aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/nfc/nfcwilink.c
blob: 5b0f1ff8036133c50a4427dfa90e08ec9d54cde7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
/*
 *  Texas Instrument's NFC Driver For Shared Transport.
 *
 *  NFC Driver acts as interface between NCI core and
 *  TI Shared Transport Layer.
 *
 *  Copyright (C) 2011 Texas Instruments, Inc.
 *
 *  Written by Ilan Elias <ilane@ti.com>
 *
 *  Acknowledgements:
 *  This file is based on btwilink.c, which was written
 *  by Raja Mani and Pavan Savoy.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
#include <linux/platform_device.h>
#include <linux/nfc.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include <linux/ti_wilink_st.h>

#define NFCWILINK_CHNL			12
#define NFCWILINK_OPCODE		7
#define NFCWILINK_MAX_FRAME_SIZE	300
#define NFCWILINK_HDR_LEN		4
#define NFCWILINK_OFFSET_LEN_IN_HDR	1
#define NFCWILINK_LEN_SIZE		2
#define NFCWILINK_REGISTER_TIMEOUT	8000	/* 8 sec */

struct nfcwilink_hdr {
	u8 chnl;
	u8 opcode;
	u16 len;
} __packed;

struct nfcwilink {
	struct platform_device		*pdev;
	struct nci_dev			*ndev;
	unsigned long			flags;

	char				st_register_cb_status;
	long				(*st_write) (struct sk_buff *);
	struct completion		st_register_completed;
};

/* NFCWILINK driver flags */
enum {
	NFCWILINK_RUNNING,
};

/* Called by ST when registration is complete */
static void nfcwilink_register_complete(void *priv_data, char data)
{
	struct nfcwilink *drv = priv_data;

	nfc_dev_dbg(&drv->pdev->dev, "register_complete entry");

	/* store ST registration status */
	drv->st_register_cb_status = data;

	/* complete the wait in nfc_st_open() */
	complete(&drv->st_register_completed);
}

/* Called by ST when receive data is available */
static long nfcwilink_receive(void *priv_data, struct sk_buff *skb)
{
	struct nfcwilink *drv = priv_data;
	int rc;

	nfc_dev_dbg(&drv->pdev->dev, "receive entry, len %d", skb->len);

	if (!skb)
		return -EFAULT;

	if (!drv) {
		kfree_skb(skb);
		return -EFAULT;
	}

	/* strip the ST header
	(apart for the chnl byte, which is not received in the hdr) */
	skb_pull(skb, (NFCWILINK_HDR_LEN-1));

	skb->dev = (void *) drv->ndev;

	/* Forward skb to NCI core layer */
	rc = nci_recv_frame(skb);
	if (rc < 0) {
		nfc_dev_err(&drv->pdev->dev, "nci_recv_frame failed %d", rc);
		return rc;
	}

	return 0;
}

/* protocol structure registered with ST */
static struct st_proto_s nfcwilink_proto = {
	.chnl_id = NFCWILINK_CHNL,
	.max_frame_size = NFCWILINK_MAX_FRAME_SIZE,
	.hdr_len = (NFCWILINK_HDR_LEN-1),	/* not including chnl byte */
	.offset_len_in_hdr = NFCWILINK_OFFSET_LEN_IN_HDR,
	.len_size = NFCWILINK_LEN_SIZE,
	.reserve = 0,
	.recv = nfcwilink_receive,
	.reg_complete_cb = nfcwilink_register_complete,
	.write = NULL,
};

static int nfcwilink_open(struct nci_dev *ndev)
{
	struct nfcwilink *drv = nci_get_drvdata(ndev);
	unsigned long comp_ret;
	int rc;

	nfc_dev_dbg(&drv->pdev->dev, "open entry");

	if (test_and_set_bit(NFCWILINK_RUNNING, &drv->flags)) {
		rc = -EBUSY;
		goto exit;
	}

	nfcwilink_proto.priv_data = drv;

	init_completion(&drv->st_register_completed);
	drv->st_register_cb_status = -EINPROGRESS;

	rc = st_register(&nfcwilink_proto);
	if (rc < 0) {
		if (rc == -EINPROGRESS) {
			comp_ret = wait_for_completion_timeout(
			&drv->st_register_completed,
			msecs_to_jiffies(NFCWILINK_REGISTER_TIMEOUT));

			nfc_dev_dbg(&drv->pdev->dev,
			"wait_for_completion_timeout returned %ld",
			comp_ret);

			if (comp_ret == 0) {
				/* timeout */
				rc = -ETIMEDOUT;
				goto clear_exit;
			} else if (drv->st_register_cb_status != 0) {
				rc = drv->st_register_cb_status;
				nfc_dev_err(&drv->pdev->dev,
				"st_register_cb failed %d", rc);
				goto clear_exit;
			}
		} else {
			nfc_dev_err(&drv->pdev->dev,
				"st_register failed %d", rc);
			goto clear_exit;
		}
	}

