summaryrefslogtreecommitdiff
path: root/drivers/char/xilinx_hwicap/xilinx_hwicap.c
blob: ed132fe55d3d35aad97339593d5a131fc601b8ba (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
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
892
893
894
895
896
897
/*****************************************************************************
 *
 *     Author: Xilinx, Inc.
 *
 *     This program is free software; you can redistribute it and/or modify it
 *     under the terms of the GNU General Public License as published by the
 *     Free Software Foundation; either version 2 of the License, or (at your
 *     option) any later version.
 *
 *     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
 *     AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
 *     SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
 *     OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
 *     APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
 *     THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
 *     AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
 *     FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
 *     WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
 *     IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
 *     REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
 *     INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *     FOR A PARTICULAR PURPOSE.
 *
 *     Xilinx products are not intended for use in life support appliances,
 *     devices, or systems. Use in such applications is expressly prohibited.
 *
 *     (c) Copyright 2002 Xilinx Inc., Systems Engineering Group
 *     (c) Copyright 2004 Xilinx Inc., Systems Engineering Group
 *     (c) Copyright 2007-2008 Xilinx Inc.
 *     All rights reserved.
 *
 *     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.,
 *     675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *****************************************************************************/

/*
 * This is the code behind /dev/icap* -- it allows a user-space
 * application to use the Xilinx ICAP subsystem.
 *
 * The following operations are possible:
 *
 * open         open the port and initialize for access.
 * release      release port
 * write        Write a bitstream to the configuration processor.
 * read         Read a data stream from the configuration processor.
 *
 * After being opened, the port is initialized and accessed to avoid a
 * corrupted first read which may occur with some hardware.  The port
 * is left in a desynched state, requiring that a synch sequence be
 * transmitted before any valid configuration data.  A user will have
 * exclusive access to the device while it remains open, and the state
 * of the ICAP cannot be guaranteed after the device is closed.  Note
 * that a complete reset of the core and the state of the ICAP cannot
 * be performed on many versions of the cores, hence users of this
 * device should avoid making inconsistent accesses to the device.  In
 * particular, accessing the read interface, without first generating
 * a write containing a readback packet can leave the ICAP in an
 * inaccessible state.
 *
 * Note that in order to use the read interface, it is first necessary
 * to write a request packet to the write interface.  i.e., it is not
 * possible to simply readback the bitstream (or any configuration
 * bits) from a device without specifically requesting them first.
 * The code to craft such packets is intended to be part of the
 * user-space application code that uses this device.  The simplest
 * way to use this interface is simply:
 *
 * cp foo.bit /dev/icap0
 *
 * Note that unless foo.bit is an appropriately constructed partial
 * bitstream, this has a high likelyhood of overwriting the design
 * currently programmed in the FPGA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/smp_lock.h>
#include <linux/sysctl.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/platform_device.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>

#ifdef CONFIG_OF
/* For open firmware. */
#include <linux/of_device.h>
#include <linux/of_platform.h>
#endif

#include "xilinx_hwicap.h"
#include "buffer_icap.h"
#include "fifo_icap.h"

#define DRIVER_NAME "icap"

#define HWICAP_REGS   (0x10000)

#define XHWICAP_MAJOR 259
#define XHWICAP_MINOR 0
#define HWICAP_DEVICES 1

/* An array, which is set to true when the device is registered. */
static bool probed_devices[HWICAP_DEVICES];
static struct mutex icap_sem;

static struct class *icap_class;

#define UNIMPLEMENTED 0xFFFF

static const struct config_registers v2_config_registers = {
	.CRC = 0,
	.FAR = 1,
	.FDRI = 2,
	.FDRO = 3,
	.CMD = 4,
	.CTL = 5,
	.MASK = 6,
	.STAT = 7,
	.LOUT = 8,
	.COR = 9,
	.MFWR = 10,
	.FLR = 11,
	.KEY = 12,
	.CBC = 13,
	.IDCODE = 14,
	.AXSS = UNIMPLEMENTED,
	.C0R_1 = UNIMPLEMENTED,
	.CSOB = UNIMPLEMENTED,
	.WBSTAR = UNIMPLEMENTED,
	.TIMER = UNIMPLEMENTED,
	.BOOTSTS = UNIMPLEMENTED,
	.CTL_1 = UNIMPLEMENTED,
};

