xref: /openbmc/linux/net/nfc/nci/ntf.c (revision 004161cb)
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  *  Acknowledgements:
10  *  This file is based on hci_event.c, which was written
11  *  by Maxim Krasnyansky.
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License version 2
15  *  as published by the Free Software Foundation
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; if not, write to the Free Software
24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  */
27 
28 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
29 
30 #include <linux/types.h>
31 #include <linux/interrupt.h>
32 #include <linux/bitops.h>
33 #include <linux/skbuff.h>
34 
35 #include "../nfc.h"
36 #include <net/nfc/nci.h>
37 #include <net/nfc/nci_core.h>
38 #include <linux/nfc.h>
39 
40 /* Handle NCI Notification packets */
41 
42 static void nci_core_conn_credits_ntf_packet(struct nci_dev *ndev,
43 						struct sk_buff *skb)
44 {
45 	struct nci_core_conn_credit_ntf *ntf = (void *) skb->data;
46 	int i;
47 
48 	pr_debug("num_entries %d\n", ntf->num_entries);
49 
50 	if (ntf->num_entries > NCI_MAX_NUM_CONN)
51 		ntf->num_entries = NCI_MAX_NUM_CONN;
52 
53 	/* update the credits */
54 	for (i = 0; i < ntf->num_entries; i++) {
55 		ntf->conn_entries[i].conn_id =
56 			nci_conn_id(&ntf->conn_entries[i].conn_id);
57 
58 		pr_debug("entry[%d]: conn_id %d, credits %d\n",
59 			 i, ntf->conn_entries[i].conn_id,
60 			 ntf->conn_entries[i].credits);
61 
62 		if (ntf->conn_entries[i].conn_id == NCI_STATIC_RF_CONN_ID) {
63 			/* found static rf connection */
64 			atomic_add(ntf->conn_entries[i].credits,
65 				&ndev->credits_cnt);
66 		}
67 	}
68 
69 	/* trigger the next tx */
70 	if (!skb_queue_empty(&ndev->tx_q))
71 		queue_work(ndev->tx_wq, &ndev->tx_work);
72 }
73 
74 static void nci_core_conn_intf_error_ntf_packet(struct nci_dev *ndev,
75 						struct sk_buff *skb)
76 {
77 	struct nci_core_intf_error_ntf *ntf = (void *) skb->data;
78 
79 	ntf->conn_id = nci_conn_id(&ntf->conn_id);
80 
81 	pr_debug("status 0x%x, conn_id %d\n", ntf->status, ntf->conn_id);
82 
83 	/* complete the data exchange transaction, if exists */
84 	if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
85 		nci_data_exchange_complete(ndev, NULL, -EIO);
86 }
87 
88 static __u8 *nci_extract_rf_params_nfca_passive_poll(struct nci_dev *ndev,
89 			struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
90 {
91 	struct rf_tech_specific_params_nfca_poll *nfca_poll;
92 
93 	nfca_poll = &ntf->rf_tech_specific_params.nfca_poll;
94 
95 	nfca_poll->sens_res = __le16_to_cpu(*((__u16 *)data));
96 	data += 2;
97 
98 	nfca_poll->nfcid1_len = *data++;
99 
100 	pr_debug("sens_res 0x%x, nfcid1_len %d\n",
101 		 nfca_poll->sens_res, nfca_poll->nfcid1_len);
102 
103 	memcpy(nfca_poll->nfcid1, data, nfca_poll->nfcid1_len);
104 	data += nfca_poll->nfcid1_len;
105 
106 	nfca_poll->sel_res_len = *data++;
107 
108 	if (nfca_poll->sel_res_len != 0)
109 		nfca_poll->sel_res = *data++;
110 
111 	pr_debug("sel_res_len %d, sel_res 0x%x\n",
112 		 nfca_poll->sel_res_len,
113 		 nfca_poll->sel_res);
114 
115 	return data;
