doxygen: add doxygen module 'utils'
diff --git a/include/osmocom/core/utils.h b/include/osmocom/core/utils.h
index 1e5fab7..940c25f 100644
--- a/include/osmocom/core/utils.h
+++ b/include/osmocom/core/utils.h
@@ -1,10 +1,12 @@
 #ifndef OSMOCORE_UTIL_H
 #define OSMOCORE_UTIL_H
 
-/*! \file utils.h
- *  \brief General-purpose utilities in the Osmocom core library
+/*! \defgroup utils General-purpose utility functions
+ *  @{
  */
 
+/*! \file utils.h */
+
 /*! \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 */
@@ -20,74 +22,23 @@
 	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);
+char *osmo_hexdump(const unsigned char *buf, int len);
+char *osmo_osmo_hexdump_nospc(const unsigned char *buf, 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)		\
@@ -99,4 +50,6 @@
 	rem -= ret;						\
 } while (0)
 
+/*! }@ */
+
 #endif