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