116 }
117 
118 static int nci_extract_activation_params_iso_dep(struct nci_dev *ndev,
119 			struct nci_rf_intf_activated_ntf *ntf, __u8 *data)
120 {
121 	struct activation_params_nfca_poll_iso_dep *nfca_poll;
122 
123 	switch (ntf->activation_rf_tech_and_mode) {
124 	case NCI_NFC_A_PASSIVE_POLL_MODE:
125 		nfca_poll = &ntf->activation_params.nfca_poll_iso_dep;
126 		nfca_poll->rats_res_len = *data++;
127 		if (nfca_poll->rats_res_len > 0) {
128 			memcpy(nfca_poll->rats_res,
129 				data,
130 				nfca_poll->rats_res_len);
131 		}
132 		break;
133 
134 	default:
135 		pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
136 		       ntf->activation_rf_tech_and_mode);
137 		return -EPROTO;
138 	}
139 
140 	return 0;
141 }
142 
143 static void nci_target_found(struct nci_dev *ndev,
144 				struct nci_rf_intf_activated_ntf *ntf)
145 {
146 	struct nfc_target nfc_tgt;
147 
148 	if (ntf->rf_protocol == NCI_RF_PROTOCOL_T2T)	/* T2T MifareUL */
149 		nfc_tgt.supported_protocols = NFC_PROTO_MIFARE_MASK;
150 	else if (ntf->rf_protocol == NCI_RF_PROTOCOL_ISO_DEP)	/* 4A */
151 		nfc_tgt.supported_protocols = NFC_PROTO_ISO14443_MASK;
152 	else
153 		nfc_tgt.supported_protocols = 0;
154 
155 	nfc_tgt.sens_res = ntf->rf_tech_specific_params.nfca_poll.sens_res;
156 	nfc_tgt.sel_res = ntf->rf_tech_specific_params.nfca_poll.sel_res;
157 
158 	if (!(nfc_tgt.supported_protocols & ndev->poll_prots)) {
159 		pr_debug("the target found does not have the desired protocol\n");
160 		return;
161 	}
162 
163 	pr_debug("new target found,  supported_protocols 0x%x\n",
164 		 nfc_tgt.supported_protocols);
165 
166 	ndev->target_available_prots = nfc_tgt.supported_protocols;
167 	ndev->max_data_pkt_payload_size = ntf->max_data_pkt_payload_size;
168 	ndev->initial_num_credits = ntf->initial_num_credits;
169 
170 	/* set the available credits to initial value */
171 	atomic_set(&ndev->credits_cnt, ndev->initial_num_credits);
172 
173 	nfc_targets_found(ndev->nfc_dev, &nfc_tgt, 1);
174 }
175 
176 static void nci_rf_intf_activated_ntf_packet(struct nci_dev *ndev,
177 						struct sk_buff *skb)
178 {
179 	struct nci_rf_intf_activated_ntf ntf;
180 	__u8 *data = skb->data;
181 	int err = 0;
182 
183 	clear_bit(NCI_DISCOVERY, &ndev->flags);
184 	set_bit(NCI_POLL_ACTIVE, &ndev->flags);
185 
186 	ntf.rf_discovery_id = *data++;
187 	ntf.rf_interface = *data++;
188 	ntf.rf_protocol = *data++;
189 	ntf.activation_rf_tech_and_mode = *data++;
190 	ntf.max_data_pkt_payload_size = *data++;
191 	ntf.initial_num_credits = *data++;
192 	ntf.rf_tech_specific_params_len = *data++;
193 
194 	pr_debug("rf_discovery_id %d\n", ntf.rf_discovery_id);
195 	pr_debug("rf_interface 0x%x\n", ntf.rf_interface);
196 	pr_debug("rf_protocol 0x%x\n", ntf.rf_protocol);
197 	pr_debug("activation_rf_tech_and_mode 0x%x\n",
198 		 ntf.activation_rf_tech_and_mode);
199 	pr_debug("max_data_pkt_payload_size 0x%x\n",
200 		 ntf.max_data_pkt_payload_size);
201 	pr_debug("initial_num_credits 0x%x\n", ntf.initial_num_credits);
202 	pr_debug("rf_tech_specific_params_len %d\n",
203 		 ntf.rf_tech_specific_params_len);
204 
