doc: fix some Doxygen comments and add -Wdocumentation to CFLAGS_TIDY

Makefile

@@ -20,7 +20,7 @@ INC_NANOCBOR=$(NANOCBOR_ROOT)/include
 LIB_NANOCBOR_PATH=$(NANOCBOR_ROOT)/bin
 LIB_NANOCBOR=$(LIB_NANOCBOR_PATH)/libnanocbor.so
 
-CFLAGS_TIDY ?= -std=c99
+CFLAGS_TIDY ?= -std=c99 -Wdocumentation
 
 CFLAGS_COVERAGE += -coverage
 CFLAGS_DEBUG += $(CFLAGS_COVERAGE) -g3

include/cose/crypto.h

@@ -79,13 +79,12 @@ COSE_ssize_t cose_crypto_keygen(uint8_t *buf, size_t len, cose_algo_t algo);
  *
  *
  * @param[out]      c       resulting ciphertext
- * @param[inout]    clen    length of the buffer, length of resulting ciphertext
+ * @param[in,out]   clen    length of the buffer, length of resulting ciphertext
  * @param           msg     message to encrypt
  * @param           msglen  length of the message
  * @param           aad     additional authenticated data to protect
  * @param           aadlen  length of the additional authenticated data
  * @param           key     key to decrypt with
- * @param           nonce   nonce to use
  */
 int cose_crypto_aead_encrypt(uint8_t *c, size_t *clen, const uint8_t *msg, size_t msglen, const uint8_t *aad, size_t aadlen, const uint8_t *nsec, const uint8_t *npub, const uint8_t *key, cose_algo_t algo);
 int cose_crypto_aead_decrypt(uint8_t *msg,

include/cose/key.h

@@ -99,9 +99,6 @@ void cose_key_set_kid(cose_key_t *key, uint8_t *kid, size_t len);
  *
  * @param   key  The key object
  * @param   map     The cbor encoder map object to add headers to
- *
- * @return          0 on success
- * @return          Negative on error
  */
 void cose_key_protected_to_map(const cose_key_t *key, nanocbor_encoder_t *map);
 
@@ -110,9 +107,6 @@ void cose_key_protected_to_map(const cose_key_t *key, nanocbor_encoder_t *map);
  *
  * @param   key  The key object
  * @param   map     The cbor encoder map object to add headers to
- *
- * @return          0 on success
- * @return          Negative on error
  */
 void cose_key_unprotected_to_map(const cose_key_t *key, nanocbor_encoder_t *map);