| /* |
| * drivers/uio/uio.c |
| * |
| * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de> |
| * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> |
| * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de> |
| * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com> |
| * |
| * Userspace IO |
| * |
| * Base Functions |
| * |
| * Licensed under the GPLv2 only. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/poll.h> |
| #include <linux/device.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/idr.h> |
| #include <linux/sched.h> |
| #include <linux/string.h> |
| #include <linux/kobject.h> |
| #include <linux/cdev.h> |
| #include <linux/uio_driver.h> |
| |
| #define UIO_MAX_DEVICES (1U << MINORBITS) |
| |
| struct uio_device { |
| struct module *owner; |
| struct device *dev; |
| int minor; |
| atomic_t event; |
| struct fasync_struct *async_queue; |
| wait_queue_head_t wait; |
| int vma_count; |
| struct uio_info *info; |
| struct kobject *map_dir; |
| struct kobject *portio_dir; |
| }; |
| |
| static int uio_major; |
| static struct cdev *uio_cdev; |
| static DEFINE_IDR(uio_idr); |
| static const struct file_operations uio_fops; |
| |
| /* Protect idr accesses */ |
| static DEFINE_MUTEX(minor_lock); |
| |
| /* |
| * attributes |
| */ |
| |
| struct uio_map { |
| struct kobject kobj; |
| struct uio_mem *mem; |
| }; |
| #define to_map(map) container_of(map, struct uio_map, kobj) |
| |
| static ssize_t map_name_show(struct uio_mem *mem, char *buf) |
| { |
| if (unlikely(!mem->name)) |
| mem->name = ""; |
| |
| return sprintf(buf, "%s\n", mem->name); |
| } |
| |
| static ssize_t map_addr_show(struct uio_mem *mem, char *buf) |
| { |
| return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr); |
| } |
| |
| static ssize_t map_size_show(struct uio_mem *mem, char *buf) |
| { |
| return sprintf(buf, "0x%lx\n", mem->size); |
| } |
| |
| static ssize_t map_offset_show(struct uio_mem *mem, char *buf) |
| { |
| return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK); |
| } |
| |
| struct map_sysfs_entry { |
| struct attribute attr; |
| ssize_t (*show)(struct uio_mem *, char *); |
| ssize_t (*store)(struct uio_mem *, const char *, size_t); |
| }; |
| |
| static struct map_sysfs_entry name_attribute = |
| __ATTR(name, S_IRUGO, map_name_show, NULL); |
| static struct map_sysfs_entry addr_attribute = |
| __ATTR(addr, S_IRUGO, map_addr_show, NULL); |
| static struct map_sysfs_entry size_attribute = |
| __ATTR(size, S_IRUGO, map_size_show, NULL); |
| static struct map_sysfs_entry offset_attribute = |
| __ATTR(offset, S_IRUGO, map_offset_show, NULL); |
| |
| static struct attribute *attrs[] = { |
| &name_attribute.attr, |
| &addr_attribute.attr, |
| &size_attribute.attr, |
| &offset_attribute.attr, |
| NULL, /* need to NULL terminate the list of attributes */ |
| }; |
| |
| static void map_release(struct kobject *kobj) |
| { |
| struct uio_map *map = to_map(kobj); |
| kfree(map); |
| } |
| |
| static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, |
| char *buf) |
| { |
| struct uio_map *map = to_map(kobj); |
| struct uio_mem *mem = map->mem; |
| struct map_sysfs_entry *entry; |
| |
| entry = container_of(attr, struct map_sysfs_entry, attr); |
| |
| if (!entry->show) |
| return -EIO; |
| |
| return entry->show(mem, buf); |
| } |
| |
| static const struct sysfs_ops map_sysfs_ops = { |
| .show = map_type_show, |
| }; |
| |
| static struct kobj_type map_attr_type = { |
| .release = map_release, |
| .sysfs_ops = &map_sysfs_ops, |
| .default_attrs = attrs, |
| }; |
| |
| struct uio_portio { |
| struct kobject kobj; |
| struct uio_port *port; |
| }; |
| #define to_portio(portio) container_of(portio, struct uio_portio, kobj) |
| |
| static ssize_t portio_name_show(struct uio_port *port, char *buf) |
| { |
| if (unlikely(!port->name)) |
| port->name = ""; |
| |
| return sprintf(buf, "%s\n", port->name); |
| } |
| |
| static ssize_t portio_start_show(struct uio_port *port, char *buf) |
| { |
| return sprintf(buf, "0x%lx\n", port->start); |
| } |
| |
| static ssize_t portio_size_show(struct uio_port *port, char *buf) |
| { |
| return sprintf(buf, "0x%lx\n", port->size); |
| } |
| |
| static ssize_t portio_porttype_show(struct uio_port *port, char *buf) |
| { |
| const char *porttypes[] = {"none", "x86", "gpio", "other"}; |
| |
| if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) |
| return -EINVAL; |
| |
| return sprintf(buf, "port_%s\n", porttypes[port->porttype]); |
| } |
| |
| struct portio_sysfs_entry { |
| struct attribute attr; |
| ssize_t (*show)(struct uio_port *, char *); |
| ssize_t (*store)(struct uio_port *, const char *, size_t); |
| }; |
| |
