nfc: st-nci: Rename st21nfcb to st-nci

STMicroelectronics NFC NCI chips family is extending
with the new ST21NFCC using the AMS AS39230 RF booster.
The st21nfcb driver is relevant for this solution and
might be with future products.

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

1 files changed, 313 insertions, 0 deletions

diff --git a/drivers/nfc/st-nci/ndlc.c b/drivers/nfc/st-nci/ndlc.c
new file mode 100644
index 000000000000..56c6a4cb4c96
--- /dev/null
+++ b/drivers/nfc/st-nci/ndlc.c
@@ -0,0 +1,313 @@
+/*
+ * Low Level Transport (NDLC) Driver for STMicroelectronics NFC Chip
+ *
+ * Copyright (C) 2014-2015  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/>.
+ */
+
+#include <linux/sched.h>
+#include <net/nfc/nci_core.h>
+
+#include "ndlc.h"
+#include "st-nci.h"
+
+#define NDLC_TIMER_T1		100
+#define NDLC_TIMER_T1_WAIT	400
+#define NDLC_TIMER_T2		1200
+
+#define PCB_TYPE_DATAFRAME		0x80
+#define PCB_TYPE_SUPERVISOR		0xc0
+#define PCB_TYPE_MASK			PCB_TYPE_SUPERVISOR
+
+#define PCB_SYNC_ACK			0x20
+#define PCB_SYNC_NACK			0x10
+#define PCB_SYNC_WAIT			0x30
+#define PCB_SYNC_NOINFO			0x00
+#define PCB_SYNC_MASK			PCB_SYNC_WAIT
+
+#define PCB_DATAFRAME_RETRANSMIT_YES	0x00
+#define PCB_DATAFRAME_RETRANSMIT_NO	0x04
+#define PCB_DATAFRAME_RETRANSMIT_MASK	PCB_DATAFRAME_RETRANSMIT_NO
+
+#define PCB_SUPERVISOR_RETRANSMIT_YES	0x00
+#define PCB_SUPERVISOR_RETRANSMIT_NO	0x02
+#define PCB_SUPERVISOR_RETRANSMIT_MASK	PCB_SUPERVISOR_RETRANSMIT_NO
+
+#define PCB_FRAME_CRC_INFO_PRESENT	0x08
+#define PCB_FRAME_CRC_INFO_NOTPRESENT	0x00
+#define PCB_FRAME_CRC_INFO_MASK		PCB_FRAME_CRC_INFO_PRESENT
+
+#define NDLC_DUMP_SKB(info, skb)                                 \
+do {                                                             \
+	pr_debug("%s:\n", info);                                 \
+	print_hex_dump(KERN_DEBUG, "ndlc: ", DUMP_PREFIX_OFFSET, \
+			16, 1, skb->data, skb->len, 0);          \
+} while (0)
+
+int ndlc_open(struct llt_ndlc *ndlc)
+{
+	/* toggle reset pin */
+	ndlc->ops->enable(ndlc->phy_id);
+	ndlc->powered = 1;
+	return 0;
+}
+EXPORT_SYMBOL(ndlc_open);
+
+void ndlc_close(struct llt_ndlc *ndlc)
+{
+	struct nci_mode_set_cmd cmd;
+
+	cmd.cmd_type = ST_NCI_SET_NFC_MODE;
+	cmd.mode = 0;
+
+	/* toggle reset pin */
+	ndlc->ops->enable(ndlc->phy_id);
+
+	nci_prop_cmd(ndlc->ndev, ST_NCI_CORE_PROP,
+		     sizeof(struct nci_mode_set_cmd), (__u8 *)&cmd);
+
+	ndlc->powered = 0;
+	ndlc->ops->disable(ndlc->phy_id);
+}
+EXPORT_SYMBOL(ndlc_close);
+
+int ndlc_send(struct llt_ndlc *ndlc, struct sk_buff *skb)
+{
+	/* add ndlc header */
+	u8 pcb = PCB_TYPE_DATAFRAME | PCB_DATAFRAME_RETRANSMIT_NO |
+		PCB_FRAME_CRC_INFO_NOTPRESENT;
+
+	*skb_push(skb, 1) = pcb;
