summaryrefslogtreecommitdiffstats
path: root/drivers/nfc/pn544.c
blob: 401c44b6eadb8220c726bb6511cf8ae8bca15000 (plain)
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
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
/*
 * Driver for the PN544 NFC chip.
 *
 * Copyright (C) Nokia Corporation
 *
 * Author: Jari Vanhala <ext-jari.vanhala@nokia.com>
 * Contact: Matti Aaltonen <matti.j.aaltonen@nokia.com>
 *
 * 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/completion.h>
#include <linux/crc-ccitt.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nfc/pn544.h>
#include <linux/poll.h>
#include <linux/regulator/consumer.h>
#include <linux/serial_core.h> /* for TCGETS */
#include <linux/slab.h>

#define DRIVER_CARD	"PN544 NFC"
#define DRIVER_DESC	"NFC driver for PN544"

static struct i2c_device_id pn544_id_table[] = {
	{ PN544_DRIVER_NAME, 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, pn544_id_table);

#define HCI_MODE	0
#define FW_MODE		1

enum pn544_state {
	PN544_ST_COLD,
	PN544_ST_FW_READY,
	PN544_ST_READY,
};

enum pn544_irq {
	PN544_NONE,
	PN544_INT,
};

struct pn544_info {
	struct miscdevice miscdev;
	struct i2c_client *i2c_dev;
	struct regulator_bulk_data regs[2];

	enum pn544_state state;
	wait_queue_head_t read_wait;
	loff_t read_offset;
	enum pn544_irq read_irq;
	struct mutex read_mutex; /* Serialize read_irq access */
	struct mutex mutex; /* Serialize info struct access */
	u8 *buf;
	unsigned int buflen;
};

static const char reg_vdd_io[]	= "Vdd_IO";
static const char reg_vbat[]	= "VBat";

/* sysfs interface */
static ssize_t pn544_test(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	struct pn544_info *info = dev_get_drvdata(dev);
	struct i2c_client *client = info->i2c_dev;
	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;

	return snprintf(buf, PAGE_SIZE, "%d\n", pdata->test());
}

static int pn544_enable(struct pn544_info *info, int mode)
{
	struct pn544_nfc_platform_data *pdata;
	struct i2c_client *client = info->i2c_dev;

	int r;

	r = regulator_bulk_enable(ARRAY_SIZE(info->regs), info->regs);
	if (r < 0)
		return r;

	pdata = client->dev.platform_data;
	info->read_irq = PN544_NONE;
	if (pdata->enable)
		pdata->enable(mode);

	if (mode) {
		info->state = PN544_ST_FW_READY;
		dev_dbg(&client->dev, "now in FW-mode\n");
	} else {
		info->state = PN544_ST_READY;
		dev_dbg(&client->dev, "now in HCI-mode\n");
	}

	usleep_range(10000, 15000);

	return 0;
}

static void pn544_disable(struct pn544_info *info)
{
	struct pn544_nfc_platform_data *pdata;
	struct i2c_client *client = info->i2c_dev;

	pdata = client->dev.platform_data;
	if (pdata->disable)
		pdata->disable();

	info->state = PN544_ST_COLD;

	dev_dbg(&client->dev, "Now in OFF-mode\n");

	msleep(PN544_RESETVEN_TIME);

	info->read_irq = PN544_NONE;
	regulator_bulk_disable(ARRAY_SIZE(info->regs), info->regs);
}

static int check_crc(u8 *buf, int buflen)
{
	u8 len;
	u16 crc;

	len = buf[0] + 1;
	if (len < 4 || len != buflen || len > PN544_MSG_MAX_SIZE) {
		pr_err(PN544_DRIVER_NAME
		       ": CRC; corrupt packet len %u (%d)\n", len, buflen);
		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
			       16, 2, buf, buflen, false);
		return -EPERM;
	}
	crc = crc_ccitt(0xffff, buf, len - 2);
	crc = ~crc;

	if (buf[len-2] != (crc & 0xff) || buf[len-1] != (crc >> 8)) {
		pr_err(PN544_DRIVER_NAME ": CRC error 0x%x != 0x%x 0x%x\n",
		       crc, buf[len-1], buf[len-2]);