	/* st_register MUST fill the write callback */
	BUG_ON(nfcwilink_proto.write == NULL);
	drv->st_write = nfcwilink_proto.write;

	goto exit;

clear_exit:
	clear_bit(NFCWILINK_RUNNING, &drv->flags);

exit:
	return rc;
}

static int nfcwilink_close(struct nci_dev *ndev)
{
	struct nfcwilink *drv = nci_get_drvdata(ndev);
	int rc;

	nfc_dev_dbg(&drv->pdev->dev, "close entry");

	if (!test_and_clear_bit(NFCWILINK_RUNNING, &drv->flags))
		return 0;

	rc = st_unregister(&nfcwilink_proto);
	if (rc)
		nfc_dev_err(&drv->pdev->dev, "st_unregister failed %d", rc);

	drv->st_write = NULL;

	return rc;
}

static int nfcwilink_send(struct sk_buff *skb)
{
	struct nci_dev *ndev = (struct nci_dev *)skb->dev;
	struct nfcwilink *drv = nci_get_drvdata(ndev);
	struct nfcwilink_hdr hdr = {NFCWILINK_CHNL, NFCWILINK_OPCODE, 0x0000};
	long len;

	nfc_dev_dbg(&drv->pdev->dev, "send entry, len %d", skb->len);

	if (!test_bit(NFCWILINK_RUNNING, &drv->flags))
		return -EBUSY;

	/* add the ST hdr to the start of the buffer */
	hdr.len = skb->len;
	memcpy(skb_push(skb, NFCWILINK_HDR_LEN), &hdr, NFCWILINK_HDR_LEN);

	/* Insert skb to shared transport layer's transmit queue.
	 * Freeing skb memory is taken care in shared transport layer,
	 * so don't free skb memory here.
	 */
	len = drv->st_write(skb);
	if (len < 0) {
		kfree_skb(skb);
		nfc_dev_err(&drv->pdev->dev, "st_write failed %ld", len);
		return -EFAULT;
	}

	return 0;
}

static struct nci_ops nfcwilink_ops = {
	.open = nfcwilink_open,
	.close = nfcwilink_close,
	.send = nfcwilink_send,
};

static int nfcwilink_probe(struct platform_device *pdev)
{
	static struct nfcwilink *drv;
	int rc;
	u32 protocols;

	nfc_dev_dbg(&pdev->dev, "probe entry");

	drv = kzalloc(sizeof(struct nfcwilink), GFP_KERNEL);
	if (!drv) {
		rc = -ENOMEM;
		goto exit;
	}

	drv->pdev = pdev;

	protocols = NFC_PROTO_JEWEL_MASK
			| NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
			| NFC_PROTO_ISO14443_MASK
			| NFC_PROTO_NFC_DEP_MASK;

	drv->ndev = nci_allocate_device(&nfcwilink_ops,
					protocols,
					NFCWILINK_HDR_LEN,
					0);
	if (!drv->ndev) {
		nfc_dev_err(&pdev->dev, "nci_allocate_device failed");
		rc = -ENOMEM;
		goto free_exit;
	}

	nci_set_parent_dev(drv->ndev, &pdev->dev);
	nci_set_drvdata(drv->ndev, drv);

	rc = nci_register_device(drv->ndev);
	if (rc < 0) {
		nfc_dev_err(&pdev->dev, "nci_register_device failed %d", rc);
		goto free_dev_exit;
	}

	dev_set_drvdata(&pdev->dev, drv);

	goto exit;

free_dev_exit:
	nci_free_device(drv->ndev);

free_exit:
	kfree(drv);

exit:
	return rc;
}

static int nfcwilink_remove(struct platform_device *pdev)
{
	struct nfcwilink *drv = dev_get_drvdata(&pdev->dev);
	struct nci_dev *ndev;

	nfc_dev_dbg(&pdev->dev, "remove entry");

	if (!drv)
		return -EFAULT;

	ndev = drv->ndev;

	nci_unregister_device(ndev);
	nci_free_device(ndev);

	kfree(drv);

	dev_set_drvdata(&pdev->dev, NULL);

	return 0;
}

static struct platform_driver nfcwilink_driver = {
	.probe = nfcwilink_probe,
	.remove = nfcwilink_remove,
	.driver = {
		.name = "nfcwilink",
		.owner = THIS_MODULE,
	},
};

/* ------- Module Init/Exit interfaces ------ */
static int __init nfcwilink_init(void)
{
	printk(KERN_INFO "NFC Driver for TI WiLink");

	return platform_driver_register(&nfcwilink_driver);
}

static void __exit nfcwilink_exit(void)
{
	platform_driver_unregister(&nfcwilink_driver);
}

module_init(nfcwilink_init);
module_exit(nfcwilink_exit);

/* ------ Module Info ------ */

MODULE_AUTHOR("Ilan Elias <ilane@ti.com>");
MODULE_DESCRIPTION("NFC Driver for TI Shared Transport");
MODULE_LICENSE("GPL");