4 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
5 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
6 * Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
7 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
13 * Licensed under the GPLv2 only.
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/poll.h>
19 #include <linux/device.h>
21 #include <linux/idr.h>
22 #include <linux/string.h>
23 #include <linux/kobject.h>
24 #include <linux/uio_driver.h>
26 #define UIO_MAX_DEVICES 255
33 struct fasync_struct *async_queue;
34 wait_queue_head_t wait;
36 struct uio_info *info;
37 struct kobject *map_dir;
41 static DEFINE_IDR(uio_idr);
42 static const struct file_operations uio_fops;
44 /* UIO class infrastructure */
45 static struct uio_class {
50 /* Protect idr accesses */
51 static DEFINE_MUTEX(minor_lock);
61 #define to_map(map) container_of(map, struct uio_map, kobj)
63 static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
65 return sprintf(buf, "0x%lx\n", mem->addr);
68 static ssize_t map_size_show(struct uio_mem *mem, char *buf)
70 return sprintf(buf, "0x%lx\n", mem->size);
73 static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
75 return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
78 struct uio_sysfs_entry {
79 struct attribute attr;
80 ssize_t (*show)(struct uio_mem *, char *);
81 ssize_t (*store)(struct uio_mem *, const char *, size_t);
84 static struct uio_sysfs_entry addr_attribute =
85 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
86 static struct uio_sysfs_entry size_attribute =
87 __ATTR(size, S_IRUGO, map_size_show, NULL);
88 static struct uio_sysfs_entry offset_attribute =
89 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
91 static struct attribute *attrs[] = {
94 &offset_attribute.attr,
95 NULL, /* need to NULL terminate the list of attributes */
98 static void map_release(struct kobject *kobj)
100 struct uio_map *map = to_map(kobj);
104 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
107 struct uio_map *map = to_map(kobj);
108 struct uio_mem *mem = map->mem;
109 struct uio_sysfs_entry *entry;
111 entry = container_of(attr, struct uio_sysfs_entry, attr);
116 return entry->show(mem, buf);
119 static struct sysfs_ops uio_sysfs_ops = {
120 .show = map_type_show,
123 static struct kobj_type map_attr_type = {
124 .release = map_release,
125 .sysfs_ops = &uio_sysfs_ops,
126 .default_attrs = attrs,
129 static ssize_t show_name(struct device *dev,
130 struct device_attribute *attr, char *buf)
132 struct uio_device *idev = dev_get_drvdata(dev);
134 return sprintf(buf, "%s\n", idev->info->name);
138 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
140 static ssize_t show_version(struct device *dev,
141 struct device_attribute *attr, char *buf)
143 struct uio_device *idev = dev_get_drvdata(dev);
145 return sprintf(buf, "%s\n", idev->info->version);
149 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
151 static ssize_t show_event(struct device *dev,
152 struct device_attribute *attr, char *buf)
154 struct uio_device *idev = dev_get_drvdata(dev);
156 return sprintf(buf, "%u\n",
157 (unsigned int)atomic_read(&idev->event));
161 static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
163 static struct attribute *uio_attrs[] = {
165 &dev_attr_version.attr,
166 &dev_attr_event.attr,
170 static struct attribute_group uio_attr_grp = {
177 static int uio_dev_add_attributes(struct uio_device *idev)
185 ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
189 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
190 mem = &idev->info->mem[mi];
195 idev->map_dir = kobject_create_and_add("maps",
200 map = kzalloc(sizeof(*map), GFP_KERNEL);
203 kobject_init(&map->kobj, &map_attr_type);
206 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
209 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
217 for (mi--; mi>=0; mi--) {
218 mem = &idev->info->mem[mi];
220 kobject_put(&map->kobj);
222 kobject_put(idev->map_dir);
223 sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
225 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
229 static void uio_dev_del_attributes(struct uio_device *idev)
233 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
234 mem = &idev->info->mem[mi];
237 kobject_put(&mem->map->kobj);
239 kobject_put(idev->map_dir);
240 sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
243 static int uio_get_minor(struct uio_device *idev)
245 int retval = -ENOMEM;
248 mutex_lock(&minor_lock);
249 if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
252 retval = idr_get_new(&uio_idr, idev, &id);
