1 // SPDX-License-Identifier: GPL-2.0-only
3 * The NFC Controller Interface is the communication protocol between an
4 * NFC Controller (NFCC) and a Device Host (DH).
6 * Copyright (C) 2011 Texas Instruments, Inc.
7 * Copyright (C) 2014 Marvell International Ltd.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
14 #include <linux/types.h>
15 #include <linux/interrupt.h>
16 #include <linux/wait.h>
17 #include <linux/bitops.h>
18 #include <linux/skbuff.h>
21 #include <net/nfc/nci.h>
22 #include <net/nfc/nci_core.h>
23 #include <linux/nfc.h>
25 /* Complete data exchange transaction and forward skb to nfc core */
26 void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
27 __u8 conn_id, int err)
29 struct nci_conn_info *conn_info;
30 data_exchange_cb_t cb;
33 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
39 cb = conn_info->data_exchange_cb;
40 cb_context = conn_info->data_exchange_cb_context;
42 pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
44 /* data exchange is complete, stop the data timer */
45 del_timer_sync(&ndev->data_timer);
46 clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
49 /* forward skb to nfc core */
50 cb(cb_context, skb, err);
52 pr_err("no rx callback, dropping rx data...\n");
54 /* no waiting callback, free skb */
59 clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
62 /* ----------------- NCI TX Data ----------------- */
64 static inline void nci_push_data_hdr(struct nci_dev *ndev,
69 struct nci_data_hdr *hdr;
72 hdr = skb_push(skb, NCI_DATA_HDR_SIZE);
73 hdr->conn_id = conn_id;
77 nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
78 nci_pbf_set((__u8 *)hdr, pbf);
81 int nci_conn_max_data_pkt_payload_size(struct nci_dev *ndev, __u8 conn_id)
83 struct nci_conn_info *conn_info;
85 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
89 return conn_info->max_pkt_payload_len;
91 EXPORT_SYMBOL(nci_conn_max_data_pkt_payload_size);
93 static int nci_queue_tx_data_frags(struct nci_dev *ndev,
95 struct sk_buff *skb) {
96 struct nci_conn_info *conn_info;
97 int total_len = skb->len;
98 unsigned char *data = skb->data;
100 struct sk_buff_head frags_q;
101 struct sk_buff *skb_frag;
105 pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
107 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
113 __skb_queue_head_init(&frags_q);
117 min_t(int, total_len, conn_info->max_pkt_payload_len);
119 skb_frag = nci_skb_alloc(ndev,
120 (NCI_DATA_HDR_SIZE + frag_len),
122 if (skb_frag == NULL) {
126 skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
128 /* first, copy the data */
129 skb_put_data(skb_frag, data, frag_len);
131 /* second, set the header */
132 nci_push_data_hdr(ndev, conn_id, skb_frag,
133 ((total_len == frag_len) ?
134 (NCI_PBF_LAST) : (NCI_PBF_CONT)));
136 __skb_queue_tail(&frags_q, skb_frag);
139 total_len -= frag_len;
141 pr_debug("frag_len %d, remaining total_len %d\n",
142 frag_len, total_len);
145 /* queue all fragments atomically */
146 spin_lock_irqsave(&ndev->tx_q.lock, flags);
148 while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
149 __skb_queue_tail(&ndev->tx_q, skb_frag);
151 spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
153 /* free the original skb */
159 while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
167 int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
169 struct nci_conn_info *conn_info;
172 pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
174 conn_info = nci_get_conn_info_by_conn_id(ndev, conn_id);
180 /* check if the packet need to be fragmented */
181 if (skb->len <= conn_info->max_pkt_payload_len) {
182 /* no need to fragment packet */
183 nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
185 skb_queue_tail(&ndev->tx_q, skb);
187 /* fragment packet and queue the fragments */
188 rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
190 pr_err("failed to fragment tx data packet\n");
195 ndev->cur_conn_id = conn_id;
196 queue_work(ndev->tx_wq, &ndev->tx_work);
206 EXPORT_SYMBOL(nci_send_data);
208 /* ----------------- NCI RX Data ----------------- */
210 static void nci_add_rx_data_frag(struct nci_dev *ndev,
212 __u8 pbf, __u8 conn_id, __u8 status)
222 if (ndev->rx_data_reassembly) {
223 reassembly_len = ndev->rx_data_reassembly->len;
225 /* first, make enough room for the already accumulated data */
226 if (skb_cow_head(skb, reassembly_len)) {
227 pr_err("error adding room for accumulated rx data\n");
232 kfree_skb(ndev->rx_data_reassembly);
233 ndev->rx_data_reassembly = NULL;
239 /* second, combine the two fragments */
240 memcpy(skb_push(skb, reassembly_len),
241 ndev->rx_data_reassembly->data,
244 /* third, free old reassembly */
245 kfree_skb(ndev->rx_data_reassembly);
246 ndev->rx_data_reassembly = NULL;
249 if (pbf == NCI_PBF_CONT) {
250 /* need to wait for next fragment, store skb and exit */
251 ndev->rx_data_reassembly = skb;
256 if (ndev->nfc_dev->rf_mode == NFC_RF_TARGET) {
257 /* Data received in Target mode, forward to nfc core */
258 err = nfc_tm_data_received(ndev->nfc_dev, skb);
260 pr_err("unable to handle received data\n");
262 nci_data_exchange_complete(ndev, skb, conn_id, err);
267 void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
269 __u8 pbf = nci_pbf(skb->data);
271 __u8 conn_id = nci_conn_id(skb->data);
272 struct nci_conn_info *conn_info;
274 pr_debug("len %d\n", skb->len);
276 pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
278 nci_conn_id(skb->data),
279 nci_plen(skb->data));
281 conn_info = nci_get_conn_info_by_conn_id(ndev, nci_conn_id(skb->data));
285 /* strip the nci data header */
286 skb_pull(skb, NCI_DATA_HDR_SIZE);
288 if (ndev->target_active_prot == NFC_PROTO_MIFARE ||
289 ndev->target_active_prot == NFC_PROTO_JEWEL ||
290 ndev->target_active_prot == NFC_PROTO_FELICA ||
291 ndev->target_active_prot == NFC_PROTO_ISO15693) {
292 /* frame I/F => remove the status byte */
293 pr_debug("frame I/F => remove the status byte\n");
294 status = skb->data[skb->len - 1];
295 skb_trim(skb, (skb->len - 1));
298 nci_add_rx_data_frag(ndev, skb, pbf, conn_id, nci_to_errno(status));