diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index a1a18e3..1e5fab7 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -1,32 +1,93 @@
 #ifndef OSMOCORE_UTIL_H
 #define OSMOCORE_UTIL_H
 
+/*! \file utils.h
+ *  \brief General-purpose utilities in the Osmocom core library
+ */
+
+/*! \brief Determine number of elements in an array of static size */
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+/*! \brief Return the maximum of two specified values */
 #define OSMO_MAX(a, b) (a) >= (b) ? (a) : (b)
+/*! \brief Return the minimum of two specified values */
 #define OSMO_MIN(a, b) (a) >= (b) ? (b) : (a)
 
 #include <stdint.h>
 
+/*! \brief A mapping between human-readable string and numeric value */
 struct value_string {
-	unsigned int value;
-	const char *str;
+	unsigned int value;	/*!< \brief numeric value */
+	const char *str;	/*!< \brief human-readable string */
 };
 
+/*! \fn get_value_string(const struct value_string *vs, uint32_t val)
+ * \brief get human-readable string for given value
+ * \param[in] vs Array of value_string tuples
+ * \param[in] val Value to be converted
+ * \returns pointer to human-readable string
+ */
 const char *get_value_string(const struct value_string *vs, uint32_t val);
+
+/*! \fn get_string_value(const struct value_string *vs, const char *str)
+ * \brief get numeric value for given human-readable string
+ * \param[in] vs Array of value_string tuples
+ * \param[in] str human-readable string
+ * \returns numeric value (>0) or negative numer in case of error
+ */
 int get_string_value(const struct value_string *vs, const char *str);
 
+/*! \fn osmo_bcd2char(uint8_t bcd)
+ * \brief Convert BCD-encoded digit into printable character
+ * \param[in] bcd A single BCD-encoded digit
+ * \returns single printable character
+ */
 char osmo_bcd2char(uint8_t bcd);
 /* only works for numbers in ascci */
 uint8_t osmo_char2bcd(char c);
 
 int osmo_hexparse(const char *str, uint8_t *b, int max_len);
+
+/*! \fn osmo_hexdump(const unsigned char *buf, int len)
+ * \brief Convert binary sequence to hexadecimal ASCII string
+ * This function will print a sequence of bytes as hexadecimal numbers,
+ * adding one space character between each byte (e.g. "1a ef d9")
+ * \param[in] buf pointer to sequence of bytes
+ * \param[in] len length of buf in number of bytes
+ * \returns pointer to zero-terminated string
+ */
 char *osmo_hexdump(const unsigned char *buf, int len);
+
+/*! \fn osmo_hexdump_nospc(const unsigned char *buf, int len)
+ * \brief Convert binary sequence to hexadecimal ASCII string
+ * This function will print a sequence of bytes as hexadecimal numbers,
+ * without any space character between each byte (e.g. "1aefd9")
+ * \param[in] buf pointer to sequence of bytes
+ * \param[in] len length of buf in number of bytes
+ * \returns pointer to zero-terminated string
+ */
 char *osmo_osmo_hexdump_nospc(const unsigned char *buf, int len);
+
+/*! \fn osmo_ubit_dump(const uint8_t *bits, unsigned int len)
+ * \brief Convert a sequence of unpacked bits to ASCII string
+ * \param[in] bits A sequence of unpacked bits
+ * \param[in] len Length of bits
+ */
 char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);
 
 #define osmo_static_assert(exp, name) typedef int dummy##name [(exp) ? 1 : -1];
 
+/*! \fn osmo_str2lower(char *out, const char *in)
+ * \brief Convert an entire string to lower case
+ * \param[out] out output string, caller-allocated
+ * \param[in] in input string
+ */
 void osmo_str2lower(char *out, const char *in);
+
+/*! \fn osmo_str2upper(char *out, const char *in)
+ * \brief Convert an entire string to upper case
+ * \param[out] out output string, caller-allocated
+ * \param[in] in input string
+ */
 void osmo_str2upper(char *out, const char *in);
 
 #define OSMO_SNPRINTF_RET(ret, rem, offset, len)		\