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
19static 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 */
39static 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
55static 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
91int 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}
105EXPORT_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 */
112int 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	pipe = hdev->gate2pipe[gate];
118	if (pipe == NFC_HCI_INVALID_PIPE)
119		return -EADDRNOTAVAIL;
120
121	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
122}
123EXPORT_SYMBOL(nfc_hci_send_cmd);
124
125int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
126			   const u8 *param, size_t param_len,
127			   data_exchange_cb_t cb, void *cb_context)
128{
129	u8 pipe;
130
131	pipe = hdev->gate2pipe[gate];
132	if (pipe == NFC_HCI_INVALID_PIPE)
133		return -EADDRNOTAVAIL;
134
135	return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
136					 cb, cb_context);
137}
138EXPORT_SYMBOL(nfc_hci_send_cmd_async);
139
140int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
141		      const u8 *param, size_t param_len)
142{
143	int r;
144	u8 *tmp;
145
146	/* TODO ELa: reg idx must be inserted before param, but we don't want
147	 * to ask the caller to do it to keep a simpler API.
148	 * For now, just create a new temporary param buffer. This is far from
149	 * optimal though, and the plan is to modify APIs to pass idx down to
150	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
151	 * eliminating the need for the temp allocation-copy here.
152	 */
153
154	pr_debug("idx=%d to gate %d\n", idx, gate);
155
156	tmp = kmalloc(1 + param_len, GFP_KERNEL);
157	if (tmp == NULL)
158		return -ENOMEM;
159
160	*tmp = idx;
161	memcpy(tmp + 1, param, param_len);
162
163	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
164			     tmp, param_len + 1, NULL);
165
166	kfree(tmp);
167
168	return r;
169}
170EXPORT_SYMBOL(nfc_hci_set_param);
171
172int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
173		      struct sk_buff **skb)
174{
175	pr_debug("gate=%d regidx=%d\n", gate, idx);
176
177	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
178				&idx, 1, skb);
179}
180EXPORT_SYMBOL(nfc_hci_get_param);
181
182static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
183{
184	struct sk_buff *skb;
185	int r;
186
187	pr_debug("pipe=%d\n", pipe);
188
189	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
190				NULL, 0, &skb);
191	if (r == 0) {
192		/* dest host other than host controller will send
193		 * number of pipes already open on this gate before
194		 * execution. The number can be found in skb->data[0]
195		 */
196		kfree_skb(skb);
197	}
198
199	return r;
200}
201
202static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
203{
204	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
205				   NULL, 0, NULL);
206}
207
208static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
209			      u8 dest_gate, int *result)
210{
211	struct sk_buff *skb;
212	struct hci_create_pipe_params params;
213	struct hci_create_pipe_resp *resp;
214	u8 pipe;
215
216	pr_debug("gate=%d\n", dest_gate);
217
218	params.src_gate = NFC_HCI_ADMIN_GATE;
219	params.dest_host = dest_host;
220	params.dest_gate = dest_gate;
221
222	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
223				      NFC_HCI_ADM_CREATE_PIPE,
224				      (u8 *) &params, sizeof(params), &skb);
225	if (*result < 0)
226		return NFC_HCI_INVALID_PIPE;
227
228	resp = (struct hci_create_pipe_resp *)skb->data;
229	pipe = resp->pipe;
230	kfree_skb(skb);
231
232	pr_debug("pipe created=%d\n", pipe);
233
234	return pipe;
235}
236
237static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
238{
239	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
240				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
241}
242
243static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
244{
245	u8 param[2];
246	size_t param_len = 2;
247
248	/* TODO: Find out what the identity reference data is
249	 * and fill param with it. HCI spec 6.1.3.5 */
250
251	if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
252		param_len = 0;
253
254	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
255				   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
256				   NULL);
257}
258
259int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
260{
261	int r;
262	u8 pipe = hdev->gate2pipe[gate];
263
264	if (pipe == NFC_HCI_INVALID_PIPE)
265		return -EADDRNOTAVAIL;
266
267	r = nfc_hci_close_pipe(hdev, pipe);
268	if (r < 0)
269		return r;
270
271	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
272		r = nfc_hci_delete_pipe(hdev, pipe);
273		if (r < 0)
274			return r;
275	}
276
277	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
278
279	return 0;
280}
281EXPORT_SYMBOL(nfc_hci_disconnect_gate);
282
283int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
284{
285	int r;
286
287	r = nfc_hci_clear_all_pipes(hdev);
288	if (r < 0)
289		return r;
290
291	nfc_hci_reset_pipes(hdev);
292
293	return 0;
294}
295EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
296
297int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
298			 u8 pipe)
299{
300	bool pipe_created = false;
301	int r;
302
303	if (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)
304		return 0;
305
306	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
307		return -EADDRINUSE;
308
309	if (pipe != NFC_HCI_INVALID_PIPE)
310		goto open_pipe;
311
312	switch (dest_gate) {
313	case NFC_HCI_LINK_MGMT_GATE:
314		pipe = NFC_HCI_LINK_MGMT_PIPE;
315		break;
316	case NFC_HCI_ADMIN_GATE:
317		pipe = NFC_HCI_ADMIN_PIPE;
318		break;
319	default:
320		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
321		if (pipe == NFC_HCI_INVALID_PIPE)
322			return r;
323		pipe_created = true;
324		break;
325	}
326
327open_pipe:
328	r = nfc_hci_open_pipe(hdev, pipe);
329	if (r < 0) {
330		if (pipe_created)
331			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
332				/* TODO: Cannot clean by deleting pipe...
333				 * -> inconsistent state */
334			}
335		return r;
336	}
337
338	hdev->pipes[pipe].gate = dest_gate;
339	hdev->pipes[pipe].dest_host = dest_host;
340	hdev->gate2pipe[dest_gate] = pipe;
341
342	return 0;
343}
344EXPORT_SYMBOL(nfc_hci_connect_gate);
345