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/signal.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->offs);
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);
220 mutex_lock(&idev->info_lock);
223 dev_err(dev, "the device has been unregistered\n");
227 ret = sprintf(buf, "%s\n", idev->info->name);
230 mutex_unlock(&idev->info_lock);
233 static DEVICE_ATTR_RO(name);
235 static ssize_t version_show(struct device *dev,
236 struct device_attribute *attr, char *buf)
238 struct uio_device *idev = dev_get_drvdata(dev);
241 mutex_lock(&idev->info_lock);
244 dev_err(dev, "the device has been unregistered\n");
248 ret = sprintf(buf, "%s\n", idev->info->version);
251 mutex_unlock(&idev->info_lock);
254 static DEVICE_ATTR_RO(version);
256 static ssize_t event_show(struct device *dev,
257 struct device_attribute *attr, char *buf)
259 struct uio_device *idev = dev_get_drvdata(dev);
260 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
262 static DEVICE_ATTR_RO(event);
264 static struct attribute *uio_attrs[] = {
266 &dev_attr_version.attr,
267 &dev_attr_event.attr,
270 ATTRIBUTE_GROUPS(uio);
272 /* UIO class infrastructure */
273 static struct class uio_class = {
275 .dev_groups = uio_groups,
281 static int uio_dev_add_attributes(struct uio_device *idev)
286 int portio_found = 0;
289 struct uio_port *port;
290 struct uio_portio *portio;
292 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
293 mem = &idev->info->mem[mi];
298 idev->map_dir = kobject_create_and_add("maps",
300 if (!idev->map_dir) {
305 map = kzalloc(sizeof(*map), GFP_KERNEL);
310 kobject_init(&map->kobj, &map_attr_type);
313 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
316 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
321 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
322 port = &idev->info->port[pi];
327 idev->portio_dir = kobject_create_and_add("portio",
329 if (!idev->portio_dir) {
334 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
339 kobject_init(&portio->kobj, &portio_attr_type);
341 port->portio = portio;
342 ret = kobject_add(&portio->kobj, idev->portio_dir,
345 goto err_portio_kobj;
346 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
348 goto err_portio_kobj;
356 for (; pi >= 0; pi--) {
357 port = &idev->info->port[pi];
358 portio = port->portio;
359 kobject_put(&portio->kobj);
361 kobject_put(idev->portio_dir);
365 for (; mi >= 0; mi--) {
366 mem = &idev->info->mem[mi];
368 kobject_put(&map->kobj);
370 kobject_put(idev->map_dir);
371 dev_err(&idev->dev, "error creating sysfs files (%d)\n", ret);
375 static void uio_dev_del_attributes(struct uio_device *idev)
379 struct uio_port *port;
381 for (i = 0; i < MAX_UIO_MAPS; i++) {
382 mem = &idev->info->mem[i];
385 kobject_put(&mem->map->kobj);
387 kobject_put(idev->map_dir);
389 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
390 port = &idev->info->port[i];
393 kobject_put(&port->portio->kobj);
395 kobject_put(idev->portio_dir);
398 static int uio_get_minor(struct uio_device *idev)
400 int retval = -ENOMEM;
402 mutex_lock(&minor_lock);
403 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
405 idev->minor = retval;
407 } else if (retval == -ENOSPC) {
408 dev_err(&idev->dev, "too many uio devices\n");
411 mutex_unlock(&minor_lock);
415 static void uio_free_minor(struct uio_device *idev)
417 mutex_lock(&minor_lock);
418 idr_remove(&uio_idr, idev->minor);
419 mutex_unlock(&minor_lock);
423 * uio_event_notify - trigger an interrupt event
424 * @info: UIO device capabilities
426 void uio_event_notify(struct uio_info *info)
428 struct uio_device *idev = info->uio_dev;
430 atomic_inc(&idev->event);
431 wake_up_interruptible(&idev->wait);
432 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
434 EXPORT_SYMBOL_GPL(uio_event_notify);
437 * uio_interrupt - hardware interrupt handler
438 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
439 * @dev_id: Pointer to the devices uio_device structure
441 static irqreturn_t uio_interrupt(int irq, void *dev_id)
443 struct uio_device *idev = (struct uio_device *)dev_id;
446 mutex_lock(&idev->info_lock);
448 ret = idev->info->handler(irq, idev->info);
449 if (ret == IRQ_HANDLED)
450 uio_event_notify(idev->info);
452 mutex_unlock(&idev->info_lock);
456 struct uio_listener {
457 struct uio_device *dev;
461 static int uio_open(struct inode *inode, struct file *filep)
463 struct uio_device *idev;
464 struct uio_listener *listener;
467 mutex_lock(&minor_lock);
468 idev = idr_find(&uio_idr, iminor(inode));
469 mutex_unlock(&minor_lock);
475 get_device(&idev->dev);
477 if (!try_module_get(idev->owner)) {
482 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
