1 /*****************************************************************************
2  *
3  *     Author: Xilinx, Inc.
4  *
5  *     This program is free software; you can redistribute it and/or modify it
6  *     under the terms of the GNU General Public License as published by the
7  *     Free Software Foundation; either version 2 of the License, or (at your
8  *     option) any later version.
9  *
10  *     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
11  *     AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
12  *     SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
13  *     OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
14  *     APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
15  *     THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
16  *     AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
17  *     FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
18  *     WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
19  *     IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
20  *     REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
21  *     INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22  *     FOR A PARTICULAR PURPOSE.
23  *
24  *     (c) Copyright 2002 Xilinx Inc., Systems Engineering Group
25  *     (c) Copyright 2004 Xilinx Inc., Systems Engineering Group
26  *     (c) Copyright 2007-2008 Xilinx Inc.
27  *     All rights reserved.
28  *
29  *     You should have received a copy of the GNU General Public License along
30  *     with this program; if not, write to the Free Software Foundation, Inc.,
31  *     675 Mass Ave, Cambridge, MA 02139, USA.
32  *
33  *****************************************************************************/
34 
35 /*
36  * This is the code behind /dev/icap* -- it allows a user-space
37  * application to use the Xilinx ICAP subsystem.
38  *
39  * The following operations are possible:
40  *
41  * open         open the port and initialize for access.
42  * release      release port
43  * write        Write a bitstream to the configuration processor.
44  * read         Read a data stream from the configuration processor.
45  *
46  * After being opened, the port is initialized and accessed to avoid a
47  * corrupted first read which may occur with some hardware.  The port
48  * is left in a desynched state, requiring that a synch sequence be
49  * transmitted before any valid configuration data.  A user will have
50  * exclusive access to the device while it remains open, and the state
51  * of the ICAP cannot be guaranteed after the device is closed.  Note
52  * that a complete reset of the core and the state of the ICAP cannot
53  * be performed on many versions of the cores, hence users of this
54  * device should avoid making inconsistent accesses to the device.  In
55  * particular, accessing the read interface, without first generating
56  * a write containing a readback packet can leave the ICAP in an
57  * inaccessible state.
58  *
59  * Note that in order to use the read interface, it is first necessary
60  * to write a request packet to the write interface.  i.e., it is not
61  * possible to simply readback the bitstream (or any configuration
62  * bits) from a device without specifically requesting them first.
63  * The code to craft such packets is intended to be part of the
64  * user-space application code that uses this device.  The simplest
65  * way to use this interface is simply:
66  *
67  * cp foo.bit /dev/icap0
68  *
69  * Note that unless foo.bit is an appropriately constructed partial
70  * bitstream, this has a high likelyhood of overwriting the design
71  * currently programmed in the FPGA.