		print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
			       16, 2, buf, buflen, false);
		return -EPERM;
	}
	return 0;
}

static int pn544_i2c_write(struct i2c_client *client, u8 *buf, int len)
{
	int r;

	if (len < 4 || len != (buf[0] + 1)) {
		dev_err(&client->dev, "%s: Illegal message length: %d\n",
			__func__, len);
		return -EINVAL;
	}

	if (check_crc(buf, len))
		return -EINVAL;

	usleep_range(3000, 6000);

	r = i2c_master_send(client, buf, len);
	dev_dbg(&client->dev, "send: %d\n", r);

	if (r == -EREMOTEIO) { /* Retry, chip was in standby */
		usleep_range(6000, 10000);
		r = i2c_master_send(client, buf, len);
		dev_dbg(&client->dev, "send2: %d\n", r);
	}

	if (r != len)
		return -EREMOTEIO;

	return r;
}

static int pn544_i2c_read(struct i2c_client *client, u8 *buf, int buflen)
{
	int r;
	u8 len;

	/*
	 * You could read a packet in one go, but then you'd need to read
	 * max size and rest would be 0xff fill, so we do split reads.
	 */
	r = i2c_master_recv(client, &len, 1);
	dev_dbg(&client->dev, "recv1: %d\n", r);

	if (r != 1)
		return -EREMOTEIO;

	if (len < PN544_LLC_HCI_OVERHEAD)
		len = PN544_LLC_HCI_OVERHEAD;
	else if (len > (PN544_MSG_MAX_SIZE - 1))
		len = PN544_MSG_MAX_SIZE - 1;

	if (1 + len > buflen) /* len+(data+crc16) */
		return -EMSGSIZE;

	buf[0] = len;

	r = i2c_master_recv(client, buf + 1, len);
	dev_dbg(&client->dev, "recv2: %d\n", r);

	if (r != len)
		return -EREMOTEIO;

	usleep_range(3000, 6000);

	return r + 1;
}

static int pn544_fw_write(struct i2c_client *client, u8 *buf, int len)
{
	int r;

	dev_dbg(&client->dev, "%s\n", __func__);

	if (len < PN544_FW_HEADER_SIZE ||
	    (PN544_FW_HEADER_SIZE + (buf[1] << 8) + buf[2]) != len)
		return -EINVAL;

	r = i2c_master_send(client, buf, len);
	dev_dbg(&client->dev, "fw send: %d\n", r);

	if (r == -EREMOTEIO) { /* Retry, chip was in standby */
		usleep_range(6000, 10000);
		r = i2c_master_send(client, buf, len);
		dev_dbg(&client->dev, "fw send2: %d\n", r);
	}

	if (r != len)
		return -EREMOTEIO;

	return r;
}

static int pn544_fw_read(struct i2c_client *client, u8 *buf, int buflen)
{
	int r, len;

	if (buflen < PN544_FW_HEADER_SIZE)
		return -EINVAL;

	r = i2c_master_recv(client, buf, PN544_FW_HEADER_SIZE);
	dev_dbg(&client->dev, "FW recv1: %d\n", r);

	if (r < 0)
		return r;

	if (r < PN544_FW_HEADER_SIZE)
		return -EINVAL;

	len = (buf[1] << 8) + buf[2];
	if (len == 0) /* just header, no additional data */
		return r;

	if (len > buflen - PN544_FW_HEADER_SIZE)
		return -EMSGSIZE;

	r = i2c_master_recv(client, buf + PN544_FW_HEADER_SIZE, len);
	dev_dbg(&client->dev, "fw recv2: %d\n", r);

	if (r != len)
		return -EINVAL;

	return r + PN544_FW_HEADER_SIZE;
}

static irqreturn_t pn544_irq_thread_fn(int irq, void *dev_id)
{
	struct pn544_info *info = dev_id;
	struct i2c_client *client = info->i2c_dev;

