1 // SPDX-License-Identifier: GPL-2.0-only
3 * shdlc Link Layer Control
5 * Copyright (C) 2012 Intel Corporation. All rights reserved.
8 #define pr_fmt(fmt) "shdlc: %s: " fmt, __func__
10 #include <linux/types.h>
11 #include <linux/sched.h>
12 #include <linux/wait.h>
13 #include <linux/slab.h>
14 #include <linux/skbuff.h>
19 SHDLC_DISCONNECTED
= 0,
21 SHDLC_NEGOTIATING
= 2,
22 SHDLC_HALF_CONNECTED
= 3,
27 struct nfc_hci_dev
*hdev
;
28 xmit_to_drv_t xmit_to_drv
;
29 rcv_to_hci_t rcv_to_hci
;
31 struct mutex state_mutex
;
32 enum shdlc_state state
;
35 wait_queue_head_t
*connect_wq
;
38 struct timer_list connect_timer
;/* aka T3 in spec 10.6.1 */
40 u8 w
; /* window size */
43 struct timer_list t1_timer
; /* send ack timeout */
46 struct timer_list t2_timer
; /* guard/retransmit timeout */
49 int ns
; /* next seq num for send */
50 int nr
; /* next expected seq num for receive */
51 int dnr
; /* oldest sent unacked seq num */
53 struct sk_buff_head rcv_q
;
55 struct sk_buff_head send_q
;
56 bool rnr
; /* other side is not ready to receive */
58 struct sk_buff_head ack_pending_q
;
60 struct work_struct sm_work
;
65 llc_failure_t llc_failure
;
68 #define SHDLC_LLC_HEAD_ROOM 2
70 #define SHDLC_MAX_WINDOW 4
71 #define SHDLC_SREJ_SUPPORT false
73 #define SHDLC_CONTROL_HEAD_MASK 0xe0
74 #define SHDLC_CONTROL_HEAD_I 0x80
75 #define SHDLC_CONTROL_HEAD_I2 0xa0
76 #define SHDLC_CONTROL_HEAD_S 0xc0
77 #define SHDLC_CONTROL_HEAD_U 0xe0
79 #define SHDLC_CONTROL_NS_MASK 0x38
80 #define SHDLC_CONTROL_NR_MASK 0x07
81 #define SHDLC_CONTROL_TYPE_MASK 0x18
83 #define SHDLC_CONTROL_M_MASK 0x1f
92 enum uframe_modifier
{
97 #define SHDLC_CONNECT_VALUE_MS 5
98 #define SHDLC_T1_VALUE_MS(w) ((5 * w) / 4)
99 #define SHDLC_T2_VALUE_MS 300
101 #define SHDLC_DUMP_SKB(info, skb) \
103 pr_debug("%s:\n", info); \
104 print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \
105 16, 1, skb->data, skb->len, 0); \
108 /* checks x < y <= z modulo 8 */
109 static bool llc_shdlc_x_lt_y_lteq_z(int x
, int y
, int z
)
112 return ((x
< y
) && (y
<= z
)) ? true : false;
114 return ((y
> x
) || (y
<= z
)) ? true : false;
117 /* checks x <= y < z modulo 8 */
118 static bool llc_shdlc_x_lteq_y_lt_z(int x
, int y
, int z
)
121 return ((x
<= y
) && (y
< z
)) ? true : false;
122 else /* x > z -> z+8 > x */
123 return ((y
>= x
) || (y
< z
)) ? true : false;
126 static struct sk_buff
*llc_shdlc_alloc_skb(struct llc_shdlc
*shdlc
,
131 skb
= alloc_skb(shdlc
->tx_headroom
+ SHDLC_LLC_HEAD_ROOM
+
132 shdlc
->tx_tailroom
+ payload_len
, GFP_KERNEL
);
134 skb_reserve(skb
, shdlc
->tx_headroom
+ SHDLC_LLC_HEAD_ROOM
);
139 /* immediately sends an S frame. */
140 static int llc_shdlc_send_s_frame(struct llc_shdlc
*shdlc
,
141 enum sframe_type sframe_type
, int nr
)
