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/mutex.h>
35 #include <linux/types.h>
38 #include <linux/uaccess.h>
43 static DEFINE_MUTEX(vme_user_mutex);
44 static const char driver_name[] = "vme_user";
46 static int bus[USER_BUS_MAX];
47 static unsigned int bus_num;
49 /* Currently Documentation/devices.txt defines the following for VME:
52 * 0 = /dev/bus/vme/m0 First master image
53 * 1 = /dev/bus/vme/m1 Second master image
54 * 2 = /dev/bus/vme/m2 Third master image
55 * 3 = /dev/bus/vme/m3 Fourth master image
56 * 4 = /dev/bus/vme/s0 First slave image
57 * 5 = /dev/bus/vme/s1 Second slave image
58 * 6 = /dev/bus/vme/s2 Third slave image
59 * 7 = /dev/bus/vme/s3 Fourth slave image
60 * 8 = /dev/bus/vme/ctl Control
62 * It is expected that all VME bus drivers will use the
63 * same interface. For interface documentation see
64 * http://www.vmelinux.org/.
66 * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
67 * even support the tsi148 chipset (which has 8 master and 8 slave windows).
68 * We'll run with this or now as far as possible, however it probably makes
69 * sense to get rid of the old mappings and just do everything dynamically.
71 * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
72 * defined above and try to support at least some of the interface from
73 * http://www.vmelinux.org/ as an alternative drive can be written providing a
74 * saner interface later.
76 * The vmelinux.org driver never supported slave images, the devices reserved
77 * for slaves were repurposed to support all 8 master images on the UniverseII!
78 * We shall support 4 masters and 4 slaves with this driver.
80 #define VME_MAJOR 221 /* VME Major Device Number */
81 #define VME_DEVS 9 /* Number of dev entries */
83 #define MASTER_MINOR 0
87 #define CONTROL_MINOR 8
89 #define PCI_BUF_SIZE 0x20000 /* Size of one slave image buffer */
92 * Structure to handle image related parameters.
95 void *kern_buf; /* Buffer address in kernel space */
96 dma_addr_t pci_buf; /* Buffer address in PCI address space */
97 unsigned long long size_buf; /* Buffer size */
98 struct semaphore sem; /* Semaphore for locking image */
99 struct device *device; /* Sysfs device */
100 struct vme_resource *resource; /* VME resource */
101 int users; /* Number of current users */
103 static struct image_desc image[VME_DEVS];
105 struct driver_stats {
107 unsigned long writes;
108 unsigned long ioctls;
111 unsigned long dmaErrors;
112 unsigned long timeouts;
113 unsigned long external;
115 static struct driver_stats statistics;
117 static struct cdev *vme_user_cdev; /* Character device */
118 static struct class *vme_user_sysfs_class; /* Sysfs class */
119 static struct device *vme_user_bridge; /* Pointer to bridge device */
122 static const int type[VME_DEVS] = { MASTER_MINOR, MASTER_MINOR,
123 MASTER_MINOR, MASTER_MINOR,
124 SLAVE_MINOR, SLAVE_MINOR,
125 SLAVE_MINOR, SLAVE_MINOR,
130 static int vme_user_open(struct inode *, struct file *);
131 static int vme_user_release(struct inode *, struct file *);
132 static ssize_t vme_user_read(struct file *, char __user *, size_t, loff_t *);
133 static ssize_t vme_user_write(struct file *, const char __user *, size_t,
135 static loff_t vme_user_llseek(struct file *, loff_t, int);
136 static long vme_user_unlocked_ioctl(struct file *, unsigned int, unsigned long);
138 static int __devinit vme_user_probe(struct device *, int, int);
139 static int __devexit vme_user_remove(struct device *, int, int);
141 static const struct file_operations vme_user_fops = {
142 .open = vme_user_open,
143 .release = vme_user_release,
144 .read = vme_user_read,
145 .write = vme_user_write,
146 .llseek = vme_user_llseek,
