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
31static 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 */
51static 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
67static 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
103int 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}
117EXPORT_SYMBOL(nfc_hci_send_event);
118
119int 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}
134EXPORT_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 */
141int 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}
154EXPORT_SYMBOL(nfc_hci_send_cmd);
155
156int 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}
171EXPORT_SYMBOL(nfc_hci_send_cmd_async);
172
173int 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}
203EXPORT_SYMBOL(nfc_hci_set_param);
204
205int 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}
213EXPORT_SYMBOL(nfc_hci_get_param);
214
215static 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
235static 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
243static 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
272static 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
280static 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
298int 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}
322EXPORT_SYMBOL(nfc_hci_disconnect_gate);
323
324int 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}
338EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
339
340int 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_INVALID_PIPE)
349		return -EADDRINUSE;
350
351	if (pipe != NFC_HCI_INVALID_PIPE)
352		goto open_pipe;
353
354	switch (dest_gate) {
355	case NFC_HCI_LINK_MGMT_GATE:
356		pipe = NFC_HCI_LINK_MGMT_PIPE;
357		break;
358	case NFC_HCI_ADMIN_GATE:
359		pipe = NFC_HCI_ADMIN_PIPE;
360		break;
361	default:
362		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
363		if (pipe == NFC_HCI_INVALID_PIPE)
364			return r;
365		pipe_created = true;
366		break;
367	}
368
369open_pipe:
370	r = nfc_hci_open_pipe(hdev, pipe);
371	if (r < 0) {
372		if (pipe_created)
373			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
374				/* TODO: Cannot clean by deleting pipe...
375				 * -> inconsistent state */
376			}
377		return r;
378	}
379
380	hdev->gate2pipe[dest_gate] = pipe;
381
382	return 0;
383}
384EXPORT_SYMBOL(nfc_hci_connect_gate);
385