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
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 */
124int 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}
137EXPORT_SYMBOL(nfc_hci_send_cmd);
138
139int 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}
154EXPORT_SYMBOL(nfc_hci_send_cmd_async);
155
156int 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}
186EXPORT_SYMBOL(nfc_hci_set_param);
187
188int 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}
196EXPORT_SYMBOL(nfc_hci_get_param);
197
198static 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
218static 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
226static 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
255static 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
263static 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
281int 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}
305EXPORT_SYMBOL(nfc_hci_disconnect_gate);
306
307int 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}
321EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
322
323int 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
355open_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}
372EXPORT_SYMBOL(nfc_hci_connect_gate);
373