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@hansjkoch.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>
20 #include <linux/slab.h>
22 #include <linux/idr.h>
23 #include <linux/sched.h>
24 #include <linux/string.h>
25 #include <linux/kobject.h>
26 #include <linux/cdev.h>
27 #include <linux/uio_driver.h>
29 #define UIO_MAX_DEVICES (1U << MINORBITS)
32 static struct cdev *uio_cdev;
33 static DEFINE_IDR(uio_idr);
34 static const struct file_operations uio_fops;
36 /* Protect idr accesses */
37 static DEFINE_MUTEX(minor_lock);
47 #define to_map(map) container_of(map, struct uio_map, kobj)
49 static ssize_t map_name_show(struct uio_mem *mem, char *buf)
51 if (unlikely(!mem->name))
54 return sprintf(buf, "%s\n", mem->name);
57 static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
59 return sprintf(buf, "%pa\n", &mem->addr);
62 static ssize_t map_size_show(struct uio_mem *mem, char *buf)
64 return sprintf(buf, "%pa\n", &mem->size);
67 static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
69 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
72 struct map_sysfs_entry {
73 struct attribute attr;
74 ssize_t (*show)(struct uio_mem *, char *);
75 ssize_t (*store)(struct uio_mem *, const char *, size_t);
78 static struct map_sysfs_entry name_attribute =
79 __ATTR(name, S_IRUGO, map_name_show, NULL);
80 static struct map_sysfs_entry addr_attribute =
81 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
82 static struct map_sysfs_entry size_attribute =
83 __ATTR(size, S_IRUGO, map_size_show, NULL);
84 static struct map_sysfs_entry offset_attribute =
85 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
87 static struct attribute *attrs[] = {
91 &offset_attribute.attr,
92 NULL, /* need to NULL terminate the list of attributes */
95 static void map_release(struct kobject *kobj)
97 struct uio_map *map = to_map(kobj);
101 static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
104 struct uio_map *map = to_map(kobj);
105 struct uio_mem *mem = map->mem;
106 struct map_sysfs_entry *entry;
108 entry = container_of(attr, struct map_sysfs_entry, attr);
113 return entry->show(mem, buf);
116 static const struct sysfs_ops map_sysfs_ops = {
117 .show = map_type_show,
120 static struct kobj_type map_attr_type = {
121 .release = map_release,
122 .sysfs_ops = &map_sysfs_ops,
123 .default_attrs = attrs,
128 struct uio_port *port;
130 #define to_portio(portio) container_of(portio, struct uio_portio, kobj)
132 static ssize_t portio_name_show(struct uio_port *port, char *buf)
134 if (unlikely(!port->name))
137 return sprintf(buf, "%s\n", port->name);
140 static ssize_t portio_start_show(struct uio_port *port, char *buf)
142 return sprintf(buf, "0x%lx\n", port->start);
145 static ssize_t portio_size_show(struct uio_port *port, char *buf)
147 return sprintf(buf, "0x%lx\n", port->size);
150 static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
152 const char *porttypes[] = {"none", "x86", "gpio", "other"};
154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
160 struct portio_sysfs_entry {
161 struct attribute attr;
162 ssize_t (*show)(struct uio_port *, char *);
163 ssize_t (*store)(struct uio_port *, const char *, size_t);
166 static struct portio_sysfs_entry portio_name_attribute =
167 __ATTR(name, S_IRUGO, portio_name_show, NULL);
168 static struct portio_sysfs_entry portio_start_attribute =
169 __ATTR(start, S_IRUGO, portio_start_show, NULL);
170 static struct portio_sysfs_entry portio_size_attribute =
171 __ATTR(size, S_IRUGO, portio_size_show, NULL);
172 static struct portio_sysfs_entry portio_porttype_attribute =
173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
175 static struct attribute *portio_attrs[] = {
176 &portio_name_attribute.attr,
177 &portio_start_attribute.attr,
178 &portio_size_attribute.attr,
179 &portio_porttype_attribute.attr,
183 static void portio_release(struct kobject *kobj)
185 struct uio_portio *portio = to_portio(kobj);
189 static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
192 struct uio_portio *portio = to_portio(kobj);
193 struct uio_port *port = portio->port;
194 struct portio_sysfs_entry *entry;
196 entry = container_of(attr, struct portio_sysfs_entry, attr);
201 return entry->show(port, buf);
