drivers/bme680: add SAUL capabilities

drivers/Makefile.dep

@@ -97,6 +97,9 @@ endif
 ifneq (,$(filter bme680_%,$(USEMODULE)))
   USEPKG += driver_bme680
   USEMODULE += bme680
+  ifneq (,$(filter saul%,$(USEMODULE)))
+    USEMODULE += xtimer
+  endif
 endif
 
 ifneq (,$(filter bme680_i2c,$(USEMODULE)))

drivers/bme680/bme680_saul.c

@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2020 Gunar Schorcht
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     drivers_bme680
+ * @brief       SAUL adaption for BME680 devices
+ * @author      Gunar Schorcht <gunar@schorcht.net>
+ * @file
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "phydat.h"
+#include "saul.h"
+#include "bme680.h"
+#include "bme680_params.h"
+#include "xtimer.h"
+
+extern bme680_t bme680_devs_saul[BME680_NUMOF];
+
+/**
+ * Temperature, pressure, humidity and gas sensor values are fetched by separate
+ * saul functions. To avoid multiple waiting for the sensor, we read all sensor
+ * values once, if necessary, and store them in local variables to provide them
+ * in the separate saul read functions.
+ */
+static bool _temp_valid[BME680_NUMOF] = { false };
+static bool _press_valid[BME680_NUMOF] = { false };
+static bool _hum_valid[BME680_NUMOF] = { false };
+static bool _gas_valid[BME680_NUMOF] = { false };
+static int16_t _temp[BME680_NUMOF];
+static int16_t _press[BME680_NUMOF];
+static int16_t _hum[BME680_NUMOF];
+static uint32_t _gas[BME680_NUMOF];
+
+static unsigned _dev2index (const bme680_t *dev)
+{
+    /*
+     * returns the index of the device in bme680_devs_saul[] or BME680_NUMOF
+     * if not found
+     */
+    for (unsigned i = 0; i < BME680_NUMOF; i++) {
+        if (dev == &bme680_devs_saul[i]) {
+            return i;
+        }
+    }
+    return BME680_NUMOF;
+}
+
+static int read(int dev)
+{
+    /* measure and read sensor values */
+    int res;
+    if ((res = bme680_force_measurement(&bme680_devs_saul[dev])) != BME680_OK) {
+        return res;
+    }
+    int drt;
+    if ((drt = bme680_get_duration(&bme680_devs_saul[dev])) < 0) {
+        return BME680_INVALID;
+    }
+    xtimer_usleep(drt * US_PER_MS);
+
+    bme680_field_data_t data;
+    if ((res = bme680_get_data(&bme680_devs_saul[dev], &data)) != BME680_OK) {
+        return res;
+    }
+
+#if MODULE_BME680_FP
+    _temp[dev] = data.temperature * 100;
+    _press[dev] = data.pressure / 100;
+    _hum[dev] = data.humidity * 100;
+#else
+    _temp[dev] = data.temperature;
+    _press[dev] = data.pressure / 100;
+    _hum[dev] = data.humidity / 10;
+#endif
+    _gas[dev] = (data.status & BME680_GASM_VALID_MSK) ? data.gas_resistance : 0;
+
+    /* mark sensor values as valid */
+    _temp_valid[dev] = true;
+    _press_valid[dev] = true;
+    _hum_valid[dev] = true;
+    _gas_valid[dev] = true;
+    return BME680_OK;
+}
+
+static int read_temp(const void *dev, phydat_t *data)
+{
+    /* find the device index */
+    unsigned dev_index = _dev2index((const bme680_t *)dev);
+    if (dev_index == BME680_NUMOF) {
+        /* return with error if device index could not be found */
+        return -ECANCELED;
+    }
+
+    /* either local variable is valid or fetching it was successful */
+    if (_temp_valid[dev_index] || read(dev_index) == BME680_OK) {
+        /* mark local variable as invalid */
+        _temp_valid[dev_index] = false;
+
+        data->val[0] = _temp[dev_index];
+        data->unit = UNIT_TEMP_C;
+        data->scale = -2;
+        return 1;
+    }
+    return -ECANCELED;
+}
+
+static int read_press(const void *dev, phydat_t *data)
+{
+    /* find the device index */
+    unsigned dev_index = _dev2index((const bme680_t *)dev);
+    if (dev_index == BME680_NUMOF) {
+        /* return with error if device index could not be found */
+        return -ECANCELED;
+    }
+
+    /* either local variable is valid or fetching it was successful */
+    if (_press_valid[dev_index] || read(dev_index) == BME680_OK) {
+        /* mark local variable as invalid */
+        _press_valid[dev_index] = false;
+
+        data->val[0] = _press[dev_index];
+        data->unit = UNIT_PA;
+        data->scale = 2;
+        return 1;
+    }
+    return -ECANCELED;
+}
+
+static int read_hum(const void *dev, phydat_t *data)
+{
+    /* find the device index */
+    unsigned dev_index = _dev2index((const bme680_t *)dev);
+    if (dev_index == BME680_NUMOF) {
+        /* return with error if device index could not be found */
+        return -ECANCELED;
+    }
+
+    /* either local variable is valid or fetching it was successful */
+    if (_hum_valid[dev_index] || read(dev_index) == BME680_OK) {
+        /* mark local variable as invalid */
+        _hum_valid[dev_index] = false;
+
+        data->val[0] = _hum[dev_index];
+        data->unit = UNIT_PERCENT;
+        data->scale = -2;
+        return 1;
+    }
+    return -ECANCELED;
+}
+
+static int read_gas(const void *dev, phydat_t *data)
+{
+    /* find the device index */
+    unsigned dev_index = _dev2index((const bme680_t *)dev);
+    if (dev_index == BME680_NUMOF) {
+        /* return with error if device index could not be found */
+        return -ECANCELED;
+    }
+
+    /* either local variable is valid or fetching it was successful */
+    if (_gas_valid[dev_index] || read(dev_index) == BME680_OK) {
+        /* mark local variable as invalid */
+        _gas_valid[dev_index] = false;
+
+        if (_gas[dev_index] > INT16_MAX) {
+            data->val[0] = _gas[dev_index] / 1000;
+            data->scale = 3;
+        }
+        else {
+            data->val[0] = _gas[dev_index];
+            data->scale = 0;
+        }
+        data->unit = UNIT_OHM;
+        return 1;
+    }
+    return -ECANCELED;
+}
+
+const saul_driver_t bme680_saul_driver_temperature = {
+    .read = read_temp,
+    .write = saul_notsup,
+    .type = SAUL_SENSE_TEMP
+};
+
+const saul_driver_t bme680_saul_driver_pressure = {
+    .read = read_press,
+    .write = saul_notsup,
+    .type = SAUL_SENSE_PRESS
+};
+
+const saul_driver_t bme680_saul_driver_humidity = {
+    .read = read_hum,
+    .write = saul_notsup,
+    .type = SAUL_SENSE_HUM
+};
+
+const saul_driver_t bme680_saul_driver_gas = {
+    .read = read_gas,
+    .write = saul_notsup,
+    .type = SAUL_SENSE_GAS
+};

