// SPDX-License-Identifier: GPL-2.0-only
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/*
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* shdlc Link Layer Control
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*
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* Copyright (C) 2012 Intel Corporation. All rights reserved.
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*/
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#define pr_fmt(fmt) "shdlc: %s: " fmt, __func__
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/slab.h>
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#include <linux/skbuff.h>
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#include "llc.h"
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enum shdlc_state {
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SHDLC_DISCONNECTED = 0,
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SHDLC_CONNECTING = 1,
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SHDLC_NEGOTIATING = 2,
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SHDLC_HALF_CONNECTED = 3,
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SHDLC_CONNECTED = 4
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};
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struct llc_shdlc {
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struct nfc_hci_dev *hdev;
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xmit_to_drv_t xmit_to_drv;
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rcv_to_hci_t rcv_to_hci;
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struct mutex state_mutex;
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enum shdlc_state state;
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int hard_fault;
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wait_queue_head_t *connect_wq;
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int connect_tries;
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int connect_result;
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struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */
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u8 w; /* window size */
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bool srej_support;
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struct timer_list t1_timer; /* send ack timeout */
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bool t1_active;
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struct timer_list t2_timer; /* guard/retransmit timeout */
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bool t2_active;
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int ns; /* next seq num for send */
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int nr; /* next expected seq num for receive */
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int dnr; /* oldest sent unacked seq num */
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struct sk_buff_head rcv_q;
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struct sk_buff_head send_q;
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bool rnr; /* other side is not ready to receive */
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struct sk_buff_head ack_pending_q;
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struct work_struct sm_work;
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int tx_headroom;
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int tx_tailroom;
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llc_failure_t llc_failure;
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};
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#define SHDLC_LLC_HEAD_ROOM 2
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#define SHDLC_MAX_WINDOW 4
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#define SHDLC_SREJ_SUPPORT false
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#define SHDLC_CONTROL_HEAD_MASK 0xe0
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#define SHDLC_CONTROL_HEAD_I 0x80
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#define SHDLC_CONTROL_HEAD_I2 0xa0
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#define SHDLC_CONTROL_HEAD_S 0xc0
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#define SHDLC_CONTROL_HEAD_U 0xe0
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#define SHDLC_CONTROL_NS_MASK 0x38
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#define SHDLC_CONTROL_NR_MASK 0x07
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#define SHDLC_CONTROL_TYPE_MASK 0x18
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#define SHDLC_CONTROL_M_MASK 0x1f
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enum sframe_type {
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S_FRAME_RR = 0x00,
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S_FRAME_REJ = 0x01,
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S_FRAME_RNR = 0x02,
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S_FRAME_SREJ = 0x03
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};
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enum uframe_modifier {
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U_FRAME_UA = 0x06,
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U_FRAME_RSET = 0x19
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};
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#define SHDLC_CONNECT_VALUE_MS 5
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#define SHDLC_T1_VALUE_MS(w) ((5 * w) / 4)
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#define SHDLC_T2_VALUE_MS 300
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#define SHDLC_DUMP_SKB(info, skb) \
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do { \
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pr_debug("%s:\n", info); \
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print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \
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16, 1, skb->data, skb->len, 0); \
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} while (0)
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/* checks x < y <= z modulo 8 */
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static bool llc_shdlc_x_lt_y_lteq_z(int x, int y, int z)
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{
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if (x < z)
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return ((x < y) && (y <= z)) ? true : false;
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else
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return ((y > x) || (y <= z)) ? true : false;
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}
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/* checks x <= y < z modulo 8 */
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static bool llc_shdlc_x_lteq_y_lt_z(int x, int y, int z)
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{
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if (x <= z)
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return ((x <= y) && (y < z)) ? true : false;
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else /* x > z -> z+8 > x */
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return ((y >= x) || (y < z)) ? true : false;
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}
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static struct sk_buff *llc_shdlc_alloc_skb(struct llc_shdlc *shdlc,
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int payload_len)
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{
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struct sk_buff *skb;
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skb = alloc_skb(shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM +
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shdlc->tx_tailroom + payload_len, GFP_KERNEL);
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if (skb)
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skb_reserve(skb, shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM);
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return skb;
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}
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/* immediately sends an S frame. */
