1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * VMEbus User access driver
4  *
5  * Author: Martyn Welch <martyn.welch@ge.com>
6  * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
7  *
8  * Based on work by:
9  *   Tom Armistead and Ajit Prem
10  *     Copyright 2004 Motorola Inc.
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/refcount.h>
16 #include <linux/cdev.h>
17 #include <linux/delay.h>
18 #include <linux/device.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/ioctl.h>
23 #include <linux/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/pagemap.h>
27 #include <linux/pci.h>
28 #include <linux/mutex.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/syscalls.h>
32 #include <linux/types.h>
33 
34 #include <linux/io.h>
35 #include <linux/uaccess.h>
36 
37 #include "vme.h"
38 #include "vme_user.h"
39 
40 static const char driver_name[] = "vme_user";
41 
42 static int bus[VME_USER_BUS_MAX];
43 static unsigned int bus_num;
44 
45 /* Currently Documentation/admin-guide/devices.rst defines the
46  * following for VME:
47  *
48  * 221 char	VME bus
49  *		  0 = /dev/bus/vme/m0		First master image
50  *		  1 = /dev/bus/vme/m1		Second master image
51  *		  2 = /dev/bus/vme/m2		Third master image
52  *		  3 = /dev/bus/vme/m3		Fourth master image
53  *		  4 = /dev/bus/vme/s0		First slave image
54  *		  5 = /dev/bus/vme/s1		Second slave image
55  *		  6 = /dev/bus/vme/s2		Third slave image
56  *		  7 = /dev/bus/vme/s3		Fourth slave image
57  *		  8 = /dev/bus/vme/ctl		Control
58  *
59  *		It is expected that all VME bus drivers will use the
60  *		same interface.  For interface documentation see
61  *		http://www.vmelinux.org/.
62  *
63  * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
64  * even support the tsi148 chipset (which has 8 master and 8 slave windows).
65  * We'll run with this for now as far as possible, however it probably makes
66  * sense to get rid of the old mappings and just do everything dynamically.
67  *
68  * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
69  * defined above and try to support at least some of the interface from
70  * http://www.vmelinux.org/ as an alternative the driver can be written
71  * providing a saner interface later.
72  *
73  * The vmelinux.org driver never supported slave images, the devices reserved
74  * for slaves were repurposed to support all 8 master images on the UniverseII!
75  * We shall support 4 masters and 4 slaves with this driver.
76  */
77 #define VME_MAJOR	221	/* VME Major Device Number */
78 #define VME_DEVS	9	/* Number of dev entries */
79 
80 #define MASTER_MINOR	0
81 #define MASTER_MAX	3
82 #define SLAVE_MINOR	4
83 #define SLAVE_MAX	7
84 #define CONTROL_MINOR	8
85 
86 #define PCI_BUF_SIZE  0x20000	/* Size of one slave image buffer */
87 
88 /*
89  * Structure to handle image related parameters.
90  */
91 struct image_desc {
92 	void *kern_buf;	/* Buffer address in kernel space */
93 	dma_addr_t pci_buf;	/* Buffer address in PCI address space */
94 	unsigned long long size_buf;	/* Buffer size */
95 	struct mutex mutex;	/* Mutex for locking image */
96 	struct device *device;	/* Sysfs device */
97 	struct vme_resource *resource;	/* VME resource */
98 	int mmap_count;		/* Number of current mmap's */
99 };
100 
101 static struct image_desc image[VME_DEVS];
102 
103 static struct cdev *vme_user_cdev;		/* Character device */
104 static struct class *vme_user_sysfs_class;	/* Sysfs class */
105 static struct vme_dev *vme_user_bridge;		/* Pointer to user device */
106 
107 static const int type[VME_DEVS] = {	MASTER_MINOR,	MASTER_MINOR,
108 					MASTER_MINOR,	MASTER_MINOR,
109 					SLAVE_MINOR,	SLAVE_MINOR,
110 					SLAVE_MINOR,	SLAVE_MINOR,
111 					CONTROL_MINOR
112 				};
113 
114 struct vme_user_vma_priv {
115 	unsigned int minor;
116 	refcount_t refcnt;
117 };
118 
resource_to_user(int minor,char __user * buf,size_t count,loff_t * ppos)119 static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
120 				loff_t *ppos)
121 {
122 	ssize_t copied = 0;
123 
124 	if (count > image[minor].size_buf)
125 		count = image[minor].size_buf;
126 
127 	copied = vme_master_read(image[minor].resource, image[minor].kern_buf,
128 				 count, *ppos);
129 	if (copied < 0)
130 		return (int)copied;
131 
132 	if (copy_to_user(buf, image[minor].kern_buf, (unsigned long)copied))
133 		return -EFAULT;
134 
135 	return copied;
136 }
137 
