2 * VMEbus User access driver
4 * Author: Martyn Welch <martyn.welch@ge.com>
5 * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
8 * Tom Armistead and Ajit Prem
9 * Copyright 2004 Motorola Inc.
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version.
18 #include <linux/cdev.h>
19 #include <linux/delay.h>
20 #include <linux/device.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/ioctl.h>
25 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/pagemap.h>
29 #include <linux/pci.h>
30 #include <linux/semaphore.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/syscalls.h>
34 #include <linux/types.h>
37 #include <asm/uaccess.h>
42 static char driver_name[] = "vme_user";
44 static int bus[USER_BUS_MAX];
47 /* Currently Documentation/devices.txt defines the following for VME:
50 * 0 = /dev/bus/vme/m0 First master image
51 * 1 = /dev/bus/vme/m1 Second master image
52 * 2 = /dev/bus/vme/m2 Third master image
53 * 3 = /dev/bus/vme/m3 Fourth master image
54 * 4 = /dev/bus/vme/s0 First slave image
55 * 5 = /dev/bus/vme/s1 Second slave image
56 * 6 = /dev/bus/vme/s2 Third slave image
57 * 7 = /dev/bus/vme/s3 Fourth slave image
58 * 8 = /dev/bus/vme/ctl Control
60 * It is expected that all VME bus drivers will use the
61 * same interface. For interface documentation see
62 * http://www.vmelinux.org/.
64 * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
65 * even support the tsi148 chipset (which has 8 master and 8 slave windows).
66 * We'll run with this or now as far as possible, however it probably makes
67 * sense to get rid of the old mappings and just do everything dynamically.
69 * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
70 * defined above and try to support at least some of the interface from
71 * http://www.vmelinux.org/ as an alternative drive can be written providing a
72 * saner interface later.
74 * The vmelinux.org driver never supported slave images, the devices reserved
75 * for slaves were repurposed to support all 8 master images on the UniverseII!
76 * We shall support 4 masters and 4 slaves with this driver.
78 #define VME_MAJOR 221 /* VME Major Device Number */
79 #define VME_DEVS 9 /* Number of dev entries */
81 #define MASTER_MINOR 0
85 #define CONTROL_MINOR 8
87 #define PCI_BUF_SIZE 0x20000 /* Size of one slave image buffer */
90 * Structure to handle image related parameters.
93 void __iomem *kern_buf; /* Buffer address in kernel space */
94 dma_addr_t pci_buf; /* Buffer address in PCI address space */
95 unsigned long long size_buf; /* Buffer size */
96 struct semaphore sem; /* Semaphore for locking image */
97 struct device *device; /* Sysfs device */
98 struct vme_resource *resource; /* VME resource */
99 int users; /* Number of current users */
101 static image_desc_t image[VME_DEVS];
105 unsigned long writes;
106 unsigned long ioctls;
109 unsigned long dmaErrors;
110 unsigned long timeouts;
111 unsigned long external;
113 static driver_stats_t statistics;
115 struct cdev *vme_user_cdev; /* Character device */
116 struct class *vme_user_sysfs_class; /* Sysfs class */
117 struct device *vme_user_bridge; /* Pointer to the bridge device */
120 static const int type[VME_DEVS] = { MASTER_MINOR, MASTER_MINOR,
121 MASTER_MINOR, MASTER_MINOR,
122 SLAVE_MINOR, SLAVE_MINOR,
123 SLAVE_MINOR, SLAVE_MINOR,
128 static int vme_user_open(struct inode *, struct file *);
129 static int vme_user_release(struct inode *, struct file *);
130 static ssize_t vme_user_read(struct file *, char *, size_t, loff_t *);
131 static ssize_t vme_user_write(struct file *, const char *, size_t, loff_t *);
132 static loff_t vme_user_llseek(struct file *, loff_t, int);
133 static int vme_user_ioctl(struct inode *, struct file *, unsigned int,
136 static int __init vme_user_probe(struct device *, int, int);
137 static int __exit vme_user_remove(struct device *, int, int);
139 static struct file_operations vme_user_fops = {
140 .open = vme_user_open,
141 .release = vme_user_release,
142 .read = vme_user_read,
143 .write = vme_user_write,
144 .llseek = vme_user_llseek,
145 .ioctl = vme_user_ioctl,
150 * Reset all the statistic counters
152 static void reset_counters(void)
154 statistics.reads = 0;
155 statistics.writes = 0;
156 statistics.ioctls = 0;
158 statistics.berrs = 0;
159 statistics.dmaErrors = 0;
160 statistics.timeouts = 0;
163 static int vme_user_open(struct inode *inode, struct file *file)
166 unsigned int minor = MINOR(inode->i_rdev);
168 down(&image[minor].sem);
169 /* Only allow device to be opened if a resource is allocated */
170 if (image[minor].resource == NULL) {
171 printk(KERN_ERR "No resources allocated for device\n");
176 /* Increment user count */
177 image[minor].users++;
179 up(&image[minor].sem);
184 up(&image[minor].sem);
189 static int vme_user_release(struct inode *inode, struct file *file)
191 unsigned int minor = MINOR(inode->i_rdev);
193 down(&image[minor].sem);
195 /* Decrement user count */
196 image[minor].users--;
198 up(&image[minor].sem);
204 * We are going ot alloc a page during init per window for small transfers.