147 .unlocked_ioctl = vme_user_unlocked_ioctl,
152 * Reset all the statistic counters
154 static void reset_counters(void)
156 statistics.reads = 0;
157 statistics.writes = 0;
158 statistics.ioctls = 0;
160 statistics.berrs = 0;
161 statistics.dmaErrors = 0;
162 statistics.timeouts = 0;
165 static int vme_user_open(struct inode *inode, struct file *file)
168 unsigned int minor = MINOR(inode->i_rdev);
170 down(&image[minor].sem);
171 /* Allow device to be opened if a resource is needed and allocated. */
172 if (minor < CONTROL_MINOR && image[minor].resource == NULL) {
173 printk(KERN_ERR "No resources allocated for device\n");
178 /* Increment user count */
179 image[minor].users++;
181 up(&image[minor].sem);
186 up(&image[minor].sem);
191 static int vme_user_release(struct inode *inode, struct file *file)
193 unsigned int minor = MINOR(inode->i_rdev);
195 down(&image[minor].sem);
197 /* Decrement user count */
198 image[minor].users--;
200 up(&image[minor].sem);
206 * We are going ot alloc a page during init per window for small transfers.
207 * Small transfers will go VME -> buffer -> user space. Larger (more than a
208 * page) transfers will lock the user space buffer into memory and then
209 * transfer the data directly into the user space buffers.
211 static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
217 if (count <= image[minor].size_buf) {
218 /* We copy to kernel buffer */
219 copied = vme_master_read(image[minor].resource,
220 image[minor].kern_buf, count, *ppos);
224 retval = __copy_to_user(buf, image[minor].kern_buf,
225 (unsigned long)copied);
227 copied = (copied - retval);
228 printk(KERN_INFO "User copy failed\n");
233 /* XXX Need to write this */
234 printk(KERN_INFO "Currently don't support large transfers\n");
235 /* Map in pages from userspace */
237 /* Call vme_master_read to do the transfer */
245 * We are going ot alloc a page during init per window for small transfers.
246 * Small transfers will go user space -> buffer -> VME. Larger (more than a
247 * page) transfers will lock the user space buffer into memory and then
248 * transfer the data directly from the user space buffers out to VME.
250 static ssize_t resource_from_user(unsigned int minor, const char __user *buf,
251 size_t count, loff_t *ppos)
256 if (count <= image[minor].size_buf) {
257 retval = __copy_from_user(image[minor].kern_buf, buf,
258 (unsigned long)count);
260 copied = (copied - retval);
264 copied = vme_master_write(image[minor].resource,
265 image[minor].kern_buf, copied, *ppos);
267 /* XXX Need to write this */
268 printk(KERN_INFO "Currently don't support large transfers\n");
269 /* Map in pages from userspace */
271 /* Call vme_master_write to do the transfer */
278 static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
279 size_t count, loff_t *ppos)
284 image_ptr = image[minor].kern_buf + *ppos;
286 retval = __copy_to_user(buf, image_ptr, (unsigned long)count);
288 retval = (count - retval);
289 printk(KERN_WARNING "Partial copy to userspace\n");
293 /* Return number of bytes successfully read */
297 static ssize_t buffer_from_user(unsigned int minor, const char __user *buf,
298 size_t count, loff_t *ppos)
303 image_ptr = image[minor].kern_buf + *ppos;
305 retval = __copy_from_user(image_ptr, buf, (unsigned long)count);
307 retval = (count - retval);
308 printk(KERN_WARNING "Partial copy to userspace\n");
312 /* Return number of bytes successfully read */
316 static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count,
319 unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
324 if (minor == CONTROL_MINOR)
327 down(&image[minor].sem);
329 /* XXX Do we *really* want this helper - we can use vme_*_get ? */