	BUG_ON(!info);
	BUG_ON(irq != info->i2c_dev->irq);

	dev_dbg(&client->dev, "IRQ\n");

	mutex_lock(&info->read_mutex);
	info->read_irq = PN544_INT;
	mutex_unlock(&info->read_mutex);

	wake_up_interruptible(&info->read_wait);

	return IRQ_HANDLED;
}

static enum pn544_irq pn544_irq_state(struct pn544_info *info)
{
	enum pn544_irq irq;

	mutex_lock(&info->read_mutex);
	irq = info->read_irq;
	mutex_unlock(&info->read_mutex);
	/*
	 * XXX: should we check GPIO-line status directly?
	 * return pdata->irq_status() ? PN544_INT : PN544_NONE;
	 */

	return irq;
}

static ssize_t pn544_read(struct file *file, char __user *buf,
			  size_t count, loff_t *offset)
{
	struct pn544_info *info = container_of(file->private_data,
					       struct pn544_info, miscdev);
	struct i2c_client *client = info->i2c_dev;
	enum pn544_irq irq;
	size_t len;
	int r = 0;

	dev_dbg(&client->dev, "%s: info: %p, count: %zu\n", __func__,
		info, count);

	mutex_lock(&info->mutex);

	if (info->state == PN544_ST_COLD) {
		r = -ENODEV;
		goto out;
	}

	irq = pn544_irq_state(info);
	if (irq == PN544_NONE) {
		if (file->f_flags & O_NONBLOCK) {
			r = -EAGAIN;
			goto out;
		}

		if (wait_event_interruptible(info->read_wait,
					     (info->read_irq == PN544_INT))) {
			r = -ERESTARTSYS;
			goto out;
		}
	}

	if (info->state == PN544_ST_FW_READY) {
		len = min(count, info->buflen);

		mutex_lock(&info->read_mutex);
		r = pn544_fw_read(info->i2c_dev, info->buf, len);
		info->read_irq = PN544_NONE;
		mutex_unlock(&info->read_mutex);

		if (r < 0) {
			dev_err(&info->i2c_dev->dev, "FW read failed: %d\n", r);
			goto out;
		}

		print_hex_dump(KERN_DEBUG, "FW read: ", DUMP_PREFIX_NONE,
			       16, 2, info->buf, r, false);

		*offset += r;
		if (copy_to_user(buf, info->buf, r)) {
			r = -EFAULT;
			goto out;
		}
	} else {
		len = min(count, info->buflen);

		mutex_lock(&info->read_mutex);
		r = pn544_i2c_read(info->i2c_dev, info->buf, len);
		info->read_irq = PN544_NONE;
		mutex_unlock(&info->read_mutex);

		if (r < 0) {
			dev_err(&info->i2c_dev->dev, "read failed (%d)\n", r);
			goto out;
		}
		print_hex_dump(KERN_DEBUG, "read: ", DUMP_PREFIX_NONE,
			       16, 2, info->buf, r, false);

		*offset += r;
		if (copy_to_user(buf, info->buf, r)) {
			r = -EFAULT;
			goto out;
		}
	}

out:
	mutex_unlock(&info->mutex);

	return r;
}

static unsigned int pn544_poll(struct file *file, poll_table *wait)
{
	struct pn544_info *info = container_of(file->private_data,
					       struct pn544_info, miscdev);
	struct i2c_client *client = info->i2c_dev;
	int r = 0;

	dev_dbg(&client->dev, "%s: info: %p\n", __func__, info);

	mutex_lock(&info->mutex);

	if (info->state == PN544_ST_COLD) {
		r = -ENODEV;
		goto out;
	}

	poll_wait(file, &info->read_wait, wait);

	if (pn544_irq_state(info) == PN544_INT) {
		r = POLLIN | POLLRDNORM;
		goto out;
	}
out:
	mutex_unlock(&info->mutex);

	return r;
}

static ssize_t pn544_write(struct file *file, const char __user *buf,
			   size_t count, loff_t *ppos)
{
	struct pn544_info *info = container_of(file->private_data,
					       struct pn544_info, miscdev);
	struct i2c_client *client = info->i2c_dev;
	ssize_t	len;
	int r;

