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7#include <linux/device.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/ctype.h>
11#include <linux/debugfs.h>
12#include <linux/nfc.h>
13#include <net/nfc/nfc.h>
14#include <net/nfc/digital.h>
15
16#define NFCSIM_ERR(d, fmt, args...) nfc_err(&d->nfc_digital_dev->nfc_dev->dev, \
17 "%s: " fmt, __func__, ## args)
18
19#define NFCSIM_DBG(d, fmt, args...) dev_dbg(&d->nfc_digital_dev->nfc_dev->dev, \
20 "%s: " fmt, __func__, ## args)
21
22#define NFCSIM_VERSION "0.2"
23
24#define NFCSIM_MODE_NONE 0
25#define NFCSIM_MODE_INITIATOR 1
26#define NFCSIM_MODE_TARGET 2
27
28#define NFCSIM_CAPABILITIES (NFC_DIGITAL_DRV_CAPS_IN_CRC | \
29 NFC_DIGITAL_DRV_CAPS_TG_CRC)
30
31struct nfcsim {
32 struct nfc_digital_dev *nfc_digital_dev;
33
34 struct work_struct recv_work;
35 struct delayed_work send_work;
36
37 struct nfcsim_link *link_in;
38 struct nfcsim_link *link_out;
39
40 bool up;
41 u8 mode;
42 u8 rf_tech;
43
44 u16 recv_timeout;
45
46 nfc_digital_cmd_complete_t cb;
47 void *arg;
48
49 u8 dropframe;
50};
51
52struct nfcsim_link {
53 struct mutex lock;
54
55 u8 rf_tech;
56 u8 mode;
57
58 u8 shutdown;
59
60 struct sk_buff *skb;
61 wait_queue_head_t recv_wait;
62 u8 cond;
63};
64
65static struct nfcsim_link *nfcsim_link_new(void)
66{
67 struct nfcsim_link *link;
68
69 link = kzalloc(sizeof(struct nfcsim_link), GFP_KERNEL);
70 if (!link)
71 return NULL;
72
73 mutex_init(&link->lock);
74 init_waitqueue_head(&link->recv_wait);
75
76 return link;
77}
78
79static void nfcsim_link_free(struct nfcsim_link *link)
80{
81 dev_kfree_skb(link->skb);
82 kfree(link);
83}
84
85static void nfcsim_link_recv_wake(struct nfcsim_link *link)
86{
87 link->cond = 1;
88 wake_up_interruptible(&link->recv_wait);
89}
90
91static void nfcsim_link_set_skb(struct nfcsim_link *link, struct sk_buff *skb,
92 u8 rf_tech, u8 mode)
93{
94 mutex_lock(&link->lock);
95
96 dev_kfree_skb(link->skb);
97 link->skb = skb;
98 link->rf_tech = rf_tech;
99 link->mode = mode;
100
101 mutex_unlock(&link->lock);
102}
103
104static void nfcsim_link_recv_cancel(struct nfcsim_link *link)
105{
106 mutex_lock(&link->lock);
107
108 link->mode = NFCSIM_MODE_NONE;
109
110 mutex_unlock(&link->lock);
111
112 nfcsim_link_recv_wake(link);
113}
114
115static void nfcsim_link_shutdown(struct nfcsim_link *link)
116{
117 mutex_lock(&link->lock);
118
119 link->shutdown = 1;
120 link->mode = NFCSIM_MODE_NONE;
121
122 mutex_unlock(&link->lock);
123
124 nfcsim_link_recv_wake(link);
125}
126
127static struct sk_buff *nfcsim_link_recv_skb(struct nfcsim_link *link,
128 int timeout, u8 rf_tech, u8 mode)
129{
130 int rc;
131 struct sk_buff *skb;
132
133 rc = wait_event_interruptible_timeout(link->recv_wait,
134 link->cond,
135 msecs_to_jiffies(timeout));
136
137 mutex_lock(&link->lock);
138
139 skb = link->skb;
140 link->skb = NULL;
141
142 if (!rc) {
143 rc = -ETIMEDOUT;
144 goto done;
145 }
146
147 if (!skb || link->rf_tech != rf_tech || link->mode == mode) {
148 rc = -EINVAL;
149 goto done;
150 }
151
152 if (link->shutdown) {
153 rc = -ENODEV;
154 goto done;
155 }
156
157done:
158 mutex_unlock(&link->lock);
159
160 if (rc < 0) {
161 dev_kfree_skb(skb);
162 skb = ERR_PTR(rc);
163 }
164
165 link->cond = 0;
166
167 return skb;
168}
169
170static void nfcsim_send_wq(struct work_struct *work)
171{
172 struct nfcsim *dev = container_of(work, struct nfcsim, send_work.work);
173
174
175
176
177
178
179 nfcsim_link_recv_wake(dev->link_out);
180}
181
182static void nfcsim_recv_wq(struct work_struct *work)
183{
184 struct nfcsim *dev = container_of(work, struct nfcsim, recv_work);
185 struct sk_buff *skb;
186