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static int llc_shdlc_send_s_frame(struct llc_shdlc *shdlc,
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enum sframe_type sframe_type, int nr)
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{
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int r;
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struct sk_buff *skb;
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pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr);
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skb = llc_shdlc_alloc_skb(shdlc, 0);
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if (skb == NULL)
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return -ENOMEM;
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*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr;
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r = shdlc->xmit_to_drv(shdlc->hdev, skb);
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kfree_skb(skb);
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return r;
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}
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/* immediately sends an U frame. skb may contain optional payload */
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static int llc_shdlc_send_u_frame(struct llc_shdlc *shdlc,
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struct sk_buff *skb,
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enum uframe_modifier uframe_modifier)
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{
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int r;
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pr_debug("uframe_modifier=%d\n", uframe_modifier);
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*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier;
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r = shdlc->xmit_to_drv(shdlc->hdev, skb);
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kfree_skb(skb);
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return r;
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}
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/*
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* Free ack_pending frames until y_nr - 1, and reset t2 according to
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* the remaining oldest ack_pending frame sent time
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*/
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static void llc_shdlc_reset_t2(struct llc_shdlc *shdlc, int y_nr)
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{
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struct sk_buff *skb;
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int dnr = shdlc->dnr; /* MUST initially be < y_nr */
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pr_debug("release ack pending up to frame %d excluded\n", y_nr);
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while (dnr != y_nr) {
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pr_debug("release ack pending frame %d\n", dnr);
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skb = skb_dequeue(&shdlc->ack_pending_q);
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kfree_skb(skb);
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dnr = (dnr + 1) % 8;
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}
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if (skb_queue_empty(&shdlc->ack_pending_q)) {
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if (shdlc->t2_active) {
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del_timer_sync(&shdlc->t2_timer);
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shdlc->t2_active = false;
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pr_debug
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("All sent frames acked. Stopped T2(retransmit)\n");
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}
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} else {
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skb = skb_peek(&shdlc->ack_pending_q);
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mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb +
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msecs_to_jiffies(SHDLC_T2_VALUE_MS));
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shdlc->t2_active = true;
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pr_debug
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("Start T2(retransmit) for remaining unacked sent frames\n");
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}
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}
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/*
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* Receive validated frames from lower layer. skb contains HCI payload only.
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* Handle according to algorithm at spec:10.8.2
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*/
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static void llc_shdlc_rcv_i_frame(struct llc_shdlc *shdlc,
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struct sk_buff *skb, int ns, int nr)
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{
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int x_ns = ns;
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int y_nr = nr;
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pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr);
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if (shdlc->state != SHDLC_CONNECTED)
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goto exit;
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if (x_ns != shdlc->nr) {
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llc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr);
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goto exit;
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}
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if (shdlc->t1_active == false) {
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shdlc->t1_active = true;
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mod_timer(&shdlc->t1_timer, jiffies +
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msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w)));
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pr_debug("(re)Start T1(send ack)\n");
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}
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if (skb->len) {
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shdlc->rcv_to_hci(shdlc->hdev, skb);
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skb = NULL;
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}
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shdlc->nr = (shdlc->nr + 1) % 8;
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if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) {
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llc_shdlc_reset_t2(shdlc, y_nr);
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shdlc->dnr = y_nr;
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}
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exit:
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kfree_skb(skb);
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}
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static void llc_shdlc_rcv_ack(struct llc_shdlc *shdlc, int y_nr)
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{
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pr_debug("remote acked up to frame %d excluded\n", y_nr);
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if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) {
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llc_shdlc_reset_t2(shdlc, y_nr);
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shdlc->dnr = y_nr;
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}
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}
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static void llc_shdlc_requeue_ack_pending(struct llc_shdlc *shdlc)
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{
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struct sk_buff *skb;
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pr_debug("ns reset to %d\n", shdlc->dnr);
