2 * NFC hardware simulation driver
3 * Copyright (c) 2013, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 #include <linux/device.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/ctype.h>
20 #include <linux/debugfs.h>
21 #include <linux/nfc.h>
22 #include <net/nfc/nfc.h>
23 #include <net/nfc/digital.h>
25 #define NFCSIM_ERR(d, fmt, args...) nfc_err(&d->nfc_digital_dev->nfc_dev->dev, \
26 "%s: " fmt, __func__, ## args)
28 #define NFCSIM_DBG(d, fmt, args...) dev_dbg(&d->nfc_digital_dev->nfc_dev->dev, \
29 "%s: " fmt, __func__, ## args)
31 #define NFCSIM_VERSION "0.2"
33 #define NFCSIM_MODE_NONE 0
34 #define NFCSIM_MODE_INITIATOR 1
35 #define NFCSIM_MODE_TARGET 2
37 #define NFCSIM_CAPABILITIES (NFC_DIGITAL_DRV_CAPS_IN_CRC | \
38 NFC_DIGITAL_DRV_CAPS_TG_CRC)
41 struct nfc_digital_dev *nfc_digital_dev;
43 struct work_struct recv_work;
44 struct delayed_work send_work;
46 struct nfcsim_link *link_in;
47 struct nfcsim_link *link_out;
55 nfc_digital_cmd_complete_t cb;
70 wait_queue_head_t recv_wait;
74 static struct nfcsim_link *nfcsim_link_new(void)
76 struct nfcsim_link *link;
78 link = kzalloc(sizeof(struct nfcsim_link), GFP_KERNEL);
82 mutex_init(&link->lock);
83 init_waitqueue_head(&link->recv_wait);
88 static void nfcsim_link_free(struct nfcsim_link *link)
90 dev_kfree_skb(link->skb);
94 static void nfcsim_link_recv_wake(struct nfcsim_link *link)
97 wake_up_interruptible(&link->recv_wait);
100 static void nfcsim_link_set_skb(struct nfcsim_link *link, struct sk_buff *skb,
103 mutex_lock(&link->lock);
105 dev_kfree_skb(link->skb);
107 link->rf_tech = rf_tech;
110 mutex_unlock(&link->lock);
113 static void nfcsim_link_recv_cancel(struct nfcsim_link *link)
115 mutex_lock(&link->lock);
117 link->mode = NFCSIM_MODE_NONE;
119 mutex_unlock(&link->lock);
121 nfcsim_link_recv_wake(link);
124 static void nfcsim_link_shutdown(struct nfcsim_link *link)
126 mutex_lock(&link->lock);
129 link->mode = NFCSIM_MODE_NONE;
131 mutex_unlock(&link->lock);
133 nfcsim_link_recv_wake(link);
136 static struct sk_buff *nfcsim_link_recv_skb(struct nfcsim_link *link,
137 int timeout, u8 rf_tech, u8 mode)
142 rc = wait_event_interruptible_timeout(link->recv_wait,
144 msecs_to_jiffies(timeout));
146 mutex_lock(&link->lock);
156 if (!skb || link->rf_tech != rf_tech || link->mode == mode) {
161 if (link->shutdown) {
167 mutex_unlock(&link->lock);
179 static void nfcsim_send_wq(struct work_struct *work)
181 struct nfcsim *dev = container_of(work, struct nfcsim, send_work.work);
184 * To effectively send data, the device just wake up its link_out which
185 * is the link_in of the peer device. The exchanged skb has already been
186 * stored in the dev->link_out through nfcsim_link_set_skb().
188 nfcsim_link_recv_wake(dev->link_out);
191 static void nfcsim_recv_wq(struct work_struct *work)
193 struct nfcsim *dev = container_of(work, struct nfcsim, recv_work);
196 skb = nfcsim_link_recv_skb(dev->link_in, dev->recv_timeout,
197 dev->rf_tech, dev->mode);
200 NFCSIM_ERR(dev, "Device is down\n");
207 dev->cb(dev->nfc_digital_dev, dev->arg, skb);
210 static int nfcsim_send(struct nfc_digital_dev *ddev, struct sk_buff *skb,
211 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
213 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
217 NFCSIM_ERR(dev, "Device is down\n");
221 dev->recv_timeout = timeout;
225 schedule_work(&dev->recv_work);
227 if (dev->dropframe) {
228 NFCSIM_DBG(dev, "dropping frame (out of %d)\n", dev->dropframe);
236 nfcsim_link_set_skb(dev->link_out, skb, dev->rf_tech,
239 /* Add random delay (between 3 and 10 ms) before sending data */
240 get_random_bytes(&delay, 1);
241 delay = 3 + (delay & 0x07);
243 schedule_delayed_work(&dev->send_work, msecs_to_jiffies(delay));
249 static void nfcsim_abort_cmd(struct nfc_digital_dev *ddev)
251 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
253 nfcsim_link_recv_cancel(dev->link_in);
256 static int nfcsim_switch_rf(struct nfc_digital_dev *ddev, bool on)
258 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
265 static int nfcsim_in_configure_hw(struct nfc_digital_dev *ddev,
268 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
271 case NFC_DIGITAL_CONFIG_RF_TECH:
273 dev->mode = NFCSIM_MODE_INITIATOR;
274 dev->rf_tech = param;
277 case NFC_DIGITAL_CONFIG_FRAMING:
281 NFCSIM_ERR(dev, "Invalid configuration type: %d\n", type);
288 static int nfcsim_in_send_cmd(struct nfc_digital_dev *ddev,
289 struct sk_buff *skb, u16 timeout,
290 nfc_digital_cmd_complete_t cb, void *arg)
292 return nfcsim_send(ddev, skb, timeout, cb, arg);
295 static int nfcsim_tg_configure_hw(struct nfc_digital_dev *ddev,
298 struct nfcsim *dev = nfc_digital_get_drvdata(ddev);
301 case NFC_DIGITAL_CONFIG_RF_TECH:
303 dev->mode = NFCSIM_MODE_TARGET;
304 dev->rf_tech = param;
307 case NFC_DIGITAL_CONFIG_FRAMING:
311 NFCSIM_ERR(dev, "Invalid configuration type: %d\n", type);
318 static int nfcsim_tg_send_cmd(struct nfc_digital_dev *ddev,
319 struct sk_buff *skb, u16 timeout,
320 nfc_digital_cmd_complete_t cb, void *arg)
322 return nfcsim_send(ddev, skb, timeout, cb, arg);
325 static int nfcsim_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
326 nfc_digital_cmd_complete_t cb, void *arg)
328 return nfcsim_send(ddev, NULL, timeout, cb, arg);
331 static struct nfc_digital_ops nfcsim_digital_ops = {
332 .in_configure_hw = nfcsim_in_configure_hw,
333 .in_send_cmd = nfcsim_in_send_cmd,
335 .tg_listen = nfcsim_tg_listen,
336 .tg_configure_hw = nfcsim_tg_configure_hw,
337 .tg_send_cmd = nfcsim_tg_send_cmd,
339 .abort_cmd = nfcsim_abort_cmd,
340 .switch_rf = nfcsim_switch_rf,
343 static struct dentry *nfcsim_debugfs_root;
345 static void nfcsim_debugfs_init(void)
347 nfcsim_debugfs_root = debugfs_create_dir("nfcsim", NULL);
349 if (!nfcsim_debugfs_root)
350 pr_err("Could not create debugfs entry\n");
354 static void nfcsim_debugfs_remove(void)
356 debugfs_remove_recursive(nfcsim_debugfs_root);
359 static void nfcsim_debugfs_init_dev(struct nfcsim *dev)
361 struct dentry *dev_dir;
362 char devname[5]; /* nfcX\0 */
366 if (!nfcsim_debugfs_root) {
367 NFCSIM_ERR(dev, "nfcsim debugfs not initialized\n");
371 idx = dev->nfc_digital_dev->nfc_dev->idx;
372 n = snprintf(devname, sizeof(devname), "nfc%d", idx);
373 if (n >= sizeof(devname)) {
374 NFCSIM_ERR(dev, "Could not compute dev name for dev %d\n", idx);
378 dev_dir = debugfs_create_dir(devname, nfcsim_debugfs_root);
380 NFCSIM_ERR(dev, "Could not create debugfs entries for nfc%d\n",
385 debugfs_create_u8("dropframe", 0664, dev_dir, &dev->dropframe);
388 static struct nfcsim *nfcsim_device_new(struct nfcsim_link *link_in,
389 struct nfcsim_link *link_out)
394 dev = kzalloc(sizeof(struct nfcsim), GFP_KERNEL);
396 return ERR_PTR(-ENOMEM);
398 INIT_DELAYED_WORK(&dev->send_work, nfcsim_send_wq);
399 INIT_WORK(&dev->recv_work, nfcsim_recv_wq);
401 dev->nfc_digital_dev =
402 nfc_digital_allocate_device(&nfcsim_digital_ops,
403 NFC_PROTO_NFC_DEP_MASK,
406 if (!dev->nfc_digital_dev) {
408 return ERR_PTR(-ENOMEM);
411 nfc_digital_set_drvdata(dev->nfc_digital_dev, dev);
413 dev->link_in = link_in;
414 dev->link_out = link_out;
416 rc = nfc_digital_register_device(dev->nfc_digital_dev);
418 pr_err("Could not register digital device (%d)\n", rc);
419 nfc_digital_free_device(dev->nfc_digital_dev);
425 nfcsim_debugfs_init_dev(dev);
430 static void nfcsim_device_free(struct nfcsim *dev)
432 nfc_digital_unregister_device(dev->nfc_digital_dev);
436 nfcsim_link_shutdown(dev->link_in);
438 cancel_delayed_work_sync(&dev->send_work);
439 cancel_work_sync(&dev->recv_work);
441 nfc_digital_free_device(dev->nfc_digital_dev);
446 static struct nfcsim *dev0;
447 static struct nfcsim *dev1;
449 static int __init nfcsim_init(void)
451 struct nfcsim_link *link0, *link1;
454 link0 = nfcsim_link_new();
455 link1 = nfcsim_link_new();
456 if (!link0 || !link1) {
461 nfcsim_debugfs_init();
463 dev0 = nfcsim_device_new(link0, link1);
469 dev1 = nfcsim_device_new(link1, link0);
471 nfcsim_device_free(dev0);
477 pr_info("nfcsim " NFCSIM_VERSION " initialized\n");
482 pr_err("Failed to initialize nfcsim driver (%d)\n", rc);
484 nfcsim_link_free(link0);
485 nfcsim_link_free(link1);
490 static void __exit nfcsim_exit(void)
492 struct nfcsim_link *link0, *link1;
494 link0 = dev0->link_in;
495 link1 = dev0->link_out;
497 nfcsim_device_free(dev0);
498 nfcsim_device_free(dev1);
500 nfcsim_link_free(link0);
501 nfcsim_link_free(link1);
503 nfcsim_debugfs_remove();
506 module_init(nfcsim_init);
507 module_exit(nfcsim_exit);
509 MODULE_DESCRIPTION("NFCSim driver ver " NFCSIM_VERSION);
510 MODULE_VERSION(NFCSIM_VERSION);
511 MODULE_LICENSE("GPL");