	dev_dbg(&client->dev, "%s: info: %p, count %zu\n", __func__,
		info, count);

	mutex_lock(&info->mutex);

	if (info->state == PN544_ST_COLD) {
		r = -ENODEV;
		goto out;
	}

	/*
	 * XXX: should we detect rset-writes and clean possible
	 * read_irq state
	 */
	if (info->state == PN544_ST_FW_READY) {
		size_t fw_len;

		if (count < PN544_FW_HEADER_SIZE) {
			r = -EINVAL;
			goto out;
		}

		len = min(count, info->buflen);
		if (copy_from_user(info->buf, buf, len)) {
			r = -EFAULT;
			goto out;
		}

		print_hex_dump(KERN_DEBUG, "FW write: ", DUMP_PREFIX_NONE,
			       16, 2, info->buf, len, false);

		fw_len = PN544_FW_HEADER_SIZE + (info->buf[1] << 8) +
			info->buf[2];

		if (len > fw_len) /* 1 msg at a time */
			len = fw_len;

		r = pn544_fw_write(info->i2c_dev, info->buf, len);
	} else {
		if (count < PN544_LLC_MIN_SIZE) {
			r = -EINVAL;
			goto out;
		}

		len = min(count, info->buflen);
		if (copy_from_user(info->buf, buf, len)) {
			r = -EFAULT;
			goto out;
		}

		print_hex_dump(KERN_DEBUG, "write: ", DUMP_PREFIX_NONE,
			       16, 2, info->buf, len, false);

		if (len > (info->buf[0] + 1)) /* 1 msg at a time */
			len  = info->buf[0] + 1;

		r = pn544_i2c_write(info->i2c_dev, info->buf, len);
	}
out:
	mutex_unlock(&info->mutex);

	return r;

}

static long pn544_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct pn544_info *info = container_of(file->private_data,
					       struct pn544_info, miscdev);
	struct i2c_client *client = info->i2c_dev;
	struct pn544_nfc_platform_data *pdata;
	unsigned int val;
	int r = 0;

	dev_dbg(&client->dev, "%s: info: %p, cmd: 0x%x\n", __func__, info, cmd);

	mutex_lock(&info->mutex);

	if (info->state == PN544_ST_COLD) {
		r = -ENODEV;
		goto out;
	}

	pdata = info->i2c_dev->dev.platform_data;
	switch (cmd) {
	case PN544_GET_FW_MODE:
		dev_dbg(&client->dev, "%s:  PN544_GET_FW_MODE\n", __func__);

		val = (info->state == PN544_ST_FW_READY);
		if (copy_to_user((void __user *)arg, &val, sizeof(val))) {
			r = -EFAULT;
			goto out;
		}

		break;

	case PN544_SET_FW_MODE:
		dev_dbg(&client->dev, "%s:  PN544_SET_FW_MODE\n", __func__);

		if (copy_from_user(&val, (void __user *)arg, sizeof(val))) {
			r = -EFAULT;
			goto out;
		}

		if (val) {
			if (info->state == PN544_ST_FW_READY)
				break;

			pn544_disable(info);
			r = pn544_enable(info, FW_MODE);
			if (r < 0)
				goto out;
		} else {
			if (info->state == PN544_ST_READY)
				break;
			pn544_disable(info);
			r = pn544_enable(info, HCI_MODE);
			if (r < 0)
				goto out;
		}
		file->f_pos = info->read_offset;
		break;

	case TCGETS:
		dev_dbg(&client->dev, "%s:  TCGETS\n", __func__);

		r = -ENOIOCTLCMD;
		break;

	default:
		dev_err(&client->dev, "Unknown ioctl 0x%x\n", cmd);
		r = -ENOIOCTLCMD;
		break;
	}

out:
	mutex_unlock(&info->mutex);

	return r;
}

static int pn544_open(struct inode *inode, struct file *file)
{
	struct pn544_info *info = container_of(file->private_data,
					       struct pn544_info, miscdev);
	struct i2c_client *client = info->i2c_dev;
	int r = 0;

	dev_dbg(&client->dev, "%s: info: %p, client %p\n", __func__,
		info, info->i2c_dev);

	mutex_lock(&info->mutex);