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while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) {
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skb_pull(skb, 1); /* remove control field */
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skb_queue_head(&shdlc->send_q, skb);
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}
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shdlc->ns = shdlc->dnr;
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}
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static void llc_shdlc_rcv_rej(struct llc_shdlc *shdlc, int y_nr)
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{
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struct sk_buff *skb;
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pr_debug("remote asks retransmission from frame %d\n", y_nr);
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if (llc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) {
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if (shdlc->t2_active) {
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del_timer_sync(&shdlc->t2_timer);
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shdlc->t2_active = false;
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pr_debug("Stopped T2(retransmit)\n");
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}
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if (shdlc->dnr != y_nr) {
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while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) {
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skb = skb_dequeue(&shdlc->ack_pending_q);
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kfree_skb(skb);
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}
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}
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llc_shdlc_requeue_ack_pending(shdlc);
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}
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}
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/* See spec RR:10.8.3 REJ:10.8.4 */
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static void llc_shdlc_rcv_s_frame(struct llc_shdlc *shdlc,
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enum sframe_type s_frame_type, int nr)
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{
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struct sk_buff *skb;
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if (shdlc->state != SHDLC_CONNECTED)
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return;
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switch (s_frame_type) {
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case S_FRAME_RR:
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llc_shdlc_rcv_ack(shdlc, nr);
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if (shdlc->rnr == true) { /* see SHDLC 10.7.7 */
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shdlc->rnr = false;
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if (shdlc->send_q.qlen == 0) {
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skb = llc_shdlc_alloc_skb(shdlc, 0);
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if (skb)
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skb_queue_tail(&shdlc->send_q, skb);
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}
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}
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break;
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case S_FRAME_REJ:
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llc_shdlc_rcv_rej(shdlc, nr);
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break;
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case S_FRAME_RNR:
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llc_shdlc_rcv_ack(shdlc, nr);
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shdlc->rnr = true;
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break;
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default:
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break;
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}
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}
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static void llc_shdlc_connect_complete(struct llc_shdlc *shdlc, int r)
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{
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pr_debug("result=%d\n", r);
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del_timer_sync(&shdlc->connect_timer);
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if (r == 0) {
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shdlc->ns = 0;
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shdlc->nr = 0;
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shdlc->dnr = 0;
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shdlc->state = SHDLC_HALF_CONNECTED;
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} else {
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shdlc->state = SHDLC_DISCONNECTED;
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}
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shdlc->connect_result = r;
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wake_up(shdlc->connect_wq);
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}
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static int llc_shdlc_connect_initiate(struct llc_shdlc *shdlc)
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{
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struct sk_buff *skb;
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pr_debug("\n");
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skb = llc_shdlc_alloc_skb(shdlc, 2);
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if (skb == NULL)
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return -ENOMEM;
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skb_put_u8(skb, SHDLC_MAX_WINDOW);
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skb_put_u8(skb, SHDLC_SREJ_SUPPORT ? 1 : 0);
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return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET);
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}
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static int llc_shdlc_connect_send_ua(struct llc_shdlc *shdlc)
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{
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struct sk_buff *skb;
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pr_debug("\n");
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skb = llc_shdlc_alloc_skb(shdlc, 0);
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if (skb == NULL)
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return -ENOMEM;
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return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA);
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}
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static void llc_shdlc_rcv_u_frame(struct llc_shdlc *shdlc,
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struct sk_buff *skb,
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enum uframe_modifier u_frame_modifier)
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{
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u8 w = SHDLC_MAX_WINDOW;
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bool srej_support = SHDLC_SREJ_SUPPORT;
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int r;
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pr_debug("u_frame_modifier=%d\n", u_frame_modifier);
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switch (u_frame_modifier) {
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case U_FRAME_RSET:
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switch (shdlc->state) {
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case SHDLC_NEGOTIATING:
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case SHDLC_CONNECTING:
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/*
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* We sent RSET, but chip wants to negociate or we
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* got RSET before we managed to send out our.