static const struct config_registers v4_config_registers = {
	.CRC = 0,
	.FAR = 1,
	.FDRI = 2,
	.FDRO = 3,
	.CMD = 4,
	.CTL = 5,
	.MASK = 6,
	.STAT = 7,
	.LOUT = 8,
	.COR = 9,
	.MFWR = 10,
	.FLR = UNIMPLEMENTED,
	.KEY = UNIMPLEMENTED,
	.CBC = 11,
	.IDCODE = 12,
	.AXSS = 13,
	.C0R_1 = UNIMPLEMENTED,
	.CSOB = UNIMPLEMENTED,
	.WBSTAR = UNIMPLEMENTED,
	.TIMER = UNIMPLEMENTED,
	.BOOTSTS = UNIMPLEMENTED,
	.CTL_1 = UNIMPLEMENTED,
};
static const struct config_registers v5_config_registers = {
	.CRC = 0,
	.FAR = 1,
	.FDRI = 2,
	.FDRO = 3,
	.CMD = 4,
	.CTL = 5,
	.MASK = 6,
	.STAT = 7,
	.LOUT = 8,
	.COR = 9,
	.MFWR = 10,
	.FLR = UNIMPLEMENTED,
	.KEY = UNIMPLEMENTED,
	.CBC = 11,
	.IDCODE = 12,
	.AXSS = 13,
	.C0R_1 = 14,
	.CSOB = 15,
	.WBSTAR = 16,
	.TIMER = 17,
	.BOOTSTS = 18,
	.CTL_1 = 19,
};

/**
 * hwicap_command_desync - Send a DESYNC command to the ICAP port.
 * @drvdata: a pointer to the drvdata.
 *
 * This command desynchronizes the ICAP After this command, a
 * bitstream containing a NULL packet, followed by a SYNCH packet is
 * required before the ICAP will recognize commands.
 */
static int hwicap_command_desync(struct hwicap_drvdata *drvdata)
{
	u32 buffer[4];
	u32 index = 0;

	/*
	 * Create the data to be written to the ICAP.
	 */
	buffer[index++] = hwicap_type_1_write(drvdata->config_regs->CMD) | 1;
	buffer[index++] = XHI_CMD_DESYNCH;
	buffer[index++] = XHI_NOOP_PACKET;
	buffer[index++] = XHI_NOOP_PACKET;

	/*
	 * Write the data to the FIFO and intiate the transfer of data present
	 * in the FIFO to the ICAP device.
	 */
	return drvdata->config->set_configuration(drvdata,
			&buffer[0], index);
}

/**
 * hwicap_get_configuration_register - Query a configuration register.
 * @drvdata: a pointer to the drvdata.
 * @reg: a constant which represents the configuration
 *		register value to be returned.
 * 		Examples:  XHI_IDCODE, XHI_FLR.
 * @reg_data: returns the value of the register.
 *
 * Sends a query packet to the ICAP and then receives the response.
 * The icap is left in Synched state.
 */
static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata,
		u32 reg, u32 *reg_data)
{
	int status;
	u32 buffer[6];
	u32 index = 0;

	/*
	 * Create the data to be written to the ICAP.
	 */
	buffer[index++] = XHI_DUMMY_PACKET;
	buffer[index++] = XHI_NOOP_PACKET;
	buffer[index++] = XHI_SYNC_PACKET;
	buffer[index++] = XHI_NOOP_PACKET;
	buffer[index++] = XHI_NOOP_PACKET;

	/*
	 * Write the data to the FIFO and initiate the transfer of data present
	 * in the FIFO to the ICAP device.
	 */
	status = drvdata->config->set_configuration(drvdata,
						    &buffer[0], index);
	if (status)
		return status;

	/* If the syncword was not found, then we need to start over. */
	status = drvdata->config->get_status(drvdata);
	if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK)
		return -EIO;

	index = 0;
	buffer[index++] = hwicap_type_1_read(reg) | 1;
	buffer[index++] = XHI_NOOP_PACKET;
	buffer[index++] = XHI_NOOP_PACKET;

	/*
	 * Write the data to the FIFO and intiate the transfer of data present
	 * in the FIFO to the ICAP device.
	 */
	status = drvdata->config->set_configuration(drvdata,
			&buffer[0], index);
	if (status)
		return status;