485 goto err_alloc_listener;
488 listener->dev = idev;
489 listener->event_count = atomic_read(&idev->event);
490 filep->private_data = listener;
492 mutex_lock(&idev->info_lock);
494 mutex_unlock(&idev->info_lock);
496 goto err_alloc_listener;
499 if (idev->info && idev->info->open)
500 ret = idev->info->open(idev->info, inode);
501 mutex_unlock(&idev->info_lock);
511 module_put(idev->owner);
514 put_device(&idev->dev);
520 static int uio_fasync(int fd, struct file *filep, int on)
522 struct uio_listener *listener = filep->private_data;
523 struct uio_device *idev = listener->dev;
525 return fasync_helper(fd, filep, on, &idev->async_queue);
528 static int uio_release(struct inode *inode, struct file *filep)
531 struct uio_listener *listener = filep->private_data;
532 struct uio_device *idev = listener->dev;
534 mutex_lock(&idev->info_lock);
535 if (idev->info && idev->info->release)
536 ret = idev->info->release(idev->info, inode);
537 mutex_unlock(&idev->info_lock);
539 module_put(idev->owner);
541 put_device(&idev->dev);
545 static __poll_t uio_poll(struct file *filep, poll_table *wait)
547 struct uio_listener *listener = filep->private_data;
548 struct uio_device *idev = listener->dev;
551 mutex_lock(&idev->info_lock);
552 if (!idev->info || !idev->info->irq)
554 mutex_unlock(&idev->info_lock);
559 poll_wait(filep, &idev->wait, wait);
560 if (listener->event_count != atomic_read(&idev->event))
561 return EPOLLIN | EPOLLRDNORM;
565 static ssize_t uio_read(struct file *filep, char __user *buf,
566 size_t count, loff_t *ppos)
568 struct uio_listener *listener = filep->private_data;
569 struct uio_device *idev = listener->dev;
570 DECLARE_WAITQUEUE(wait, current);
574 mutex_lock(&idev->info_lock);
575 if (!idev->info || !idev->info->irq)
577 mutex_unlock(&idev->info_lock);
582 if (count != sizeof(s32))
585 add_wait_queue(&idev->wait, &wait);
588 set_current_state(TASK_INTERRUPTIBLE);
590 event_count = atomic_read(&idev->event);
591 if (event_count != listener->event_count) {
592 __set_current_state(TASK_RUNNING);
593 if (copy_to_user(buf, &event_count, count))
596 listener->event_count = event_count;
602 if (filep->f_flags & O_NONBLOCK) {
607 if (signal_pending(current)) {
608 retval = -ERESTARTSYS;
614 __set_current_state(TASK_RUNNING);
615 remove_wait_queue(&idev->wait, &wait);
620 static ssize_t uio_write(struct file *filep, const char __user *buf,
621 size_t count, loff_t *ppos)
623 struct uio_listener *listener = filep->private_data;
624 struct uio_device *idev = listener->dev;
628 mutex_lock(&idev->info_lock);
634 if (!idev->info || !idev->info->irq) {
639 if (count != sizeof(s32)) {
644 if (!idev->info->irqcontrol) {
649 if (copy_from_user(&irq_on, buf, count)) {
654 retval = idev->info->irqcontrol(idev->info, irq_on);
657 mutex_unlock(&idev->info_lock);
658 return retval ? retval : sizeof(s32);
661 static int uio_find_mem_index(struct vm_area_struct *vma)
663 struct uio_device *idev = vma->vm_private_data;
665 if (vma->vm_pgoff < MAX_UIO_MAPS) {
666 if (idev->info->mem[vma->vm_pgoff].size == 0)
668 return (int)vma->vm_pgoff;
673 static vm_fault_t uio_vma_fault(struct vm_fault *vmf)
675 struct uio_device *idev = vmf->vma->vm_private_data;
677 unsigned long offset;
682 mutex_lock(&idev->info_lock);
684 ret = VM_FAULT_SIGBUS;
688 mi = uio_find_mem_index(vmf->vma);
690 ret = VM_FAULT_SIGBUS;
695 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
698 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
700 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset;
701 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
702 page = virt_to_page(addr);
704 page = vmalloc_to_page(addr);
709 mutex_unlock(&idev->info_lock);
714 static const struct vm_operations_struct uio_logical_vm_ops = {
715 .fault = uio_vma_fault,
718 static int uio_mmap_logical(struct vm_area_struct *vma)
720 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
721 vma->vm_ops = &uio_logical_vm_ops;
725 static const struct vm_operations_struct uio_physical_vm_ops = {
726 #ifdef CONFIG_HAVE_IOREMAP_PROT
727 .access = generic_access_phys,
731 static int uio_mmap_physical(struct vm_area_struct *vma)
733 struct uio_device *idev = vma->vm_private_data;
734 int mi = uio_find_mem_index(vma);
739 mem = idev->info->mem + mi;
741 if (mem->addr & ~PAGE_MASK)
743 if (vma->vm_end - vma->vm_start > mem->size)
746 vma->vm_ops = &uio_physical_vm_ops;
747 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
750 * We cannot use the vm_iomap_memory() helper here,
751 * because vma->vm_pgoff is the map index we looked
752 * up above in uio_find_mem_index(), rather than an
753 * actual page offset into the mmap.