205 * Small transfers will go VME -> buffer -> user space. Larger (more than a
206 * page) transfers will lock the user space buffer into memory and then
207 * transfer the data directly into the user space buffers.
209 static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
215 if (count <= image[minor].size_buf) {
216 /* We copy to kernel buffer */
217 copied = vme_master_read(image[minor].resource,
218 image[minor].kern_buf, count, *ppos);
223 retval = __copy_to_user(buf, image[minor].kern_buf,
224 (unsigned long)copied);
226 copied = (copied - retval);
227 printk("User copy failed\n");
232 /* XXX Need to write this */
233 printk("Currently don't support large transfers\n");
234 /* Map in pages from userspace */
236 /* Call vme_master_read to do the transfer */
244 * We are going ot alloc a page during init per window for small transfers.
245 * Small transfers will go user space -> buffer -> VME. Larger (more than a
246 * page) transfers will lock the user space buffer into memory and then
247 * transfer the data directly from the user space buffers out to VME.
249 static ssize_t resource_from_user(unsigned int minor, const char *buf,
250 size_t count, loff_t *ppos)
255 if (count <= image[minor].size_buf) {
256 retval = __copy_from_user(image[minor].kern_buf, buf,
257 (unsigned long)count);
259 copied = (copied - retval);
263 copied = vme_master_write(image[minor].resource,
264 image[minor].kern_buf, copied, *ppos);
266 /* XXX Need to write this */
267 printk("Currently don't support large transfers\n");
268 /* Map in pages from userspace */
270 /* Call vme_master_write to do the transfer */
277 static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
278 size_t count, loff_t *ppos)
280 void __iomem *image_ptr;
283 image_ptr = image[minor].kern_buf + *ppos;
285 retval = __copy_to_user(buf, image_ptr, (unsigned long)count);
287 retval = (count - retval);
288 printk(KERN_WARNING "Partial copy to userspace\n");
292 /* Return number of bytes successfully read */
296 static ssize_t buffer_from_user(unsigned int minor, const char *buf,
297 size_t count, loff_t *ppos)
299 void __iomem *image_ptr;
302 image_ptr = image[minor].kern_buf + *ppos;
304 retval = __copy_from_user(image_ptr, buf, (unsigned long)count);
306 retval = (count - retval);
307 printk(KERN_WARNING "Partial copy to userspace\n");
311 /* Return number of bytes successfully read */
315 static ssize_t vme_user_read(struct file *file, char *buf, size_t count,
318 unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
323 down(&image[minor].sem);
325 /* XXX Do we *really* want this helper - we can use vme_*_get ? */
326 image_size = vme_get_size(image[minor].resource);
328 /* Ensure we are starting at a valid location */
329 if ((*ppos < 0) || (*ppos > (image_size - 1))) {
330 up(&image[minor].sem);
334 /* Ensure not reading past end of the image */
335 if (*ppos + count > image_size)
336 okcount = image_size - *ppos;
340 switch (type[minor]){
342 retval = resource_to_user(minor, buf, okcount, ppos);
345 retval = buffer_to_user(minor, buf, okcount, ppos);
351 up(&image[minor].sem);
359 static ssize_t vme_user_write(struct file *file, const char *buf, size_t count,
362 unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
367 down(&image[minor].sem);
369 image_size = vme_get_size(image[minor].resource);
371 /* Ensure we are starting at a valid location */
372 if ((*ppos < 0) || (*ppos > (image_size - 1))) {
373 up(&image[minor].sem);
377 /* Ensure not reading past end of the image */
378 if (*ppos + count > image_size)
379 okcount = image_size - *ppos;
383 switch (type[minor]){
385 retval = resource_from_user(minor, buf, okcount, ppos);
388 retval = buffer_from_user(minor, buf, okcount, ppos);
394 up(&image[minor].sem);
402 static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
404 loff_t absolute = -1;
405 unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
408 down(&image[minor].sem);
409 image_size = vme_get_size(image[minor].resource);
416 absolute = file->f_pos + off;
419 absolute = image_size + off;
422 up(&image[minor].sem);
427 if ((absolute < 0) || (absolute >= image_size)) {
428 up(&image[minor].sem);
432 file->f_pos = absolute;
434 up(&image[minor].sem);
440 * The ioctls provided by the old VME access method (the one at vmelinux.org)
441 * are most certainly wrong as the effectively push the registers layout
442 * through to user space. Given that the VME core can handle multiple bridges,
443 * with different register layouts this is most certainly not the way to go.