146 pr_debug("sframe_type=%d nr=%d\n", sframe_type
, nr
);
148 skb
= llc_shdlc_alloc_skb(shdlc
, 0);
152 *(u8
*)skb_push(skb
, 1) = SHDLC_CONTROL_HEAD_S
| (sframe_type
<< 3) | nr
;
154 r
= shdlc
->xmit_to_drv(shdlc
->hdev
, skb
);
161 /* immediately sends an U frame. skb may contain optional payload */
162 static int llc_shdlc_send_u_frame(struct llc_shdlc
*shdlc
,
164 enum uframe_modifier uframe_modifier
)
168 pr_debug("uframe_modifier=%d\n", uframe_modifier
);
170 *(u8
*)skb_push(skb
, 1) = SHDLC_CONTROL_HEAD_U
| uframe_modifier
;
172 r
= shdlc
->xmit_to_drv(shdlc
->hdev
, skb
);
180 * Free ack_pending frames until y_nr - 1, and reset t2 according to
181 * the remaining oldest ack_pending frame sent time
183 static void llc_shdlc_reset_t2(struct llc_shdlc
*shdlc
, int y_nr
)
186 int dnr
= shdlc
->dnr
; /* MUST initially be < y_nr */
188 pr_debug("release ack pending up to frame %d excluded\n", y_nr
);
190 while (dnr
!= y_nr
) {
191 pr_debug("release ack pending frame %d\n", dnr
);
193 skb
= skb_dequeue(&shdlc
->ack_pending_q
);
199 if (skb_queue_empty(&shdlc
->ack_pending_q
)) {
200 if (shdlc
->t2_active
) {
201 del_timer_sync(&shdlc
->t2_timer
);
202 shdlc
->t2_active
= false;
205 ("All sent frames acked. Stopped T2(retransmit)\n");
208 skb
= skb_peek(&shdlc
->ack_pending_q
);
210 mod_timer(&shdlc
->t2_timer
, *(unsigned long *)skb
->cb
+
211 msecs_to_jiffies(SHDLC_T2_VALUE_MS
));
212 shdlc
->t2_active
= true;
215 ("Start T2(retransmit) for remaining unacked sent frames\n");
220 * Receive validated frames from lower layer. skb contains HCI payload only.
221 * Handle according to algorithm at spec:10.8.2
223 static void llc_shdlc_rcv_i_frame(struct llc_shdlc
*shdlc
,
224 struct sk_buff
*skb
, int ns
, int nr
)
229 pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns
, nr
);
231 if (shdlc
->state
!= SHDLC_CONNECTED
)
234 if (x_ns
!= shdlc
->nr
) {
235 llc_shdlc_send_s_frame(shdlc
, S_FRAME_REJ
, shdlc
->nr
);
239 if (shdlc
->t1_active
== false) {
240 shdlc
->t1_active
= true;
241 mod_timer(&shdlc
->t1_timer
, jiffies
+
242 msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc
->w
)));
243 pr_debug("(re)Start T1(send ack)\n");
247 shdlc
->rcv_to_hci(shdlc
->hdev
, skb
);
251 shdlc
->nr
= (shdlc
->nr
+ 1) % 8;
253 if (llc_shdlc_x_lt_y_lteq_z(shdlc
->dnr
, y_nr
, shdlc
->ns
)) {
254 llc_shdlc_reset_t2(shdlc
, y_nr
);
263 static void llc_shdlc_rcv_ack(struct llc_shdlc
*shdlc
, int y_nr
)
265 pr_debug("remote acked up to frame %d excluded\n", y_nr
);
267 if (llc_shdlc_x_lt_y_lteq_z(shdlc
->dnr
, y_nr
, shdlc
->ns
)) {
268 llc_shdlc_reset_t2(shdlc
, y_nr
);
273 static void llc_shdlc_requeue_ack_pending(struct llc_shdlc
*shdlc
)
277 pr_debug("ns reset to %d\n", shdlc
->dnr
);
279 while ((skb
= skb_dequeue_tail(&shdlc
->ack_pending_q