	/*
	 * Read the configuration register
	 */
	status = drvdata->config->get_configuration(drvdata, reg_data, 1);
	if (status)
		return status;

	return 0;
}

static int hwicap_initialize_hwicap(struct hwicap_drvdata *drvdata)
{
	int status;
	u32 idcode;

	dev_dbg(drvdata->dev, "initializing\n");

	/* Abort any current transaction, to make sure we have the
	 * ICAP in a good state. */
	dev_dbg(drvdata->dev, "Reset...\n");
	drvdata->config->reset(drvdata);

	dev_dbg(drvdata->dev, "Desync...\n");
	status = hwicap_command_desync(drvdata);
	if (status)
		return status;

	/* Attempt to read the IDCODE from ICAP.  This
	 * may not be returned correctly, due to the design of the
	 * hardware.
	 */
	dev_dbg(drvdata->dev, "Reading IDCODE...\n");
	status = hwicap_get_configuration_register(
			drvdata, drvdata->config_regs->IDCODE, &idcode);
	dev_dbg(drvdata->dev, "IDCODE = %x\n", idcode);
	if (status)
		return status;

	dev_dbg(drvdata->dev, "Desync...\n");
	status = hwicap_command_desync(drvdata);
	if (status)
		return status;

	return 0;
}

static ssize_t
hwicap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	struct hwicap_drvdata *drvdata = file->private_data;
	ssize_t bytes_to_read = 0;
	u32 *kbuf;
	u32 words;
	u32 bytes_remaining;
	int status;

	status = mutex_lock_interruptible(&drvdata->sem);
	if (status)
		return status;

	if (drvdata->read_buffer_in_use) {
		/* If there are leftover bytes in the buffer, just */
		/* return them and don't try to read more from the */
		/* ICAP device. */
		bytes_to_read =
			(count < drvdata->read_buffer_in_use) ? count :
			drvdata->read_buffer_in_use;

		/* Return the data currently in the read buffer. */
		if (copy_to_user(buf, drvdata->read_buffer, bytes_to_read)) {
			status = -EFAULT;
			goto error;
		}
		drvdata->read_buffer_in_use -= bytes_to_read;
		memmove(drvdata->read_buffer,
		       drvdata->read_buffer + bytes_to_read,
		       4 - bytes_to_read);
	} else {
		/* Get new data from the ICAP, and return was was requested. */
		kbuf = (u32 *) get_zeroed_page(GFP_KERNEL);
		if (!kbuf) {
			status = -ENOMEM;
			goto error;
		}

		/* The ICAP device is only able to read complete */
		/* words.  If a number of bytes that do not correspond */
		/* to complete words is requested, then we read enough */
		/* words to get the required number of bytes, and then */
		/* save the remaining bytes for the next read. */

		/* Determine the number of words to read, rounding up */
		/* if necessary. */
		words = ((count + 3) >> 2);
		bytes_to_read = words << 2;

		if (bytes_to_read > PAGE_SIZE)
			bytes_to_read = PAGE_SIZE;

		/* Ensure we only read a complete number of words. */
		bytes_remaining = bytes_to_read & 3;
		bytes_to_read &= ~3;
		words = bytes_to_read >> 2;

		status = drvdata->config->get_configuration(drvdata,
				kbuf, words);

		/* If we didn't read correctly, then bail out. */
		if (status) {
			free_page((unsigned long)kbuf);
			goto error;
		}

		/* If we fail to return the data to the user, then bail out. */
		if (copy_to_user(buf, kbuf, bytes_to_read)) {
			free_page((unsigned long)kbuf);
			status = -EFAULT;
			goto error;
		}
		memcpy(drvdata->read_buffer,
		       kbuf,
		       bytes_remaining);
		drvdata->read_buffer_in_use = bytes_remaining;
		free_page((unsigned long)kbuf);
	}
	status = bytes_to_read;
 error:
	mutex_unlock(&drvdata->sem);
	return status;
}

static ssize_t
hwicap_write(struct file *file, const char __user *buf,
		size_t count, loff_t *ppos)
{
	struct hwicap_drvdata *drvdata = file->private_data;
	ssize_t written = 0;
	ssize_t left = count;
	u32 *kbuf;
	ssize_t len;
	ssize_t status;

	status = mutex_lock_interruptible(&drvdata->sem);
	if (status)
		return status;

	left += drvdata->write_buffer_in_use;

