diff options
Diffstat (limited to 'net/nfc/hci/llc_shdlc.c')
| -rw-r--r-- | net/nfc/hci/llc_shdlc.c | 857 |
1 files changed, 857 insertions, 0 deletions
diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c new file mode 100644 index 000000000000..01cbc72943cd --- /dev/null +++ b/net/nfc/hci/llc_shdlc.c @@ -0,0 +1,857 @@ +/* + * shdlc Link Layer Control + * + * Copyright (C) 2012 Intel Corporation. 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, write to the + * Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#define pr_fmt(fmt) "shdlc: %s: " fmt, __func__ + +#include <linux/types.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/slab.h> +#include <linux/skbuff.h> + +#include "llc.h" + +enum shdlc_state { + SHDLC_DISCONNECTED = 0, + SHDLC_CONNECTING = 1, + SHDLC_NEGOTIATING = 2, + SHDLC_HALF_CONNECTED = 3, + SHDLC_CONNECTED = 4 +}; + +struct llc_shdlc { + struct nfc_hci_dev *hdev; + xmit_to_drv_t xmit_to_drv; + rcv_to_hci_t rcv_to_hci; + + struct mutex state_mutex; + enum shdlc_state state; + int hard_fault; + + wait_queue_head_t *connect_wq; + int connect_tries; + int connect_result; + struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */ + + u8 w; /* window size */ + bool srej_support; + + struct timer_list t1_timer; /* send ack timeout */ + bool t1_active; + + struct timer_list t2_timer; /* guard/retransmit timeout */ + bool t2_active; + + int ns; /* next seq num for send */ + int nr; /* next expected seq num for receive */ + int dnr; /* oldest sent unacked seq num */ + + struct sk_buff_head rcv_q; + + struct sk_buff_head send_q; + bool rnr; /* other side is not ready to receive */ + + struct sk_buff_head ack_pending_q; + + struct work_struct sm_work; + + int tx_headroom; + int tx_tailroom; + + llc_failure_t llc_failure; +}; + +#define SHDLC_LLC_HEAD_ROOM 2 + +#define SHDLC_MAX_WINDOW 4 +#define SHDLC_SREJ_SUPPORT false + +#define SHDLC_CONTROL_HEAD_MASK 0xe0 +#define SHDLC_CONTROL_HEAD_I 0x80 +#define SHDLC_CONTROL_HEAD_I2 0xa0 +#define SHDLC_CONTROL_HEAD_S 0xc0 +#define SHDLC_CONTROL_HEAD_U 0xe0 + +#define SHDLC_CONTROL_NS_MASK 0x38 +#define SHDLC_CONTROL_NR_MASK 0x07 +#define SHDLC_CONTROL_TYPE_MASK 0x18 + +#define SHDLC_CONTROL_M_MASK 0x1f + +enum sframe_type { + S_FRAME_RR = 0x00, + S_FRAME_REJ = 0x01, + S_FRAME_RNR = 0x02, + S_FRAME_SREJ = 0x03 +}; + +enum uframe_modifier { + U_FRAME_UA = 0x06, + U_FRAME_RSET = 0x19 +}; + +#define SHDLC_CONNECT_VALUE_MS 5 +#define SHDLC_T1_VALUE_MS(w) ((5 * w) / 4) +#define SHDLC_T2_VALUE_MS 300 + +#define SHDLC_DUMP_SKB(info, skb) \ +do { \ + pr_debug("%s:\n", info); \ + print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \ + 16, 1, skb->data, skb->len, 0); \ +} while (0) + +/* checks x < y <= z modulo 8 */ +static bool llc_shdlc_x_lt_y_lteq_z(int x, int y, int z) +{ + if (x < z) + return ((x < y) && (y <= z)) ? true : false; + else + return ((y > x) || (y <= z)) ? true : false; +} + +/* checks x <= y < z modulo 8 */ +static bool llc_shdlc_x_lteq_y_lt_z(int x, int y, int z) +{ + if (x <= z) + return ((x <= y) && (y < z)) ? true : false; + else /* x > z -> z+8 > x */ + return ((y >= x) || (y < z)) ? true : false; +} + +static struct sk_buff *llc_shdlc_alloc_skb(struct llc_shdlc *shdlc, + int payload_len) +{ + struct sk_buff *skb; + + skb = alloc_skb(shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM + + shdlc->tx_tailroom + payload_len, GFP_KERNEL); + if (skb) + skb_reserve(skb, shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM); + + return skb; +} + +/* immediately sends an S frame. */ +static int llc_shdlc_send_s_frame(struct llc_shdlc *shdlc, + enum sframe_type sframe_type, int nr) +{ + int r; + struct sk_buff *skb; + + pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr); + + skb = llc_shdlc_alloc_skb(shdlc, 0); + if (skb == NULL) + return -ENOMEM; + + *skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr; + + r = shdlc->xmit_to_drv(shdlc->hdev, skb); + + kfree_skb(skb); + + return r; +} + +/* immediately sends an U frame. skb may contain optional payload */ +static int llc_shdlc_send_u_frame(struct llc_shdlc *shdlc, + struct sk_buff *skb, + enum uframe_modifier uframe_modifier) +{ + int r; + + pr_debug("uframe_modifier=%d\n", uframe_modifier); + + *skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier; + + r = shdlc->xmit_to_drv(shdlc->hdev, skb); + + kfree_skb(skb); + + return r; +} + +/* + * Free ack_pending frames until y_nr - 1, and reset t2 according to + * the remaining oldest ack_pending frame sent time + */ +static void llc_shdlc_reset_t2(struct llc_shdlc *shdlc, int y_nr) +{ + struct sk_buff *skb; + int dnr = shdlc->dnr; /* MUST initially be < y_nr */ + + pr_debug("release ack pending up to frame %d excluded\n", y_nr); + + while (dnr != y_nr) { + pr_debug("release ack pending frame %d\n", dnr); + + skb = skb_dequeue(&shdlc->ack_pending_q); + kfree_skb(skb); + + dnr = (dnr + 1) % 8; + } + + if (skb_queue_empty(&shdlc->ack_pending_q)) { + if (shdlc->t2_active) { + del_timer_sync(&shdlc->t2_timer); + shdlc->t2_active = false; + + pr_debug + ("All sent frames acked. Stopped T2(retransmit)\n"); + } + } else { + skb = skb_peek(&shdlc->ack_pending_q); + + mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb + + msecs_to_jiffies(SHDLC_T2_VALUE_MS)); + shdlc->t2_active = true; + + pr_debug + ("Start T2(retransmit) for remaining unacked sent frames\n"); + } +} + +/* + * Receive validated frames from lower layer. skb contains HCI payload only. + * Handle according to algorithm at spec:10.8.2 + */ +static void llc_shdlc_rcv_i_frame(struct llc_shdlc *shdlc, + struct sk_buff *skb, int ns, int nr) +{ + int x_ns = ns; + int y_nr = nr; + + pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr); + + if (shdlc->state != SHDLC_CONNECTED) + goto exit; + + if (x_ns != shdlc->nr) { + llc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr); + goto exit; + } + + if (shdlc->t1_active == false) { + shdlc->t1_active = true; + mod_timer(&shdlc->t1_timer, jiffies + + msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w))); + pr_debug("(re)Start T1(send ack)\n"); + } + + if (skb->len) { + shdlc->rcv_to_hci(shdlc->hdev, skb); + skb = NULL; + } + + shdlc->nr = (shdlc->nr + 1) % 8; + + if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { + llc_shdlc_reset_t2(shdlc, y_nr); + + shdlc->dnr = y_nr; + } + +exit: + kfree_skb(skb); +} + +static void llc_shdlc_rcv_ack(struct llc_shdlc *shdlc, int y_nr) +{ + pr_debug("remote acked up to frame %d excluded\n", y_nr); + + if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { + llc_shdlc_reset_t2(shdlc, y_nr); + shdlc->dnr = y_nr; + } +} + +static void