resource_from_user(unsigned int minor,const char __user * buf,size_t count,loff_t * ppos)138 static ssize_t resource_from_user(unsigned int minor, const char __user *buf,
139 				  size_t count, loff_t *ppos)
140 {
141 	if (count > image[minor].size_buf)
142 		count = image[minor].size_buf;
143 
144 	if (copy_from_user(image[minor].kern_buf, buf, (unsigned long)count))
145 		return -EFAULT;
146 
147 	return vme_master_write(image[minor].resource, image[minor].kern_buf,
148 				count, *ppos);
149 }
150 
buffer_to_user(unsigned int minor,char __user * buf,size_t count,loff_t * ppos)151 static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
152 			      size_t count, loff_t *ppos)
153 {
154 	void *image_ptr;
155 
156 	image_ptr = image[minor].kern_buf + *ppos;
157 	if (copy_to_user(buf, image_ptr, (unsigned long)count))
158 		return -EFAULT;
159 
160 	return count;
161 }
162 
buffer_from_user(unsigned int minor,const char __user * buf,size_t count,loff_t * ppos)163 static ssize_t buffer_from_user(unsigned int minor, const char __user *buf,
164 				size_t count, loff_t *ppos)
165 {
166 	void *image_ptr;
167 
168 	image_ptr = image[minor].kern_buf + *ppos;
169 	if (copy_from_user(image_ptr, buf, (unsigned long)count))
170 		return -EFAULT;
171 
172 	return count;
173 }
174 
vme_user_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)175 static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count,
176 			     loff_t *ppos)
177 {
178 	unsigned int minor = iminor(file_inode(file));
179 	ssize_t retval;
180 	size_t image_size;
181 
182 	if (minor == CONTROL_MINOR)
183 		return 0;
184 
185 	mutex_lock(&image[minor].mutex);
186 
187 	/* XXX Do we *really* want this helper - we can use vme_*_get ? */
188 	image_size = vme_get_size(image[minor].resource);
189 
190 	/* Ensure we are starting at a valid location */
191 	if ((*ppos < 0) || (*ppos > (image_size - 1))) {
192 		mutex_unlock(&image[minor].mutex);
193 		return 0;
194 	}
195 
196 	/* Ensure not reading past end of the image */
197 	if (*ppos + count > image_size)
198 		count = image_size - *ppos;
199 
200 	switch (type[minor]) {
201 	case MASTER_MINOR:
202 		retval = resource_to_user(minor, buf, count, ppos);
203 		break;
204 	case SLAVE_MINOR:
205 		retval = buffer_to_user(minor, buf, count, ppos);
206 		break;
207 	default:
208 		retval = -EINVAL;
209 	}
210 
211 	mutex_unlock(&image[minor].mutex);
212 	if (retval > 0)
213 		*ppos += retval;
214 
215 	return retval;
216 }
217 
vme_user_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)218 static ssize_t vme_user_write(struct file *file, const char __user *buf,
219 			      size_t count, loff_t *ppos)
220 {
221 	unsigned int minor = iminor(file_inode(file));
222 	ssize_t retval;
223 	size_t image_size;
224 
225 	if (minor == CONTROL_MINOR)
226 		return 0;
227 
228 	mutex_lock(&image[minor].mutex);
229 
230 	image_size = vme_get_size(image[minor].resource);
231 
232 	/* Ensure we are starting at a valid location */
233 	if ((*ppos < 0) || (*ppos > (image_size - 1))) {
234 		mutex_unlock(&image[minor].mutex);
235 		return 0;
236 	}
237 
238 	/* Ensure not reading past end of the image */
239 	if (*ppos + count > image_size)
240 		count = image_size - *ppos;
241 
242 	switch (type[minor]) {
243 	case MASTER_MINOR:
244 		retval = resource_from_user(minor, buf, count, ppos);
245 		break;
246 	case SLAVE_MINOR:
247 		retval = buffer_from_user(minor, buf, count, ppos);
248 		break;
249 	default:
250 		retval = -EINVAL;
251 	}
252 
253 	mutex_unlock(&image[minor].mutex);
254 
255 	if (retval > 0)
256 		*ppos += retval;
257 
258 	return retval;
259 }
260 
vme_user_llseek(struct file * file,loff_t off,int whence)261 static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
262 {
263 	unsigned int minor = iminor(file_inode(file));
264 	size_t image_size;
265 	loff_t res;
266 
267 	switch (type[minor]) {
268 	case MASTER_MINOR:
269 	case SLAVE_MINOR:
270 		mutex_lock(&image[minor].mutex);
271 		image_size = vme_get_size(image[minor].resource);
272 		res = fixed_size_llseek(file, off, whence, image_size);
273 		mutex_unlock(&image[minor].mutex);
274 		return res;
275 	}
276 
277 	return -EINVAL;
278 }
279 
280 /*
281  * The ioctls provided by the old VME access method (the one at vmelinux.org)
282  * are most certainly wrong as the effectively push the registers layout
283  * through to user space. Given that the VME core can handle multiple bridges,
284  * with different register layouts this is most certainly not the way to go.