72  */
73 
74 #include <linux/module.h>
75 #include <linux/kernel.h>
76 #include <linux/types.h>
77 #include <linux/ioport.h>
78 #include <linux/interrupt.h>
79 #include <linux/fcntl.h>
80 #include <linux/init.h>
81 #include <linux/poll.h>
82 #include <linux/proc_fs.h>
83 #include <linux/mutex.h>
84 #include <linux/smp_lock.h>
85 #include <linux/sysctl.h>
86 #include <linux/fs.h>
87 #include <linux/cdev.h>
88 #include <linux/platform_device.h>
89 
90 #include <asm/io.h>
91 #include <asm/uaccess.h>
92 #include <asm/system.h>
93 
94 #ifdef CONFIG_OF
95 /* For open firmware. */
96 #include <linux/of_device.h>
97 #include <linux/of_platform.h>
98 #endif
99 
100 #include "xilinx_hwicap.h"
101 #include "buffer_icap.h"
102 #include "fifo_icap.h"
103 
104 #define DRIVER_NAME "icap"
105 
106 #define HWICAP_REGS   (0x10000)
107 
108 #define XHWICAP_MAJOR 259
109 #define XHWICAP_MINOR 0
110 #define HWICAP_DEVICES 1
111 
112 /* An array, which is set to true when the device is registered. */
113 static bool probed_devices[HWICAP_DEVICES];
114 static struct mutex icap_sem;
115 
116 static struct class *icap_class;
117 
118 #define UNIMPLEMENTED 0xFFFF
119 
120 static const struct config_registers v2_config_registers = {
121 	.CRC = 0,
122 	.FAR = 1,
123 	.FDRI = 2,
124 	.FDRO = 3,
125 	.CMD = 4,
126 	.CTL = 5,
127 	.MASK = 6,
128 	.STAT = 7,
129 	.LOUT = 8,
130 	.COR = 9,
131 	.MFWR = 10,
132 	.FLR = 11,
133 	.KEY = 12,
134 	.CBC = 13,
135 	.IDCODE = 14,
136 	.AXSS = UNIMPLEMENTED,
137 	.C0R_1 = UNIMPLEMENTED,
138 	.CSOB = UNIMPLEMENTED,
139 	.WBSTAR = UNIMPLEMENTED,
140 	.TIMER = UNIMPLEMENTED,
141 	.BOOTSTS = UNIMPLEMENTED,
142 	.CTL_1 = UNIMPLEMENTED,
143 };
144 
145 static const struct config_registers v4_config_registers = {
146 	.CRC = 0,
147 	.FAR = 1,
148 	.FDRI = 2,
149 	.FDRO = 3,
150 	.CMD = 4,
151 	.CTL = 5,
152 	.MASK = 6,
153 	.STAT = 7,
154 	.LOUT = 8,
155 	.COR = 9,
156 	.MFWR = 10,
157 	.FLR = UNIMPLEMENTED,
158 	.KEY = UNIMPLEMENTED,
159 	.CBC = 11,
160 	.IDCODE = 12,
161 	.AXSS = 13,
162 	.C0R_1 = UNIMPLEMENTED,
163 	.CSOB = UNIMPLEMENTED,
164 	.WBSTAR = UNIMPLEMENTED,
165 	.TIMER = UNIMPLEMENTED,
166 	.BOOTSTS = UNIMPLEMENTED,
167 	.CTL_1 = UNIMPLEMENTED,
168 };
169 static const struct config_registers v5_config_registers = {
170 	.CRC = 0,
171 	.FAR = 1,
172 	.FDRI = 2,
173 	.FDRO = 3,
174 	.CMD = 4,
175 	.CTL = 5,
176 	.MASK = 6,
177 	.STAT = 7,
178 	.LOUT = 8,
179 	.COR = 9,
180 	.MFWR = 10,
181 	.FLR = UNIMPLEMENTED,
182 	.KEY = UNIMPLEMENTED,
183 	.CBC = 11,
184 	.IDCODE = 12,
185 	.AXSS = 13,
186 	.C0R_1 = 14,
187 	.CSOB = 15,
188 	.WBSTAR = 16,
189 	.TIMER = 17,
190 	.BOOTSTS = 18,
191 	.CTL_1 = 19,
192 };
193 
194 /**
195  * hwicap_command_desync - Send a DESYNC command to the ICAP port.
196  * @drvdata: a pointer to the drvdata.
197  *
198  * This command desynchronizes the ICAP After this command, a
199  * bitstream containing a NULL packet, followed by a SYNCH packet is
200  * required before the ICAP will recognize commands.
201  */
202 static int hwicap_command_desync(struct hwicap_drvdata *drvdata)
203 {
204 	u32 buffer[4];
205 	u32 index = 0;
206 
207 	/*
208 	 * Create the data to be written to the ICAP.
209 	 */
210 	buffer[index++] = hwicap_type_1_write(drvdata->config_regs->CMD) | 1;
211 	buffer[index++] = XHI_CMD_DESYNCH;
212 	buffer[index++] = XHI_NOOP_PACKET;
213 	buffer[index++] = XHI_NOOP_PACKET;
214 
215 	/*
216 	 * Write the data to the FIFO and intiate the transfer of data present
217 	 * in the FIFO to the ICAP device.