llc_shdlc_requeue_ack_pending(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + + pr_debug("ns reset to %d\n", shdlc->dnr); + + while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) { + skb_pull(skb, 1); /* remove control field */ + skb_queue_head(&shdlc->send_q, skb); + } + shdlc->ns = shdlc->dnr; +} + +static void llc_shdlc_rcv_rej(struct llc_shdlc *shdlc, int y_nr) +{ + struct sk_buff *skb; + + pr_debug("remote asks retransmition from frame %d\n", y_nr); + + if (llc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) { + if (shdlc->t2_active) { + del_timer_sync(&shdlc->t2_timer); + shdlc->t2_active = false; + pr_debug("Stopped T2(retransmit)\n"); + } + + if (shdlc->dnr != y_nr) { + while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) { + skb = skb_dequeue(&shdlc->ack_pending_q); + kfree_skb(skb); + } + } + + llc_shdlc_requeue_ack_pending(shdlc); + } +} + +/* See spec RR:10.8.3 REJ:10.8.4 */ +static void llc_shdlc_rcv_s_frame(struct llc_shdlc *shdlc, + enum sframe_type s_frame_type, int nr) +{ + struct sk_buff *skb; + + if (shdlc->state != SHDLC_CONNECTED) + return; + + switch (s_frame_type) { + case S_FRAME_RR: + llc_shdlc_rcv_ack(shdlc, nr); + if (shdlc->rnr == true) { /* see SHDLC 10.7.7 */ + shdlc->rnr = false; + if (shdlc->send_q.qlen == 0) { + skb = llc_shdlc_alloc_skb(shdlc, 0); + if (skb) + skb_queue_tail(&shdlc->send_q, skb); + } + } + break; + case S_FRAME_REJ: + llc_shdlc_rcv_rej(shdlc, nr); + break; + case S_FRAME_RNR: + llc_shdlc_rcv_ack(shdlc, nr); + shdlc->rnr = true; + break; + default: + break; + } +} + +static void llc_shdlc_connect_complete(struct llc_shdlc *shdlc, int r) +{ + pr_debug("result=%d\n", r); + + del_timer_sync(&shdlc->connect_timer); + + if (r == 0) { + shdlc->ns = 0; + shdlc->nr = 0; + shdlc->dnr = 0; + + shdlc->state = SHDLC_HALF_CONNECTED; + } else { + shdlc->state = SHDLC_DISCONNECTED; + } + + shdlc->connect_result = r; + + wake_up(shdlc->connect_wq); +} + +static int llc_shdlc_connect_initiate(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + + pr_debug("\n"); + + skb = llc_shdlc_alloc_skb(shdlc, 2); + if (skb == NULL) + return -ENOMEM; + + *skb_put(skb, 1) = SHDLC_MAX_WINDOW; + *skb_put(skb, 1) = SHDLC_SREJ_SUPPORT ? 1 : 0; + + return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET); +} + +static int llc_shdlc_connect_send_ua(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + + pr_debug("\n"); + + skb = llc_shdlc_alloc_skb(shdlc, 0); + if (skb == NULL) + return -ENOMEM; + + return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA); +} + +static void llc_shdlc_rcv_u_frame(struct llc_shdlc *shdlc, + struct sk_buff *skb, + enum uframe_modifier u_frame_modifier) +{ + u8 w = SHDLC_MAX_WINDOW; + bool srej_support = SHDLC_SREJ_SUPPORT; + int r; + + pr_debug("u_frame_modifier=%d\n", u_frame_modifier); + + switch (u_frame_modifier) { + case U_FRAME_RSET: + switch (shdlc->state) { + case SHDLC_NEGOTIATING: + case SHDLC_CONNECTING: + /* + * We sent RSET, but chip wants to negociate or we + * got RSET before we managed to send out our. + */ + if (skb->len > 0) + w = skb->data[0]; + + if (skb->len > 1) + srej_support = skb->data[1] & 0x01 ? true : + false; + + if ((w <= SHDLC_MAX_WINDOW) && + (SHDLC_SREJ_SUPPORT || (srej_support == false))) { + shdlc->w = w; + shdlc->srej_support = srej_support; + r = llc_shdlc_connect_send_ua(shdlc); + llc_shdlc_connect_complete(shdlc, r); + } + break; + case SHDLC_HALF_CONNECTED: + /* + * Chip resent RSET due to its timeout - Ignote it + * as we already sent UA. + */ + break; + case SHDLC_CONNECTED: + /* + * Chip wants to reset link. This is unexpected and + * unsupported. + */ + shdlc->hard_fault = -ECONNRESET; + break; + default: + break; + } + break; + case U_FRAME_UA: + if ((shdlc->state == SHDLC_CONNECTING && + shdlc->connect_tries > 0) || + (shdlc->state == SHDLC_NEGOTIATING)) { + llc_shdlc_connect_complete(shdlc, 0); + shdlc->state = SHDLC_CONNECTED; + } + break; + default: + break; + } + + kfree_skb(skb); +} + +static void llc_shdlc_handle_rcv_queue(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + u8 control; + int nr; + int ns; + enum sframe_type s_frame_type; + enum uframe_modifier u_frame_modifier; + + if (shdlc->rcv_q.qlen) + pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen); + + while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) { + control = skb->data[0]; + skb_pull(skb, 1); + switch (control & SHDLC_CONTROL_HEAD_MASK) { + case SHDLC_CONTROL_HEAD_I: + case SHDLC_CONTROL_HEAD_I2: + if (shdlc->state == SHDLC_HALF_CONNECTED) + shdlc->state = SHDLC_CONNECTED; + + ns = (control & SHDLC_CONTROL_NS_MASK) >> 3; + nr = control & SHDLC_CONTROL_NR_MASK; + llc_shdlc_rcv_i_frame(shdlc, skb, ns, nr); + break; + case SHDLC_CONTROL_HEAD_S: + if (shdlc->state == SHDLC_HALF_CONNECTED) + shdlc->state = SHDLC_CONNECTED; + + s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3; + nr = control & SHDLC_CONTROL_NR_MASK; + llc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr); + kfree_skb(skb); + break; + case SHDLC_CONTROL_HEAD_U: + u_frame_modifier = control & SHDLC_CONTROL_M_MASK; + llc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier); + break; + default: + pr_err("UNKNOWN Control=%d\n", control); + kfree_skb(skb); + break; + } + } +} + +static int llc_shdlc_w_used(int ns, int dnr) +{ + int unack_count; + + if (dnr <= ns) + unack_count = ns - dnr; + else + unack_count = 8 - dnr + ns; + + return unack_count; +} + +/* Send frames according to algorithm at spec:10.8.1 */ +static void llc_shdlc_handle_send_queue(struct llc_shdlc *shdlc) +{ + struct sk_buff *skb; + int r; + unsigned long time_sent; + + if (shdlc->send_q.qlen) + pr_debug + ("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n", + shdlc->send_q.qlen, shdlc->ns, shdlc->dnr, + shdlc->rnr == false ? "false" : "true", + shdlc->w - llc_shdlc_w_used(shdlc->ns, shdlc->dnr), + shdlc->ack_pending_q.qlen); + + while (shdlc->send_q.qlen && shdlc->ack_pending_q.qlen < shdlc->w && + (shdlc->rnr == false)) { + + if (shdlc->t1_active) { + del_timer_sync(&shdlc->t1_timer); + shdlc->t1_active = false; + pr_debug("Stopped T1(send ack)\n"); + } + + skb = skb_dequeue(&shdlc->send_q); + + *skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) | + shdlc->nr; + + pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns, + shdlc->nr); + SHDLC_DUMP_SKB("shdlc frame written", skb); + + r = shdlc->xmit_to_drv(shdlc->hdev, skb); + if (r < 0) { + shdlc->hard_fault = r; + break; + } + + shdlc->ns = (shdlc->ns + 1) % 8; + + time_sent = jiffies; + *(unsigned long *)skb->cb = time_sent; + + skb_queue_tail(&shdlc->ack_pending_q, skb); + + if (shdlc->t2_active == false) { + shdlc->t2_active = true; + mod_timer(&shdlc->t2_timer, time_sent + + msecs_to_jiffies(SHDLC_T2_VALUE_MS)); + pr_debug("Started T2 (retransmit)\n"); + } + } +} + +static void llc_shdlc_connect_timeout(unsigned long data) +{ + struct llc_shdlc *shdlc = (struct llc_shdlc *)data; + + pr_debug("\n"); + + schedule_work(&shdlc->sm_work); +} + +static void llc_shdlc_t1_timeout(unsigned long data) +{ + struct llc_shdlc *shdlc = (struct llc_shdlc *)data; + + pr_debug("SoftIRQ: need to send ack\n"); + + schedule_work(&shdlc->sm_work); +} + +static void llc_shdlc_t2_timeout(unsigned long data) +{ + struct llc_shdlc *shdlc = (struct llc_shdlc *)data; + + pr_debug("SoftIRQ: need to retransmit\n"); + + schedule_work(&shdlc->sm_work); +} + +static void llc_shdlc_sm_work(struct work_struct *work) +{ + struct llc_shdlc *shdlc = container_of(work, struct llc_shdlc, sm_work); + int r; + + pr_debug("\n"); + + mutex_lock(&shdlc->state_mutex); + + switch (shdlc->state) { + case SHDLC_DISCONNECTED: + skb_queue_purge(&shdlc->rcv_q); + skb_queue_purge(&shdlc->send_q); + skb_queue_purge(&shdlc->ack_pending_q); + break; + case SHDLC_CONNECTING: + if (shdlc->hard_fault) { + llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); + break; + } + + if (shdlc->connect_tries++ < 5) + r = llc_shdlc_connect_initiate(shdlc); + else + r = -ETIME; + if (r < 0) + llc_shdlc_connect_complete(shdlc, r); + else { + mod_timer(&shdlc->connect_timer, jiffies + + msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS)); + + shdlc->state = SHDLC_NEGOTIATING; + } + break; + case SHDLC_NEGOTIATING: + if (timer_pending(&shdlc->connect_timer) == 0) { + shdlc->state = SHDLC_CONNECTING; + schedule_work(&shdlc->sm_work); + } + + llc_shdlc_handle_rcv_queue(shdlc); + + if (shdlc->hard_fault) { + llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); + break; + } + break; + case SHDLC_HALF_CONNECTED: + case SHDLC_CONNECTED: + llc_shdlc_handle_rcv_queue(shdlc); + llc_shdlc_handle_send_queue(shdlc); + + if (shdlc->t1_active && timer_pending(&shdlc->t1_timer) == 0) { + pr_debug + ("Handle T1(send ack) elapsed (T1 now inactive)\n"); + + shdlc->t1_active = false; + r = llc_shdlc_send_s_frame(shdlc, S_FRAME_RR, + shdlc->nr); + if (r < 0) + shdlc->hard_fault = r; + } + + if (shdlc->t2_active && timer_pending(&shdlc->t2_timer) == 0) { + pr_debug + ("Handle T2(retransmit) elapsed (T2 inactive)\n"); + + shdlc->t2_active = false; + + llc_shdlc_requeue_ack_pending(shdlc); + llc_shdlc_handle_send_queue(shdlc); + } + + if (shdlc->hard_fault) { + shdlc->llc_failure(shdlc->hdev, shdlc->hard_fault); + } + break; + default: + break; + } + mutex_unlock(&shdlc->state_mutex); +} + +/* + * Called from syscall context to establish shdlc link. Sleeps until + * link is ready or failure. + */ +static int llc_shdlc_connect(struct llc_shdlc *shdlc) +{ + DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq); + + pr_debug("\n"); + + mutex_lock(&shdlc->state_mutex); + + shdlc->state = SHDLC_CONNECTING; + shdlc->connect_wq = &connect_wq; + shdlc->connect_tries = 0; + shdlc->connect_result = 1; + + mutex_unlock(&shdlc->state_mutex); + + schedule_work(&shdlc->sm_work); + + wait_event(connect_wq, shdlc->connect_result != 1); + + return shdlc->connect_result; +} + +static void llc_shdlc_disconnect(struct