xref: /linux/net/nfc/hci/command.c (revision add4b1b02da7e7ec35c34dd04d351ac53f3f0dd8)
1 /*
2  * Copyright (C) 2012  Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
19 
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/module.h>
24 
25 #include <net/nfc/hci.h>
26 
27 #include "hci.h"
28 
29 #define MAX_FWI 4949
30 
31 static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
32 			       const u8 *param, size_t param_len,
33 			       data_exchange_cb_t cb, void *cb_context)
34 {
35 	pr_debug("exec cmd async through pipe=%d, cmd=%d, plen=%zd\n", pipe,
36 		 cmd, param_len);
37 
38 	/* TODO: Define hci cmd execution delay. Should it be the same
39 	 * for all commands?
40 	 */
41 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,
42 				      param, param_len, cb, cb_context, MAX_FWI);
43 }
44 
45 /*
46  * HCI command execution completion callback.
47  * err will be a standard linux error (may be converted from HCI response)
48  * skb contains the response data and must be disposed, or may be NULL if
49  * an error occured
50  */
51 static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)
52 {
53 	struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)context;
54 
55 	pr_debug("HCI Cmd completed with result=%d\n", err);
56 
57 	hcp_ew->exec_result = err;
58 	if (hcp_ew->exec_result == 0)
59 		hcp_ew->result_skb = skb;
60 	else
61 		kfree_skb(skb);
62 	hcp_ew->exec_complete = true;
63 
64 	wake_up(hcp_ew->wq);
65 }
66 
67 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
68 			       const u8 *param, size_t param_len,
69 			       struct sk_buff **skb)
70 {
71 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
72 	struct hcp_exec_waiter hcp_ew;
73 	hcp_ew.wq = &ew_wq;
74 	hcp_ew.exec_complete = false;
75 	hcp_ew.result_skb = NULL;
76 
77 	pr_debug("exec cmd sync through pipe=%d, cmd=%d, plen=%zd\n", pipe,
78 		 cmd, param_len);
79 
80 	/* TODO: Define hci cmd execution delay. Should it be the same
81 	 * for all commands?
82 	 */
83 	hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
84 						    NFC_HCI_HCP_COMMAND, cmd,
85 						    param, param_len,
86 						    nfc_hci_execute_cb, &hcp_ew,
87 						    MAX_FWI);
88 	if (hcp_ew.exec_result < 0)
89 		return hcp_ew.exec_result;
90 
91 	wait_event(ew_wq, hcp_ew.exec_complete == true);
92 
93 	if (hcp_ew.exec_result == 0) {
94 		if (skb)
95 			*skb = hcp_ew.result_skb;
96 		else
97 			kfree_skb(hcp_ew.result_skb);
98 	}
99 
100 	return hcp_ew.exec_result;
101 }
102 
103 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
104 		       const u8 *param, size_t param_len)
105 {
106 	u8 pipe;
107 
108 	pr_debug("%d to gate %d\n", event, gate);
109 
110 	pipe = hdev->gate2pipe[gate];
111 	if (pipe == NFC_HCI_INVALID_PIPE)
112 		return -EADDRNOTAVAIL;
113 
114 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
115 				      param, param_len, NULL, NULL, 0);
116 }
117 EXPORT_SYMBOL(nfc_hci_send_event);
118 
119 int nfc_hci_send_response(struct nfc_hci_dev *hdev, u8 gate, u8 response,
120 			  const u8 *param, size_t param_len)
121 {
122 	u8 pipe;
123 
124 	pr_debug("\n");
125 
126 	pipe = hdev->gate2pipe[gate];
127 	if (pipe == NFC_HCI_INVALID_PIPE)
128 		return -EADDRNOTAVAIL;
129 
130 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
131 				      response, param, param_len, NULL, NULL,
132 				      0);
133 }
134 EXPORT_SYMBOL(nfc_hci_send_response);
135 
136 /*
137  * Execute an hci command sent to gate.
138  * skb will contain response data if success. skb can be NULL if you are not
139  * interested by the response.
140  */
141 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
142 		     const u8 *param, size_t param_len, struct sk_buff **skb)
143 {
144 	u8 pipe;
145 
146 	pr_debug("\n");
147 
148 	pipe = hdev->gate2pipe[gate];
149 	if (pipe == NFC_HCI_INVALID_PIPE)
150 		return -EADDRNOTAVAIL;
151 
152 	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
153 }
154 EXPORT_SYMBOL(nfc_hci_send_cmd);
155 
156 int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
157 			   const u8 *param, size_t param_len,
158 			   data_exchange_cb_t cb, void *cb_context)
159 {
160 	u8 pipe;
161 
162 	pr_debug("\n");
163 
164 	pipe = hdev->gate2pipe[gate];
165 	if (pipe == NFC_HCI_INVALID_PIPE)
166 		return -EADDRNOTAVAIL;
167 
168 	return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
169 					 cb, cb_context);
170 }
171 EXPORT_SYMBOL(nfc_hci_send_cmd_async);
172 
173 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
174 		      const u8 *param, size_t param_len)
175 {
176 	int r;
177 	u8 *tmp;
178 
179 	/* TODO ELa: reg idx must be inserted before param, but we don't want
180 	 * to ask the caller to do it to keep a simpler API.