285  *
286  * We aren't using the structures defined in the Motorola driver either - these
287  * are also quite low level, however we should use the definitions that have
288  * already been defined.
289  */
vme_user_ioctl(struct inode * inode,struct file * file,unsigned int cmd,unsigned long arg)290 static int vme_user_ioctl(struct inode *inode, struct file *file,
291 			  unsigned int cmd, unsigned long arg)
292 {
293 	struct vme_master master;
294 	struct vme_slave slave;
295 	struct vme_irq_id irq_req;
296 	unsigned long copied;
297 	unsigned int minor = iminor(inode);
298 	int retval;
299 	dma_addr_t pci_addr;
300 	void __user *argp = (void __user *)arg;
301 
302 	switch (type[minor]) {
303 	case CONTROL_MINOR:
304 		switch (cmd) {
305 		case VME_IRQ_GEN:
306 			copied = copy_from_user(&irq_req, argp,
307 						sizeof(irq_req));
308 			if (copied) {
309 				pr_warn("Partial copy from userspace\n");
310 				return -EFAULT;
311 			}
312 
313 			return vme_irq_generate(vme_user_bridge,
314 						  irq_req.level,
315 						  irq_req.statid);
316 		}
317 		break;
318 	case MASTER_MINOR:
319 		switch (cmd) {
320 		case VME_GET_MASTER:
321 			memset(&master, 0, sizeof(master));
322 
323 			/* XXX	We do not want to push aspace, cycle and width
324 			 *	to userspace as they are
325 			 */
326 			retval = vme_master_get(image[minor].resource,
327 						&master.enable,
328 						&master.vme_addr,
329 						&master.size, &master.aspace,
330 						&master.cycle, &master.dwidth);
331 
332 			copied = copy_to_user(argp, &master,
333 					      sizeof(master));
334 			if (copied) {
335 				pr_warn("Partial copy to userspace\n");
336 				return -EFAULT;
337 			}
338 
339 			return retval;
340 
341 		case VME_SET_MASTER:
342 
343 			if (image[minor].mmap_count != 0) {
344 				pr_warn("Can't adjust mapped window\n");
345 				return -EPERM;
346 			}
347 
348 			copied = copy_from_user(&master, argp, sizeof(master));
349 			if (copied) {
350 				pr_warn("Partial copy from userspace\n");
351 				return -EFAULT;
352 			}
353 
354 			/* XXX	We do not want to push aspace, cycle and width
355 			 *	to userspace as they are
356 			 */
357 			return vme_master_set(image[minor].resource,
358 				master.enable, master.vme_addr, master.size,
359 				master.aspace, master.cycle, master.dwidth);
360 
361 			break;
362 		}
363 		break;
364 	case SLAVE_MINOR:
365 		switch (cmd) {
366 		case VME_GET_SLAVE:
367 			memset(&slave, 0, sizeof(slave));
368 
369 			/* XXX	We do not want to push aspace, cycle and width
370 			 *	to userspace as they are
371 			 */
372 			retval = vme_slave_get(image[minor].resource,
373 					       &slave.enable, &slave.vme_addr,
374 					       &slave.size, &pci_addr,
375 					       &slave.aspace, &slave.cycle);
376 
377 			copied = copy_to_user(argp, &slave,
378 					      sizeof(slave));
379 			if (copied) {
380 				pr_warn("Partial copy to userspace\n");
381 				return -EFAULT;
382 			}
383 
384 			return retval;
385 
386 		case VME_SET_SLAVE:
387 
388 			copied = copy_from_user(&slave, argp, sizeof(slave));
389 			if (copied) {
390 				pr_warn("Partial copy from userspace\n");
391 				return -EFAULT;
392 			}
393 
394 			/* XXX	We do not want to push aspace, cycle and width
395 			 *	to userspace as they are
396 			 */
397 			return vme_slave_set(image[minor].resource,
398 				slave.enable, slave.vme_addr, slave.size,