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*/
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if (skb->len > 0)
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w = skb->data[0];
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if (skb->len > 1)
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srej_support = skb->data[1] & 0x01 ? true :
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false;
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if ((w <= SHDLC_MAX_WINDOW) &&
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(SHDLC_SREJ_SUPPORT || (srej_support == false))) {
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shdlc->w = w;
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shdlc->srej_support = srej_support;
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r = llc_shdlc_connect_send_ua(shdlc);
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llc_shdlc_connect_complete(shdlc, r);
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}
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break;
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case SHDLC_HALF_CONNECTED:
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/*
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* Chip resent RSET due to its timeout - Ignote it
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* as we already sent UA.
|
*/
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break;
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case SHDLC_CONNECTED:
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/*
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* Chip wants to reset link. This is unexpected and
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* unsupported.
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*/
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shdlc->hard_fault = -ECONNRESET;
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break;
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default:
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break;
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}
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break;
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case U_FRAME_UA:
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if ((shdlc->state == SHDLC_CONNECTING &&
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shdlc->connect_tries > 0) ||
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(shdlc->state == SHDLC_NEGOTIATING)) {
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llc_shdlc_connect_complete(shdlc, 0);
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shdlc->state = SHDLC_CONNECTED;
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}
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break;
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default:
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break;
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}
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kfree_skb(skb);
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}
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static void llc_shdlc_handle_rcv_queue(struct llc_shdlc *shdlc)
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{
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struct sk_buff *skb;
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u8 control;
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int nr;
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int ns;
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enum sframe_type s_frame_type;
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enum uframe_modifier u_frame_modifier;
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if (shdlc->rcv_q.qlen)
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pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen);
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while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) {
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control = skb->data[0];
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skb_pull(skb, 1);
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switch (control & SHDLC_CONTROL_HEAD_MASK) {
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case SHDLC_CONTROL_HEAD_I:
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case SHDLC_CONTROL_HEAD_I2:
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if (shdlc->state == SHDLC_HALF_CONNECTED)
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shdlc->state = SHDLC_CONNECTED;
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ns = (control & SHDLC_CONTROL_NS_MASK) >> 3;
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nr = control & SHDLC_CONTROL_NR_MASK;
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llc_shdlc_rcv_i_frame(shdlc, skb, ns, nr);
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break;
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case SHDLC_CONTROL_HEAD_S:
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if (shdlc->state == SHDLC_HALF_CONNECTED)
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shdlc->state = SHDLC_CONNECTED;
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s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3;
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nr = control & SHDLC_CONTROL_NR_MASK;
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llc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr);
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kfree_skb(skb);
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break;
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case SHDLC_CONTROL_HEAD_U:
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u_frame_modifier = control & SHDLC_CONTROL_M_MASK;
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llc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier);
|
break;
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default:
|
pr_err("UNKNOWN Control=%d\n", control);
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kfree_skb(skb);
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break;
|
}
|
}
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}
|
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static int llc_shdlc_w_used(int ns, int dnr)
|
{
|
int unack_count;
|
|
if (dnr <= ns)
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unack_count = ns - dnr;
|
else
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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);
|
|
*(u8 *)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(struct timer_list *t)
|
{
|
struct llc_shdlc *shdlc = from_timer(shdlc, t, connect_timer);
|
|
pr_debug("\n");
|
|
schedule_work(&shdlc->sm_work);
|
}
|
|
static void llc_shdlc_t1_timeout(struct timer_list *t)
|
{
|
struct llc_shdlc *shdlc = from_timer(shdlc, t, t1_timer);
|
|
pr_debug("SoftIRQ: need to send ack\n");
|
|
schedule_work(&shdlc->sm_work);
|
}
|
|
static void llc_shdlc_t2_timeout(struct timer_list *t)
|
{
|
struct llc_shdlc *shdlc = from_timer(shdlc, t, t2_timer);
|
|
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;
|
|
timer_setup(&shdlc->connect_timer, llc_shdlc_connect_timeout, 0);
|
timer_setup(&shdlc->t1_timer, llc_shdlc_t1_timeout, 0);
|
timer_setup(&shdlc->t2_timer, llc_shdlc_t2_timeout, 0);
|
|
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);
|
}
|