))) {
280 skb_pull(skb
, 1); /* remove control field */
281 skb_queue_head(&shdlc
->send_q
, skb
);
283 shdlc
->ns
= shdlc
->dnr
;
286 static void llc_shdlc_rcv_rej(struct llc_shdlc
*shdlc
, int y_nr
)
290 pr_debug("remote asks retransmission from frame %d\n", y_nr
);
292 if (llc_shdlc_x_lteq_y_lt_z(shdlc
->dnr
, y_nr
, shdlc
->ns
)) {
293 if (shdlc
->t2_active
) {
294 del_timer_sync(&shdlc
->t2_timer
);
295 shdlc
->t2_active
= false;
296 pr_debug("Stopped T2(retransmit)\n");
299 if (shdlc
->dnr
!= y_nr
) {
300 while ((shdlc
->dnr
= ((shdlc
->dnr
+ 1) % 8)) != y_nr
) {
301 skb
= skb_dequeue(&shdlc
->ack_pending_q
);
306 llc_shdlc_requeue_ack_pending(shdlc
);
310 /* See spec RR:10.8.3 REJ:10.8.4 */
311 static void llc_shdlc_rcv_s_frame(struct llc_shdlc
*shdlc
,
312 enum sframe_type s_frame_type
, int nr
)
316 if (shdlc
->state
!= SHDLC_CONNECTED
)
319 switch (s_frame_type
) {
321 llc_shdlc_rcv_ack(shdlc
, nr
);
322 if (shdlc
->rnr
== true) { /* see SHDLC 10.7.7 */
324 if (shdlc
->send_q
.qlen
== 0) {
325 skb
= llc_shdlc_alloc_skb(shdlc
, 0);
327 skb_queue_tail(&shdlc
->send_q
, skb
);
332 llc_shdlc_rcv_rej(shdlc
, nr
);
335 llc_shdlc_rcv_ack(shdlc
, nr
);
343 static void llc_shdlc_connect_complete(struct llc_shdlc
*shdlc
, int r
)
345 pr_debug("result=%d\n", r
);
347 del_timer_sync(&shdlc
->connect_timer
);
354 shdlc
->state
= SHDLC_HALF_CONNECTED
;
356 shdlc
->state
= SHDLC_DISCONNECTED
;
359 shdlc
->connect_result
= r
;
361 wake_up(shdlc
->connect_wq
);
364 static int llc_shdlc_connect_initiate(struct llc_shdlc
*shdlc
)
370 skb
= llc_shdlc_alloc_skb(shdlc
, 2);
374 skb_put_u8(skb
, SHDLC_MAX_WINDOW
);
375 skb_put_u8(skb
, SHDLC_SREJ_SUPPORT
? 1 : 0);
377 return llc_shdlc_send_u_frame(shdlc
, skb
, U_FRAME_RSET
);
380 static int llc_shdlc_connect_send_ua(struct llc_shdlc
*shdlc
)
386 skb
= llc_shdlc_alloc_skb(shdlc
, 0);
390 return llc_shdlc_send_u_frame(shdlc
, skb
, U_FRAME_UA
);
393 static void llc_shdlc_rcv_u_frame(struct llc_shdlc
*shdlc
,
395 enum uframe_modifier u_frame_modifier
)
397 u8 w
= SHDLC_MAX_WINDOW
;
398 bool srej_support
= SHDLC_SREJ_SUPPORT
;
401 pr_debug("u_frame_modifier=%d\n", u_frame_modifier
);
403 switch (u_frame_modifier
) {
405 switch (shdlc
->state
) {
406 case SHDLC_NEGOTIATING
:
407 case SHDLC_CONNECTING
:
409 * We sent RSET, but chip wants to negociate or we
410 * got RSET before we managed to send out our.
416 srej_support
= skb
->data
[1] & 0x01 ? true :
419 if ((w
<= SHDLC_MAX_WINDOW
) &&
420 (SHDLC_SREJ_SUPPORT
|| (srej_support
== false))) {
422 shdlc
->srej_support
= srej_support
;
423 r
= llc_shdlc_connect_send_ua(shdlc
);
424 llc_shdlc_connect_complete(shdlc
, r
);
427 case SHDLC_HALF_CONNECTED
:
429 * Chip resent RSET due to its timeout - Ignote it
430 * as we already sent UA.
