xref: /openbmc/linux/net/nfc/hci/command.c (revision e2c75e76)
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 /*
120  * Execute an hci command sent to gate.
121  * skb will contain response data if success. skb can be NULL if you are not
122  * interested by the response.
123  */
124 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
125 		     const u8 *param, size_t param_len, struct sk_buff **skb)
126 {
127 	u8 pipe;
128 
129 	pr_debug("\n");
130 
131 	pipe = hdev->gate2pipe[gate];
132 	if (pipe == NFC_HCI_INVALID_PIPE)
133 		return -EADDRNOTAVAIL;
134 
135 	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
136 }
137 EXPORT_SYMBOL(nfc_hci_send_cmd);
138 
139 int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
140 			   const u8 *param, size_t param_len,
141 			   data_exchange_cb_t cb, void *cb_context)
142 {
143 	u8 pipe;
144 
145 	pr_debug("\n");
146 
147 	pipe = hdev->gate2pipe[gate];
148 	if (pipe == NFC_HCI_INVALID_PIPE)
149 		return -EADDRNOTAVAIL;
150 
151 	return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
152 					 cb, cb_context);
153 }
154 EXPORT_SYMBOL(nfc_hci_send_cmd_async);
155 
156 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
157 		      const u8 *param, size_t param_len)
158 {
159 	int r;
160 	u8 *tmp;
161 
162 	/* TODO ELa: reg idx must be inserted before param, but we don't want
163 	 * to ask the caller to do it to keep a simpler API.
164 	 * For now, just create a new temporary param buffer. This is far from
165 	 * optimal though, and the plan is to modify APIs to pass idx down to
166 	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
167 	 * eliminating the need for the temp allocation-copy here.
168 	 */
169 
170 	pr_debug("idx=%d to gate %d\n", idx, gate);
171 
172 	tmp = kmalloc(1 + param_len, GFP_KERNEL);
173 	if (tmp == NULL)
174 		return -ENOMEM;
175 
176 	*tmp = idx;
177 	memcpy(tmp + 1, param, param_len);
178 
179 	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
180 			     tmp, param_len + 1, NULL);
181 
182 	kfree(tmp);
183 
184 	return r;
185 }
186 EXPORT_SYMBOL(nfc_hci_set_param);
187 
188 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
189 		      struct sk_buff **skb)
190 {
191 	pr_debug("gate=%d regidx=%d\n", gate, idx);
192 
193 	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
194 				&idx, 1, skb);
195 }
196 EXPORT_SYMBOL(nfc_hci_get_param);
197 
198 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
199 {
200 	struct sk_buff *skb;
201 	int r;
202 
203 	pr_debug("pipe=%d\n", pipe);
204 
205 	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
206 				NULL, 0, &skb);
207 	if (r == 0) {
208 		/* dest host other than host controller will send
209 		 * number of pipes already open on this gate before
210 		 * execution. The number can be found in skb->data[0]
211 		 */
212 		kfree_skb(skb);
213 	}
214 
215 	return r;
216 }
217 
218 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
219 {
220 	pr_debug("\n");
221 
222 	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
223 				   NULL, 0, NULL);
224 }
225 
226 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
227 			      u8 dest_gate, int *result)
228 {
229 	struct sk_buff *skb;
230 	struct hci_create_pipe_params params;
231 	struct hci_create_pipe_resp *resp;
232 	u8 pipe;
233 
234 	pr_debug("gate=%d\n", dest_gate);
235 
236 	params.src_gate = NFC_HCI_ADMIN_GATE;
237 	params.dest_host = dest_host;
238 	params.dest_gate = dest_gate;
239 
240 	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
241 				      NFC_HCI_ADM_CREATE_PIPE,
242 				      (u8 *) &params, sizeof(params), &skb);
243 	if (*result < 0)
244 		return NFC_HCI_INVALID_PIPE;
245 
246 	resp = (struct hci_create_pipe_resp *)skb->data;
247 	pipe = resp->pipe;
248 	kfree_skb(skb);
249 
250 	pr_debug("pipe created=%d\n", pipe);
251 
252 	return pipe;
253 }
254 
255 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
256 {
257 	pr_debug("\n");
258 
259 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
260 				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
261 }
262 
263 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
264 {
265 	u8 param[2];
266 	size_t param_len = 2;
267 
268 	/* TODO: Find out what the identity reference data is
269 	 * and fill param with it. HCI spec 6.1.3.5 */
270 
271 	pr_debug("\n");
272 
273 	if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
274 		param_len = 0;
275 
276 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
277 				   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
278 				   NULL);
279 }
280 
281 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
282 {
283 	int r;
284 	u8 pipe = hdev->gate2pipe[gate];
285 
286 	pr_debug("\n");
287 
288 	if (pipe == NFC_HCI_INVALID_PIPE)
289 		return -EADDRNOTAVAIL;
290 
291 	r = nfc_hci_close_pipe(hdev, pipe);
292 	if (r < 0)
293 		return r;
294 
295 	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
296 		r = nfc_hci_delete_pipe(hdev, pipe);
297 		if (r < 0)
298 			return r;
299 	}
300 
301 	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
302 
303 	return 0;
304 }
305 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
306 
307 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
308 {
309 	int r;
310 
311 	pr_debug("\n");
312 
313 	r = nfc_hci_clear_all_pipes(hdev);
314 	if (r < 0)
315 		return r;
316 
317 	nfc_hci_reset_pipes(hdev);
318 
319 	return 0;
320 }
321 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
322 
323 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
324 			 u8 pipe)
325 {
326 	bool pipe_created = false;
327 	int r;
328 
329 	pr_debug("\n");
330 
331 	if (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)
332 		return 0;
333 
334 	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
335 		return -EADDRINUSE;
336 
337 	if (pipe != NFC_HCI_INVALID_PIPE)
338 		goto open_pipe;
339 
340 	switch (dest_gate) {
341 	case NFC_HCI_LINK_MGMT_GATE:
342 		pipe = NFC_HCI_LINK_MGMT_PIPE;
343 		break;
344 	case NFC_HCI_ADMIN_GATE:
345 		pipe = NFC_HCI_ADMIN_PIPE;
346 		break;
347 	default:
348 		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
349 		if (pipe == NFC_HCI_INVALID_PIPE)
350 			return r;
351 		pipe_created = true;
352 		break;
353 	}
354 
355 open_pipe:
356 	r = nfc_hci_open_pipe(hdev, pipe);
357 	if (r < 0) {
358 		if (pipe_created)
359 			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
360 				/* TODO: Cannot clean by deleting pipe...
361 				 * -> inconsistent state */
362 			}
363 		return r;
364 	}
365 
366 	hdev->pipes[pipe].gate = dest_gate;
367 	hdev->pipes[pipe].dest_host = dest_host;
368 	hdev->gate2pipe[dest_gate] = pipe;
369 
370 	return 0;
371 }
372 EXPORT_SYMBOL(nfc_hci_connect_gate);
373