drivers/bme680/include/bme680_params.h

@@ -23,6 +23,7 @@
 
 #include "board.h"
 #include "bme680.h"
+#include "saul_reg.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -96,6 +97,18 @@ extern "C" {
         .intf.spi.dev       = BME680_PARAM_SPI_DEV,     \
         .intf.spi.nss_pin   = BME680_PARAM_SPI_NSS_PIN, \
 }
+
+/**
+ * @brief   Default SAUL meta information
+ */
+#ifndef BME680_SAUL_INFO
+#if MODULE_BME680_I2C && MODULE_BME680_SPI
+#define BME680_SAUL_INFO    { .name = "bme680:0" }, \
+                            { .name = "bme680:1" },
+#else /* MODULE_BME680_I2C && MODULE_BME680_SPI */
+#define BME680_SAUL_INFO    { .name = "bme680" }
+#endif /* MODULE_BME680_I2C && MODULE_BME680_SPI */
+#endif /* BME680_SAUL_INFO */
 /**@}*/
 
 /**
@@ -111,6 +124,14 @@ static const bme680_params_t bme680_params[] =
 #endif
 };
 
+/**
+ * @brief   Additional meta information to keep in the SAUL registry
+ */
+static const saul_reg_info_t bme680_saul_info[] =
+{
+    BME680_SAUL_INFO
+};
+
 /**
  * @brief   The number of configured sensors
  */

drivers/include/bme680.h

@@ -10,7 +10,7 @@
 /**
  * @defgroup    drivers_bme680 BME680 Temperature/Humidity/Pressure/Gas sensor
  * @ingroup     drivers_sensors
- * @brief       Driver for the Bosch BME680  sensor
+ * @brief       Driver for the Bosch BME680 sensor
  *
  * ### Introduction
  *