433 case SHDLC_CONNECTED
:
435 * Chip wants to reset link. This is unexpected and
438 shdlc
->hard_fault
= -ECONNRESET
;
445 if ((shdlc
->state
== SHDLC_CONNECTING
&&
446 shdlc
->connect_tries
> 0) ||
447 (shdlc
->state
== SHDLC_NEGOTIATING
)) {
448 llc_shdlc_connect_complete(shdlc
, 0);
449 shdlc
->state
= SHDLC_CONNECTED
;
459 static void llc_shdlc_handle_rcv_queue(struct llc_shdlc
*shdlc
)
465 enum sframe_type s_frame_type
;
466 enum uframe_modifier u_frame_modifier
;
468 if (shdlc
->rcv_q
.qlen
)
469 pr_debug("rcvQlen=%d\n", shdlc
->rcv_q
.qlen
);
471 while ((skb
= skb_dequeue(&shdlc
->rcv_q
)) != NULL
) {
472 control
= skb
->data
[0];
474 switch (control
& SHDLC_CONTROL_HEAD_MASK
) {
475 case SHDLC_CONTROL_HEAD_I
:
476 case SHDLC_CONTROL_HEAD_I2
:
477 if (shdlc
->state
== SHDLC_HALF_CONNECTED
)
478 shdlc
->state
= SHDLC_CONNECTED
;
480 ns
= (control
& SHDLC_CONTROL_NS_MASK
) >> 3;
481 nr
= control
& SHDLC_CONTROL_NR_MASK
;
482 llc_shdlc_rcv_i_frame(shdlc
, skb
, ns
, nr
);
484 case SHDLC_CONTROL_HEAD_S
:
485 if (shdlc
->state
== SHDLC_HALF_CONNECTED
)
486 shdlc
->state
= SHDLC_CONNECTED
;
488 s_frame_type
= (control
& SHDLC_CONTROL_TYPE_MASK
) >> 3;
489 nr
= control
& SHDLC_CONTROL_NR_MASK
;
490 llc_shdlc_rcv_s_frame(shdlc
, s_frame_type
, nr
);
493 case SHDLC_CONTROL_HEAD_U
:
494 u_frame_modifier
= control
& SHDLC_CONTROL_M_MASK
;
495 llc_shdlc_rcv_u_frame(shdlc
, skb
, u_frame_modifier
);
498 pr_err("UNKNOWN Control=%d\n", control
);
505 static int llc_shdlc_w_used(int ns
, int dnr
)
510 unack_count
= ns
- dnr
;
512 unack_count
= 8 - dnr
+ ns
;
517 /* Send frames according to algorithm at spec:10.8.1 */
518 static void llc_shdlc_handle_send_queue(struct llc_shdlc
*shdlc
)
522 unsigned long time_sent
;
524 if (shdlc
->send_q
.qlen
)
526 ("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n",
527 shdlc
->send_q
.qlen
, shdlc
->ns
, shdlc
->dnr
,
528 shdlc
->rnr
== false ? "false" : "true",
529 shdlc
->w
- llc_shdlc_w_used(shdlc
->ns
, shdlc
->dnr
),
530 shdlc
->ack_pending_q
.qlen
);
532 while (shdlc
->send_q
.qlen
&& shdlc
->ack_pending_q
.qlen
< shdlc
->w
&&
533 (shdlc
->rnr
== false)) {
535 if (shdlc
->t1_active
) {
536 del_timer_sync(&shdlc
->t1_timer
);
537 shdlc
->t1_active
= false;
538 pr_debug("Stopped T1(send ack)\n");
541 skb
= skb_dequeue(&shdlc
->send_q
);
543 *(u8
*)skb_push(skb
, 1) = SHDLC_CONTROL_HEAD_I
| (shdlc
->ns
<< 3) |
546 pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc
->ns
,
548 SHDLC_DUMP_SKB("shdlc frame written", skb
);
550 r
= shdlc
->xmit_to_drv(shdlc
->hdev
, skb
);
552 shdlc
->hard_fault
= r
;
556 shdlc
->ns
= (shdlc
->ns
+ 1) % 8;
559 *(unsigned long *)skb
->cb
= time_sent
;
561 skb_queue_tail(&shdlc
->ack_pending_q
, skb
);
563 if (shdlc
->t2_active
== false) {
564 shdlc
->t2_active
= true;
565 mod_timer(&shdlc
->t2_timer
, time_sent
+
566 msecs_to_jiffies(SHDLC_T2_VALUE_MS
));
567 pr_debug("Started T2 (retransmit)\n");
572 static void llc_shdlc_connect_timeout(struct timer_list
*t
)
574 struct llc_shdlc
*shdlc
= from_timer(shdlc
, t
, connect_timer
);
578 schedule_work(&shdlc
->sm_work
);
581 static void llc_shdlc_t1_timeout(struct timer_list