204 static const struct sysfs_ops portio_sysfs_ops = {
205 .show = portio_type_show,
208 static struct kobj_type portio_attr_type = {
209 .release = portio_release,
210 .sysfs_ops = &portio_sysfs_ops,
211 .default_attrs = portio_attrs,
214 static ssize_t name_show(struct device *dev,
215 struct device_attribute *attr, char *buf)
217 struct uio_device *idev = dev_get_drvdata(dev);
218 return sprintf(buf, "%s\n", idev->info->name);
220 static DEVICE_ATTR_RO(name);
222 static ssize_t version_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
225 struct uio_device *idev = dev_get_drvdata(dev);
226 return sprintf(buf, "%s\n", idev->info->version);
228 static DEVICE_ATTR_RO(version);
230 static ssize_t event_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
233 struct uio_device *idev = dev_get_drvdata(dev);
234 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
236 static DEVICE_ATTR_RO(event);
238 static struct attribute *uio_attrs[] = {
240 &dev_attr_version.attr,
241 &dev_attr_event.attr,
244 ATTRIBUTE_GROUPS(uio);
246 /* UIO class infrastructure */
247 static struct class uio_class = {
249 .dev_groups = uio_groups,
255 static int uio_dev_add_attributes(struct uio_device *idev)
260 int portio_found = 0;
263 struct uio_port *port;
264 struct uio_portio *portio;
266 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
267 mem = &idev->info->mem[mi];
272 idev->map_dir = kobject_create_and_add("maps",
277 map = kzalloc(sizeof(*map), GFP_KERNEL);
280 kobject_init(&map->kobj, &map_attr_type);
283 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
286 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
291 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
292 port = &idev->info->port[pi];
297 idev->portio_dir = kobject_create_and_add("portio",
299 if (!idev->portio_dir)
302 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
304 goto err_portio_kobj;
305 kobject_init(&portio->kobj, &portio_attr_type);
307 port->portio = portio;
308 ret = kobject_add(&portio->kobj, idev->portio_dir,
311 goto err_portio_kobj;
312 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
322 for (; pi >= 0; pi--) {
323 port = &idev->info->port[pi];
324 portio = port->portio;
325 kobject_put(&portio->kobj);
327 kobject_put(idev->portio_dir);
331 for (; mi >= 0; mi--) {
332 mem = &idev->info->mem[mi];
334 kobject_put(&map->kobj);
336 kobject_put(idev->map_dir);
337 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
341 static void uio_dev_del_attributes(struct uio_device *idev)
345 struct uio_port *port;
347 for (i = 0; i < MAX_UIO_MAPS; i++) {
348 mem = &idev->info->mem[i];
351 kobject_put(&mem->map->kobj);
353 kobject_put(idev->map_dir);
355 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
356 port = &idev->info->port[i];
359 kobject_put(&port->portio->kobj);
361 kobject_put(idev->portio_dir);
364 static int uio_get_minor(struct uio_device *idev)
366 int retval = -ENOMEM;
368 mutex_lock(&minor_lock);
369 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
371 idev->minor = retval;
373 } else if (retval == -ENOSPC) {
374 dev_err(idev->dev, "too many uio devices\n");
377 mutex_unlock(&minor_lock);
381 static void uio_free_minor(struct uio_device *idev)
383 mutex_lock(&minor_lock);
384 idr_remove(&uio_idr, idev->minor);
385 mutex_unlock(&minor_lock);
389 * uio_event_notify - trigger an interrupt event
390 * @info: UIO device capabilities
392 void uio_event_notify(struct uio_info *info)
394 struct uio_device *idev = info->uio_dev;
396 atomic_inc(&idev->event);
397 wake_up_interruptible(&idev->wait);
398 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
400 EXPORT_SYMBOL_GPL(uio_event_notify);
403 * uio_interrupt - hardware interrupt handler
404 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
405 * @dev_id: Pointer to the devices uio_device structure
407 static irqreturn_t uio_interrupt(int irq, void *dev_id)
409 struct uio_device *idev = (struct uio_device *)dev_id;
410 irqreturn_t ret = idev->info->handler(irq, idev->info);
412 if (ret == IRQ_HANDLED)
413 uio_event_notify(idev->info);
418 struct uio_listener {
419 struct uio_device *dev;
423 static int uio_open(struct inode *inode, struct file *filep)
425 struct uio_device *idev;