330 image_size = vme_get_size(image[minor].resource);
332 /* Ensure we are starting at a valid location */
333 if ((*ppos < 0) || (*ppos > (image_size - 1))) {
334 up(&image[minor].sem);
338 /* Ensure not reading past end of the image */
339 if (*ppos + count > image_size)
340 okcount = image_size - *ppos;
344 switch (type[minor]) {
346 retval = resource_to_user(minor, buf, okcount, ppos);
349 retval = buffer_to_user(minor, buf, okcount, ppos);
355 up(&image[minor].sem);
363 static ssize_t vme_user_write(struct file *file, const char __user *buf,
364 size_t count, loff_t *ppos)
366 unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
371 if (minor == CONTROL_MINOR)
374 down(&image[minor].sem);
376 image_size = vme_get_size(image[minor].resource);
378 /* Ensure we are starting at a valid location */
379 if ((*ppos < 0) || (*ppos > (image_size - 1))) {
380 up(&image[minor].sem);
384 /* Ensure not reading past end of the image */
385 if (*ppos + count > image_size)
386 okcount = image_size - *ppos;
390 switch (type[minor]) {
392 retval = resource_from_user(minor, buf, okcount, ppos);
395 retval = buffer_from_user(minor, buf, okcount, ppos);
401 up(&image[minor].sem);
409 static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
411 loff_t absolute = -1;
412 unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
415 if (minor == CONTROL_MINOR)
418 down(&image[minor].sem);
419 image_size = vme_get_size(image[minor].resource);
426 absolute = file->f_pos + off;
429 absolute = image_size + off;
432 up(&image[minor].sem);
437 if ((absolute < 0) || (absolute >= image_size)) {
438 up(&image[minor].sem);
442 file->f_pos = absolute;
444 up(&image[minor].sem);
450 * The ioctls provided by the old VME access method (the one at vmelinux.org)
451 * are most certainly wrong as the effectively push the registers layout
452 * through to user space. Given that the VME core can handle multiple bridges,
453 * with different register layouts this is most certainly not the way to go.
455 * We aren't using the structures defined in the Motorola driver either - these
456 * are also quite low level, however we should use the definitions that have
457 * already been defined.
459 static int vme_user_ioctl(struct inode *inode, struct file *file,
460 unsigned int cmd, unsigned long arg)
462 struct vme_master master;
463 struct vme_slave slave;
464 struct vme_irq_id irq_req;
465 unsigned long copied;
466 unsigned int minor = MINOR(inode->i_rdev);
469 void __user *argp = (void __user *)arg;
473 switch (type[minor]) {
477 copied = copy_from_user(&irq_req, (char *)arg,
478 sizeof(struct vme_irq_id));
480 printk(KERN_WARNING "Partial copy from userspace\n");
484 retval = vme_irq_generate(vme_user_bridge,
494 memset(&master, 0, sizeof(struct vme_master));
496 /* XXX We do not want to push aspace, cycle and width
497 * to userspace as they are
499 retval = vme_master_get(image[minor].resource,
500 &master.enable, &master.vme_addr,
501 &master.size, &master.aspace,
502 &master.cycle, &master.dwidth);
504 copied = copy_to_user(argp, &master,
505 sizeof(struct vme_master));
507 printk(KERN_WARNING "Partial copy to "
517 copied = copy_from_user(&master, argp, sizeof(master));
519 printk(KERN_WARNING "Partial copy from "
524 /* XXX We do not want to push aspace, cycle and width
525 * to userspace as they are
527 return vme_master_set(image[minor].resource,
528 master.enable, master.vme_addr, master.size,
529 master.aspace, master.cycle, master.dwidth);
537 memset(&slave, 0, sizeof(struct vme_slave));
539 /* XXX We do not want to push aspace, cycle and width
540 * to userspace as they are
542 retval = vme_slave_get(image[minor].resource,
543 &slave.enable, &slave.vme_addr,