755 * So we just do the physical mmap without a page
758 return remap_pfn_range(vma,
760 mem->addr >> PAGE_SHIFT,
761 vma->vm_end - vma->vm_start,
765 static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
767 struct uio_listener *listener = filep->private_data;
768 struct uio_device *idev = listener->dev;
770 unsigned long requested_pages, actual_pages;
773 if (vma->vm_end < vma->vm_start)
776 vma->vm_private_data = idev;
778 mutex_lock(&idev->info_lock);
784 mi = uio_find_mem_index(vma);
790 requested_pages = vma_pages(vma);
791 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
792 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
793 if (requested_pages > actual_pages) {
798 if (idev->info->mmap) {
799 ret = idev->info->mmap(idev->info, vma);
803 switch (idev->info->mem[mi].memtype) {
805 ret = uio_mmap_physical(vma);
807 case UIO_MEM_LOGICAL:
808 case UIO_MEM_VIRTUAL:
809 ret = uio_mmap_logical(vma);
816 mutex_unlock(&idev->info_lock);
820 static const struct file_operations uio_fops = {
821 .owner = THIS_MODULE,
823 .release = uio_release,
828 .fasync = uio_fasync,
829 .llseek = noop_llseek,
832 static int uio_major_init(void)
834 static const char name[] = "uio";
835 struct cdev *cdev = NULL;
839 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
848 cdev->owner = THIS_MODULE;
849 cdev->ops = &uio_fops;
850 kobject_set_name(&cdev->kobj, "%s", name);
852 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
856 uio_major = MAJOR(uio_dev);
860 kobject_put(&cdev->kobj);
862 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
867 static void uio_major_cleanup(void)
869 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
873 static int init_uio_class(void)
877 /* This is the first time in here, set everything up properly */
878 ret = uio_major_init();
882 ret = class_register(&uio_class);
884 printk(KERN_ERR "class_register failed for uio\n");
885 goto err_class_register;
895 static void release_uio_class(void)
897 class_unregister(&uio_class);
901 static void uio_device_release(struct device *dev)
903 struct uio_device *idev = dev_get_drvdata(dev);
909 * uio_register_device - register a new userspace IO device
910 * @owner: module that creates the new device
911 * @parent: parent device
912 * @info: UIO device capabilities
914 * returns zero on success or a negative error code.
916 int __uio_register_device(struct module *owner,
917 struct device *parent,
918 struct uio_info *info)
920 struct uio_device *idev;
923 if (!parent || !info || !info->name || !info->version)
926 info->uio_dev = NULL;
928 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
935 mutex_init(&idev->info_lock);
936 init_waitqueue_head(&idev->wait);
937 atomic_set(&idev->event, 0);
939 ret = uio_get_minor(idev);
943 idev->dev.devt = MKDEV(uio_major, idev->minor);
944 idev->dev.class = &uio_class;
945 idev->dev.parent = parent;
946 idev->dev.release = uio_device_release;
947 dev_set_drvdata(&idev->dev, idev);
949 ret = dev_set_name(&idev->dev, "uio%d", idev->minor);
951 goto err_device_create;
953 ret = device_register(&idev->dev);
955 goto err_device_create;
957 ret = uio_dev_add_attributes(idev);
959 goto err_uio_dev_add_attributes;
961 info->uio_dev = idev;
963 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
965 * Note that we deliberately don't use devm_request_irq
966 * here. The parent module can unregister the UIO device
967 * and call pci_disable_msi, which requires that this
968 * irq has been freed. However, the device may have open
969 * FDs at the time of unregister and therefore may not be
970 * freed until they are released.
972 ret = request_threaded_irq(info->irq, NULL, uio_interrupt,
973 info->irq_flags, info->name, idev);
976 goto err_request_irq;
982 uio_dev_del_attributes(idev);
983 err_uio_dev_add_attributes:
984 device_unregister(&idev->dev);
986 uio_free_minor(idev);
989 EXPORT_SYMBOL_GPL(__uio_register_device);
992 * uio_unregister_device - unregister a industrial IO device
993 * @info: UIO device capabilities
996 void uio_unregister_device(struct uio_info *info)
998 struct uio_device *idev;
1000 if (!info || !info->uio_dev)
1003 idev = info->uio_dev;
1005 uio_free_minor(idev);
1007 mutex_lock(&idev->info_lock);
1008 uio_dev_del_attributes(idev);
1010 if (info->irq && info->irq != UIO_IRQ_CUSTOM)
1011 free_irq(info->irq, idev);
1014 mutex_unlock(&idev->info_lock);
1016 device_unregister(&idev->dev);
1020 EXPORT_SYMBOL_GPL(uio_unregister_device);
1022 static int __init uio_init(void)
1024 return init_uio_class();
1027 static void __exit uio_exit(void)
1029 release_uio_class();
1030 idr_destroy(&uio_idr);
1033 module_init(uio_init)
1034 module_exit(uio_exit)
1035 MODULE_LICENSE("GPL v2");