	/*
	 * Only 1 at a time.
	 * XXX: maybe user (counter) would work better
	 */
	if (info->state != PN544_ST_COLD) {
		r = -EBUSY;
		goto out;
	}

	file->f_pos = info->read_offset;
	r = pn544_enable(info, HCI_MODE);

out:
	mutex_unlock(&info->mutex);
	return r;
}

static int pn544_close(struct inode *inode, struct file *file)
{
	struct pn544_info *info = container_of(file->private_data,
					       struct pn544_info, miscdev);
	struct i2c_client *client = info->i2c_dev;

	dev_dbg(&client->dev, "%s: info: %p, client %p\n",
		__func__, info, info->i2c_dev);

	mutex_lock(&info->mutex);
	pn544_disable(info);
	mutex_unlock(&info->mutex);

	return 0;
}

static const struct file_operations pn544_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= pn544_read,
	.write		= pn544_write,
	.poll		= pn544_poll,
	.open		= pn544_open,
	.release	= pn544_close,
	.unlocked_ioctl	= pn544_ioctl,
};

#ifdef CONFIG_PM
static int pn544_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct pn544_info *info;
	int r = 0;

	dev_info(&client->dev, "***\n%s: client %p\n***\n", __func__, client);

	info = i2c_get_clientdata(client);
	dev_info(&client->dev, "%s: info: %p, client %p\n", __func__,
		 info, client);

	mutex_lock(&info->mutex);

	switch (info->state) {
	case PN544_ST_FW_READY:
		/* Do not suspend while upgrading FW, please! */
		r = -EPERM;
		break;

	case PN544_ST_READY:
		/*
		 * CHECK: Device should be in standby-mode. No way to check?
		 * Allowing low power mode for the regulator is potentially
		 * dangerous if pn544 does not go to suspension.
		 */
		break;

	case PN544_ST_COLD:
		break;
	};

	mutex_unlock(&info->mutex);
	return r;
}

static int pn544_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct pn544_info *info = i2c_get_clientdata(client);
	int r = 0;

	dev_dbg(&client->dev, "%s: info: %p, client %p\n", __func__,
		info, client);

	mutex_lock(&info->mutex);

	switch (info->state) {
	case PN544_ST_READY:
		/*
		 * CHECK: If regulator low power mode is allowed in
		 * pn544_suspend, we should go back to normal mode
		 * here.
		 */
		break;

	case PN544_ST_COLD:
		break;

	case PN544_ST_FW_READY:
		break;
	};

	mutex_unlock(&info->mutex);

	return r;
}

static SIMPLE_DEV_PM_OPS(pn544_pm_ops, pn544_suspend, pn544_resume);
#endif

static struct device_attribute pn544_attr =
	__ATTR(nfc_test, S_IRUGO, pn544_test, NULL);

static int __devinit pn544_probe(struct i2c_client *client,
				 const struct i2c_device_id *id)
{
	struct pn544_info *info;
	struct pn544_nfc_platform_data *pdata;
	int r = 0;

	dev_dbg(&client->dev, "%s\n", __func__);
	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);

	/* private data allocation */
	info = kzalloc(sizeof(struct pn544_info), GFP_KERNEL);
	if (!info) {
		dev_err(&client->dev,
			"Cannot allocate memory for pn544_info.\n");
		r = -ENOMEM;
		goto err_info_alloc;
	}

	info->buflen = max(PN544_MSG_MAX_SIZE, PN544_MAX_I2C_TRANSFER);
	info->buf = kzalloc(info->buflen, GFP_KERNEL);
	if (!info->buf) {
		dev_err(&client->dev,
			"Cannot allocate memory for pn544_info->buf.\n");
		r = -ENOMEM;
		goto err_buf_alloc;
	}

	info->regs[0].supply = reg_vdd_io;
	info->regs[1].supply = reg_vbat;
	r = regulator_bulk_get(&client->dev, ARRAY_SIZE(info->regs),
				 info->regs);
	if (r < 0)
		goto err_kmalloc;

