NFC: st21nfcb: Add driver for STMicroelectronics ST21NFCB NFC chip

Add driver for STMicroelectronics ST21NFCB NFC controller.
ST21NFCB is using NCI protocol and a proprietary low level transport
protocol called NDLC used on top.

NDLC:
The protocol defines 2 types of frame:
- One type carrying NCI data (referred as DATAFRAME frames).
- One type carrying protocol information used for flow control and error
control mechanisms (referred as SUPERVISOR frames).

After each frame transmission to the NFC controller, the device host
SHALL waitfor  an ACK (SUPERVISOR frame) reception before sending a
new frame.
The NFC controller MAY send a frame at anytime to the device host.
The NFC controller MAY send a specific WAIT supervisor frame to indicate
to device host that a NCI data packet has been received but that it could
take significant time before the NFC controller sends an ACK and thus
allows next data reception.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/drivers/nfc/st21nfcb/ndlc.h b/drivers/nfc/st21nfcb/ndlc.h
new file mode 100644
index 00000000000..c30a2f0faa5
--- /dev/null
+++ b/drivers/nfc/st21nfcb/ndlc.h
@@ -0,0 +1,55 @@
+/*
+ * NCI based Driver for STMicroelectronics NFC Chip
+ *
+ * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LOCAL_NDLC_H_
+#define __LOCAL_NDLC_H_
+
+#include <linux/skbuff.h>
+#include <net/nfc/nfc.h>
+
+/* Low Level Transport description */
+struct llt_ndlc {
+	struct nci_dev *ndev;
+	struct nfc_phy_ops *ops;
+	void *phy_id;
+
+	struct timer_list t1_timer;
+	bool t1_active;
+
+	struct timer_list t2_timer;
+	bool t2_active;
+
+	struct sk_buff_head rcv_q;
+	struct sk_buff_head send_q;
+	struct sk_buff_head ack_pending_q;
+
+	struct work_struct sm_work;
+
+	struct device *dev;
+
+	int hard_fault;
+};
+
+int ndlc_open(struct llt_ndlc *ndlc);
+void ndlc_close(struct llt_ndlc *ndlc);
+int ndlc_send(struct llt_ndlc *ndlc, struct sk_buff *skb);
+void ndlc_recv(struct llt_ndlc *ndlc, struct sk_buff *skb);
+int ndlc_probe(void *phy_id, struct nfc_phy_ops *phy_ops, struct device *dev,
+	int phy_headroom, int phy_tailroom, struct llt_ndlc **ndlc_id);
+void ndlc_remove(struct llt_ndlc *ndlc);
+#endif /* __LOCAL_NDLC_H__ */