	/* Only write multiples of 4 bytes. */
	if (left < 4) {
		status = 0;
		goto error;
	}

	kbuf = (u32 *) __get_free_page(GFP_KERNEL);
	if (!kbuf) {
		status = -ENOMEM;
		goto error;
	}

	while (left > 3) {
		/* only write multiples of 4 bytes, so there might */
		/* be as many as 3 bytes left (at the end). */
		len = left;

		if (len > PAGE_SIZE)
			len = PAGE_SIZE;
		len &= ~3;

		if (drvdata->write_buffer_in_use) {
			memcpy(kbuf, drvdata->write_buffer,
					drvdata->write_buffer_in_use);
			if (copy_from_user(
			    (((char *)kbuf) + drvdata->write_buffer_in_use),
			    buf + written,
			    len - (drvdata->write_buffer_in_use))) {
				free_page((unsigned long)kbuf);
				status = -EFAULT;
				goto error;
			}
		} else {
			if (copy_from_user(kbuf, buf + written, len)) {
				free_page((unsigned long)kbuf);
				status = -EFAULT;
				goto error;
			}
		}

		status = drvdata->config->set_configuration(drvdata,
				kbuf, len >> 2);

		if (status) {
			free_page((unsigned long)kbuf);
			status = -EFAULT;
			goto error;
		}
		if (drvdata->write_buffer_in_use) {
			len -= drvdata->write_buffer_in_use;
			left -= drvdata->write_buffer_in_use;
			drvdata->write_buffer_in_use = 0;
		}
		written += len;
		left -= len;
	}
	if ((left > 0) && (left < 4)) {
		if (!copy_from_user(drvdata->write_buffer,
						buf + written, left)) {
			drvdata->write_buffer_in_use = left;
			written += left;
			left = 0;
		}
	}

	free_page((unsigned long)kbuf);
	status = written;
 error:
	mutex_unlock(&drvdata->sem);
	return status;
}

static int hwicap_open(struct inode *inode, struct file *file)
{
	struct hwicap_drvdata *drvdata;
	int status;

	lock_kernel();
	drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);

	status = mutex_lock_interruptible(&drvdata->sem);
	if (status)
		goto out;

	if (drvdata->is_open) {
		status = -EBUSY;
		goto error;
	}

	status = hwicap_initialize_hwicap(drvdata);
	if (status) {
		dev_err(drvdata->dev, "Failed to open file");
		goto error;
	}

	file->private_data = drvdata;
	drvdata->write_buffer_in_use = 0;
	drvdata->read_buffer_in_use = 0;
	drvdata->is_open = 1;

 error:
	mutex_unlock(&drvdata->sem);
 out:
	unlock_kernel();
	return status;
}

static int hwicap_release(struct inode *inode, struct file *file)
{
	struct hwicap_drvdata *drvdata = file->private_data;
	int i;
	int status = 0;

	mutex_lock(&drvdata->sem);

	if (drvdata->write_buffer_in_use) {
		/* Flush write buffer. */
		for (i = drvdata->write_buffer_in_use; i < 4; i++)
			drvdata->write_buffer[i] = 0;

		status = drvdata->config->set_configuration(drvdata,
				(u32 *) drvdata->write_buffer, 1);
		if (status)
			goto error;
	}

	status = hwicap_command_desync(drvdata);
	if (status)
		goto error;

 error:
	drvdata->is_open = 0;
	mutex_unlock(&drvdata->sem);
	return status;
}

static struct file_operations hwicap_fops = {
	.owner = THIS_MODULE,
	.write = hwicap_write,
	.read = hwicap_read,
	.open = hwicap_open,
	.release = hwicap_release,
};

static int __devinit hwicap_setup(struct device *dev, int id,
		const struct resource *regs_res,
		const struct hwicap_driver_config *config,
		const struct config_registers *config_regs)
{
	dev_t devt;
	struct hwicap_drvdata *drvdata = NULL;
	int retval = 0;

	dev_info(dev, "Xilinx icap port driver\n");

	mutex_lock(&icap_sem);

	if (id < 0) {
		for (id = 0; id < HWICAP_DEVICES; id++)
			if (!probed_devices[id])
				break;
	}
	if (id < 0 || id >= HWICAP_DEVICES) {
		mutex_unlock(&icap_sem);
		dev_err(dev, "%s%i too large\n", DRIVER_NAME, id);
		return -EINVAL;
	}
	if (probed_devices[id]) {
		mutex_unlock(&icap_sem);
		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
			DRIVER_NAME, id);
		return -EBUSY;
	}

