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6a2968aa IE |
1 | /* |
2 | * The NFC Controller Interface is the communication protocol between an | |
3 | * NFC Controller (NFCC) and a Device Host (DH). | |
4 | * | |
5 | * Copyright (C) 2011 Texas Instruments, Inc. | |
6 | * | |
7 | * Written by Ilan Elias <ilane@ti.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 | |
11 | * as published by the Free Software Foundation | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
98b32dec | 19 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
6a2968aa IE |
20 | * |
21 | */ | |
22 | ||
52858b51 | 23 | #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__ |
ed1e0ad8 | 24 | |
6a2968aa IE |
25 | #include <linux/types.h> |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/wait.h> | |
28 | #include <linux/bitops.h> | |
29 | #include <linux/skbuff.h> | |
30 | ||
31 | #include "../nfc.h" | |
32 | #include <net/nfc/nci.h> | |
33 | #include <net/nfc/nci_core.h> | |
34 | #include <linux/nfc.h> | |
35 | ||
36 | /* Complete data exchange transaction and forward skb to nfc core */ | |
eb9bc6e9 | 37 | void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb, |
6a2968aa IE |
38 | int err) |
39 | { | |
40 | data_exchange_cb_t cb = ndev->data_exchange_cb; | |
41 | void *cb_context = ndev->data_exchange_cb_context; | |
42 | ||
24bf3304 | 43 | pr_debug("len %d, err %d\n", skb ? skb->len : 0, err); |
6a2968aa | 44 | |
c4bf98b2 IE |
45 | /* data exchange is complete, stop the data timer */ |
46 | del_timer_sync(&ndev->data_timer); | |
47 | clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags); | |
48 | ||
6a2968aa IE |
49 | if (cb) { |
50 | ndev->data_exchange_cb = NULL; | |
040487f3 | 51 | ndev->data_exchange_cb_context = NULL; |
6a2968aa IE |
52 | |
53 | /* forward skb to nfc core */ | |
54 | cb(cb_context, skb, err); | |
55 | } else if (skb) { | |
ed1e0ad8 | 56 | pr_err("no rx callback, dropping rx data...\n"); |
6a2968aa IE |
57 | |
58 | /* no waiting callback, free skb */ | |
59 | kfree_skb(skb); | |
60 | } | |
38f04c6b IE |
61 | |
62 | clear_bit(NCI_DATA_EXCHANGE, &ndev->flags); | |
6a2968aa IE |
63 | } |
64 | ||
65 | /* ----------------- NCI TX Data ----------------- */ | |
66 | ||
67 | static inline void nci_push_data_hdr(struct nci_dev *ndev, | |
eb9bc6e9 SO |
68 | __u8 conn_id, |
69 | struct sk_buff *skb, | |
70 | __u8 pbf) | |
6a2968aa IE |
71 | { |
72 | struct nci_data_hdr *hdr; | |
73 | int plen = skb->len; | |
74 | ||
75 | hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE); | |
76 | hdr->conn_id = conn_id; | |
77 | hdr->rfu = 0; | |
78 | hdr->plen = plen; | |
79 | ||
80 | nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT); | |
81 | nci_pbf_set((__u8 *)hdr, pbf); | |
6a2968aa IE |
82 | } |
83 | ||
84 | static int nci_queue_tx_data_frags(struct nci_dev *ndev, | |
eb9bc6e9 SO |
85 | __u8 conn_id, |
86 | struct sk_buff *skb) { | |
6a2968aa IE |
87 | int total_len = skb->len; |
88 | unsigned char *data = skb->data; | |
89 | unsigned long flags; | |
90 | struct sk_buff_head frags_q; | |
91 | struct sk_buff *skb_frag; | |
92 | int frag_len; | |
93 | int rc = 0; | |
94 | ||
24bf3304 | 95 | pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len); |
6a2968aa IE |
96 | |
97 | __skb_queue_head_init(&frags_q); | |
98 | ||
99 | while (total_len) { | |
e8c0dacd IE |
100 | frag_len = |
101 | min_t(int, total_len, ndev->max_data_pkt_payload_size); | |
6a2968aa IE |
102 | |
103 | skb_frag = nci_skb_alloc(ndev, | |
eb9bc6e9 SO |
104 | (NCI_DATA_HDR_SIZE + frag_len), |
105 | GFP_KERNEL); | |
6a2968aa IE |
106 | if (skb_frag == NULL) { |
107 | rc = -ENOMEM; | |
108 | goto free_exit; | |
109 | } | |
110 | skb_reserve(skb_frag, NCI_DATA_HDR_SIZE); | |
111 | ||
112 | /* first, copy the data */ | |
113 | memcpy(skb_put(skb_frag, frag_len), data, frag_len); | |
114 | ||
115 | /* second, set the header */ | |
116 | nci_push_data_hdr(ndev, conn_id, skb_frag, | |
eb9bc6e9 SO |
117 | ((total_len == frag_len) ? |
118 | (NCI_PBF_LAST) : (NCI_PBF_CONT))); | |
6a2968aa IE |
119 | |
120 | __skb_queue_tail(&frags_q, skb_frag); | |
121 | ||
122 | data += frag_len; | |
123 | total_len -= frag_len; | |
124 | ||
20c239c1 JP |
125 | pr_debug("frag_len %d, remaining total_len %d\n", |
