1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
|
/*
* 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);
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 = ST21NFCB_NCI_SET_NFC_MODE;
cmd.mode = 0;
/* toggle reset pin */
ndlc->ops->enable(ndlc->phy_id);
nci_prop_cmd(ndlc->ndev, ST21NFCB_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 st21nfcb_nci_probe(ndlc, phy_headroom, phy_tailroom);
}
EXPORT_SYMBOL(ndlc_probe);
void ndlc_remove(struct llt_ndlc *ndlc)
{
st21nfcb_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);
|
