NFC: Initial LLCP support

This patch is an initial implementation for the NFC Logical Link Control
protocol. It's also known as NFC peer to peer mode.
This is a basic implementation as it lacks SDP (services Discovery
Protocol), frames aggregation support, and frame rejecion parsing.
Follow up patches will implement those missing features.
This code has been tested against a Nexus S phone implementing LLCP 1.0.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/nfc/nfc.h b/net/nfc/nfc.h
index 4d0fb12..2c2c401 100644
--- a/net/nfc/nfc.h
+++ b/net/nfc/nfc.h
@@ -46,6 +46,60 @@
 #define to_rawsock_sk(_tx_work) \
 	((struct sock *) container_of(_tx_work, struct nfc_rawsock, tx_work))
 
+#ifdef CONFIG_NFC_LLCP
+
+void nfc_llcp_mac_is_down(struct nfc_dev *dev);
+void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
+			u8 comm_mode, u8 rf_mode);
+int nfc_llcp_register_device(struct nfc_dev *dev);
+void nfc_llcp_unregister_device(struct nfc_dev *dev);
+int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len);
+u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, u8 *general_bytes_len);
+int __init nfc_llcp_init(void);
+void nfc_llcp_exit(void);
+
+#else
+
+void nfc_llcp_mac_is_down(struct nfc_dev *dev)
+{
+}
+
+void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
+			u8 comm_mode, u8 rf_mode)
+{
+}
+
+static inline int nfc_llcp_register_device(struct nfc_dev *dev)
+{
+	return 0;
+}
+
+static inline void nfc_llcp_unregister_device(struct nfc_dev *dev)
+{
+}
+
+static inline int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
+{
+	return 0;
+}
+
+static inline u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, u8 *gb_len)
+{
+	*gb_len = 0;
+	return NULL;
+}
+
+static inline int nfc_llcp_init(void)
+{
+	return 0;
+}
+
+static inline void nfc_llcp_exit(void)
+{
+}
+
+#endif
+
 int __init rawsock_init(void);
 void rawsock_exit(void);