218 	 */
219 	return drvdata->config->set_configuration(drvdata,
220 			&buffer[0], index);
221 }
222 
223 /**
224  * hwicap_get_configuration_register - Query a configuration register.
225  * @drvdata: a pointer to the drvdata.
226  * @reg: a constant which represents the configuration
227  *		register value to be returned.
228  * 		Examples:  XHI_IDCODE, XHI_FLR.
229  * @reg_data: returns the value of the register.
230  *
231  * Sends a query packet to the ICAP and then receives the response.
232  * The icap is left in Synched state.
233  */
234 static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata,
235 		u32 reg, u32 *reg_data)
236 {
237 	int status;
238 	u32 buffer[6];
239 	u32 index = 0;
240 
241 	/*
242 	 * Create the data to be written to the ICAP.
243 	 */
244 	buffer[index++] = XHI_DUMMY_PACKET;
245 	buffer[index++] = XHI_NOOP_PACKET;
246 	buffer[index++] = XHI_SYNC_PACKET;
247 	buffer[index++] = XHI_NOOP_PACKET;
248 	buffer[index++] = XHI_NOOP_PACKET;
249 
250 	/*
251 	 * Write the data to the FIFO and initiate the transfer of data present
252 	 * in the FIFO to the ICAP device.
253 	 */
254 	status = drvdata->config->set_configuration(drvdata,
255 						    &buffer[0], index);
256 	if (status)
257 		return status;
258 
259 	/* If the syncword was not found, then we need to start over. */
260 	status = drvdata->config->get_status(drvdata);
261 	if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK)
262 		return -EIO;
263 
264 	index = 0;
265 	buffer[index++] = hwicap_type_1_read(reg) | 1;
266 	buffer[index++] = XHI_NOOP_PACKET;
267 	buffer[index++] = XHI_NOOP_PACKET;
268 
269 	/*
270 	 * Write the data to the FIFO and intiate the transfer of data present
271 	 * in the FIFO to the ICAP device.
272 	 */
273 	status = drvdata->config->set_configuration(drvdata,
274 			&buffer[0], index);
275 	if (status)
276 		return status;
277 
278 	/*
279 	 * Read the configuration register
280 	 */
281 	status = drvdata->config->get_configuration(drvdata, reg_data, 1);
282 	if (status)
283 		return status;
284 
285 	return 0;
286 }
287 
288 static int hwicap_initialize_hwicap(struct hwicap_drvdata *drvdata)
289 {
290 	int status;
291 	u32 idcode;
292 
293 	dev_dbg(drvdata->dev, "initializing\n");
294 
295 	/* Abort any current transaction, to make sure we have the
296 	 * ICAP in a good state. */
297 	dev_dbg(drvdata->dev, "Reset...\n");
298 	drvdata->config->reset(drvdata);
299 
300 	dev_dbg(drvdata->dev, "Desync...\n");
301 	status = hwicap_command_desync(drvdata);
302 	if (status)
303 		return status;
304 
305 	/* Attempt to read the IDCODE from ICAP.  This
306 	 * may not be returned correctly, due to the design of the
307 	 * hardware.
