+++ /dev/null
-/*
- * 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));
- /* 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_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 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);
-}
-EXPORT_SYMBOL(ndlc_remove);
Code Review / kvmfornfv.git / blobdiff