xref: /openbmc/linux/net/nfc/hci/command.c (revision 0ad53fe3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2012  Intel Corporation. All rights reserved.
4  */
5 
6 #define pr_fmt(fmt) "hci: %s: " fmt, __func__
7 
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/module.h>
12 
13 #include <net/nfc/hci.h>
14 
15 #include "hci.h"
16 
17 #define MAX_FWI 4949
18 
19 static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
20 			       const u8 *param, size_t param_len,
21 			       data_exchange_cb_t cb, void *cb_context)
22 {
23 	pr_debug("exec cmd async through pipe=%d, cmd=%d, plen=%zd\n", pipe,
24 		 cmd, param_len);
25 
26 	/* TODO: Define hci cmd execution delay. Should it be the same
27 	 * for all commands?
28 	 */
29 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,
30 				      param, param_len, cb, cb_context, MAX_FWI);
31 }
32 
33 /*
34  * HCI command execution completion callback.
35  * err will be a standard linux error (may be converted from HCI response)
36  * skb contains the response data and must be disposed, or may be NULL if
37  * an error occurred
38  */
39 static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)
40 {
41 	struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)context;
42 
43 	pr_debug("HCI Cmd completed with result=%d\n", err);
44 
45 	hcp_ew->exec_result = err;
46 	if (hcp_ew->exec_result == 0)
47 		hcp_ew->result_skb = skb;
48 	else
49 		kfree_skb(skb);
50 	hcp_ew->exec_complete = true;
51 
52 	wake_up(hcp_ew->wq);
53 }
54 
55 static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
56 			       const u8 *param, size_t param_len,
57 			       struct sk_buff **skb)
58 {
59 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
60 	struct hcp_exec_waiter hcp_ew;
61 	hcp_ew.wq = &ew_wq;
62 	hcp_ew.exec_complete = false;
63 	hcp_ew.result_skb = NULL;
64 
65 	pr_debug("exec cmd sync through pipe=%d, cmd=%d, plen=%zd\n", pipe,
66 		 cmd, param_len);
67 
68 	/* TODO: Define hci cmd execution delay. Should it be the same
69 	 * for all commands?
70 	 */
71 	hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
72 						    NFC_HCI_HCP_COMMAND, cmd,
73 						    param, param_len,
74 						    nfc_hci_execute_cb, &hcp_ew,
75 						    MAX_FWI);
76 	if (hcp_ew.exec_result < 0)
77 		return hcp_ew.exec_result;
78 
79 	wait_event(ew_wq, hcp_ew.exec_complete == true);
80 
81 	if (hcp_ew.exec_result == 0) {
82 		if (skb)
83 			*skb = hcp_ew.result_skb;
84 		else
85 			kfree_skb(hcp_ew.result_skb);
86 	}
87 
88 	return hcp_ew.exec_result;
89 }
90 
91 int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
92 		       const u8 *param, size_t param_len)
93 {
94 	u8 pipe;
95 
96 	pr_debug("%d to gate %d\n", event, gate);
97 
98 	pipe = hdev->gate2pipe[gate];
99 	if (pipe == NFC_HCI_INVALID_PIPE)
100 		return -EADDRNOTAVAIL;
101 
102 	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
103 				      param, param_len, NULL, NULL, 0);
104 }
105 EXPORT_SYMBOL(nfc_hci_send_event);
106 
107 /*
108  * Execute an hci command sent to gate.
109  * skb will contain response data if success. skb can be NULL if you are not
110  * interested by the response.
111  */
112 int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
113 		     const u8 *param, size_t param_len, struct sk_buff **skb)
114 {
115 	u8 pipe;
116 
117 	pr_debug("\n");
118 
119 	pipe = hdev->gate2pipe[gate];
120 	if (pipe == NFC_HCI_INVALID_PIPE)
121 		return -EADDRNOTAVAIL;
122 
123 	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
124 }
125 EXPORT_SYMBOL(nfc_hci_send_cmd);
126 
127 int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
128 			   const u8 *param, size_t param_len,
129 			   data_exchange_cb_t cb, void *cb_context)
130 {
131 	u8 pipe;
132 
133 	pr_debug("\n");
134 
135 	pipe = hdev->gate2pipe[gate];
136 	if (pipe == NFC_HCI_INVALID_PIPE)
137 		return -EADDRNOTAVAIL;
138 
139 	return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
140 					 cb, cb_context);
141 }
142 EXPORT_SYMBOL(nfc_hci_send_cmd_async);
143 
144 int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
145 		      const u8 *param, size_t param_len)
146 {
147 	int r;
148 	u8 *tmp;
149 
150 	/* TODO ELa: reg idx must be inserted before param, but we don't want
151 	 * to ask the caller to do it to keep a simpler API.
152 	 * For now, just create a new temporary param buffer. This is far from
153 	 * optimal though, and the plan is to modify APIs to pass idx down to
154 	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
155 	 * eliminating the need for the temp allocation-copy here.