445 * We aren't using the structures defined in the Motorola driver either - these
446 * are also quite low level, however we should use the definitions that have
447 * already been defined.
449 static int vme_user_ioctl(struct inode *inode, struct file *file,
450 unsigned int cmd, unsigned long arg)
452 struct vme_master master;
453 struct vme_slave slave;
454 unsigned long copied;
455 unsigned int minor = MINOR(inode->i_rdev);
461 switch (type[minor]) {
467 memset(&master, 0, sizeof(struct vme_master));
469 /* XXX We do not want to push aspace, cycle and width
470 * to userspace as they are
472 retval = vme_master_get(image[minor].resource,
473 &(master.enable), &(master.vme_addr),
474 &(master.size), &(master.aspace),
475 &(master.cycle), &(master.dwidth));
477 copied = copy_to_user((char *)arg, &master,
478 sizeof(struct vme_master));
480 printk(KERN_WARNING "Partial copy to "
490 copied = copy_from_user(&master, (char *)arg,
493 printk(KERN_WARNING "Partial copy from "
498 /* XXX We do not want to push aspace, cycle and width
499 * to userspace as they are
501 return vme_master_set(image[minor].resource,
502 master.enable, master.vme_addr, master.size,
503 master.aspace, master.cycle, master.dwidth);
511 memset(&slave, 0, sizeof(struct vme_slave));
513 /* XXX We do not want to push aspace, cycle and width
514 * to userspace as they are
516 retval = vme_slave_get(image[minor].resource,
517 &(slave.enable), &(slave.vme_addr),
518 &(slave.size), &pci_addr, &(slave.aspace),
521 copied = copy_to_user((char *)arg, &slave,
522 sizeof(struct vme_slave));
524 printk(KERN_WARNING "Partial copy to "
534 copied = copy_from_user(&slave, (char *)arg,
537 printk(KERN_WARNING "Partial copy from "
542 /* XXX We do not want to push aspace, cycle and width
543 * to userspace as they are
545 return vme_slave_set(image[minor].resource,
546 slave.enable, slave.vme_addr, slave.size,
547 image[minor].pci_buf, slave.aspace,
560 * Unallocate a previously allocated buffer
562 static void buf_unalloc (int num)
564 if (image[num].kern_buf) {
566 printk(KERN_DEBUG "UniverseII:Releasing buffer at %p\n",
570 vme_free_consistent(image[num].resource, image[num].size_buf,
571 image[num].kern_buf, image[num].pci_buf);
573 image[num].kern_buf = NULL;
574 image[num].pci_buf = 0;
575 image[num].size_buf = 0;
579 printk(KERN_DEBUG "UniverseII: Buffer not allocated\n");
584 static struct vme_driver vme_user_driver = {
586 .probe = vme_user_probe,
587 .remove = vme_user_remove,
591 static int __init vme_user_init(void)
595 struct vme_device_id *ids;
597 printk(KERN_INFO "VME User Space Access Driver\n");
600 printk(KERN_ERR "%s: No cards, skipping registration\n",
605 /* Let's start by supporting one bus, we can support more than one
606 * in future revisions if that ever becomes necessary.
608 if (bus_num > USER_BUS_MAX) {
609 printk(KERN_ERR "%s: Driver only able to handle %d buses\n",
610 driver_name, USER_BUS_MAX);
611 bus_num = USER_BUS_MAX;
615 /* Dynamically create the bind table based on module parameters */
616 ids = kmalloc(sizeof(struct vme_device_id) * (bus_num + 1), GFP_KERNEL);
618 printk(KERN_ERR "%s: Unable to allocate ID table\n",
623 memset(ids, 0, (sizeof(struct vme_device_id) * (bus_num + 1)));
625 for (i = 0; i < bus_num; i++) {
628 * We register the driver against the slot occupied by *this*
629 * card, since it's really a low level way of controlling
632 ids[i].slot = VME_SLOT_CURRENT;
635 vme_user_driver.bind_table = ids;
637 retval = vme_register_driver(&vme_user_driver);
643 vme_unregister_driver(&vme_user_driver);
652 * In this simple access driver, the old behaviour is being preserved as much
653 * as practical. We will therefore reserve the buffers and request the images
654 * here so that we don't have to do it later.