llc_shdlc *shdlc) +{ + pr_debug("\n"); + + mutex_lock(&shdlc->state_mutex); + + shdlc->state = SHDLC_DISCONNECTED; + + mutex_unlock(&shdlc->state_mutex); + + schedule_work(&shdlc->sm_work); +} + +/* + * Receive an incoming shdlc frame. Frame has already been crc-validated. + * skb contains only LLC header and payload. + * If skb == NULL, it is a notification that the link below is dead. + */ +static void llc_shdlc_recv_frame(struct llc_shdlc *shdlc, struct sk_buff *skb) +{ + if (skb == NULL) { + pr_err("NULL Frame -> link is dead\n"); + shdlc->hard_fault = -EREMOTEIO; + } else { + SHDLC_DUMP_SKB("incoming frame", skb); + skb_queue_tail(&shdlc->rcv_q, skb); + } + + schedule_work(&shdlc->sm_work); +} + +static void *llc_shdlc_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv, + rcv_to_hci_t rcv_to_hci, int tx_headroom, + int tx_tailroom, int *rx_headroom, int *rx_tailroom, + llc_failure_t llc_failure) +{ + struct llc_shdlc *shdlc; + + *rx_headroom = SHDLC_LLC_HEAD_ROOM; + *rx_tailroom = 0; + + shdlc = kzalloc(sizeof(struct llc_shdlc), GFP_KERNEL); + if (shdlc == NULL) + return NULL; + + mutex_init(&shdlc->state_mutex); + shdlc->state = SHDLC_DISCONNECTED; + + init_timer(&shdlc->connect_timer); + shdlc->connect_timer.data = (unsigned long)shdlc; + shdlc->connect_timer.function = llc_shdlc_connect_timeout; + + init_timer(&shdlc->t1_timer); + shdlc->t1_timer.data = (unsigned long)shdlc; + shdlc->t1_timer.function = llc_shdlc_t1_timeout; + + init_timer(&shdlc->t2_timer); + shdlc->t2_timer.data = (unsigned long)shdlc; + shdlc->t2_timer.function = llc_shdlc_t2_timeout; + + shdlc->w = SHDLC_MAX_WINDOW; + shdlc->srej_support = SHDLC_SREJ_SUPPORT; + + skb_queue_head_init(&shdlc->rcv_q); + skb_queue_head_init(&shdlc->send_q); + skb_queue_head_init(&shdlc->ack_pending_q); + + INIT_WORK(&shdlc->sm_work, llc_shdlc_sm_work); + + shdlc->hdev = hdev; + shdlc->xmit_to_drv = xmit_to_drv; + shdlc->rcv_to_hci = rcv_to_hci; + shdlc->tx_headroom = tx_headroom; + shdlc->tx_tailroom = tx_tailroom; + shdlc->llc_failure = llc_failure; + + return shdlc; +} + +static void llc_shdlc_deinit(struct nfc_llc *llc) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + skb_queue_purge(&shdlc->rcv_q); + skb_queue_purge(&shdlc->send_q); + skb_queue_purge(&shdlc->ack_pending_q); + + kfree(shdlc); +} + +static int llc_shdlc_start(struct nfc_llc *llc) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + return llc_shdlc_connect(shdlc); +} + +static int llc_shdlc_stop(struct nfc_llc *llc) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + llc_shdlc_disconnect(shdlc); + + return 0; +} + +static void llc_shdlc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + llc_shdlc_recv_frame(shdlc, skb); +} + +static int llc_shdlc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) +{ + struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + + skb_queue_tail(&shdlc->send_q, skb); + + schedule_work(&shdlc->sm_work); + + return 0; +} + +static struct nfc_llc_ops llc_shdlc_ops = { + .init = llc_shdlc_init, + .deinit = llc_shdlc_deinit, + .start = llc_shdlc_start, + .stop = llc_shdlc_stop, + .rcv_from_drv = llc_shdlc_rcv_from_drv, + .xmit_from_hci = llc_shdlc_xmit_from_hci, +}; + +int nfc_llc_shdlc_register(void) +{ + return nfc_llc_register(LLC_SHDLC_NAME, &llc_shdlc_ops); +} |