544 &slave.size, &pci_addr, &slave.aspace,
547 copied = copy_to_user(argp, &slave,
548 sizeof(struct vme_slave));
550 printk(KERN_WARNING "Partial copy to "
560 copied = copy_from_user(&slave, argp, sizeof(slave));
562 printk(KERN_WARNING "Partial copy from "
567 /* XXX We do not want to push aspace, cycle and width
568 * to userspace as they are
570 return vme_slave_set(image[minor].resource,
571 slave.enable, slave.vme_addr, slave.size,
572 image[minor].pci_buf, slave.aspace,
584 vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
588 mutex_lock(&vme_user_mutex);
589 ret = vme_user_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
590 mutex_unlock(&vme_user_mutex);
597 * Unallocate a previously allocated buffer
599 static void buf_unalloc(int num)
601 if (image[num].kern_buf) {
603 printk(KERN_DEBUG "UniverseII:Releasing buffer at %p\n",
607 vme_free_consistent(image[num].resource, image[num].size_buf,
608 image[num].kern_buf, image[num].pci_buf);
610 image[num].kern_buf = NULL;
611 image[num].pci_buf = 0;
612 image[num].size_buf = 0;
616 printk(KERN_DEBUG "UniverseII: Buffer not allocated\n");
621 static struct vme_driver vme_user_driver = {
623 .probe = vme_user_probe,
624 .remove = __devexit_p(vme_user_remove),
628 static int __init vme_user_init(void)
632 struct vme_device_id *ids;
634 printk(KERN_INFO "VME User Space Access Driver\n");
637 printk(KERN_ERR "%s: No cards, skipping registration\n",
643 /* Let's start by supporting one bus, we can support more than one
644 * in future revisions if that ever becomes necessary.
646 if (bus_num > USER_BUS_MAX) {
647 printk(KERN_ERR "%s: Driver only able to handle %d buses\n",
648 driver_name, USER_BUS_MAX);
649 bus_num = USER_BUS_MAX;
653 /* Dynamically create the bind table based on module parameters */
654 ids = kmalloc(sizeof(struct vme_device_id) * (bus_num + 1), GFP_KERNEL);
656 printk(KERN_ERR "%s: Unable to allocate ID table\n",
662 memset(ids, 0, (sizeof(struct vme_device_id) * (bus_num + 1)));
664 for (i = 0; i < bus_num; i++) {
667 * We register the driver against the slot occupied by *this*
668 * card, since it's really a low level way of controlling
671 ids[i].slot = VME_SLOT_CURRENT;
674 vme_user_driver.bind_table = ids;
676 retval = vme_register_driver(&vme_user_driver);
690 * In this simple access driver, the old behaviour is being preserved as much
691 * as practical. We will therefore reserve the buffers and request the images
692 * here so that we don't have to do it later.
694 static int __devinit vme_user_probe(struct device *dev, int cur_bus,
700 /* Save pointer to the bridge device */
701 if (vme_user_bridge != NULL) {
702 printk(KERN_ERR "%s: Driver can only be loaded for 1 device\n",
707 vme_user_bridge = dev;
709 /* Initialise descriptors */
710 for (i = 0; i < VME_DEVS; i++) {
711 image[i].kern_buf = NULL;
712 image[i].pci_buf = 0;
713 sema_init(&image[i].sem, 1);
714 image[i].device = NULL;
715 image[i].resource = NULL;
719 /* Initialise statistics counters */
722 /* Assign major and minor numbers for the driver */
723 err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
726 printk(KERN_WARNING "%s: Error getting Major Number %d for "
727 "driver.\n", driver_name, VME_MAJOR);
731 /* Register the driver as a char device */
732 vme_user_cdev = cdev_alloc();
733 vme_user_cdev->ops = &vme_user_fops;
734 vme_user_cdev->owner = THIS_MODULE;
735 err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
737 printk(KERN_WARNING "%s: cdev_all failed\n", driver_name);
741 /* Request slave resources and allocate buffers (128kB wide) */
742 for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
743 /* XXX Need to properly request attributes */
