1 /*
2 * Texas Instrument's NFC Driver For Shared Transport.
3 *
4 * NFC Driver acts as interface between NCI core and
5 * TI Shared Transport Layer.
6 *
7 * Copyright (C) 2011 Texas Instruments, Inc.
8 *
9 * Written by Ilan Elias <ilane@ti.com>
10 *
11 * Acknowledgements:
12 * This file is based on btwilink.c, which was written
13 * by Raja Mani and Pavan Savoy.
14 *
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2 as
17 * published by the Free Software Foundation.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 *
28 */
29 #include <linux/platform_device.h>
30 #include <linux/module.h>
31 #include <linux/nfc.h>
32 #include <net/nfc/nci.h>
33 #include <net/nfc/nci_core.h>
34 #include <linux/ti_wilink_st.h>
35
36 #define NFCWILINK_CHNL 12
37 #define NFCWILINK_OPCODE 7
38 #define NFCWILINK_MAX_FRAME_SIZE 300
39 #define NFCWILINK_HDR_LEN 4
40 #define NFCWILINK_OFFSET_LEN_IN_HDR 1
41 #define NFCWILINK_LEN_SIZE 2
42 #define NFCWILINK_REGISTER_TIMEOUT 8000 /* 8 sec */
43
44 struct nfcwilink_hdr {
45 u8 chnl;
46 u8 opcode;
47 u16 len;
48 } __packed;
49
50 struct nfcwilink {
51 struct platform_device *pdev;
52 struct nci_dev *ndev;
53 unsigned long flags;
54
55 char st_register_cb_status;
56 long (*st_write) (struct sk_buff *);
57 struct completion st_register_completed;
58 };
59
60 /* NFCWILINK driver flags */
61 enum {
62 NFCWILINK_RUNNING,
63 };
64
65 /* Called by ST when registration is complete */
nfcwilink_register_complete(void * priv_data,char data)66 static void nfcwilink_register_complete(void *priv_data, char data)
67 {
68 struct nfcwilink *drv = priv_data;
69
70 nfc_dev_dbg(&drv->pdev->dev, "register_complete entry");
71
72 /* store ST registration status */
73 drv->st_register_cb_status = data;
74
75 /* complete the wait in nfc_st_open() */
76 complete(&drv->st_register_completed);
77 }
78
79 /* Called by ST when receive data is available */
nfcwilink_receive(void * priv_data,struct sk_buff * skb)80 static long nfcwilink_receive(void *priv_data, struct sk_buff *skb)
81 {
82 struct nfcwilink *drv = priv_data;
83 int rc;
84
85 nfc_dev_dbg(&drv->pdev->dev, "receive entry, len %d", skb->len);
86
87 if (!skb)
88 return -EFAULT;
89
90 if (!drv) {
91 kfree_skb(skb);
92 return -EFAULT;
93 }
94
95 /* strip the ST header
96 (apart for the chnl byte, which is not received in the hdr) */
97 skb_pull(skb, (NFCWILINK_HDR_LEN-1));
98
99 skb->dev = (void *) drv->ndev;
100
101 /* Forward skb to NCI core layer */
102 rc = nci_recv_frame(skb);
103 if (rc < 0) {
104 nfc_dev_err(&drv->pdev->dev, "nci_recv_frame failed %d", rc);
105 return rc;
106 }
107
108 return 0;
109 }
110
111 /* protocol structure registered with ST */
112 static struct st_proto_s nfcwilink_proto = {
113 .chnl_id = NFCWILINK_CHNL,
114 .max_frame_size = NFCWILINK_MAX_FRAME_SIZE,
115 .hdr_len = (NFCWILINK_HDR_LEN-1), /* not including chnl byte */
116 .offset_len_in_hdr = NFCWILINK_OFFSET_LEN_IN_HDR,
117 .len_size = NFCWILINK_LEN_SIZE,
118 .reserve = 0,
119 .recv = nfcwilink_receive,
120 .reg_complete_cb = nfcwilink_register_complete,
121 .write = NULL,
122 };
123
nfcwilink_open(struct nci_dev * ndev)124 static int nfcwilink_open(struct nci_dev *ndev)
125 {
126 struct nfcwilink *drv = nci_get_drvdata(ndev);
127 unsigned long comp_ret;
128 int rc;
129
130 nfc_dev_dbg(&drv->pdev->dev, "open entry");
131
132 if (test_and_set_bit(NFCWILINK_RUNNING, &drv->flags)) {
133 rc = -EBUSY;
134 goto exit;
135 }
136
137 nfcwilink_proto.priv_data = drv;
138
139 init_completion(&drv->st_register_completed);
140 drv->st_register_cb_status = -EINPROGRESS;
141
142 rc = st_register(&nfcwilink_proto);
143 if (rc < 0) {
144 if (rc == -EINPROGRESS) {
145 comp_ret = wait_for_completion_timeout(
146 &drv->st_register_completed,
147 msecs_to_jiffies(NFCWILINK_REGISTER_TIMEOUT));
148
149 nfc_dev_dbg(&drv->pdev->dev,
150 "wait_for_completion_timeout returned %ld",
151 comp_ret);
152
153 if (comp_ret == 0) {
154 /* timeout */
155 rc = -ETIMEDOUT;
156 goto clear_exit;
157 } else if (drv->st_register_cb_status != 0) {
158 rc = drv->st_register_cb_status;
159 nfc_dev_err(&drv->pdev->dev,
160 "st_register_cb failed %d", rc);
161 goto clear_exit;
162 }
163 } else {
164 nfc_dev_err(&drv->pdev->dev,
165 "st_register failed %d", rc);
166 goto clear_exit;
167 }
168 }
169