	probed_devices[id] = 1;
	mutex_unlock(&icap_sem);

	devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR + id);

	drvdata = kzalloc(sizeof(struct hwicap_drvdata), GFP_KERNEL);
	if (!drvdata) {
		dev_err(dev, "Couldn't allocate device private record\n");
		retval = -ENOMEM;
		goto failed0;
	}
	dev_set_drvdata(dev, (void *)drvdata);

	if (!regs_res) {
		dev_err(dev, "Couldn't get registers resource\n");
		retval = -EFAULT;
		goto failed1;
	}

	drvdata->mem_start = regs_res->start;
	drvdata->mem_end = regs_res->end;
	drvdata->mem_size = regs_res->end - regs_res->start + 1;

	if (!request_mem_region(drvdata->mem_start,
					drvdata->mem_size, DRIVER_NAME)) {
		dev_err(dev, "Couldn't lock memory region at %Lx\n",
			regs_res->start);
		retval = -EBUSY;
		goto failed1;
	}

	drvdata->devt = devt;
	drvdata->dev = dev;
	drvdata->base_address = ioremap(drvdata->mem_start, drvdata->mem_size);
	if (!drvdata->base_address) {
		dev_err(dev, "ioremap() failed\n");
		goto failed2;
	}

	drvdata->config = config;
	drvdata->config_regs = config_regs;

	mutex_init(&drvdata->sem);
	drvdata->is_open = 0;

	dev_info(dev, "ioremap %lx to %p with size %Lx\n",
		 (unsigned long int)drvdata->mem_start,
			drvdata->base_address, drvdata->mem_size);

	cdev_init(&drvdata->cdev, &hwicap_fops);
	drvdata->cdev.owner = THIS_MODULE;
	retval = cdev_add(&drvdata->cdev, devt, 1);
	if (retval) {
		dev_err(dev, "cdev_add() failed\n");
		goto failed3;
	}

	device_create(icap_class, dev, devt, NULL, "%s%d", DRIVER_NAME, id);
	return 0;		/* success */

 failed3:
	iounmap(drvdata->base_address);

 failed2:
	release_mem_region(regs_res->start, drvdata->mem_size);

 failed1:
	kfree(drvdata);

 failed0:
	mutex_lock(&icap_sem);
	probed_devices[id] = 0;
	mutex_unlock(&icap_sem);

	return retval;
}

static struct hwicap_driver_config buffer_icap_config = {
	.get_configuration = buffer_icap_get_configuration,
	.set_configuration = buffer_icap_set_configuration,
	.get_status = buffer_icap_get_status,
	.reset = buffer_icap_reset,
};

static struct hwicap_driver_config fifo_icap_config = {
	.get_configuration = fifo_icap_get_configuration,
	.set_configuration = fifo_icap_set_configuration,
	.get_status = fifo_icap_get_status,
	.reset = fifo_icap_reset,
};

static int __devexit hwicap_remove(struct device *dev)
{
	struct hwicap_drvdata *drvdata;

	drvdata = (struct hwicap_drvdata *)dev_get_drvdata(dev);

	if (!drvdata)
		return 0;

	device_destroy(icap_class, drvdata->devt);
	cdev_del(&drvdata->cdev);
	iounmap(drvdata->base_address);
	release_mem_region(drvdata->mem_start, drvdata->mem_size);
	kfree(drvdata);
	dev_set_drvdata(dev, NULL);

	mutex_lock(&icap_sem);
	probed_devices[MINOR(dev->devt)-XHWICAP_MINOR] = 0;
	mutex_unlock(&icap_sem);
	return 0;		/* success */
}

static int __devinit hwicap_drv_probe(struct platform_device *pdev)
{
	struct resource *res;
	const struct config_registers *regs;
	const char *family;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	/* It's most likely that we're using V4, if the family is not
	   specified */
	regs = &v4_config_registers;
	family = pdev->dev.platform_data;

	if (family) {
		if (!strcmp(family, "virtex2p")) {
			regs = &v2_config_registers;
		} else if (!strcmp(family, "virtex4")) {
			regs = &v4_config_registers;
		} else if (!strcmp(family, "virtex5")) {
			regs = &v5_config_registers;
		}
	}

	return hwicap_setup(&pdev->dev, pdev->id, res,
			&buffer_icap_config, regs);
}

static int __devexit hwicap_drv_remove(struct platform_device *pdev)
{
	return hwicap_remove(&pdev->dev);
}

static struct platform_driver hwicap_platform_driver = {
	.probe = hwicap_drv_probe,
	.remove = hwicap_drv_remove,
	.driver = {
		.owner = THIS_MODULE,
		.name = DRIVER_NAME,
	},
};