*t
)
583 struct llc_shdlc
*shdlc
= from_timer(shdlc
, t
, t1_timer
);
585 pr_debug("SoftIRQ: need to send ack\n");
587 schedule_work(&shdlc
->sm_work
);
590 static void llc_shdlc_t2_timeout(struct timer_list
*t
)
592 struct llc_shdlc
*shdlc
= from_timer(shdlc
, t
, t2_timer
);
594 pr_debug("SoftIRQ: need to retransmit\n");
596 schedule_work(&shdlc
->sm_work
);
599 static void llc_shdlc_sm_work(struct work_struct
*work
)
601 struct llc_shdlc
*shdlc
= container_of(work
, struct llc_shdlc
, sm_work
);
606 mutex_lock(&shdlc
->state_mutex
);
608 switch (shdlc
->state
) {
609 case SHDLC_DISCONNECTED
:
610 skb_queue_purge(&shdlc
->rcv_q
);
611 skb_queue_purge(&shdlc
->send_q
);
612 skb_queue_purge(&shdlc
->ack_pending_q
);
614 case SHDLC_CONNECTING
:
615 if (shdlc
->hard_fault
) {
616 llc_shdlc_connect_complete(shdlc
, shdlc
->hard_fault
);
620 if (shdlc
->connect_tries
++ < 5)
621 r
= llc_shdlc_connect_initiate(shdlc
);
625 llc_shdlc_connect_complete(shdlc
, r
);
627 mod_timer(&shdlc
->connect_timer
, jiffies
+
628 msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS
));
630 shdlc
->state
= SHDLC_NEGOTIATING
;
633 case SHDLC_NEGOTIATING
:
634 if (timer_pending(&shdlc
->connect_timer
) == 0) {
635 shdlc
->state
= SHDLC_CONNECTING
;
636 schedule_work(&shdlc
->sm_work
);
639 llc_shdlc_handle_rcv_queue(shdlc
);
641 if (shdlc
->hard_fault
) {
642 llc_shdlc_connect_complete(shdlc
, shdlc
->hard_fault
);
646 case SHDLC_HALF_CONNECTED
:
647 case SHDLC_CONNECTED
:
648 llc_shdlc_handle_rcv_queue(shdlc
);
649 llc_shdlc_handle_send_queue(shdlc
);
651 if (shdlc
->t1_active
&& timer_pending(&shdlc
->t1_timer
) == 0) {
653 ("Handle T1(send ack) elapsed (T1 now inactive)\n");
655 shdlc
->t1_active
= false;
656 r
= llc_shdlc_send_s_frame(shdlc
, S_FRAME_RR
,
659 shdlc
->hard_fault
= r
;
662 if (shdlc
->t2_active
&& timer_pending(&shdlc
->t2_timer
) == 0) {
664 ("Handle T2(retransmit) elapsed (T2 inactive)\n");
666 shdlc
->t2_active
= false;
668 llc_shdlc_requeue_ack_pending(shdlc
);
669 llc_shdlc_handle_send_queue(shdlc
);
672 if (shdlc
->hard_fault
)
673 shdlc
->llc_failure(shdlc
->hdev
, shdlc
->hard_fault
);
678 mutex_unlock(&shdlc
->state_mutex
);
682 * Called from syscall context to establish shdlc link. Sleeps until
683 * link is ready or failure.
685 static int llc_shdlc_connect(struct llc_shdlc
*shdlc
)
687 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq
);
691 mutex_lock(&shdlc
->state_mutex
);
693 shdlc
->state
= SHDLC_CONNECTING
;
694 shdlc
->connect_wq
= &connect_wq
;
695 shdlc
->connect_tries
= 0;
696 shdlc
->connect_result
= 1;
698 mutex_unlock(&shdlc
->state_mutex
);
700 schedule_work(&shdlc
->sm_work
);
702 wait_event(connect_wq
, shdlc
->connect_result
!= 1);
704 return shdlc
->connect_result
;
707 static void llc_shdlc_disconnect(struct llc_shdlc
*shdlc
)
711 mutex_lock(&shdlc
->state_mutex
);
713 shdlc
->state
= SHDLC_DISCONNECTED
;
715 mutex_unlock(&shdlc
->state_mutex
);
717 schedule_work(&shdlc
->sm_work
);
721 * Receive an incoming shdlc frame. Frame has already been crc-validated.
722 * skb contains only LLC header and payload.