254 if (retval == -EAGAIN)
258 idev->minor = id & MAX_ID_MASK;
260 mutex_unlock(&minor_lock);
264 static void uio_free_minor(struct uio_device *idev)
266 mutex_lock(&minor_lock);
267 idr_remove(&uio_idr, idev->minor);
268 mutex_unlock(&minor_lock);
272 * uio_event_notify - trigger an interrupt event
273 * @info: UIO device capabilities
275 void uio_event_notify(struct uio_info *info)
277 struct uio_device *idev = info->uio_dev;
279 atomic_inc(&idev->event);
280 wake_up_interruptible(&idev->wait);
281 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
283 EXPORT_SYMBOL_GPL(uio_event_notify);
286 * uio_interrupt - hardware interrupt handler
287 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
288 * @dev_id: Pointer to the devices uio_device structure
290 static irqreturn_t uio_interrupt(int irq, void *dev_id)
292 struct uio_device *idev = (struct uio_device *)dev_id;
293 irqreturn_t ret = idev->info->handler(irq, idev->info);
295 if (ret == IRQ_HANDLED)
296 uio_event_notify(idev->info);
301 struct uio_listener {
302 struct uio_device *dev;
306 static int uio_open(struct inode *inode, struct file *filep)
308 struct uio_device *idev;
309 struct uio_listener *listener;
312 mutex_lock(&minor_lock);
313 idev = idr_find(&uio_idr, iminor(inode));
314 mutex_unlock(&minor_lock);
320 if (!try_module_get(idev->owner)) {
325 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
328 goto err_alloc_listener;
331 listener->dev = idev;
332 listener->event_count = atomic_read(&idev->event);
333 filep->private_data = listener;
335 if (idev->info->open) {
336 ret = idev->info->open(idev->info, inode);
346 module_put(idev->owner);
352 static int uio_fasync(int fd, struct file *filep, int on)
354 struct uio_listener *listener = filep->private_data;
355 struct uio_device *idev = listener->dev;
357 return fasync_helper(fd, filep, on, &idev->async_queue);
360 static int uio_release(struct inode *inode, struct file *filep)
363 struct uio_listener *listener = filep->private_data;
364 struct uio_device *idev = listener->dev;
366 if (idev->info->release)
367 ret = idev->info->release(idev->info, inode);
369 module_put(idev->owner);
371 if (filep->f_flags & FASYNC)
372 ret = uio_fasync(-1, filep, 0);
377 static unsigned int uio_poll(struct file *filep, poll_table *wait)
379 struct uio_listener *listener = filep->private_data;
380 struct uio_device *idev = listener->dev;
382 if (idev->info->irq == UIO_IRQ_NONE)
385 poll_wait(filep, &idev->wait, wait);
386 if (listener->event_count != atomic_read(&idev->event))
387 return POLLIN | POLLRDNORM;
391 static ssize_t uio_read(struct file *filep, char __user *buf,
392 size_t count, loff_t *ppos)
394 struct uio_listener *listener = filep->private_data;
395 struct uio_device *idev = listener->dev;
396 DECLARE_WAITQUEUE(wait, current);
400 if (idev->info->irq == UIO_IRQ_NONE)
403 if (count != sizeof(s32))
406 add_wait_queue(&idev->wait, &wait);
409 set_current_state(TASK_INTERRUPTIBLE);
411 event_count = atomic_read(&idev->event);
412 if (event_count != listener->event_count) {
413 if (copy_to_user(buf, &event_count, count))
416 listener->event_count = event_count;
422 if (filep->f_flags & O_NONBLOCK) {
427 if (signal_pending(current)) {
428 retval = -ERESTARTSYS;
434 __set_current_state(TASK_RUNNING);
435 remove_wait_queue(&idev->wait, &wait);
440 static ssize_t uio_write(struct file *filep, const char __user *buf,
441 size_t count, loff_t *ppos)
443 struct uio_listener *listener = filep->private_data;
444 struct uio_device *idev = listener->dev;
448 if (idev->info->irq == UIO_IRQ_NONE)
451 if (count != sizeof(s32))
454 if (!idev->info->irqcontrol)
457 if (copy_from_user(&irq_on, buf, count))
460 retval = idev->info->irqcontrol(idev->info, irq_on);
462 return retval ? retval : sizeof(s32);
465 static int uio_find_mem_index(struct vm_area_struct *vma)
468 struct uio_device *idev = vma->vm_private_data;
470 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
471 if (idev->info->mem[mi].size == 0)
473 if (vma->vm_pgoff == mi)
479 static void uio_vma_open(struct vm_area_struct *vma)
481 struct uio_device *idev = vma->vm_private_data;
485 static void uio_vma_close(struct vm_area_struct *vma)
487 struct uio_device *idev = vma->vm_private_data;
491 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
493 struct uio_device *idev = vma->vm_private_data;
495 unsigned long offset;
497 int mi = uio_find_mem_index(vma);
499 return VM_FAULT_SIGBUS;
502 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
505 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