426 struct uio_listener *listener;
429 mutex_lock(&minor_lock);
430 idev = idr_find(&uio_idr, iminor(inode));
431 mutex_unlock(&minor_lock);
437 if (!try_module_get(idev->owner)) {
442 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
445 goto err_alloc_listener;
448 listener->dev = idev;
449 listener->event_count = atomic_read(&idev->event);
450 filep->private_data = listener;
452 if (idev->info->open) {
453 ret = idev->info->open(idev->info, inode);
463 module_put(idev->owner);
469 static int uio_fasync(int fd, struct file *filep, int on)
471 struct uio_listener *listener = filep->private_data;
472 struct uio_device *idev = listener->dev;
474 return fasync_helper(fd, filep, on, &idev->async_queue);
477 static int uio_release(struct inode *inode, struct file *filep)
480 struct uio_listener *listener = filep->private_data;
481 struct uio_device *idev = listener->dev;
483 if (idev->info->release)
484 ret = idev->info->release(idev->info, inode);
486 module_put(idev->owner);
491 static unsigned int uio_poll(struct file *filep, poll_table *wait)
493 struct uio_listener *listener = filep->private_data;
494 struct uio_device *idev = listener->dev;
496 if (!idev->info->irq)
499 poll_wait(filep, &idev->wait, wait);
500 if (listener->event_count != atomic_read(&idev->event))
501 return POLLIN | POLLRDNORM;
505 static ssize_t uio_read(struct file *filep, char __user *buf,
506 size_t count, loff_t *ppos)
508 struct uio_listener *listener = filep->private_data;
509 struct uio_device *idev = listener->dev;
510 DECLARE_WAITQUEUE(wait, current);
514 if (!idev->info->irq)
517 if (count != sizeof(s32))
520 add_wait_queue(&idev->wait, &wait);
523 set_current_state(TASK_INTERRUPTIBLE);
525 event_count = atomic_read(&idev->event);
526 if (event_count != listener->event_count) {
527 __set_current_state(TASK_RUNNING);
528 if (copy_to_user(buf, &event_count, count))
531 listener->event_count = event_count;
537 if (filep->f_flags & O_NONBLOCK) {
542 if (signal_pending(current)) {
543 retval = -ERESTARTSYS;
549 __set_current_state(TASK_RUNNING);
550 remove_wait_queue(&idev->wait, &wait);
555 static ssize_t uio_write(struct file *filep, const char __user *buf,
556 size_t count, loff_t *ppos)
558 struct uio_listener *listener = filep->private_data;
559 struct uio_device *idev = listener->dev;
563 if (!idev->info->irq)
566 if (count != sizeof(s32))
569 if (!idev->info->irqcontrol)
572 if (copy_from_user(&irq_on, buf, count))
575 retval = idev->info->irqcontrol(idev->info, irq_on);
577 return retval ? retval : sizeof(s32);
580 static int uio_find_mem_index(struct vm_area_struct *vma)
582 struct uio_device *idev = vma->vm_private_data;
584 if (vma->vm_pgoff < MAX_UIO_MAPS) {
585 if (idev->info->mem[vma->vm_pgoff].size == 0)
587 return (int)vma->vm_pgoff;
592 static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
594 struct uio_device *idev = vma->vm_private_data;
596 unsigned long offset;
599 int mi = uio_find_mem_index(vma);
601 return VM_FAULT_SIGBUS;
604 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
607 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
609 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
610 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
611 page = virt_to_page(addr);
613 page = vmalloc_to_page(addr);
619 static const struct vm_operations_struct uio_logical_vm_ops = {
620 .fault = uio_vma_fault,
623 static int uio_mmap_logical(struct vm_area_struct *vma)
625 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
626 vma->vm_ops = &uio_logical_vm_ops;
630 static const struct vm_operations_struct uio_physical_vm_ops = {
631 #ifdef CONFIG_HAVE_IOREMAP_PROT
632 .access = generic_access_phys,
636 static int uio_mmap_physical(struct vm_area_struct *vma)
638 struct uio_device *idev = vma->vm_private_data;
639 int mi = uio_find_mem_index(vma);
643 mem = idev->info->mem + mi;
645 if (mem->addr & ~PAGE_MASK)
647 if (vma->vm_end - vma->vm_start > mem->size)
650 vma->vm_ops = &uio_physical_vm_ops;
651 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
654 * We cannot use the vm_iomap_memory() helper here,
655 * because vma->vm_pgoff is the map index we looked
656 * up above in uio_find_mem_index(), rather than an
657 * actual page offset into the mmap.