/* ---------------------------------------------------------------------
 * OF bus binding
 */

#if defined(CONFIG_OF)
static int __devinit
hwicap_of_probe(struct of_device *op, const struct of_device_id *match)
{
	struct resource res;
	const unsigned int *id;
	const char *family;
	int rc;
	const struct hwicap_driver_config *config = match->data;
	const struct config_registers *regs;

	dev_dbg(&op->dev, "hwicap_of_probe(%p, %p)\n", op, match);

	rc = of_address_to_resource(op->node, 0, &res);
	if (rc) {
		dev_err(&op->dev, "invalid address\n");
		return rc;
	}

	id = of_get_property(op->node, "port-number", NULL);

	/* It's most likely that we're using V4, if the family is not
	   specified */
	regs = &v4_config_registers;
	family = of_get_property(op->node, "xlnx,family", NULL);

	if (family) {
		if (!strcmp(family, "virtex2p")) {
			regs = &v2_config_registers;
		} else if (!strcmp(family, "virtex4")) {
			regs = &v4_config_registers;
		} else if (!strcmp(family, "virtex5")) {
			regs = &v5_config_registers;
		}
	}
	return hwicap_setup(&op->dev, id ? *id : -1, &res, config,
			regs);
}

static int __devexit hwicap_of_remove(struct of_device *op)
{
	return hwicap_remove(&op->dev);
}

/* Match table for of_platform binding */
static const struct of_device_id __devinitconst hwicap_of_match[] = {
	{ .compatible = "xlnx,opb-hwicap-1.00.b", .data = &buffer_icap_config},
	{ .compatible = "xlnx,xps-hwicap-1.00.a", .data = &fifo_icap_config},
	{},
};
MODULE_DEVICE_TABLE(of, hwicap_of_match);

static struct of_platform_driver hwicap_of_driver = {
	.owner = THIS_MODULE,
	.name = DRIVER_NAME,
	.match_table = hwicap_of_match,
	.probe = hwicap_of_probe,
	.remove = __devexit_p(hwicap_of_remove),
	.driver = {
		.name = DRIVER_NAME,
	},
};

/* Registration helpers to keep the number of #ifdefs to a minimum */
static inline int __init hwicap_of_register(void)
{
	pr_debug("hwicap: calling of_register_platform_driver()\n");
	return of_register_platform_driver(&hwicap_of_driver);
}

static inline void __exit hwicap_of_unregister(void)
{
	of_unregister_platform_driver(&hwicap_of_driver);
}
#else /* CONFIG_OF */
/* CONFIG_OF not enabled; do nothing helpers */
static inline int __init hwicap_of_register(void) { return 0; }
static inline void __exit hwicap_of_unregister(void) { }
#endif /* CONFIG_OF */

static int __init hwicap_module_init(void)
{
	dev_t devt;
	int retval;

	icap_class = class_create(THIS_MODULE, "xilinx_config");
	mutex_init(&icap_sem);

	devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
	retval = register_chrdev_region(devt,
					HWICAP_DEVICES,
					DRIVER_NAME);
	if (retval < 0)
		return retval;

	retval = platform_driver_register(&hwicap_platform_driver);

	if (retval)
		goto failed1;

	retval = hwicap_of_register();

	if (retval)
		goto failed2;

	return retval;

 failed2:
	platform_driver_unregister(&hwicap_platform_driver);

 failed1:
	unregister_chrdev_region(devt, HWICAP_DEVICES);

	return retval;
}

static void __exit hwicap_module_cleanup(void)
{
	dev_t devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);

	class_destroy(icap_class);

	platform_driver_unregister(&hwicap_platform_driver);

	hwicap_of_unregister();

	unregister_chrdev_region(devt, HWICAP_DEVICES);
}

module_init(hwicap_module_init);
module_exit(hwicap_module_cleanup);

MODULE_AUTHOR("Xilinx, Inc; Xilinx Research Labs Group");
MODULE_DESCRIPTION("Xilinx ICAP Port Driver");
MODULE_LICENSE("GPL");