723 * If skb == NULL, it is a notification that the link below is dead.
725 static void llc_shdlc_recv_frame(struct llc_shdlc
*shdlc
, struct sk_buff
*skb
)
728 pr_err("NULL Frame -> link is dead\n");
729 shdlc
->hard_fault
= -EREMOTEIO
;
731 SHDLC_DUMP_SKB("incoming frame", skb
);
732 skb_queue_tail(&shdlc
->rcv_q
, skb
);
735 schedule_work(&shdlc
->sm_work
);
738 static void *llc_shdlc_init(struct nfc_hci_dev
*hdev
, xmit_to_drv_t xmit_to_drv
,
739 rcv_to_hci_t rcv_to_hci
, int tx_headroom
,
740 int tx_tailroom
, int *rx_headroom
, int *rx_tailroom
,
741 llc_failure_t llc_failure
)
743 struct llc_shdlc
*shdlc
;
745 *rx_headroom
= SHDLC_LLC_HEAD_ROOM
;
748 shdlc
= kzalloc(sizeof(struct llc_shdlc
), GFP_KERNEL
);
752 mutex_init(&shdlc
->state_mutex
);
753 shdlc
->state
= SHDLC_DISCONNECTED
;
755 timer_setup(&shdlc
->connect_timer
, llc_shdlc_connect_timeout
, 0);
756 timer_setup(&shdlc
->t1_timer
, llc_shdlc_t1_timeout
, 0);
757 timer_setup(&shdlc
->t2_timer
, llc_shdlc_t2_timeout
, 0);
759 shdlc
->w
= SHDLC_MAX_WINDOW
;
760 shdlc
->srej_support
= SHDLC_SREJ_SUPPORT
;
762 skb_queue_head_init(&shdlc
->rcv_q
);
763 skb_queue_head_init(&shdlc
->send_q
);
764 skb_queue_head_init(&shdlc
->ack_pending_q
);
766 INIT_WORK(&shdlc
->sm_work
, llc_shdlc_sm_work
);
769 shdlc
->xmit_to_drv
= xmit_to_drv
;
770 shdlc
->rcv_to_hci
= rcv_to_hci
;
771 shdlc
->tx_headroom
= tx_headroom
;
772 shdlc
->tx_tailroom
= tx_tailroom
;
773 shdlc
->llc_failure
= llc_failure
;
778 static void llc_shdlc_deinit(struct nfc_llc
*llc
)
780 struct llc_shdlc
*shdlc
= nfc_llc_get_data(llc
);
782 skb_queue_purge(&shdlc
->rcv_q
);
783 skb_queue_purge(&shdlc
->send_q
);
784 skb_queue_purge(&shdlc
->ack_pending_q
);
789 static int llc_shdlc_start(struct nfc_llc
*llc
)
791 struct llc_shdlc
*shdlc
= nfc_llc_get_data(llc
);
793 return llc_shdlc_connect(shdlc
);
796 static int llc_shdlc_stop(struct nfc_llc
*llc
)
798 struct llc_shdlc
*shdlc
= nfc_llc_get_data(llc
);
800 llc_shdlc_disconnect(shdlc
);
805 static void llc_shdlc_rcv_from_drv(struct nfc_llc
*llc
, struct sk_buff
*skb
)
807 struct llc_shdlc
*shdlc
= nfc_llc_get_data(llc
);
809 llc_shdlc_recv_frame(shdlc
, skb
);
812 static int llc_shdlc_xmit_from_hci(struct nfc_llc
*llc
, struct sk_buff
*skb
)
814 struct llc_shdlc
*shdlc
= nfc_llc_get_data(llc
);
816 skb_queue_tail(&shdlc
->send_q
, skb
);
818 schedule_work(&shdlc
->sm_work
);
823 static struct nfc_llc_ops llc_shdlc_ops
= {
824 .init
= llc_shdlc_init
,
825 .deinit
= llc_shdlc_deinit
,
826 .start
= llc_shdlc_start
,
827 .stop
= llc_shdlc_stop
,
828 .rcv_from_drv
= llc_shdlc_rcv_from_drv
,
829 .xmit_from_hci
= llc_shdlc_xmit_from_hci
,
832 int nfc_llc_shdlc_register(void)
834 return nfc_llc_register(LLC_SHDLC_NAME
, &llc_shdlc_ops
);