205 	if (ntf.rf_tech_specific_params_len > 0) {
206 		switch (ntf.activation_rf_tech_and_mode) {
207 		case NCI_NFC_A_PASSIVE_POLL_MODE:
208 			data = nci_extract_rf_params_nfca_passive_poll(ndev,
209 				&ntf, data);
210 			break;
211 
212 		default:
213 			pr_err("unsupported activation_rf_tech_and_mode 0x%x\n",
214 			       ntf.activation_rf_tech_and_mode);
215 			return;
216 		}
217 	}
218 
219 	ntf.data_exch_rf_tech_and_mode = *data++;
220 	ntf.data_exch_tx_bit_rate = *data++;
221 	ntf.data_exch_rx_bit_rate = *data++;
222 	ntf.activation_params_len = *data++;
223 
224 	pr_debug("data_exch_rf_tech_and_mode 0x%x\n",
225 		 ntf.data_exch_rf_tech_and_mode);
226 	pr_debug("data_exch_tx_bit_rate 0x%x\n",
227 		 ntf.data_exch_tx_bit_rate);
228 	pr_debug("data_exch_rx_bit_rate 0x%x\n",
229 		 ntf.data_exch_rx_bit_rate);
230 	pr_debug("activation_params_len %d\n",
231 		 ntf.activation_params_len);
232 
233 	if (ntf.activation_params_len > 0) {
234 		switch (ntf.rf_interface) {
235 		case NCI_RF_INTERFACE_ISO_DEP:
236 			err = nci_extract_activation_params_iso_dep(ndev,
237 				&ntf, data);
238 			break;
239 
240 		case NCI_RF_INTERFACE_FRAME:
241 			/* no activation params */
242 			break;
243 
244 		default:
245 			pr_err("unsupported rf_interface 0x%x\n",
246 			       ntf.rf_interface);
247 			return;
248 		}
249 	}
250 
251 	if (!err)
252 		nci_target_found(ndev, &ntf);
253 }
254 
255 static void nci_rf_deactivate_ntf_packet(struct nci_dev *ndev,
256 					struct sk_buff *skb)
257 {
258 	struct nci_rf_deactivate_ntf *ntf = (void *) skb->data;
259 
260 	pr_debug("entry, type 0x%x, reason 0x%x\n", ntf->type, ntf->reason);
261 
262 	clear_bit(NCI_POLL_ACTIVE, &ndev->flags);
263 	ndev->target_active_prot = 0;
264 
265 	/* drop tx data queue */
266 	skb_queue_purge(&ndev->tx_q);
267 
268 	/* drop partial rx data packet */
269 	if (ndev->rx_data_reassembly) {
270 		kfree_skb(ndev->rx_data_reassembly);
271 		ndev->rx_data_reassembly = 0;
272 	}
273 
274 	/* complete the data exchange transaction, if exists */
275 	if (test_bit(NCI_DATA_EXCHANGE, &ndev->flags))
276 		nci_data_exchange_complete(ndev, NULL, -EIO);
277 }
278 
279 void nci_ntf_packet(struct nci_dev *ndev, struct sk_buff *skb)
280 {
281 	__u16 ntf_opcode = nci_opcode(skb->data);
282 
283 	pr_debug("NCI RX: MT=ntf, PBF=%d, GID=0x%x, OID=0x%x, plen=%d\n",
284 		 nci_pbf(skb->data),
285 		 nci_opcode_gid(ntf_opcode),
286 		 nci_opcode_oid(ntf_opcode),
287 		 nci_plen(skb->data));
288 
289 	/* strip the nci control header */
290 	skb_pull(skb, NCI_CTRL_HDR_SIZE);
291 
292 	switch (ntf_opcode) {
293 	case NCI_OP_CORE_CONN_CREDITS_NTF:
294 		nci_core_conn_credits_ntf_packet(ndev, skb);
295 		break;
296 
297 	case NCI_OP_CORE_INTF_ERROR_NTF:
298 		nci_core_conn_intf_error_ntf_packet(ndev, skb);
299 		break;
300 
301 	case NCI_OP_RF_INTF_ACTIVATED_NTF:
302 		nci_rf_intf_activated_ntf_packet(ndev, skb);
303 		break;
304 
305 	case NCI_OP_RF_DEACTIVATE_NTF:
306 		nci_rf_deactivate_ntf_packet(ndev, skb);
307 		break;
308 
309 	default:
310 		pr_err("unknown ntf opcode 0x%x\n", ntf_opcode);
311 		break;
312 	}
313 
314 	kfree_skb(skb);
315 }
316