399 				image[minor].pci_buf, slave.aspace,
400 				slave.cycle);
401 
402 			break;
403 		}
404 		break;
405 	}
406 
407 	return -EINVAL;
408 }
409 
410 static long
vme_user_unlocked_ioctl(struct file * file,unsigned int cmd,unsigned long arg)411 vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
412 {
413 	int ret;
414 	struct inode *inode = file_inode(file);
415 	unsigned int minor = iminor(inode);
416 
417 	mutex_lock(&image[minor].mutex);
418 	ret = vme_user_ioctl(inode, file, cmd, arg);
419 	mutex_unlock(&image[minor].mutex);
420 
421 	return ret;
422 }
423 
vme_user_vm_open(struct vm_area_struct * vma)424 static void vme_user_vm_open(struct vm_area_struct *vma)
425 {
426 	struct vme_user_vma_priv *vma_priv = vma->vm_private_data;
427 
428 	refcount_inc(&vma_priv->refcnt);
429 }
430 
vme_user_vm_close(struct vm_area_struct * vma)431 static void vme_user_vm_close(struct vm_area_struct *vma)
432 {
433 	struct vme_user_vma_priv *vma_priv = vma->vm_private_data;
434 	unsigned int minor = vma_priv->minor;
435 
436 	if (!refcount_dec_and_test(&vma_priv->refcnt))
437 		return;
438 
439 	mutex_lock(&image[minor].mutex);
440 	image[minor].mmap_count--;
441 	mutex_unlock(&image[minor].mutex);
442 
443 	kfree(vma_priv);
444 }
445 
446 static const struct vm_operations_struct vme_user_vm_ops = {
447 	.open = vme_user_vm_open,
448 	.close = vme_user_vm_close,
449 };
450 
vme_user_master_mmap(unsigned int minor,struct vm_area_struct * vma)451 static int vme_user_master_mmap(unsigned int minor, struct vm_area_struct *vma)
452 {
453 	int err;
454 	struct vme_user_vma_priv *vma_priv;
455 
456 	mutex_lock(&image[minor].mutex);
457 
458 	err = vme_master_mmap(image[minor].resource, vma);
459 	if (err) {
460 		mutex_unlock(&image[minor].mutex);
461 		return err;
462 	}
463 
464 	vma_priv = kmalloc(sizeof(*vma_priv), GFP_KERNEL);
465 	if (!vma_priv) {
466 		mutex_unlock(&image[minor].mutex);
467 		return -ENOMEM;
468 	}
469 
470 	vma_priv->minor = minor;
471 	refcount_set(&vma_priv->refcnt, 1);
472 	vma->vm_ops = &vme_user_vm_ops;
473 	vma->vm_private_data = vma_priv;
474 
475 	image[minor].mmap_count++;
476 
477 	mutex_unlock(&image[minor].mutex);
478 
479 	return 0;
480 }
481 
vme_user_mmap(struct file * file,struct vm_area_struct * vma)482 static int vme_user_mmap(struct file *file, struct vm_area_struct *vma)
483 {
484 	unsigned int minor = iminor(file_inode(file));
485 
486 	if (type[minor] == MASTER_MINOR)
487 		return vme_user_master_mmap(minor, vma);
488 
489 	return -ENODEV;
490 }
491 
492 static const struct file_operations vme_user_fops = {
493 	.read = vme_user_read,
494 	.write = vme_user_write,
495 	.llseek = vme_user_llseek,
496 	.unlocked_ioctl = vme_user_unlocked_ioctl,
497 	.compat_ioctl = compat_ptr_ioctl,
498 	.mmap = vme_user_mmap,
499 };
500 
vme_user_match(struct vme_dev * vdev)501 static int vme_user_match(struct vme_dev *vdev)
502 {
503 	int i;
504 
505 	int cur_bus = vme_bus_num(vdev);
506 	int cur_slot = vme_slot_num(vdev);
507 
508 	for (i = 0; i < bus_num; i++)
509 		if ((cur_bus == bus[i]) && (cur_slot == vdev->num))
510 			return 1;
511 
512 	return 0;
513 }
514 
515 /*
516  * In this simple access driver, the old behaviour is being preserved as much
517  * as practical. We will therefore reserve the buffers and request the images
518  * here so that we don't have to do it later.