	info->i2c_dev = client;
	info->state = PN544_ST_COLD;
	info->read_irq = PN544_NONE;
	mutex_init(&info->read_mutex);
	mutex_init(&info->mutex);
	init_waitqueue_head(&info->read_wait);
	i2c_set_clientdata(client, info);
	pdata = client->dev.platform_data;
	if (!pdata) {
		dev_err(&client->dev, "No platform data\n");
		r = -EINVAL;
		goto err_reg;
	}

	if (!pdata->request_resources) {
		dev_err(&client->dev, "request_resources() missing\n");
		r = -EINVAL;
		goto err_reg;
	}

	r = pdata->request_resources(client);
	if (r) {
		dev_err(&client->dev, "Cannot get platform resources\n");
		goto err_reg;
	}

	r = request_threaded_irq(client->irq, NULL, pn544_irq_thread_fn,
				 IRQF_TRIGGER_RISING, PN544_DRIVER_NAME,
				 info);
	if (r < 0) {
		dev_err(&client->dev, "Unable to register IRQ handler\n");
		goto err_res;
	}

	/* If we don't have the test we don't need the sysfs file */
	if (pdata->test) {
		r = device_create_file(&client->dev, &pn544_attr);
		if (r) {
			dev_err(&client->dev,
				"sysfs registration failed, error %d\n", r);
			goto err_irq;
		}
	}

	info->miscdev.minor = MISC_DYNAMIC_MINOR;
	info->miscdev.name = PN544_DRIVER_NAME;
	info->miscdev.fops = &pn544_fops;
	info->miscdev.parent = &client->dev;
	r = misc_register(&info->miscdev);
	if (r < 0) {
		dev_err(&client->dev, "Device registration failed\n");
		goto err_sysfs;
	}

	dev_dbg(&client->dev, "%s: info: %p, pdata %p, client %p\n",
		__func__, info, pdata, client);

	return 0;

err_sysfs:
	if (pdata->test)
		device_remove_file(&client->dev, &pn544_attr);
err_irq:
	free_irq(client->irq, info);
err_res:
	if (pdata->free_resources)
		pdata->free_resources();
err_reg:
	regulator_bulk_free(ARRAY_SIZE(info->regs), info->regs);
err_kmalloc:
	kfree(info->buf);
err_buf_alloc:
	kfree(info);
err_info_alloc:
	return r;
}

static __devexit int pn544_remove(struct i2c_client *client)
{
	struct pn544_info *info = i2c_get_clientdata(client);
	struct pn544_nfc_platform_data *pdata = client->dev.platform_data;

	dev_dbg(&client->dev, "%s\n", __func__);

	misc_deregister(&info->miscdev);
	if (pdata->test)
		device_remove_file(&client->dev, &pn544_attr);

	if (info->state != PN544_ST_COLD) {
		if (pdata->disable)
			pdata->disable();

		info->read_irq = PN544_NONE;
	}

	free_irq(client->irq, info);
	if (pdata->free_resources)
		pdata->free_resources();

	regulator_bulk_free(ARRAY_SIZE(info->regs), info->regs);
	kfree(info->buf);
	kfree(info);

	return 0;
}

static struct i2c_driver pn544_driver = {
	.driver = {
		.name = PN544_DRIVER_NAME,
#ifdef CONFIG_PM
		.pm = &pn544_pm_ops,
#endif
	},
	.probe = pn544_probe,
	.id_table = pn544_id_table,
	.remove = __devexit_p(pn544_remove),
};

static int __init pn544_init(void)
{
	int r;

	pr_debug(DRIVER_DESC ": %s\n", __func__);

	r = i2c_add_driver(&pn544_driver);
	if (r) {
		pr_err(PN544_DRIVER_NAME ": driver registration failed\n");
		return r;
	}

	return 0;
}

static void __exit pn544_exit(void)
{
	i2c_del_driver(&pn544_driver);
	pr_info(DRIVER_DESC ", Exiting.\n");
}

module_init(pn544_init);
module_exit(pn544_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION(DRIVER_DESC);