308 	 */
309 	dev_dbg(drvdata->dev, "Reading IDCODE...\n");
310 	status = hwicap_get_configuration_register(
311 			drvdata, drvdata->config_regs->IDCODE, &idcode);
312 	dev_dbg(drvdata->dev, "IDCODE = %x\n", idcode);
313 	if (status)
314 		return status;
315 
316 	dev_dbg(drvdata->dev, "Desync...\n");
317 	status = hwicap_command_desync(drvdata);
318 	if (status)
319 		return status;
320 
321 	return 0;
322 }
323 
324 static ssize_t
325 hwicap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
326 {
327 	struct hwicap_drvdata *drvdata = file->private_data;
328 	ssize_t bytes_to_read = 0;
329 	u32 *kbuf;
330 	u32 words;
331 	u32 bytes_remaining;
332 	int status;
333 
334 	status = mutex_lock_interruptible(&drvdata->sem);
335 	if (status)
336 		return status;
337 
338 	if (drvdata->read_buffer_in_use) {
339 		/* If there are leftover bytes in the buffer, just */
340 		/* return them and don't try to read more from the */
341 		/* ICAP device. */
342 		bytes_to_read =
343 			(count < drvdata->read_buffer_in_use) ? count :
344 			drvdata->read_buffer_in_use;
345 
346 		/* Return the data currently in the read buffer. */
347 		if (copy_to_user(buf, drvdata->read_buffer, bytes_to_read)) {
348 			status = -EFAULT;
349 			goto error;
350 		}
351 		drvdata->read_buffer_in_use -= bytes_to_read;
352 		memmove(drvdata->read_buffer,
353 		       drvdata->read_buffer + bytes_to_read,
354 		       4 - bytes_to_read);
355 	} else {
356 		/* Get new data from the ICAP, and return was was requested. */
357 		kbuf = (u32 *) get_zeroed_page(GFP_KERNEL);
358 		if (!kbuf) {
359 			status = -ENOMEM;
360 			goto error;
361 		}
362 
363 		/* The ICAP device is only able to read complete */
364 		/* words.  If a number of bytes that do not correspond */
365 		/* to complete words is requested, then we read enough */
366 		/* words to get the required number of bytes, and then */
367 		/* save the remaining bytes for the next read. */
368 
369 		/* Determine the number of words to read, rounding up */
370 		/* if necessary. */
371 		words = ((count + 3) >> 2);
372 		bytes_to_read = words << 2;
373 
374 		if (bytes_to_read > PAGE_SIZE)
375 			bytes_to_read = PAGE_SIZE;
376 
377 		/* Ensure we only read a complete number of words. */
378 		bytes_remaining = bytes_to_read & 3;
379 		bytes_to_read &= ~3;
380 		words = bytes_to_read >> 2;
381 
382 		status = drvdata->config->get_configuration(drvdata,
383 				kbuf, words);
384 
385 		/* If we didn't read correctly, then bail out. */
386 		if (status) {
387 			free_page((unsigned long)kbuf);
388 			goto error;
389 		}
390 
391 		/* If we fail to return the data to the user, then bail out. */
392 		if (copy_to_user(buf, kbuf, bytes_to_read)) {
393 			free_page((unsigned long)kbuf);
394 			status = -EFAULT;
395 			goto error;
396 		}
397 		memcpy(drvdata->read_buffer,
398 		       kbuf,
399 		       bytes_remaining);
400 		drvdata->read_buffer_in_use = bytes_remaining;
401 		free_page((unsigned long)kbuf);
402 	}
403 	status = bytes_to_read;
404  error:
405 	mutex_unlock(&drvdata->sem);
406 	return status;
407 }
408 
409 static ssize_t
410 hwicap_write(struct file *file, const char __user *buf,
411 		size_t count, loff_t *ppos)
412 {
413 	struct hwicap_drvdata *drvdata = file->private_data;