519  */
vme_user_probe(struct vme_dev * vdev)520 static int vme_user_probe(struct vme_dev *vdev)
521 {
522 	int i, err;
523 	char *name;
524 
525 	/* Save pointer to the bridge device */
526 	if (vme_user_bridge) {
527 		dev_err(&vdev->dev, "Driver can only be loaded for 1 device\n");
528 		err = -EINVAL;
529 		goto err_dev;
530 	}
531 	vme_user_bridge = vdev;
532 
533 	/* Initialise descriptors */
534 	for (i = 0; i < VME_DEVS; i++) {
535 		image[i].kern_buf = NULL;
536 		image[i].pci_buf = 0;
537 		mutex_init(&image[i].mutex);
538 		image[i].device = NULL;
539 		image[i].resource = NULL;
540 	}
541 
542 	/* Assign major and minor numbers for the driver */
543 	err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
544 				     driver_name);
545 	if (err) {
546 		dev_warn(&vdev->dev, "Error getting Major Number %d for driver.\n",
547 			 VME_MAJOR);
548 		goto err_region;
549 	}
550 
551 	/* Register the driver as a char device */
552 	vme_user_cdev = cdev_alloc();
553 	if (!vme_user_cdev) {
554 		err = -ENOMEM;
555 		goto err_char;
556 	}
557 	vme_user_cdev->ops = &vme_user_fops;
558 	vme_user_cdev->owner = THIS_MODULE;
559 	err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
560 	if (err)
561 		goto err_class;
562 
563 	/* Request slave resources and allocate buffers (128kB wide) */
564 	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
565 		/* XXX Need to properly request attributes */
566 		/* For ca91cx42 bridge there are only two slave windows
567 		 * supporting A16 addressing, so we request A24 supported
568 		 * by all windows.
569 		 */
570 		image[i].resource = vme_slave_request(vme_user_bridge,
571 						      VME_A24, VME_SCT);
572 		if (!image[i].resource) {
573 			dev_warn(&vdev->dev,
574 				 "Unable to allocate slave resource\n");
575 			err = -ENOMEM;
576 			goto err_slave;
577 		}
578 		image[i].size_buf = PCI_BUF_SIZE;
579 		image[i].kern_buf = vme_alloc_consistent(image[i].resource,
580 							 image[i].size_buf,
581 							 &image[i].pci_buf);
582 		if (!image[i].kern_buf) {
583 			dev_warn(&vdev->dev,
584 				 "Unable to allocate memory for buffer\n");
585 			image[i].pci_buf = 0;
586 			vme_slave_free(image[i].resource);
587 			err = -ENOMEM;
588 			goto err_slave;
589 		}
590 	}
591 
592 	/*
593 	 * Request master resources allocate page sized buffers for small
594 	 * reads and writes
595 	 */
596 	for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
597 		/* XXX Need to properly request attributes */
598 		image[i].resource = vme_master_request(vme_user_bridge,
599 						       VME_A32, VME_SCT,
600 						       VME_D32);
601 		if (!image[i].resource) {
602 			dev_warn(&vdev->dev,
603 				 "Unable to allocate master resource\n");
604 			err = -ENOMEM;
605 			goto err_master;
606 		}
607 		image[i].size_buf = PCI_BUF_SIZE;
608 		image[i].kern_buf = kmalloc(image[i].size_buf, GFP_KERNEL);
609 		if (!image[i].kern_buf) {
610 			err = -ENOMEM;
611 			vme_master_free(image[i].resource);
612 			goto err_master;
613 		}
614 	}
615 
616 	/* Create sysfs entries - on udev systems this creates the dev files */
617 	vme_user_sysfs_class = class_create(driver_name);
618 	if (IS_ERR(vme_user_sysfs_class)) {
619 		dev_err(&vdev->dev, "Error creating vme_user class.\n");
620 		err = PTR_ERR(vme_user_sysfs_class);
621 		goto err_master;
622 	}
623 
624 	/* Add sysfs Entries */
625 	for (i = 0; i < VME_DEVS; i++) {
626 		int num;
627 
628 		switch (type[i]) {
629 		case MASTER_MINOR:
630 			name = "bus/vme/m%d";
631 			break;
632 		case CONTROL_MINOR:
633 			name = "bus/vme/ctl";
634 			break;
635 		case SLAVE_MINOR:
636 			name = "bus/vme/s%d";
637 			break;
638 		default:
639 			err = -EINVAL;
640 			goto err_sysfs;
641 		}
642 
643 		num = (type[i] == SLAVE_MINOR) ? i - (MASTER_MAX + 1) : i;
644 		image[i].device = device_create(vme_user_sysfs_class, NULL,
