From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/nfc/st21nfcb/ndlc.c | 300 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 300 insertions(+) create mode 100644 drivers/nfc/st21nfcb/ndlc.c (limited to 'drivers/nfc/st21nfcb/ndlc.c') diff --git a/drivers/nfc/st21nfcb/ndlc.c b/drivers/nfc/st21nfcb/ndlc.c new file mode 100644 index 000000000..6014b5859 --- /dev/null +++ b/drivers/nfc/st21nfcb/ndlc.c @@ -0,0 +1,300 @@ +/* + * 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 . + */ + +#include +#include + +#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); -- cgit v1.2.3-54-g00ecf