LIS2DH12_NUM    ARRAY_SIZE(lis2dh12_params)
 
-
 /**
  * @brief   Number of defined SAUL registry info entries
  */
@@ -45,7 +44,7 @@ static lis2dh12_t lis2dh12_devs[LIS2DH12_NUM];
 /**
  * @brief   Memory for the SAUL registry entries
  */
-static saul_reg_t saul_entries[LIS2DH12_NUM];
+static saul_reg_t saul_entries[LIS2DH12_NUM * 2];
 
 void auto_init_lis2dh12(void)
 {
@@ -62,9 +61,14 @@ void auto_init_lis2dh12(void)
             continue;
         }
 
-        saul_entries[i].dev = &(lis2dh12_devs[i]);
-        saul_entries[i].name = lis2dh12_saul_info[i].name;
-        saul_entries[i].driver = &lis2dh12_saul_driver;
-        saul_reg_add(&(saul_entries[i]));
+        saul_entries[2 * i].dev = &lis2dh12_devs[i];
+        saul_entries[2 * i].name = lis2dh12_saul_info[i].name;
+        saul_entries[2 * i].driver = &lis2dh12_saul_driver;
+        saul_reg_add(&saul_entries[2 * i]);
+
+        saul_entries[2 * i + 1].dev = &lis2dh12_devs[i];
+        saul_entries[2 * i + 1].name = lis2dh12_saul_info[i].name;
+        saul_entries[2 * i + 1].driver = &lis2dh12_saul_temp_driver;
+        saul_reg_add(&saul_entries[2 * i + 1]);
     }
 }