414 	ssize_t written = 0;
415 	ssize_t left = count;
416 	u32 *kbuf;
417 	ssize_t len;
418 	ssize_t status;
419 
420 	status = mutex_lock_interruptible(&drvdata->sem);
421 	if (status)
422 		return status;
423 
424 	left += drvdata->write_buffer_in_use;
425 
426 	/* Only write multiples of 4 bytes. */
427 	if (left < 4) {
428 		status = 0;
429 		goto error;
430 	}
431 
432 	kbuf = (u32 *) __get_free_page(GFP_KERNEL);
433 	if (!kbuf) {
434 		status = -ENOMEM;
435 		goto error;
436 	}
437 
438 	while (left > 3) {
439 		/* only write multiples of 4 bytes, so there might */
440 		/* be as many as 3 bytes left (at the end). */
441 		len = left;
442 
443 		if (len > PAGE_SIZE)
444 			len = PAGE_SIZE;
445 		len &= ~3;
446 
447 		if (drvdata->write_buffer_in_use) {
448 			memcpy(kbuf, drvdata->write_buffer,
449 					drvdata->write_buffer_in_use);
450 			if (copy_from_user(
451 			    (((char *)kbuf) + drvdata->write_buffer_in_use),
452 			    buf + written,
453 			    len - (drvdata->write_buffer_in_use))) {
454 				free_page((unsigned long)kbuf);
455 				status = -EFAULT;
456 				goto error;
457 			}
458 		} else {
459 			if (copy_from_user(kbuf, buf + written, len)) {
460 				free_page((unsigned long)kbuf);
461 				status = -EFAULT;
462 				goto error;
463 			}
464 		}
465 
466 		status = drvdata->config->set_configuration(drvdata,
467 				kbuf, len >> 2);
468 
469 		if (status) {
470 			free_page((unsigned long)kbuf);
471 			status = -EFAULT;
472 			goto error;
473 		}
474 		if (drvdata->write_buffer_in_use) {
475 			len -= drvdata->write_buffer_in_use;
476 			left -= drvdata->write_buffer_in_use;
477 			drvdata->write_buffer_in_use = 0;
478 		}
479 		written += len;
480 		left -= len;
481 	}
482 	if ((left > 0) && (left < 4)) {
483 		if (!copy_from_user(drvdata->write_buffer,
484 						buf + written, left)) {
485 			drvdata->write_buffer_in_use = left;
486 			written += left;
487 			left = 0;
488 		}
489 	}
490 
491 	free_page((unsigned long)kbuf);
492 	status = written;
493  error:
494 	mutex_unlock(&drvdata->sem);
495 	return status;
496 }
497 
498 static int hwicap_open(struct inode *inode, struct file *file)
499 {
500 	struct hwicap_drvdata *drvdata;
501 	int status;
502 
503 	lock_kernel();
504 	drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);
505 
506 	status = mutex_lock_interruptible(&drvdata->sem);
507 	if (status)
508 		goto out;
509 
510 	if (drvdata->is_open) {
511 		status = -EBUSY;
512 		goto error;
513 	}
514 
515 	status = hwicap_initialize_hwicap(drvdata);
516 	if (status) {
517 		dev_err(drvdata->dev, "Failed to open file");
518 		goto error;
519 	}
520 
521 	file->private_data = drvdata;
522 	drvdata->write_buffer_in_use = 0;
523 	drvdata->read_buffer_in_use = 0;
524 	drvdata->is_open = 1;
525 
526  error:
527 	mutex_unlock(&drvdata->sem);
528  out:
529 	unlock_kernel();
530 	return status;
531 }
532 
533 static int hwicap_release(struct inode *inode, struct file *file)
534 {
535 	struct hwicap_drvdata *drvdata = file->private_data;
536 	int i;
537 	int status = 0;
538 
539 	mutex_lock(&drvdata->sem);
540 
541 	if (drvdata->write_buffer_in_use) {
542 		/* Flush write buffer. */
543 		for (i = drvdata->write_buffer_in_use; i < 4; i++)
544 			drvdata->write_buffer[i] = 0;
545 