659 * So we just do the physical mmap without a page
662 return remap_pfn_range(vma,
664 mem->addr >> PAGE_SHIFT,
665 vma->vm_end - vma->vm_start,
669 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
671 struct uio_listener *listener = filep->private_data;
672 struct uio_device *idev = listener->dev;
674 unsigned long requested_pages, actual_pages;
677 if (vma->vm_end < vma->vm_start)
680 vma->vm_private_data = idev;
682 mi = uio_find_mem_index(vma);
686 requested_pages = vma_pages(vma);
687 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
688 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
689 if (requested_pages > actual_pages)
692 if (idev->info->mmap) {
693 ret = idev->info->mmap(idev->info, vma);
697 switch (idev->info->mem[mi].memtype) {
699 return uio_mmap_physical(vma);
700 case UIO_MEM_LOGICAL:
701 case UIO_MEM_VIRTUAL:
702 return uio_mmap_logical(vma);
708 static const struct file_operations uio_fops = {
709 .owner = THIS_MODULE,
711 .release = uio_release,
716 .fasync = uio_fasync,
717 .llseek = noop_llseek,
720 static int uio_major_init(void)
722 static const char name[] = "uio";
723 struct cdev *cdev = NULL;
727 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
736 cdev->owner = THIS_MODULE;
737 cdev->ops = &uio_fops;
738 kobject_set_name(&cdev->kobj, "%s", name);
740 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
744 uio_major = MAJOR(uio_dev);
748 kobject_put(&cdev->kobj);
750 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
755 static void uio_major_cleanup(void)
757 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
761 static int init_uio_class(void)
765 /* This is the first time in here, set everything up properly */
766 ret = uio_major_init();
770 ret = class_register(&uio_class);
772 printk(KERN_ERR "class_register failed for uio\n");
773 goto err_class_register;
783 static void release_uio_class(void)
785 class_unregister(&uio_class);
790 * uio_register_device - register a new userspace IO device
791 * @owner: module that creates the new device
792 * @parent: parent device
793 * @info: UIO device capabilities
795 * returns zero on success or a negative error code.
797 int __uio_register_device(struct module *owner,
798 struct device *parent,
799 struct uio_info *info)
801 struct uio_device *idev;
804 if (!parent || !info || !info->name || !info->version)
807 info->uio_dev = NULL;
809 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
816 init_waitqueue_head(&idev->wait);
817 atomic_set(&idev->event, 0);
819 ret = uio_get_minor(idev);
823 idev->dev = device_create(&uio_class, parent,
824 MKDEV(uio_major, idev->minor), idev,
825 "uio%d", idev->minor);
826 if (IS_ERR(idev->dev)) {
827 printk(KERN_ERR "UIO: device register failed\n");
828 ret = PTR_ERR(idev->dev);
829 goto err_device_create;
832 ret = uio_dev_add_attributes(idev);
834 goto err_uio_dev_add_attributes;
836 info->uio_dev = idev;
838 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
840 * Note that we deliberately don't use devm_request_irq
841 * here. The parent module can unregister the UIO device
842 * and call pci_disable_msi, which requires that this
843 * irq has been freed. However, the device may have open
844 * FDs at the time of unregister and therefore may not be
845 * freed until they are released.
847 ret = request_irq(info->irq, uio_interrupt,
848 info->irq_flags, info->name, idev);
850 goto err_request_irq;
856 uio_dev_del_attributes(idev);
857 err_uio_dev_add_attributes:
858 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
860 uio_free_minor(idev);
863 EXPORT_SYMBOL_GPL(__uio_register_device);
866 * uio_unregister_device - unregister a industrial IO device
867 * @info: UIO device capabilities
870 void uio_unregister_device(struct uio_info *info)
872 struct uio_device *idev;
874 if (!info || !info->uio_dev)
877 idev = info->uio_dev;
879 uio_free_minor(idev);
881 uio_dev_del_attributes(idev);
883 if (info->irq && info->irq != UIO_IRQ_CUSTOM)
884 free_irq(info->irq, idev);
886 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
890 EXPORT_SYMBOL_GPL(uio_unregister_device);
892 static int __init uio_init(void)
894 return init_uio_class();
897 static void __exit uio_exit(void)
900 idr_destroy(&uio_idr);
903 module_init(uio_init)
904 module_exit(uio_exit)
905 MODULE_LICENSE("GPL v2");