187 skb = nfcsim_link_recv_skb(dev->link_in, dev->recv_timeout,
188 dev->rf_tech, dev->mode);
189
190 if (!dev->up) {
191 NFCSIM_ERR(dev, "Device is down\n");
192
193 if (!IS_ERR(skb))
194 dev_kfree_skb(skb);
195
196 skb = ERR_PTR(-ENODEV);
197 }
198
199 dev->cb(dev->nfc_digital_dev, dev->arg, skb);
200}
201
202static int nfcsim_send(struct nfc_digital_dev *ddev, struct sk_buff *skb,
203 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
204{
205 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
206 u8 delay;
207
208 if (!dev->up) {
209 NFCSIM_ERR(dev, "Device is down\n");
210 return -ENODEV;
211 }
212
213 dev->recv_timeout = timeout;
214 dev->cb = cb;
215 dev->arg = arg;
216
217 schedule_work(&dev->recv_work);
218
219 if (dev->dropframe) {
220 NFCSIM_DBG(dev, "dropping frame (out of %d)\n", dev->dropframe);
221 dev_kfree_skb(skb);
222 dev->dropframe--;
223
224 return 0;
225 }
226
227 if (skb) {
228 nfcsim_link_set_skb(dev->link_out, skb, dev->rf_tech,
229 dev->mode);
230
231
232 get_random_bytes(&delay, 1);
233 delay = 3 + (delay & 0x07);
234
235 schedule_delayed_work(&dev->send_work, msecs_to_jiffies(delay));
236 }
237
238 return 0;
239}
240
241static void nfcsim_abort_cmd(struct nfc_digital_dev *ddev)
242{
243 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
244
245 nfcsim_link_recv_cancel(dev->link_in);
246}
247
248static int nfcsim_switch_rf(struct nfc_digital_dev *ddev, bool on)
249{
250 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
251
252 dev->up = on;
253
254 return 0;
255}
256
257static int nfcsim_in_configure_hw(struct nfc_digital_dev *ddev,
258 int type, int param)
259{
260 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
261
262 switch (type) {
263 case NFC_DIGITAL_CONFIG_RF_TECH:
264 dev->up = true;
265 dev->mode = NFCSIM_MODE_INITIATOR;
266 dev->rf_tech = param;
267 break;
268
269 case NFC_DIGITAL_CONFIG_FRAMING:
270 break;
271
272 default:
273 NFCSIM_ERR(dev, "Invalid configuration type: %d\n", type);
274 return -EINVAL;
275 }
276
277 return 0;
278}
279
280static int nfcsim_in_send_cmd(struct nfc_digital_dev *ddev,
281 struct sk_buff *skb, u16 timeout,
282 nfc_digital_cmd_complete_t cb, void *arg)
283{
284 return nfcsim_send(ddev, skb, timeout, cb, arg);
285}
286
287static int nfcsim_tg_configure_hw(struct nfc_digital_dev *ddev,
288 int type, int param)
289{
290 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
291
292 switch (type) {
293 case NFC_DIGITAL_CONFIG_RF_TECH:
294 dev->up = true;
295 dev->mode = NFCSIM_MODE_TARGET;
296 dev->rf_tech = param;
297 break;
298
299 case NFC_DIGITAL_CONFIG_FRAMING:
300 break;
301
302 default:
303 NFCSIM_ERR(dev, "Invalid configuration type: %d\n", type);
304 return -EINVAL;
305 }
306
307 return 0;
308}
309
310static int nfcsim_tg_send_cmd(struct nfc_digital_dev *ddev,
311 struct sk_buff *skb, u16 timeout,
312 nfc_digital_cmd_complete_t cb, void *arg)
313{
314 return nfcsim_send(ddev, skb, timeout, cb, arg);
315}
316
317static int nfcsim_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
318 nfc_digital_cmd_complete_t cb, void *arg)
319{
320 return nfcsim_send(ddev, NULL, timeout, cb, arg);
321}
322
323static struct nfc_digital_ops nfcsim_digital_ops = {
324 .in_configure_hw = nfcsim_in_configure_hw,
325 .in_send_cmd = nfcsim_in_send_cmd,
326
327 .tg_listen = nfcsim_tg_listen,
328 .tg_configure_hw = nfcsim_tg_configure_hw,
329 .tg_send_cmd = nfcsim_tg_send_cmd,
330
331 .abort_cmd = nfcsim_abort_cmd,
332 .switch_rf = nfcsim_switch_rf,
333};
334
335static struct dentry *nfcsim_debugfs_root;
336
337static void nfcsim_debugfs_init(void)
338{
339 nfcsim_debugfs_root = debugfs_create_dir("nfcsim", NULL);
340
341 if (!nfcsim_debugfs_root)
