NFC: Introduce target mode rx data callback

This routine will be called by drivers whenever they receive data in target
mode. This should be unexpected events and as such should be handled by a
standalone API (i.e. not as a callback pointer from an existing API).
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/net/nfc/nfc.h

@@ -202,5 +202,6 @@ int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
 		     u8 *gb, size_t gb_len);
 int nfc_tm_deactivated(struct nfc_dev *dev);
+int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb);
 
 #endif /* __NET_NFC_H */

net/nfc/core.c

@@ -462,6 +462,18 @@ u8 *nfc_get_local_general_bytes(struct nfc_dev *dev, size_t *gb_len)
 }
 EXPORT_SYMBOL(nfc_get_local_general_bytes);
 
+int nfc_tm_data_received(struct nfc_dev *dev, struct sk_buff *skb)
+{
+	/* Only LLCP target mode for now */
+	if (dev->dep_link_up == false) {
+		kfree_skb(skb);
+		return -ENOLINK;
+	}
+
+	return nfc_llcp_data_received(dev, skb);
+}
+EXPORT_SYMBOL(nfc_tm_data_received);
+
 int nfc_tm_activated(struct nfc_dev *dev, u32 protocol, u8 comm_mode,
 		     u8 *gb, size_t gb_len)
 {

net/nfc/llcp/llcp.c

@@ -937,6 +937,21 @@ void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
 	return;
 }
 
+int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
+{
+	struct nfc_llcp_local *local;
+
+	local = nfc_llcp_find_local(dev);
+	if (local == NULL)
+		return -ENODEV;
+
+	local->rx_pending = skb_get(skb);
+	del_timer(&local->link_timer);
+	queue_work(local->rx_wq, &local->rx_work);
+
+	return 0;
+}
+
 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
 {
 	struct nfc_llcp_local *local;

net/nfc/nfc.h

@@ -55,6 +55,7 @@ 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, size_t *general_bytes_len);
+int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb);
 int __init nfc_llcp_init(void);
 void nfc_llcp_exit(void);
 
@@ -90,6 +91,12 @@ static inline u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *gb_len)
 	return NULL;
 }
 
+static inline int nfc_llcp_data_received(struct nfc_dev *dev,
+					 struct sk_buff *skb)
+{
+	return 0;
+}
+
 static inline int nfc_llcp_init(void)
 {
 	return 0;