546 		status = drvdata->config->set_configuration(drvdata,
547 				(u32 *) drvdata->write_buffer, 1);
548 		if (status)
549 			goto error;
550 	}
551 
552 	status = hwicap_command_desync(drvdata);
553 	if (status)
554 		goto error;
555 
556  error:
557 	drvdata->is_open = 0;
558 	mutex_unlock(&drvdata->sem);
559 	return status;
560 }
561 
562 static struct file_operations hwicap_fops = {
563 	.owner = THIS_MODULE,
564 	.write = hwicap_write,
565 	.read = hwicap_read,
566 	.open = hwicap_open,
567 	.release = hwicap_release,
568 };
569 
570 static int __devinit hwicap_setup(struct device *dev, int id,
571 		const struct resource *regs_res,
572 		const struct hwicap_driver_config *config,
573 		const struct config_registers *config_regs)
574 {
575 	dev_t devt;
576 	struct hwicap_drvdata *drvdata = NULL;
577 	int retval = 0;
578 
579 	dev_info(dev, "Xilinx icap port driver\n");
580 
581 	mutex_lock(&icap_sem);
582 
583 	if (id < 0) {
584 		for (id = 0; id < HWICAP_DEVICES; id++)
585 			if (!probed_devices[id])
586 				break;
587 	}
588 	if (id < 0 || id >= HWICAP_DEVICES) {
589 		mutex_unlock(&icap_sem);
590 		dev_err(dev, "%s%i too large\n", DRIVER_NAME, id);
591 		return -EINVAL;
592 	}
593 	if (probed_devices[id]) {
594 		mutex_unlock(&icap_sem);
595 		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
596 			DRIVER_NAME, id);
597 		return -EBUSY;
598 	}
599 
600 	probed_devices[id] = 1;
601 	mutex_unlock(&icap_sem);
602 
603 	devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR + id);
604 
605 	drvdata = kzalloc(sizeof(struct hwicap_drvdata), GFP_KERNEL);
606 	if (!drvdata) {
607 		dev_err(dev, "Couldn't allocate device private record\n");
608 		retval = -ENOMEM;
609 		goto failed0;
610 	}
611 	dev_set_drvdata(dev, (void *)drvdata);
612 
613 	if (!regs_res) {
614 		dev_err(dev, "Couldn't get registers resource\n");
615 		retval = -EFAULT;
616 		goto failed1;
617 	}
618 
619 	drvdata->mem_start = regs_res->start;
620 	drvdata->mem_end = regs_res->end;
621 	drvdata->mem_size = regs_res->end - regs_res->start + 1;
622 
623 	if (!request_mem_region(drvdata->mem_start,
624 					drvdata->mem_size, DRIVER_NAME)) {
625 		dev_err(dev, "Couldn't lock memory region at %Lx\n",
626 			(unsigned long long) regs_res->start);
627 		retval = -EBUSY;
628 		goto failed1;
629 	}
630 
631 	drvdata->devt = devt;
632 	drvdata->dev = dev;
633 	drvdata->base_address = ioremap(drvdata->mem_start, drvdata->mem_size);
634 	if (!drvdata->base_address) {
635 		dev_err(dev, "ioremap() failed\n");
636 		goto failed2;
637 	}
638 
639 	drvdata->config = config;
640 	drvdata->config_regs = config_regs;
641 
642 	mutex_init(&drvdata->sem);
643 	drvdata->is_open = 0;
644 
645 	dev_info(dev, "ioremap %llx to %p with size %llx\n",
646 		 (unsigned long long) drvdata->mem_start,
647 		 drvdata->base_address,
648 		 (unsigned long long) drvdata->mem_size);
649 
650 	cdev_init(&drvdata->cdev, &hwicap_fops);
651 	drvdata->cdev.owner = THIS_MODULE;
652 	retval = cdev_add(&drvdata->cdev, devt, 1);
653 	if (retval) {
654 		dev_err(dev, "cdev_add() failed\n");
655 		goto failed3;
656 	}
657 
658 	device_create(icap_class, dev, devt, NULL, "%s%d", DRIVER_NAME, id);
659 	return 0;		/* success */
660 
661  failed3:
662 	iounmap(drvdata->base_address);
663 
664  failed2:
665 	release_mem_region(regs_res->start, drvdata->mem_size);
666 
667  failed1:
668 	kfree(drvdata);
669 
670  failed0:
671 	mutex_lock(&icap_sem);
672 	probed_devices[id] = 0;
673 	mutex_unlock(&icap_sem);
674 
675 	return retval;
676 }
677 
678 static struct hwicap_driver_config buffer_icap_config = {
679 	.get_configuration = buffer_icap_get_configuration,
680 	.set_configuration = buffer_icap_set_configuration,
681 	.get_status = buffer_icap_get_status,
682 	.reset = buffer_icap_reset,
683 };
684 
685 static struct hwicap_driver_config fifo_icap_config = {
686 	.get_configuration = fifo_icap_get_configuration,
687 	.set_configuration = fifo_icap_set_configuration,
688 	.get_status = fifo_icap_get_status,
689 	.reset = fifo_icap_reset,
690 };
691 
692 static int __devexit hwicap_remove(struct device *dev)
693 {
694 	struct hwicap_drvdata *drvdata;
695 
696 	drvdata = (struct hwicap_drvdata *)dev_get_drvdata(dev);
697 
698 	if (!drvdata)
699 		return 0;
700 
701 	device_destroy(icap_class, drvdata->devt);
702 	cdev_del(&drvdata->cdev);
703 	iounmap(drvdata->base_address);
704 	release_mem_region(drvdata->mem_start, drvdata->mem_size);
705 	kfree(drvdata);
706 	dev_set_drvdata(dev, NULL);
707 
708 	mutex_lock(&icap_sem);
709 	probed_devices[MINOR(dev->devt)-XHWICAP_MINOR] = 0;
710 	mutex_unlock(&icap_sem);
711 	return 0;		/* success */
712 }
713 
714 static int __devinit hwicap_drv_probe(struct platform_device *pdev)
715 {
716 	struct resource *res;
717 	const struct config_registers *regs;
718 	const char *family;
719 
720 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
721 	if (!res)
722 		return -ENODEV;
723 
724 	/* It's most likely that we're using V4, if the family is not
725 	   specified */
726 	regs = &v4_config_registers;
727 	family = pdev->dev.platform_data;
728 
729 	if (family) {
730 		if (!strcmp(family, "virtex2p")) {
731 			regs = &v2_config_registers;
732 		} else if (!strcmp(family, "virtex4")) {
733 			regs = &v4_config_registers;
734 		} else if (!strcmp(family, "virtex5")) {
735 			regs = &v5_config_registers;
736 		}
737 	}
738 
739 	return hwicap_setup(&pdev->dev, pdev->id, res,
740 			&buffer_icap_config, regs);
741 }
742 
743 static int __devexit hwicap_drv_remove(struct platform_device *pdev)
744 {
745 	return hwicap_remove(&pdev->dev);
746 }
747 
748 static struct platform_driver hwicap_platform_driver = {
749 	.probe = hwicap_drv_probe,
750 	.remove = hwicap_drv_remove,
751 	.driver = {
752 		.owner = THIS_MODULE,
753 		.name = DRIVER_NAME,
754 	},
755 };
756 
757 /* ---------------------------------------------------------------------
758  * OF bus binding
759  */
760 
761 #if defined(CONFIG_OF)
762 static int __devinit
763 hwicap_of_probe(struct of_device *op, const struct of_device_id *match)
764 {
765 	struct resource res;
766 	const unsigned int *id;
767 	const char *family;
768 	int rc;
769 	const struct hwicap_driver_config *config = match->data;
770 	const struct config_registers *regs;
771 
772 	dev_dbg(&op->dev, "hwicap_of_probe(%p, %p)\n", op, match);
773 
774 	rc = of_address_to_resource(op->node, 0, &res);
775 	if (rc) {
776 		dev_err(&op->dev, "invalid address\n");
777 		return rc;
778 	}
779 
780 	id = of_get_property(op->node, "port-number", NULL);
781 
