doc: net: Fix LLDP documentation

The LLDP documentation was missing descriptions for enums
and structs.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

include/net/lldp.h

@@ -24,6 +24,8 @@
 extern "C" {
 #endif
 
+/** @cond INTERNAL_HIDDEN */
+
 #define LLDP_TLV_GET_LENGTH(type_length)	(type_length & BIT_MASK(9))
 #define LLDP_TLV_GET_TYPE(type_length)		((u8_t)(type_length >> 9))
 
@@ -101,46 +103,59 @@ extern "C" {
 
 struct net_if;
 
-/* TLV Types. Please refer to table 8-1 from IEEE 802.1AB standard. */
+/** @endcond */
+
+/** TLV Types. Please refer to table 8-1 from IEEE 802.1AB standard. */
 enum net_lldp_tlv_type {
-	LLDP_TLV_END_LLDPDU = 0,
-	LLDP_TLV_CHASSIS_ID,
-	LLDP_TLV_PORT_ID,
-	LLDP_TLV_TTL,
-	LLDP_TLV_PORT_DESC,
-	LLDP_TLV_SYSTEM_NAME,
-	LLDP_TLV_SYSTEM_DESC,
-	LLDP_TLV_SYSTEM_CAPABILITIES,
-	LLDP_TLV_MANAGEMENT_ADDR,
+	LLDP_TLV_END_LLDPDU          = 0, /**< End Of LLDPDU (optional)      */
+	LLDP_TLV_CHASSIS_ID          = 1, /**< Chassis ID (mandatory)        */
+	LLDP_TLV_PORT_ID             = 2, /**< Port ID (mandatory)           */
+	LLDP_TLV_TTL                 = 3, /**< Time To Live (mandatory)      */
+	LLDP_TLV_PORT_DESC           = 4, /**< Port Description (optional)   */
+	LLDP_TLV_SYSTEM_NAME         = 5, /**< System Name (optional)        */
+	LLDP_TLV_SYSTEM_DESC         = 6, /**< System Description (optional) */
+	LLDP_TLV_SYSTEM_CAPABILITIES = 7, /**< System Capability (optional)  */
+	LLDP_TLV_MANAGEMENT_ADDR     = 8, /**< Management Address (optional) */
 	/* Types 9 - 126 are reserved. */
-	LLDP_TLV_ORG_SPECIFIC = 127
+	LLDP_TLV_ORG_SPECIFIC       = 127, /**< Org specific TLVs (optional) */
 };
 
+/** Chassis ID TLV, see chapter 8.5.2 in IEEE 802.1AB */
 struct net_lldp_chassis_tlv {
-	uint16_t type_length;	/* 7 bits for type, 9 bits for length */
-	uint8_t subtype;	/* ID subtype. */
+	/** 7 bits for type, 9 bits for length */
+	uint16_t type_length;
+	/** ID subtype */
+	uint8_t subtype;
+	/** Chassis ID value */
 	uint8_t value[NET_LLDP_CHASSIS_ID_VALUE_LEN];
 } __packed;
 
+/** Port ID TLV, see chapter 8.5.3 in IEEE 802.1AB */
 struct net_lldp_port_tlv {
-	uint16_t type_length;	/* 7 bits for type, 9 bits for length */
-	uint8_t subtype;	/* ID subtype. */
+	/** 7 bits for type, 9 bits for length */
+	uint16_t type_length;
+	/** ID subtype */
+	uint8_t subtype;
+	/** Port ID value */
 	uint8_t value[NET_LLDP_PORT_ID_VALUE_LEN];
 } __packed;
 
+/** Time To Live TLV, see chapter 8.5.4 in IEEE 802.1AB */
 struct net_lldp_time_to_live_tlv {
-	uint16_t type_length;	/* 7 bits for type, 9 bits for length */
-	uint16_t ttl;		/* Time to live */
+	/** 7 bits for type, 9 bits for length */
+	uint16_t type_length;
+	/** Time To Live (TTL) value */
+	uint16_t ttl;
 } __packed;
 
-/*
+/**
  * LLDP Data Unit (LLDPDU) shall contain the following ordered TLVs
- * as stated in "8.2 LLDPDU format" from the Spec.
+ * as stated in "8.2 LLDPDU format" from the IEEE 802.1AB
  */
 struct net_lldpdu {
-	struct net_lldp_chassis_tlv chassis_id;	/* Mandatory TLV */
-	struct net_lldp_port_tlv port_id;	/* Mandatory TLV */
-	struct net_lldp_time_to_live_tlv ttl;	/* Mandatory TLV */
+	struct net_lldp_chassis_tlv chassis_id;	/**< Mandatory Chassis TLV */
+	struct net_lldp_port_tlv port_id;	/**< Mandatory Port TLV */
+	struct net_lldp_time_to_live_tlv ttl;	/**< Mandatory TTL TLV */
 } __packed;
 
 /**
@@ -205,25 +220,25 @@ int net_lldp_register_callback(struct net_if *iface, net_lldp_recv_cb_t cb);
  */
 enum net_verdict net_lldp_recv(struct net_if *iface, struct net_pkt *pkt);
 
-#if defined(CONFIG_NET_LLDP)
 /**
  * @brief Set LLDP protocol data unit (LLDPDU) for the network interface.
  *
  * @param iface Network interface
  *
  * @return <0 if error, index in lldp array if iface is found there
  */
+#if defined(CONFIG_NET_LLDP)
 int net_lldp_set_lldpdu(struct net_if *iface);
 #else
 #define net_lldp_set_lldpdu(iface)
 #endif
 
-#if defined(CONFIG_NET_LLDP)
 /**
  * @brief Unset LLDP protocol data unit (LLDPDU) for the network interface.
  *
  * @param iface Network interface
  */
+#if defined(CONFIG_NET_LLDP)
 void net_lldp_unset_lldpdu(struct net_if *iface);
 #else
 #define net_lldp_unset_lldpdu(iface)