342 pr_err("Could not create debugfs entry\n");
343
344}
345
346static void nfcsim_debugfs_remove(void)
347{
348 debugfs_remove_recursive(nfcsim_debugfs_root);
349}
350
351static void nfcsim_debugfs_init_dev(struct nfcsim *dev)
352{
353 struct dentry *dev_dir;
354 char devname[5];
355 u32 idx;
356 int n;
357
358 if (!nfcsim_debugfs_root) {
359 NFCSIM_ERR(dev, "nfcsim debugfs not initialized\n");
360 return;
361 }
362
363 idx = dev->nfc_digital_dev->nfc_dev->idx;
364 n = snprintf(devname, sizeof(devname), "nfc%d", idx);
365 if (n >= sizeof(devname)) {
366 NFCSIM_ERR(dev, "Could not compute dev name for dev %d\n", idx);
367 return;
368 }
369
370 dev_dir = debugfs_create_dir(devname, nfcsim_debugfs_root);
371 if (!dev_dir) {
372 NFCSIM_ERR(dev, "Could not create debugfs entries for nfc%d\n",
373 idx);
374 return;
375 }
376
377 debugfs_create_u8("dropframe", 0664, dev_dir, &dev->dropframe);
378}
379
380static struct nfcsim *nfcsim_device_new(struct nfcsim_link *link_in,
381 struct nfcsim_link *link_out)
382{
383 struct nfcsim *dev;
384 int rc;
385
386 dev = kzalloc(sizeof(struct nfcsim), GFP_KERNEL);
387 if (!dev)
388 return ERR_PTR(-ENOMEM);
389
390 INIT_DELAYED_WORK(&dev->send_work, nfcsim_send_wq);
391 INIT_WORK(&dev->recv_work, nfcsim_recv_wq);
392
393 dev->nfc_digital_dev =
394 nfc_digital_allocate_device(&nfcsim_digital_ops,
395 NFC_PROTO_NFC_DEP_MASK,
396 NFCSIM_CAPABILITIES,
397 0, 0);
398 if (!dev->nfc_digital_dev) {
399 kfree(dev);
400 return ERR_PTR(-ENOMEM);
401 }
402
403 nfc_digital_set_drvdata(dev->nfc_digital_dev, dev);
404
405 dev->link_in = link_in;
406 dev->link_out = link_out;
407
408 rc = nfc_digital_register_device(dev->nfc_digital_dev);
409 if (rc) {
410 pr_err("Could not register digital device (%d)\n", rc);
411 nfc_digital_free_device(dev->nfc_digital_dev);
412 kfree(dev);
413
414 return ERR_PTR(rc);
415 }
416
417 nfcsim_debugfs_init_dev(dev);
418
419 return dev;
420}
421
422static void nfcsim_device_free(struct nfcsim *dev)
423{
424 nfc_digital_unregister_device(dev->nfc_digital_dev);
425
426 dev->up = false;
427
428 nfcsim_link_shutdown(dev->link_in);
429
430 cancel_delayed_work_sync(&dev->send_work);
431 cancel_work_sync(&dev->recv_work);
432
433 nfc_digital_free_device(dev->nfc_digital_dev);
434
435 kfree(dev);
436}
437
438static struct nfcsim *dev0;
439static struct nfcsim *dev1;
440
441static int __init nfcsim_init(void)
442{
443 struct nfcsim_link *link0, *link1;
444 int rc;
445
446 link0 = nfcsim_link_new();
447 link1 = nfcsim_link_new();
448 if (!link0 || !link1) {
449 rc = -ENOMEM;
450 goto exit_err;
451 }
452
453 nfcsim_debugfs_init();
454
455 dev0 = nfcsim_device_new(link0, link1);
456 if (IS_ERR(dev0)) {
457 rc = PTR_ERR(dev0);
458 goto exit_err;
459 }
460
461 dev1 = nfcsim_device_new(link1, link0);
462 if (IS_ERR(dev1)) {
463 nfcsim_device_free(dev0);
464
465 rc = PTR_ERR(dev1);
466 goto exit_err;
467 }
468
469 pr_info("nfcsim " NFCSIM_VERSION " initialized\n");
470
471 return 0;
472
473exit_err:
474 pr_err("Failed to initialize nfcsim driver (%d)\n", rc);
475
476 if (link0)
477 nfcsim_link_free(link0);
478 if (link1)
479 nfcsim_link_free(link1);
480
481 return rc;
482}
483
484static void __exit nfcsim_exit(void)
485{
486 struct nfcsim_link *link0, *link1;
487
488 link0 = dev0->link_in;
489 link1 = dev0->link_out;
490
491 nfcsim_device_free(dev0);
492 nfcsim_device_free(dev1);
493
494 nfcsim_link_free(link0);
495 nfcsim_link_free(link1);
496
497 nfcsim_debugfs_remove();
498}
499
500module_init(nfcsim_init);
501module_exit(nfcsim_exit);
502
503MODULE_DESCRIPTION("NFCSim driver ver " NFCSIM_VERSION);
504MODULE_VERSION(NFCSIM_VERSION);
505MODULE_LICENSE("GPL");
506