126 | frag_len, total_len); | |
6a2968aa IE |
127 | } |
128 | ||
129 | /* queue all fragments atomically */ | |
130 | spin_lock_irqsave(&ndev->tx_q.lock, flags); | |
131 | ||
132 | while ((skb_frag = __skb_dequeue(&frags_q)) != NULL) | |
133 | __skb_queue_tail(&ndev->tx_q, skb_frag); | |
134 | ||
135 | spin_unlock_irqrestore(&ndev->tx_q.lock, flags); | |
136 | ||
137 | /* free the original skb */ | |
138 | kfree_skb(skb); | |
139 | ||
140 | goto exit; | |
141 | ||
142 | free_exit: | |
143 | while ((skb_frag = __skb_dequeue(&frags_q)) != NULL) | |
144 | kfree_skb(skb_frag); | |
145 | ||
146 | exit: | |
147 | return rc; | |
148 | } | |
149 | ||
150 | /* Send NCI data */ | |
151 | int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb) | |
152 | { | |
153 | int rc = 0; | |
154 | ||
24bf3304 | 155 | pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len); |
6a2968aa IE |
156 | |
157 | /* check if the packet need to be fragmented */ | |
e8c0dacd | 158 | if (skb->len <= ndev->max_data_pkt_payload_size) { |
6a2968aa IE |
159 | /* no need to fragment packet */ |
160 | nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST); | |
161 | ||
162 | skb_queue_tail(&ndev->tx_q, skb); | |
163 | } else { | |
164 | /* fragment packet and queue the fragments */ | |
165 | rc = nci_queue_tx_data_frags(ndev, conn_id, skb); | |
166 | if (rc) { | |
ed1e0ad8 | 167 | pr_err("failed to fragment tx data packet\n"); |
6a2968aa IE |
168 | goto free_exit; |
169 | } | |
170 | } | |
171 | ||
172 | queue_work(ndev->tx_wq, &ndev->tx_work); | |
173 | ||
174 | goto exit; | |
175 | ||
176 | free_exit: | |
177 | kfree_skb(skb); | |
178 | ||
179 | exit: | |
180 | return rc; | |
181 | } | |
182 | ||
183 | /* ----------------- NCI RX Data ----------------- */ | |
184 | ||
185 | static void nci_add_rx_data_frag(struct nci_dev *ndev, | |
eb9bc6e9 SO |
186 | struct sk_buff *skb, |
187 | __u8 pbf) | |
6a2968aa IE |
188 | { |
189 | int reassembly_len; | |
190 | int err = 0; | |
191 | ||
192 | if (ndev->rx_data_reassembly) { | |
193 | reassembly_len = ndev->rx_data_reassembly->len; | |
194 | ||
195 | /* first, make enough room for the already accumulated data */ | |
196 | if (skb_cow_head(skb, reassembly_len)) { | |
ed1e0ad8 | 197 | pr_err("error adding room for accumulated rx data\n"); |
6a2968aa IE |
198 | |
199 | kfree_skb(skb); | |
040487f3 | 200 | skb = NULL; |
6a2968aa IE |
201 | |
202 | kfree_skb(ndev->rx_data_reassembly); | |
040487f3 | 203 | ndev->rx_data_reassembly = NULL; |
6a2968aa IE |
204 | |
205 | err = -ENOMEM; | |
206 | goto exit; | |
207 | } | |
208 | ||
209 | /* second, combine the two fragments */ | |
210 | memcpy(skb_push(skb, reassembly_len), | |
eb9bc6e9 SO |
211 | ndev->rx_data_reassembly->data, |
212 | reassembly_len); | |
6a2968aa IE |
213 | |
214 | /* third, free old reassembly */ | |
215 | kfree_skb(ndev->rx_data_reassembly); | |
040487f3 | 216 | ndev->rx_data_reassembly = NULL; |
6a2968aa IE |
217 | } |
218 | ||
219 | if (pbf == NCI_PBF_CONT) { | |
220 | /* need to wait for next fragment, store skb and exit */ | |
221 | ndev->rx_data_reassembly = skb; | |
222 | return; | |
223 | } | |
224 | ||
225 | exit: | |
226 | nci_data_exchange_complete(ndev, skb, err); | |
227 | } | |
228 | ||
229 | /* Rx Data packet */ | |
230 | void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb) | |
231 | { | |
232 | __u8 pbf = nci_pbf(skb->data); | |
233 | ||
24bf3304 | 234 | pr_debug("len %d\n", skb->len); |
6a2968aa | 235 | |
20c239c1 JP |
236 | pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n", |
237 | nci_pbf(skb->data), | |
238 | nci_conn_id(skb->data), | |
239 | nci_plen(skb->data)); | |
6a2968aa IE |
240 | |
241 | /* strip the nci data header */ | |
242 | skb_pull(skb, NCI_DATA_HDR_SIZE); | |
243 | ||
83724c33 VC |
244 | if (ndev->target_active_prot == NFC_PROTO_MIFARE || |
245 | ndev->target_active_prot == NFC_PROTO_JEWEL || | |
246 | ndev->target_active_prot == NFC_PROTO_FELICA || | |
247 | ndev->target_active_prot == NFC_PROTO_ISO15693) { | |
6a2968aa | 248 | /* frame I/F => remove the status byte */ |
83724c33 | 249 | pr_debug("frame I/F => remove the status byte\n"); |
6a2968aa IE |
250 | skb_trim(skb, (skb->len - 1)); |
251 | } | |
252 | ||
253 | nci_add_rx_data_frag(ndev, skb, pbf); | |
254 | } |