wireless/ieee802154: Adds MAC character driver structure. Nonfunctional

wireless/ieee802154/Kconfig

@@ -21,6 +21,14 @@ config IEEE802154_MAC
 		such as 6lowpan. It is not required to use 802.15.4 radios,
 		but is strongly suggested to ensure exchange of valid frames.
 
+config IEEE802154_MAC_DEV
+	bool "Character driver for IEEE 802.15.4 MAC layer"
+	default n
+	depends on IEEE802154_MAC
+	---help---
+		Enable the device driver to expose the IEEE 802.15.4 MAC layer
+		access to user space as IOCTLs
+
 config IEEE802154_DEV
 	bool "Debug character driver for ieee802.15.4 radio interfaces"
 	default n

wireless/ieee802154/Make.defs

@@ -45,6 +45,10 @@ ifeq ($(CONFIG_IEEE802154_MAC),y)
 CSRCS += mac802154.c
 endif
 
+ifeq ($(CONFIG_IEEE802154_MAC_DEV),y)
+CSRCS += mac802154_device.c
+endif
+
 ifeq ($(CONFIG_IEEE802154_DEV),y)
 CSRCS += radio802154_device.c
 endif

wireless/ieee802154/mac802154.c

@@ -506,29 +506,32 @@ static int mac802154_rsporphan(FAR struct ieee802154_mac_s *mac,
  ****************************************************************************/
 
 /****************************************************************************
- * Name: mac802154_register
+ * Name: mac802154_create
  *
  * Description:
  *   Create a 802.15.4 MAC device from a 802.15.4 compatible radio device.
- *   To create a 802.15.4 MAC, you need to pass:
  *
- *     - an instance of a radio driver in radiodev
- *     - a pointer to a structure that contains MAC callback routines to
- *       handle confirmations and indications. NULL entries indicate no
- *       callback.
+ *   The returned MAC structure should be passed to either the next highest
+ *   layer in the network stack, or registered with a mac802154dev character
+ *   driver.  In either of these scenarios, the next highest layer should 
+ *   register a set of callbacks with the MAC layer by setting the mac->cbs
+ *   member.
  *
- *   In return you get a mac structure that has pointers to MAC operations
- *   and responses.
- *
- *   This API does not create any device accessible to userspace. If you
+ *   NOTE: This API does not create any device accessible to userspace. If you
  *   want to call these APIs from userspace, you have to wrap your mac in a
  *   character device via mac802154_device.c.
  *
+ * Input Parameters:
+ *   radiodev - an instance of an IEEE 802.15.4 radio
+ *
+ * Returned Value:
+ *   A MAC structure that has pointers to MAC operations
+ *   and responses.
+ *
  ****************************************************************************/
 
 FAR struct ieee802154_mac_s *
-  mac802154_register(FAR struct ieee802154_radio_s *radiodev,
-                     unsigned int minor)
+  mac802154_create(FAR struct ieee802154_radio_s *radiodev)
 {
   FAR struct ieee802154_privmac_s *mac;