744 /* For ca91cx42 bridge there are only two slave windows
745 * supporting A16 addressing, so we request A24 supported
748 image[i].resource = vme_slave_request(vme_user_bridge,
750 if (image[i].resource == NULL) {
751 printk(KERN_WARNING "Unable to allocate slave "
755 image[i].size_buf = PCI_BUF_SIZE;
756 image[i].kern_buf = vme_alloc_consistent(image[i].resource,
757 image[i].size_buf, &image[i].pci_buf);
758 if (image[i].kern_buf == NULL) {
759 printk(KERN_WARNING "Unable to allocate memory for "
761 image[i].pci_buf = 0;
762 vme_slave_free(image[i].resource);
769 * Request master resources allocate page sized buffers for small
772 for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
773 /* XXX Need to properly request attributes */
774 image[i].resource = vme_master_request(vme_user_bridge,
775 VME_A32, VME_SCT, VME_D32);
776 if (image[i].resource == NULL) {
777 printk(KERN_WARNING "Unable to allocate master "
781 image[i].size_buf = PCI_BUF_SIZE;
782 image[i].kern_buf = kmalloc(image[i].size_buf, GFP_KERNEL);
783 if (image[i].kern_buf == NULL) {
784 printk(KERN_WARNING "Unable to allocate memory for "
785 "master window buffers\n");
791 /* Create sysfs entries - on udev systems this creates the dev files */
792 vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
793 if (IS_ERR(vme_user_sysfs_class)) {
794 printk(KERN_ERR "Error creating vme_user class.\n");
795 err = PTR_ERR(vme_user_sysfs_class);
799 /* Add sysfs Entries */
800 for (i = 0; i < VME_DEVS; i++) {
804 sprintf(name, "bus/vme/m%%d");
807 sprintf(name, "bus/vme/ctl");
810 sprintf(name, "bus/vme/s%%d");
818 num = (type[i] == SLAVE_MINOR) ? i - (MASTER_MAX + 1) : i;
819 image[i].device = device_create(vme_user_sysfs_class, NULL,
820 MKDEV(VME_MAJOR, i), NULL, name, num);
821 if (IS_ERR(image[i].device)) {
822 printk(KERN_INFO "%s: Error creating sysfs device\n",
824 err = PTR_ERR(image[i].device);
831 /* Ensure counter set correcty to destroy all sysfs devices */
836 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
838 class_destroy(vme_user_sysfs_class);
840 /* Ensure counter set correcty to unalloc all master windows */
843 for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++)
844 kfree(image[i].kern_buf);
846 while (i > MASTER_MINOR) {
848 vme_master_free(image[i].resource);
852 * Ensure counter set correcty to unalloc all slave windows and buffers
856 while (i > SLAVE_MINOR) {
859 vme_slave_free(image[i].resource);
862 cdev_del(vme_user_cdev);
864 unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
870 static int __devexit vme_user_remove(struct device *dev, int cur_bus,
875 /* Remove sysfs Entries */
876 for (i = 0; i < VME_DEVS; i++)
877 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
878 class_destroy(vme_user_sysfs_class);
880 for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
881 kfree(image[i].kern_buf);
882 vme_master_free(image[i].resource);
885 for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
886 vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
888 vme_slave_free(image[i].resource);
891 /* Unregister device driver */
892 cdev_del(vme_user_cdev);
894 /* Unregiser the major and minor device numbers */
895 unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
900 static void __exit vme_user_exit(void)
902 vme_unregister_driver(&vme_user_driver);
904 kfree(vme_user_driver.bind_table);
908 MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected");
909 module_param_array(bus, int, &bus_num, 0);
911 MODULE_DESCRIPTION("VME User Space Access Driver");
912 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
913 MODULE_LICENSE("GPL");
915 module_init(vme_user_init);
916 module_exit(vme_user_exit);