645 						MKDEV(VME_MAJOR, i), NULL,
646 						name, num);
647 		if (IS_ERR(image[i].device)) {
648 			dev_info(&vdev->dev, "Error creating sysfs device\n");
649 			err = PTR_ERR(image[i].device);
650 			goto err_sysfs;
651 		}
652 	}
653 
654 	return 0;
655 
656 err_sysfs:
657 	while (i > 0) {
658 		i--;
659 		device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
660 	}
661 	class_destroy(vme_user_sysfs_class);
662 
663 	/* Ensure counter set correctly to unalloc all master windows */
664 	i = MASTER_MAX + 1;
665 err_master:
666 	while (i > MASTER_MINOR) {
667 		i--;
668 		kfree(image[i].kern_buf);
669 		vme_master_free(image[i].resource);
670 	}
671 
672 	/*
673 	 * Ensure counter set correctly to unalloc all slave windows and buffers
674 	 */
675 	i = SLAVE_MAX + 1;
676 err_slave:
677 	while (i > SLAVE_MINOR) {
678 		i--;
679 		vme_free_consistent(image[i].resource, image[i].size_buf,
680 				    image[i].kern_buf, image[i].pci_buf);
681 		vme_slave_free(image[i].resource);
682 	}
683 err_class:
684 	cdev_del(vme_user_cdev);
685 err_char:
686 	unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
687 err_region:
688 err_dev:
689 	return err;
690 }
691 
vme_user_remove(struct vme_dev * dev)692 static void vme_user_remove(struct vme_dev *dev)
693 {
694 	int i;
695 
696 	/* Remove sysfs Entries */
697 	for (i = 0; i < VME_DEVS; i++) {
698 		mutex_destroy(&image[i].mutex);
699 		device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
700 	}
701 	class_destroy(vme_user_sysfs_class);
702 
703 	for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
704 		kfree(image[i].kern_buf);
705 		vme_master_free(image[i].resource);
706 	}
707 
708 	for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
709 		vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
710 		vme_free_consistent(image[i].resource, image[i].size_buf,
711 				    image[i].kern_buf, image[i].pci_buf);
712 		vme_slave_free(image[i].resource);
713 	}
714 
715 	/* Unregister device driver */
716 	cdev_del(vme_user_cdev);
717 
718 	/* Unregister the major and minor device numbers */
719 	unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
720 }
721 
722 static struct vme_driver vme_user_driver = {
723 	.name = driver_name,
724 	.match = vme_user_match,
725 	.probe = vme_user_probe,
726 	.remove = vme_user_remove,
727 };
728 
vme_user_init(void)729 static int __init vme_user_init(void)
730 {
731 	int retval = 0;
732 
733 	pr_info("VME User Space Access Driver\n");
734 
735 	if (bus_num == 0) {
736 		pr_err("No cards, skipping registration\n");
737 		retval = -ENODEV;
738 		goto err_nocard;
739 	}
740 
741 	/* Let's start by supporting one bus, we can support more than one
742 	 * in future revisions if that ever becomes necessary.
743 	 */
744 	if (bus_num > VME_USER_BUS_MAX) {
745 		pr_err("Driver only able to handle %d buses\n",
746 		       VME_USER_BUS_MAX);
747 		bus_num = VME_USER_BUS_MAX;
748 	}
749 
750 	/*
751 	 * Here we just register the maximum number of devices we can and
752 	 * leave vme_user_match() to allow only 1 to go through to probe().
753 	 * This way, if we later want to allow multiple user access devices,
754 	 * we just change the code in vme_user_match().
755 	 */
756 	retval = vme_register_driver(&vme_user_driver, VME_MAX_SLOTS);
757 	if (retval)
758 		goto err_reg;
759 
760 	return retval;
761 
762 err_reg:
763 err_nocard:
764 	return retval;
765 }
766 
vme_user_exit(void)767 static void __exit vme_user_exit(void)
768 {
769 	vme_unregister_driver(&vme_user_driver);
770 }
771 
772 MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected");
773 module_param_array(bus, int, &bus_num, 0000);
774 
775 MODULE_DESCRIPTION("VME User Space Access Driver");
776 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
777 MODULE_LICENSE("GPL");
778 
779 module_init(vme_user_init);
780 module_exit(vme_user_exit);
781