782 	/* It's most likely that we're using V4, if the family is not
783 	   specified */
784 	regs = &v4_config_registers;
785 	family = of_get_property(op->node, "xlnx,family", NULL);
786 
787 	if (family) {
788 		if (!strcmp(family, "virtex2p")) {
789 			regs = &v2_config_registers;
790 		} else if (!strcmp(family, "virtex4")) {
791 			regs = &v4_config_registers;
792 		} else if (!strcmp(family, "virtex5")) {
793 			regs = &v5_config_registers;
794 		}
795 	}
796 	return hwicap_setup(&op->dev, id ? *id : -1, &res, config,
797 			regs);
798 }
799 
800 static int __devexit hwicap_of_remove(struct of_device *op)
801 {
802 	return hwicap_remove(&op->dev);
803 }
804 
805 /* Match table for of_platform binding */
806 static const struct of_device_id __devinitconst hwicap_of_match[] = {
807 	{ .compatible = "xlnx,opb-hwicap-1.00.b", .data = &buffer_icap_config},
808 	{ .compatible = "xlnx,xps-hwicap-1.00.a", .data = &fifo_icap_config},
809 	{},
810 };
811 MODULE_DEVICE_TABLE(of, hwicap_of_match);
812 
813 static struct of_platform_driver hwicap_of_driver = {
814 	.owner = THIS_MODULE,
815 	.name = DRIVER_NAME,
816 	.match_table = hwicap_of_match,
817 	.probe = hwicap_of_probe,
818 	.remove = __devexit_p(hwicap_of_remove),
819 	.driver = {
820 		.name = DRIVER_NAME,
821 	},
822 };
823 
824 /* Registration helpers to keep the number of #ifdefs to a minimum */
825 static inline int __init hwicap_of_register(void)
826 {
827 	pr_debug("hwicap: calling of_register_platform_driver()\n");
828 	return of_register_platform_driver(&hwicap_of_driver);
829 }
830 
831 static inline void __exit hwicap_of_unregister(void)
832 {
833 	of_unregister_platform_driver(&hwicap_of_driver);
834 }
835 #else /* CONFIG_OF */
836 /* CONFIG_OF not enabled; do nothing helpers */
837 static inline int __init hwicap_of_register(void) { return 0; }
838 static inline void __exit hwicap_of_unregister(void) { }
839 #endif /* CONFIG_OF */
840 
841 static int __init hwicap_module_init(void)
842 {
843 	dev_t devt;
844 	int retval;
845 
846 	icap_class = class_create(THIS_MODULE, "xilinx_config");
847 	mutex_init(&icap_sem);
848 
849 	devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
850 	retval = register_chrdev_region(devt,
851 					HWICAP_DEVICES,
852 					DRIVER_NAME);
853 	if (retval < 0)
854 		return retval;
855 
856 	retval = platform_driver_register(&hwicap_platform_driver);
857 
858 	if (retval)
859 		goto failed1;
860 
861 	retval = hwicap_of_register();
862 
863 	if (retval)
864 		goto failed2;
865 
866 	return retval;
867 
868  failed2:
869 	platform_driver_unregister(&hwicap_platform_driver);
870 
871  failed1:
872 	unregister_chrdev_region(devt, HWICAP_DEVICES);
873 
874 	return retval;
875 }
876 
877 static void __exit hwicap_module_cleanup(void)
878 {
879 	dev_t devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
880 
881 	class_destroy(icap_class);
882 
883 	platform_driver_unregister(&hwicap_platform_driver);
884 
885 	hwicap_of_unregister();
886 
887 	unregister_chrdev_region(devt, HWICAP_DEVICES);
888 }
889 
890 module_init(hwicap_module_init);
891 module_exit(hwicap_module_cleanup);
892 
893 MODULE_AUTHOR("Xilinx, Inc; Xilinx Research Labs Group");
894 MODULE_DESCRIPTION("Xilinx ICAP Port Driver");
895 MODULE_LICENSE("GPL");
896