181 	 * For now, just create a new temporary param buffer. This is far from
182 	 * optimal though, and the plan is to modify APIs to pass idx down to
183 	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
184 	 * eliminating the need for the temp allocation-copy here.
185 	 */
186 
187 	pr_debug("idx=%d to gate %d\n", idx, gate);
188 
189 	tmp = kmalloc(1 + param_len, GFP_KERNEL);
190 	if (tmp == NULL)
191 		return -ENOMEM;
192 
193 	*tmp = idx;
194 	memcpy(tmp + 1, param, param_len);
195 
196 	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
197 			     tmp, param_len + 1, NULL);
198 
199 	kfree(tmp);
200 
201 	return r;
202 }
203 EXPORT_SYMBOL(nfc_hci_set_param);
204 
205 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
206 		      struct sk_buff **skb)
207 {
208 	pr_debug("gate=%d regidx=%d\n", gate, idx);
209 
210 	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
211 				&idx, 1, skb);
212 }
213 EXPORT_SYMBOL(nfc_hci_get_param);
214 
215 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
216 {
217 	struct sk_buff *skb;
218 	int r;
219 
220 	pr_debug("pipe=%d\n", pipe);
221 
222 	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
223 				NULL, 0, &skb);
224 	if (r == 0) {
225 		/* dest host other than host controller will send
226 		 * number of pipes already open on this gate before
227 		 * execution. The number can be found in skb->data[0]
228 		 */
229 		kfree_skb(skb);
230 	}
231 
232 	return r;
233 }
234 
235 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
236 {
237 	pr_debug("\n");
238 
239 	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
240 				   NULL, 0, NULL);
241 }
242 
243 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
244 			      u8 dest_gate, int *result)
245 {
246 	struct sk_buff *skb;
247 	struct hci_create_pipe_params params;
248 	struct hci_create_pipe_resp *resp;
249 	u8 pipe;
250 
251 	pr_debug("gate=%d\n", dest_gate);
252 
253 	params.src_gate = NFC_HCI_ADMIN_GATE;
254 	params.dest_host = dest_host;
255 	params.dest_gate = dest_gate;
256 
257 	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
258 				      NFC_HCI_ADM_CREATE_PIPE,
259 				      (u8 *) &params, sizeof(params), &skb);
260 	if (*result < 0)
261 		return NFC_HCI_INVALID_PIPE;
262 
263 	resp = (struct hci_create_pipe_resp *)skb->data;
264 	pipe = resp->pipe;
265 	kfree_skb(skb);
266 
267 	pr_debug("pipe created=%d\n", pipe);
268 
269 	return pipe;
270 }
271 
272 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
273 {
274 	pr_debug("\n");
275 
276 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
277 				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
278 }
279 
280 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
281 {
282 	u8 param[2];
283 	size_t param_len = 2;
284 
285 	/* TODO: Find out what the identity reference data is
286 	 * and fill param with it. HCI spec 6.1.3.5 */
287 
288 	pr_debug("\n");
289 
290 	if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
291 		param_len = 0;
292 
293 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
294 				   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
295 				   NULL);
296 }
297 
298 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
299 {
300 	int r;
301 	u8 pipe = hdev->gate2pipe[gate];
302 
303 	pr_debug("\n");
304 
305 	if (pipe == NFC_HCI_INVALID_PIPE)
306 		return -EADDRNOTAVAIL;
307 
308 	r = nfc_hci_close_pipe(hdev, pipe);
309 	if (r < 0)
310 		return r;
311 
312 	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
313 		r = nfc_hci_delete_pipe(hdev, pipe);
314 		if (r < 0)
315 			return r;
316 	}
317 
318 	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
319 
320 	return 0;
321 }
322 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
323 
324 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
325 {
326 	int r;
327 
328 	pr_debug("\n");
329 
330 	r = nfc_hci_clear_all_pipes(hdev);
331 	if (r < 0)
332 		return r;
333 
334 	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
335 
336 	return 0;
337 }
338 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
339 
340 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
341 			 u8 pipe)
342 {
343 	bool pipe_created = false;
344 	int r;
345 
346 	pr_debug("\n");
347 
348 	if (hdev->gate2pipe[dest_gate] == NFC_HCI_DO_NOT_CREATE_PIPE)
349 		return 0;
350 
351 	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
352 		return -EADDRINUSE;
353 
354 	if (pipe != NFC_HCI_INVALID_PIPE)
355 		goto open_pipe;
356 
357 	switch (dest_gate) {
358 	case NFC_HCI_LINK_MGMT_GATE:
359 		pipe = NFC_HCI_LINK_MGMT_PIPE;
360 		break;
361 	case NFC_HCI_ADMIN_GATE:
362 		pipe = NFC_HCI_ADMIN_PIPE;
363 		break;
364 	default:
365 		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
366 		if (pipe == NFC_HCI_INVALID_PIPE)
367 			return r;
368 		pipe_created = true;
369 		break;
370 	}
371 
372 open_pipe:
373 	r = nfc_hci_open_pipe(hdev, pipe);
374 	if (r < 0) {
375 		if (pipe_created)
376 			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
377 				/* TODO: Cannot clean by deleting pipe...
378 				 * -> inconsistent state */
379 			}
380 		return r;
381 	}
382 
383 	hdev->gate2pipe[dest_gate] = pipe;
384 
385 	return 0;
386 }
387 EXPORT_SYMBOL(nfc_hci_connect_gate);
388