drivers: sensor: STCC4 Add Driver

This adds support for Sensirion's STCC4 co2 sensor.

Signed-off-by: Jan Faeh <[email protected]>

Author: jfaeh

drivers/sensor/sensirion/CMakeLists.txt

@@ -2,10 +2,12 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # zephyr-keep-sorted-start
+add_subdirectory(sensirion_core)
 add_subdirectory_ifdef(CONFIG_SCD4X scd4x)
 add_subdirectory_ifdef(CONFIG_SGP40 sgp40)
 add_subdirectory_ifdef(CONFIG_SHT3XD sht3xd)
 add_subdirectory_ifdef(CONFIG_SHT4X sht4x)
 add_subdirectory_ifdef(CONFIG_SHTCX shtcx)
+add_subdirectory_ifdef(CONFIG_STCC4 stcc4)
 add_subdirectory_ifdef(CONFIG_STS4X sts4x)
 # zephyr-keep-sorted-stop

drivers/sensor/sensirion/Kconfig

@@ -7,5 +7,6 @@ source "drivers/sensor/sensirion/sgp40/Kconfig"
 source "drivers/sensor/sensirion/sht3xd/Kconfig"
 source "drivers/sensor/sensirion/sht4x/Kconfig"
 source "drivers/sensor/sensirion/shtcx/Kconfig"
+source "drivers/sensor/sensirion/stcc4/Kconfig"
 source "drivers/sensor/sensirion/sts4x/Kconfig"
 # zephyr-keep-sorted-stop

drivers/sensor/sensirion/sensirion_core/CMakeLists.txt

@@ -0,0 +1,8 @@
+# Copyright (c) 2025 Sensirion
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+zephyr_library()
+
+zephyr_library_sources(sensirion_common.c)
+zephyr_library_sources(sensirion_i2c.c)

drivers/sensor/sensirion/sensirion_core/sensirion_common.c

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2025 Sensirion
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "sensirion_common.h"
+
+float sensirion_common_bytes_to_float(const uint8_t *bytes)
+{
+	union {
+		uint32_t u32_value;
+		float float32;
+	} tmp;
+
+	tmp.u32_value = sys_get_be32(bytes);
+	return tmp.float32;
+}
+
+void sensirion_common_float_to_bytes(const float value, uint8_t *bytes)
+{
+	union {
+		uint32_t u32_value;
+		float float32;
+	} tmp;
+	tmp.float32 = value;
+	sys_put_be32(tmp.u32_value, bytes);
+}
+
+void sensirion_common_to_integer(const uint8_t *source, uint8_t *destination, INT_TYPE int_type,
+				 uint8_t data_length)
+{
+	if (data_length > int_type) {
+		data_length = 0;
+	}
+
+	uint8_t offset = int_type - data_length;
+
+	for (uint8_t i = 0; i < offset; i++) {
+		destination[int_type - i - 1] = 0;
+	}
+
+	for (uint8_t i = 1; i <= data_length; i++) {
+		destination[int_type - offset - i] = source[i - 1];
+	}
+}

drivers/sensor/sensirion/sensirion_core/sensirion_common.h

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2025 Sensirion
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef SENSIRION_COMMON_H
+#define SENSIRION_COMMON_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <zephyr/sys/byteorder.h>
+
+#define NO_ERROR              0
+#define NOT_IMPLEMENTED_ERROR ENOSYS
+
+#define SENSIRION_COMMAND_SIZE     2
+#define SENSIRION_WORD_SIZE        2
+#define SENSIRION_NUM_WORDS(x)     (sizeof(x) / SENSIRION_WORD_SIZE)
+#define SENSIRION_MAX_BUFFER_WORDS 32
+
+#define sensirion_common_bytes_to_int16_t(src)  ((int16_t)sys_get_be16((src)))
+#define sensirion_common_bytes_to_uint16_t(src) (sys_get_be16((src)))
+#define sensirion_common_bytes_to_int32_t(src)  ((int32_t)sys_get_be32((src)))
+#define sensirion_common_bytes_to_uint32_t(src) (sys_get_be32((src)))
+
+#define sensirion_common_uint32_t_to_bytes(val, dst) (sys_put_be32((val), (dst)))
+#define sensirion_common_int32_t_to_bytes(val, dst)  (sys_put_be32((uint32_t)(val), (dst)))
+#define sensirion_common_uint16_t_to_bytes(val, dst) (sys_put_be16((val), (dst)))
+#define sensirion_common_int16_t_to_bytes(val, dst)  (sys_put_be16((uint16_t)(val), (dst)))
+#define sensirion_common_copy_bytes(src, dst, len)   (memcpy((dst), (src), (len)))
+
+/**
+ * Enum to describe the type of an integer
+ */
+typedef enum {
+	BYTE = 1,
+	SHORT = 2,
+	INTEGER = 4,
+	LONG_INTEGER = 8
+} INT_TYPE;
+
+/**
+ * Convert an array of bytes to a float
+ *
+ * Convert an array of bytes received from the sensor in big-endian/MSB-first
+ * format to an float value in the correct system-endianness.
+ *
+ * @param bytes An array of at least four bytes (MSB first)
+ * @return      The byte array represented as float
+ */
+float sensirion_common_bytes_to_float(const uint8_t *bytes);
+
+/**
+ * Convert an float to an array of bytes
+ *
+ * Convert an float value in system-endianness to big-endian/MBS-first
+ * format to send to the sensor.
+ *
+ * @param value Value to convert
+ * @param bytes An array of at least four bytes
+ */
+void sensirion_common_float_to_bytes(const float value, uint8_t *bytes);
+
+/**
+ *  Copy bytes from byte array to integer.
+ *
+ * @param source      Array of bytes to be copied.
+ * @param int_value Pointer to integer of bytes to be copied to.
+ * @param int_type Type (size) of the integer to be copied.
+ * @param data_length Number of bytes to copy.
+ */
+void sensirion_common_to_integer(const uint8_t *source, uint8_t *destination, INT_TYPE int_type,
+				 uint8_t data_length);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SENSIRION_COMMON_H */