656 static int __init vme_user_probe(struct device *dev, int cur_bus, int cur_slot)
661 /* Save pointer to the bridge device */
662 if (vme_user_bridge != NULL) {
663 printk(KERN_ERR "%s: Driver can only be loaded for 1 device\n",
668 vme_user_bridge = dev;
670 /* Initialise descriptors */
671 for (i = 0; i < VME_DEVS; i++) {
672 image[i].kern_buf = NULL;
673 image[i].pci_buf = 0;
674 init_MUTEX(&(image[i].sem));
675 image[i].device = NULL;
676 image[i].resource = NULL;
680 /* Initialise statistics counters */
683 /* Assign major and minor numbers for the driver */
684 err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
687 printk(KERN_WARNING "%s: Error getting Major Number %d for "
688 "driver.\n", driver_name, VME_MAJOR);
692 /* Register the driver as a char device */
693 vme_user_cdev = cdev_alloc();
694 vme_user_cdev->ops = &vme_user_fops;
695 vme_user_cdev->owner = THIS_MODULE;
696 err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
698 printk(KERN_WARNING "%s: cdev_all failed\n", driver_name);
702 /* Request slave resources and allocate buffers (128kB wide) */
703 for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
704 /* XXX Need to properly request attributes */
705 /* For ca91cx42 bridge there are only two slave windows
706 * supporting A16 addressing, so we request A24 supported
709 image[i].resource = vme_slave_request(vme_user_bridge,
711 if (image[i].resource == NULL) {
712 printk(KERN_WARNING "Unable to allocate slave "
716 image[i].size_buf = PCI_BUF_SIZE;
717 image[i].kern_buf = vme_alloc_consistent(image[i].resource,
718 image[i].size_buf, &(image[i].pci_buf));
719 if (image[i].kern_buf == NULL) {
720 printk(KERN_WARNING "Unable to allocate memory for "
722 image[i].pci_buf = 0;
723 vme_slave_free(image[i].resource);
730 * Request master resources allocate page sized buffers for small
733 for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
734 /* XXX Need to properly request attributes */
735 image[i].resource = vme_master_request(vme_user_bridge,
736 VME_A32, VME_SCT, VME_D32);
737 if (image[i].resource == NULL) {
738 printk(KERN_WARNING "Unable to allocate master "
742 image[i].size_buf = PCI_BUF_SIZE;
743 image[i].kern_buf = kmalloc(image[i].size_buf, GFP_KERNEL);
744 if (image[i].kern_buf == NULL) {
745 printk(KERN_WARNING "Unable to allocate memory for "
746 "master window buffers\n");
752 /* Create sysfs entries - on udev systems this creates the dev files */
753 vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
754 if (IS_ERR(vme_user_sysfs_class)) {
755 printk(KERN_ERR "Error creating vme_user class.\n");
756 err = PTR_ERR(vme_user_sysfs_class);
760 /* Add sysfs Entries */
761 for (i=0; i<VME_DEVS; i++) {
764 sprintf(name,"bus/vme/m%%d");
767 sprintf(name,"bus/vme/ctl");
770 sprintf(name,"bus/vme/s%%d");
779 device_create(vme_user_sysfs_class, NULL,
780 MKDEV(VME_MAJOR, i), NULL, name,
781 (type[i] == SLAVE_MINOR)? i - (MASTER_MAX + 1) : i);
782 if (IS_ERR(image[i].device)) {
783 printk("%s: Error creating sysfs device\n",
785 err = PTR_ERR(image[i].device);
792 /* Ensure counter set correcty to destroy all sysfs devices */
797 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
799 class_destroy(vme_user_sysfs_class);
801 /* Ensure counter set correcty to unalloc all master windows */
804 for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++)
805 kfree(image[i].kern_buf);
807 while (i > MASTER_MINOR) {
809 vme_master_free(image[i].resource);
813 * Ensure counter set correcty to unalloc all slave windows and buffers
817 while (i > SLAVE_MINOR) {
819 vme_slave_free(image[i].resource);
823 cdev_del(vme_user_cdev);
825 unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
831 static int __exit vme_user_remove(struct device *dev, int cur_bus, int cur_slot)
835 /* Remove sysfs Entries */
836 for(i=0; i<VME_DEVS; i++) {
837 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
839 class_destroy(vme_user_sysfs_class);
841 for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++)
842 kfree(image[i].kern_buf);
844 for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
845 vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
846 vme_slave_free(image[i].resource);
850 /* Unregister device driver */
851 cdev_del(vme_user_cdev);
853 /* Unregiser the major and minor device numbers */
854 unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
859 static void __exit vme_user_exit(void)
861 vme_unregister_driver(&vme_user_driver);
863 kfree(vme_user_driver.bind_table);
867 MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected");
868 module_param_array(bus, int, &bus_num, 0);
870 MODULE_DESCRIPTION("VME User Space Access Driver");
871 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
872 MODULE_LICENSE("GPL");
874 module_init(vme_user_init);
875 module_exit(vme_user_exit);