507 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
508 page = virt_to_page(idev->info->mem[mi].addr + offset);
510 page = vmalloc_to_page((void *)idev->info->mem[mi].addr
517 static struct vm_operations_struct uio_vm_ops = {
518 .open = uio_vma_open,
519 .close = uio_vma_close,
520 .fault = uio_vma_fault,
523 static int uio_mmap_physical(struct vm_area_struct *vma)
525 struct uio_device *idev = vma->vm_private_data;
526 int mi = uio_find_mem_index(vma);
530 vma->vm_flags |= VM_IO | VM_RESERVED;
532 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
534 return remap_pfn_range(vma,
536 idev->info->mem[mi].addr >> PAGE_SHIFT,
537 vma->vm_end - vma->vm_start,
541 static int uio_mmap_logical(struct vm_area_struct *vma)
543 vma->vm_flags |= VM_RESERVED;
544 vma->vm_ops = &uio_vm_ops;
549 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
551 struct uio_listener *listener = filep->private_data;
552 struct uio_device *idev = listener->dev;
554 unsigned long requested_pages, actual_pages;
557 if (vma->vm_end < vma->vm_start)
560 vma->vm_private_data = idev;
562 mi = uio_find_mem_index(vma);
566 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
567 actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
568 if (requested_pages > actual_pages)
571 if (idev->info->mmap) {
572 ret = idev->info->mmap(idev->info, vma);
576 switch (idev->info->mem[mi].memtype) {
578 return uio_mmap_physical(vma);
579 case UIO_MEM_LOGICAL:
580 case UIO_MEM_VIRTUAL:
581 return uio_mmap_logical(vma);
587 static const struct file_operations uio_fops = {
588 .owner = THIS_MODULE,
590 .release = uio_release,
595 .fasync = uio_fasync,
598 static int uio_major_init(void)
600 uio_major = register_chrdev(0, "uio", &uio_fops);
606 static void uio_major_cleanup(void)
608 unregister_chrdev(uio_major, "uio");
611 static int init_uio_class(void)
615 if (uio_class != NULL) {
616 kref_get(&uio_class->kref);
620 /* This is the first time in here, set everything up properly */
621 ret = uio_major_init();
625 uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
631 kref_init(&uio_class->kref);
632 uio_class->class = class_create(THIS_MODULE, "uio");
633 if (IS_ERR(uio_class->class)) {
634 ret = IS_ERR(uio_class->class);
635 printk(KERN_ERR "class_create failed for uio\n");
636 goto err_class_create;
649 static void release_uio_class(struct kref *kref)
651 /* Ok, we cheat as we know we only have one uio_class */
652 class_destroy(uio_class->class);
658 static void uio_class_destroy(void)
661 kref_put(&uio_class->kref, release_uio_class);
665 * uio_register_device - register a new userspace IO device
666 * @owner: module that creates the new device
667 * @parent: parent device
668 * @info: UIO device capabilities
670 * returns zero on success or a negative error code.
672 int __uio_register_device(struct module *owner,
673 struct device *parent,
674 struct uio_info *info)
676 struct uio_device *idev;
679 if (!parent || !info || !info->name || !info->version)
682 info->uio_dev = NULL;
684 ret = init_uio_class();
688 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
696 init_waitqueue_head(&idev->wait);
697 atomic_set(&idev->event, 0);
699 ret = uio_get_minor(idev);
703 idev->dev = device_create(uio_class->class, parent,
704 MKDEV(uio_major, idev->minor), idev,
705 "uio%d", idev->minor);
706 if (IS_ERR(idev->dev)) {
707 printk(KERN_ERR "UIO: device register failed\n");
708 ret = PTR_ERR(idev->dev);
709 goto err_device_create;
712 ret = uio_dev_add_attributes(idev);
714 goto err_uio_dev_add_attributes;
716 info->uio_dev = idev;
718 if (idev->info->irq >= 0) {
719 ret = request_irq(idev->info->irq, uio_interrupt,
720 idev->info->irq_flags, idev->info->name, idev);
722 goto err_request_irq;
728 uio_dev_del_attributes(idev);
729 err_uio_dev_add_attributes:
730 device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
732 uio_free_minor(idev);
739 EXPORT_SYMBOL_GPL(__uio_register_device);
742 * uio_unregister_device - unregister a industrial IO device
743 * @info: UIO device capabilities
746 void uio_unregister_device(struct uio_info *info)
748 struct uio_device *idev;
750 if (!info || !info->uio_dev)
753 idev = info->uio_dev;
755 uio_free_minor(idev);
758 free_irq(info->irq, idev);
760 uio_dev_del_attributes(idev);
762 dev_set_drvdata(idev->dev, NULL);
763 device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
769 EXPORT_SYMBOL_GPL(uio_unregister_device);
771 static int __init uio_init(void)
776 static void __exit uio_exit(void)
780 module_init(uio_init)
781 module_exit(uio_exit)
782 MODULE_LICENSE("GPL v2");