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path: root/drivers/nfc/st21nfcb/ndlc.c
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Diffstat (limited to 'drivers/nfc/st21nfcb/ndlc.c')
-rw-r--r--drivers/nfc/st21nfcb/ndlc.c298
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/nfc/st21nfcb/ndlc.c b/drivers/nfc/st21nfcb/ndlc.c
new file mode 100644
index 000000000000..83c97c36112b
--- /dev/null
+++ b/drivers/nfc/st21nfcb/ndlc.c
@@ -0,0 +1,298 @@
+/*
+ * Low Level Transport (NDLC) 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/>.
+ */
+
+#include <linux/sched.h>
+#include <net/nfc/nci_core.h>
+
+#include "ndlc.h"
+#include "st21nfcb.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);
+ return 0;
+}
+EXPORT_SYMBOL(ndlc_open);
+
+void ndlc_close(struct llt_ndlc *ndlc)
+{
+ /* toggle reset pin */
+ 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));
+ }
+}
+
+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);
+ break;
+ }
+ 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);
+
+ 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) {
+ nfc_err(dev, "Cannot allocate memory for ndlc.\n");
+ return -ENOMEM;
+ }
+ ndlc->ops = phy_ops;
+ ndlc->phy_id = phy_id;
+ ndlc->dev = dev;
+
+ *ndlc_id = ndlc;
+
+ /* start 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 st21nfcb_nci_probe(ndlc, phy_headroom, phy_tailroom);
+}
+EXPORT_SYMBOL(ndlc_probe);
+
+void ndlc_remove(struct llt_ndlc *ndlc)
+{
+ /* 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);
+
+ st21nfcb_nci_remove(ndlc->ndev);
+ kfree(ndlc);
+}
+EXPORT_SYMBOL(ndlc_remove);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 09:00:06 +0000