170 /* st_register MUST fill the write callback */
171 BUG_ON(nfcwilink_proto.write == NULL);
172 drv->st_write = nfcwilink_proto.write;
173
174 goto exit;
175
176 clear_exit:
177 clear_bit(NFCWILINK_RUNNING, &drv->flags);
178
179 exit:
180 return rc;
181 }
182
nfcwilink_close(struct nci_dev * ndev)183 static int nfcwilink_close(struct nci_dev *ndev)
184 {
185 struct nfcwilink *drv = nci_get_drvdata(ndev);
186 int rc;
187
188 nfc_dev_dbg(&drv->pdev->dev, "close entry");
189
190 if (!test_and_clear_bit(NFCWILINK_RUNNING, &drv->flags))
191 return 0;
192
193 rc = st_unregister(&nfcwilink_proto);
194 if (rc)
195 nfc_dev_err(&drv->pdev->dev, "st_unregister failed %d", rc);
196
197 drv->st_write = NULL;
198
199 return rc;
200 }
201
nfcwilink_send(struct sk_buff * skb)202 static int nfcwilink_send(struct sk_buff *skb)
203 {
204 struct nci_dev *ndev = (struct nci_dev *)skb->dev;
205 struct nfcwilink *drv = nci_get_drvdata(ndev);
206 struct nfcwilink_hdr hdr = {NFCWILINK_CHNL, NFCWILINK_OPCODE, 0x0000};
207 long len;
208
209 nfc_dev_dbg(&drv->pdev->dev, "send entry, len %d", skb->len);
210
211 if (!test_bit(NFCWILINK_RUNNING, &drv->flags))
212 return -EBUSY;
213
214 /* add the ST hdr to the start of the buffer */
215 hdr.len = skb->len;
216 memcpy(skb_push(skb, NFCWILINK_HDR_LEN), &hdr, NFCWILINK_HDR_LEN);
217
218 /* Insert skb to shared transport layer's transmit queue.
219 * Freeing skb memory is taken care in shared transport layer,
220 * so don't free skb memory here.
221 */
222 len = drv->st_write(skb);
223 if (len < 0) {
224 kfree_skb(skb);
225 nfc_dev_err(&drv->pdev->dev, "st_write failed %ld", len);
226 return -EFAULT;
227 }
228
229 return 0;
230 }
231
232 static struct nci_ops nfcwilink_ops = {
233 .open = nfcwilink_open,
234 .close = nfcwilink_close,
235 .send = nfcwilink_send,
236 };
237
nfcwilink_probe(struct platform_device * pdev)238 static int nfcwilink_probe(struct platform_device *pdev)
239 {
240 static struct nfcwilink *drv;
241 int rc;
242 u32 protocols;
243
244 nfc_dev_dbg(&pdev->dev, "probe entry");
245
246 drv = kzalloc(sizeof(struct nfcwilink), GFP_KERNEL);
247 if (!drv) {
248 rc = -ENOMEM;
249 goto exit;
250 }
251
252 drv->pdev = pdev;
253
254 protocols = NFC_PROTO_JEWEL_MASK
255 | NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
256 | NFC_PROTO_ISO14443_MASK
257 | NFC_PROTO_NFC_DEP_MASK;
258
259 drv->ndev = nci_allocate_device(&nfcwilink_ops,
260 protocols,
261 NFCWILINK_HDR_LEN,
262 0);
263 if (!drv->ndev) {
264 nfc_dev_err(&pdev->dev, "nci_allocate_device failed");
265 rc = -ENOMEM;
266 goto free_exit;
267 }
268
269 nci_set_parent_dev(drv->ndev, &pdev->dev);
270 nci_set_drvdata(drv->ndev, drv);
271
272 rc = nci_register_device(drv->ndev);
273 if (rc < 0) {
274 nfc_dev_err(&pdev->dev, "nci_register_device failed %d", rc);
275 goto free_dev_exit;
276 }
277
278 dev_set_drvdata(&pdev->dev, drv);
279
280 goto exit;
281
282 free_dev_exit:
283 nci_free_device(drv->ndev);
284
285 free_exit:
286 kfree(drv);
287
288 exit:
289 return rc;
290 }
291
nfcwilink_remove(struct platform_device * pdev)292 static int nfcwilink_remove(struct platform_device *pdev)
293 {
294 struct nfcwilink *drv = dev_get_drvdata(&pdev->dev);
295 struct nci_dev *ndev;
296
297 nfc_dev_dbg(&pdev->dev, "remove entry");
298
299 if (!drv)
300 return -EFAULT;
301
302 ndev = drv->ndev;
303
304 nci_unregister_device(ndev);
305 nci_free_device(ndev);
306
307 kfree(drv);
308
309 dev_set_drvdata(&pdev->dev, NULL);
310
311 return 0;
312 }
313
314 static struct platform_driver nfcwilink_driver = {
315 .probe = nfcwilink_probe,
316 .remove = nfcwilink_remove,
317 .driver = {
318 .name = "nfcwilink",
319 .owner = THIS_MODULE,
320 },
321 };
322
323 /* ------- Module Init/Exit interfaces ------ */
nfcwilink_init(void)324 static int __init nfcwilink_init(void)
325 {
326 printk(KERN_INFO "NFC Driver for TI WiLink");
327
328 return platform_driver_register(&nfcwilink_driver);
329 }
330
nfcwilink_exit(void)331 static void __exit nfcwilink_exit(void)
332 {
333 platform_driver_unregister(&nfcwilink_driver);
334 }
335
336 module_init(nfcwilink_init);
337 module_exit(nfcwilink_exit);
338
339 /* ------ Module Info ------ */
340
341 MODULE_AUTHOR("Ilan Elias <ilane@ti.com>");
342 MODULE_DESCRIPTION("NFC Driver for TI Shared Transport");
343 MODULE_LICENSE("GPL");
344