156 	 */
157 
158 	pr_debug("idx=%d to gate %d\n", idx, gate);
159 
160 	tmp = kmalloc(1 + param_len, GFP_KERNEL);
161 	if (tmp == NULL)
162 		return -ENOMEM;
163 
164 	*tmp = idx;
165 	memcpy(tmp + 1, param, param_len);
166 
167 	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
168 			     tmp, param_len + 1, NULL);
169 
170 	kfree(tmp);
171 
172 	return r;
173 }
174 EXPORT_SYMBOL(nfc_hci_set_param);
175 
176 int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
177 		      struct sk_buff **skb)
178 {
179 	pr_debug("gate=%d regidx=%d\n", gate, idx);
180 
181 	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
182 				&idx, 1, skb);
183 }
184 EXPORT_SYMBOL(nfc_hci_get_param);
185 
186 static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
187 {
188 	struct sk_buff *skb;
189 	int r;
190 
191 	pr_debug("pipe=%d\n", pipe);
192 
193 	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
194 				NULL, 0, &skb);
195 	if (r == 0) {
196 		/* dest host other than host controller will send
197 		 * number of pipes already open on this gate before
198 		 * execution. The number can be found in skb->data[0]
199 		 */
200 		kfree_skb(skb);
201 	}
202 
203 	return r;
204 }
205 
206 static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
207 {
208 	pr_debug("\n");
209 
210 	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
211 				   NULL, 0, NULL);
212 }
213 
214 static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
215 			      u8 dest_gate, int *result)
216 {
217 	struct sk_buff *skb;
218 	struct hci_create_pipe_params params;
219 	struct hci_create_pipe_resp *resp;
220 	u8 pipe;
221 
222 	pr_debug("gate=%d\n", dest_gate);
223 
224 	params.src_gate = NFC_HCI_ADMIN_GATE;
225 	params.dest_host = dest_host;
226 	params.dest_gate = dest_gate;
227 
228 	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
229 				      NFC_HCI_ADM_CREATE_PIPE,
230 				      (u8 *) &params, sizeof(params), &skb);
231 	if (*result < 0)
232 		return NFC_HCI_INVALID_PIPE;
233 
234 	resp = (struct hci_create_pipe_resp *)skb->data;
235 	pipe = resp->pipe;
236 	kfree_skb(skb);
237 
238 	pr_debug("pipe created=%d\n", pipe);
239 
240 	return pipe;
241 }
242 
243 static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
244 {
245 	pr_debug("\n");
246 
247 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
248 				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
249 }
250 
251 static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
252 {
253 	u8 param[2];
254 	size_t param_len = 2;
255 
256 	/* TODO: Find out what the identity reference data is
257 	 * and fill param with it. HCI spec 6.1.3.5 */
258 
259 	pr_debug("\n");
260 
261 	if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
262 		param_len = 0;
263 
264 	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
265 				   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
266 				   NULL);
267 }
268 
269 int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
270 {
271 	int r;
272 	u8 pipe = hdev->gate2pipe[gate];
273 
274 	pr_debug("\n");
275 
276 	if (pipe == NFC_HCI_INVALID_PIPE)
277 		return -EADDRNOTAVAIL;
278 
279 	r = nfc_hci_close_pipe(hdev, pipe);
280 	if (r < 0)
281 		return r;
282 
283 	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
284 		r = nfc_hci_delete_pipe(hdev, pipe);
285 		if (r < 0)
286 			return r;
287 	}
288 
289 	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
290 
291 	return 0;
292 }
293 EXPORT_SYMBOL(nfc_hci_disconnect_gate);
294 
295 int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
296 {
297 	int r;
298 
299 	pr_debug("\n");
300 
301 	r = nfc_hci_clear_all_pipes(hdev);
302 	if (r < 0)
303 		return r;
304 
305 	nfc_hci_reset_pipes(hdev);
306 
307 	return 0;
308 }
309 EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
310 
311 int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
312 			 u8 pipe)
313 {
314 	bool pipe_created = false;
315 	int r;
316 
317 	pr_debug("\n");
318 
319 	if (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)
320 		return 0;
321 
322 	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
323 		return -EADDRINUSE;
324 
325 	if (pipe != NFC_HCI_INVALID_PIPE)
326 		goto open_pipe;
327 
328 	switch (dest_gate) {
329 	case NFC_HCI_LINK_MGMT_GATE:
330 		pipe = NFC_HCI_LINK_MGMT_PIPE;
331 		break;
332 	case NFC_HCI_ADMIN_GATE:
333 		pipe = NFC_HCI_ADMIN_PIPE;
334 		break;
335 	default:
336 		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
337 		if (pipe == NFC_HCI_INVALID_PIPE)
338 			return r;
339 		pipe_created = true;
340 		break;
341 	}
342 
343 open_pipe:
344 	r = nfc_hci_open_pipe(hdev, pipe);
345 	if (r < 0) {
346 		if (pipe_created)
347 			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
348 				/* TODO: Cannot clean by deleting pipe...
349 				 * -> inconsistent state */
350 			}
351 		return r;
352 	}
353 
354 	hdev->pipes[pipe].gate = dest_gate;
355 	hdev->pipes[pipe].dest_host = dest_host;
356 	hdev->gate2pipe[dest_gate] = pipe;
357 
358 	return 0;
359 }
360 EXPORT_SYMBOL(nfc_hci_connect_gate);
361