+	skb_queue_tail(&ndlc->send_q, skb);
+
+	schedule_work(&ndlc->sm_work);
+
+	return 0;
+}
+EXPORT_SYMBOL(ndlc_send);
+
+static void llt_ndlc_send_queue(struct llt_ndlc *ndlc)
+{
+	struct sk_buff *skb;
+	int r;
+	unsigned long time_sent;
+
+	if (ndlc->send_q.qlen)
+		pr_debug("sendQlen=%d unackQlen=%d\n",
+			 ndlc->send_q.qlen, ndlc->ack_pending_q.qlen);
+
+	while (ndlc->send_q.qlen) {
+		skb = skb_dequeue(&ndlc->send_q);
+		NDLC_DUMP_SKB("ndlc frame written", skb);
+		r = ndlc->ops->write(ndlc->phy_id, skb);
+		if (r < 0) {
+			ndlc->hard_fault = r;
+			break;
+		}
+		time_sent = jiffies;
+		*(unsigned long *)skb->cb = time_sent;
+
+		skb_queue_tail(&ndlc->ack_pending_q, skb);
+
+		/* start timer t1 for ndlc aknowledge */
+		ndlc->t1_active = true;
+		mod_timer(&ndlc->t1_timer, time_sent +
+			msecs_to_jiffies(NDLC_TIMER_T1));
+		/* start timer t2 for chip availability */
+		ndlc->t2_active = true;
+		mod_timer(&ndlc->t2_timer, time_sent +
+			msecs_to_jiffies(NDLC_TIMER_T2));
+	}
+}
+
+static void llt_ndlc_requeue_data_pending(struct llt_ndlc *ndlc)
+{
+	struct sk_buff *skb;
+	u8 pcb;
+
+	while ((skb = skb_dequeue_tail(&ndlc->ack_pending_q))) {
+		pcb = skb->data[0];
+		switch (pcb & PCB_TYPE_MASK) {
+		case PCB_TYPE_SUPERVISOR:
+			skb->data[0] = (pcb & ~PCB_SUPERVISOR_RETRANSMIT_MASK) |
+				PCB_SUPERVISOR_RETRANSMIT_YES;
+			break;
+		case PCB_TYPE_DATAFRAME:
+			skb->data[0] = (pcb & ~PCB_DATAFRAME_RETRANSMIT_MASK) |
+				PCB_DATAFRAME_RETRANSMIT_YES;
+			break;
+		default:
+			pr_err("UNKNOWN Packet Control Byte=%d\n", pcb);
+			kfree_skb(skb);
+			continue;
+		}
+		skb_queue_head(&ndlc->send_q, skb);
+	}
+}
+
+static void llt_ndlc_rcv_queue(struct llt_ndlc *ndlc)
+{
+	struct sk_buff *skb;
+	u8 pcb;
+	unsigned long time_sent;
+
+	if (ndlc->rcv_q.qlen)
+		pr_debug("rcvQlen=%d\n", ndlc->rcv_q.qlen);
+
+	while ((skb = skb_dequeue(&ndlc->rcv_q)) != NULL) {
+		pcb = skb->data[0];
+		skb_pull(skb, 1);
+		if ((pcb & PCB_TYPE_MASK) == PCB_TYPE_SUPERVISOR) {
+			switch (pcb & PCB_SYNC_MASK) {
+			case PCB_SYNC_ACK:
+				del_timer_sync(&ndlc->t1_timer);
+				del_timer_sync(&ndlc->t2_timer);
+				ndlc->t2_active = false;
+				ndlc->t1_active = false;
+				break;
+			case PCB_SYNC_NACK:
+				llt_ndlc_requeue_data_pending(ndlc);
+				llt_ndlc_send_queue(ndlc);
+				/* start timer t1 for ndlc aknowledge */
+				time_sent = jiffies;
+				ndlc->t1_active = true;
+				mod_timer(&ndlc->t1_timer, time_sent +
+					msecs_to_jiffies(NDLC_TIMER_T1));
+				break;
+			case PCB_SYNC_WAIT:
+				time_sent = jiffies;
+				ndlc->t1_active = true;
+				mod_timer(&ndlc->t1_timer, time_sent +
+					  msecs_to_jiffies(NDLC_TIMER_T1_WAIT));
+				break;
+			default:
+				pr_err("UNKNOWN Packet Control Byte=%d\n", pcb);
+				kfree_skb(skb);
+				break;
+			}
+		} else {
+			nci_recv_frame(ndlc->ndev, skb);
+		}
+	}
+}
+
+static void llt_ndlc_sm_work(struct work_struct *work)
+{
+	struct llt_ndlc *ndlc = container_of(work, struct llt_ndlc, sm_work);
+
+	llt_ndlc_send_queue(ndlc);
+	llt_ndlc_rcv_queue(ndlc);
+
+	if (ndlc->t1_active && timer_pending(&ndlc->t1_timer) == 0) {
+		pr_debug
+		    ("Handle T1(recv SUPERVISOR) elapsed (T1 now inactive)\n");
+		ndlc->t1_active = false;
+
+		llt_ndlc_requeue_data_pending(ndlc);
+		llt_ndlc_send_queue(ndlc);
+	}
+
+	if (ndlc->t2_active && timer_pending(&ndlc->t2_timer) == 0) {
+		pr_debug("Handle T2(recv DATA) elapsed (T2 now inactive)\n");
+		ndlc->t2_active = false;
+		ndlc->t1_active = false;
+		del_timer_sync(&ndlc->t1_timer);
+		del_timer_sync(&ndlc->t2_timer);
+		ndlc_close(ndlc);
+		ndlc->hard_fault = -EREMOTEIO;
+	}
+}
+
+void ndlc_recv(struct llt_ndlc *ndlc, struct sk_buff *skb)
+{
+	if (skb == NULL) {
+		pr_err("NULL Frame -> link is dead\n");
+		ndlc->hard_fault = -EREMOTEIO;
+		ndlc_close(ndlc);
+	} else {
+		NDLC_DUMP_SKB("incoming frame", skb);
+		skb_queue_tail(&ndlc->rcv_q, skb);
+	}
+
+	schedule_work(&ndlc->sm_work);
+}
+EXPORT_SYMBOL(ndlc_recv);
+
+static void ndlc_t1_timeout(unsigned long data)
+{
+	struct llt_ndlc *ndlc = (struct llt_ndlc *)data;
+
+	pr_debug("\n");
+
+	schedule_work(&ndlc->sm_work);
+}
+
+static void ndlc_t2_timeout(unsigned long data)
+{
+	struct llt_ndlc *ndlc = (struct llt_ndlc *)data;
+
+	pr_debug("\n");
+
+	schedule_work(&ndlc->sm_work);
+}
+
+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)
+{
+	struct llt_ndlc *ndlc;
+
+	ndlc = devm_kzalloc(dev, sizeof(struct llt_ndlc), GFP_KERNEL);
+	if (!ndlc)
+		return -ENOMEM;
+
+	ndlc->ops = phy_ops;
+	ndlc->phy_id = phy_id;
+	ndlc->dev = dev;
+	ndlc->powered = 0;
+
+	*ndlc_id = ndlc;
+
+	/* initialize timers */
+	init_timer(&ndlc->t1_timer);
+	ndlc->t1_timer.data = (unsigned long)ndlc;
+	ndlc->t1_timer.function = ndlc_t1_timeout;
+
+	init_timer(&ndlc->t2_timer);
+	ndlc->t2_timer.data = (unsigned long)ndlc;
+	ndlc->t2_timer.function = ndlc_t2_timeout;
+
+	skb_queue_head_init(&ndlc->rcv_q);
+	skb_queue_head_init(&ndlc->send_q);
+	skb_queue_head_init(&ndlc->ack_pending_q);
+
+	INIT_WORK(&ndlc->sm_work, llt_ndlc_sm_work);
+
+	return st_nci_probe(ndlc, phy_headroom, phy_tailroom);
+}
+EXPORT_SYMBOL(ndlc_probe);
+
+void ndlc_remove(struct llt_ndlc *ndlc)
+{
+	st_nci_remove(ndlc->ndev);
+
+	/* cancel timers */
+	del_timer_sync(&ndlc->t1_timer);
+	del_timer_sync(&ndlc->t2_timer);
+	ndlc->t2_active = false;
+	ndlc->t1_active = false;
+
+	skb_queue_purge(&ndlc->rcv_q);
+	skb_queue_purge(&ndlc->send_q);
+}
+EXPORT_SYMBOL(ndlc_remove);