| static struct portio_sysfs_entry portio_name_attribute = |
| __ATTR(name, S_IRUGO, portio_name_show, NULL); |
| static struct portio_sysfs_entry portio_start_attribute = |
| __ATTR(start, S_IRUGO, portio_start_show, NULL); |
| static struct portio_sysfs_entry portio_size_attribute = |
| __ATTR(size, S_IRUGO, portio_size_show, NULL); |
| static struct portio_sysfs_entry portio_porttype_attribute = |
| __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); |
| |
| static struct attribute *portio_attrs[] = { |
| &portio_name_attribute.attr, |
| &portio_start_attribute.attr, |
| &portio_size_attribute.attr, |
| &portio_porttype_attribute.attr, |
| NULL, |
| }; |
| |
| static void portio_release(struct kobject *kobj) |
| { |
| struct uio_portio *portio = to_portio(kobj); |
| kfree(portio); |
| } |
| |
| static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, |
| char *buf) |
| { |
| struct uio_portio *portio = to_portio(kobj); |
| struct uio_port *port = portio->port; |
| struct portio_sysfs_entry *entry; |
| |
| entry = container_of(attr, struct portio_sysfs_entry, attr); |
| |
| if (!entry->show) |
| return -EIO; |
| |
| return entry->show(port, buf); |
| } |
| |
| static const struct sysfs_ops portio_sysfs_ops = { |
| .show = portio_type_show, |
| }; |
| |
| static struct kobj_type portio_attr_type = { |
| .release = portio_release, |
| .sysfs_ops = &portio_sysfs_ops, |
| .default_attrs = portio_attrs, |
| }; |
| |
| static ssize_t show_name(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct uio_device *idev = dev_get_drvdata(dev); |
| return sprintf(buf, "%s\n", idev->info->name); |
| } |
| |
| static ssize_t show_version(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct uio_device *idev = dev_get_drvdata(dev); |
| return sprintf(buf, "%s\n", idev->info->version); |
| } |
| |
| static ssize_t show_event(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct uio_device *idev = dev_get_drvdata(dev); |
| return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); |
| } |
| |
| static struct device_attribute uio_class_attributes[] = { |
| __ATTR(name, S_IRUGO, show_name, NULL), |
| __ATTR(version, S_IRUGO, show_version, NULL), |
| __ATTR(event, S_IRUGO, show_event, NULL), |
| {} |
| }; |
| |
| /* UIO class infrastructure */ |
| static struct class uio_class = { |
| .name = "uio", |
| .dev_attrs = uio_class_attributes, |
| }; |
| |
| /* |
| * device functions |
| */ |
| static int uio_dev_add_attributes(struct uio_device *idev) |
| { |
| int ret; |
| int mi, pi; |
| int map_found = 0; |
| int portio_found = 0; |
| struct uio_mem *mem; |
| struct uio_map *map; |
| struct uio_port *port; |
| struct uio_portio *portio; |
| |
| for (mi = 0; mi < MAX_UIO_MAPS; mi++) { |
| mem = &idev->info->mem[mi]; |
| if (mem->size == 0) |
| break; |
| if (!map_found) { |
| map_found = 1; |
| idev->map_dir = kobject_create_and_add("maps", |
| &idev->dev->kobj); |
| if (!idev->map_dir) |
| goto err_map; |
| } |
| map = kzalloc(sizeof(*map), GFP_KERNEL); |
| if (!map) |
| goto err_map; |
| kobject_init(&map->kobj, &map_attr_type); |
| map->mem = mem; |
| mem->map = map; |
| ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); |
| if (ret) |
| goto err_map; |
| ret = kobject_uevent(&map->kobj, KOBJ_ADD); |
| if (ret) |
| goto err_map; |
| } |
| |
| for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { |
| port = &idev->info->port[pi]; |
| if (port->size == 0) |
| break; |
| if (!portio_found) { |
| portio_found = 1; |
| idev->portio_dir = kobject_create_and_add("portio", |
| &idev->dev->kobj); |
| if (!idev->portio_dir) |
| goto err_portio; |
| } |
| portio = kzalloc(sizeof(*portio), GFP_KERNEL); |
| if (!portio) |
| goto err_portio; |
| kobject_init(&portio->kobj, &portio_attr_type); |
| portio->port = port; |
| port->portio = portio; |
| ret = kobject_add(&portio->kobj, idev->portio_dir, |
| "port%d", pi); |
| if (ret) |
| goto err_portio; |
| ret = kobject_uevent(&portio->kobj, KOBJ_ADD); |
| if (ret) |
| goto err_portio; |
| } |
| |
| return 0; |
| |
| err_portio: |
| for (pi--; pi >= 0; pi--) { |
| port = &idev->info->port[pi]; |
| portio = port->portio; |
| kobject_put(&portio->kobj); |
| } |
| kobject_put(idev->portio_dir); |
| err_map: |
| for (mi--; mi>=0; mi--) { |
| mem = &idev->info->mem[mi]; |
| map = mem->map; |
| kobject_put(&map->kobj); |
| } |
| kobject_put(idev->map_dir); |
| dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); |
| return ret; |
| } |
| |
| static void uio_dev_del_attributes(struct uio_device *idev) |
| { |
| int i; |
| struct uio_mem *mem; |
| struct uio_port *port; |
| |
| for (i = 0; i < MAX_UIO_MAPS; i++) { |
| mem = &idev->info->mem[i]; |
| if (mem->size == 0) |
| break; |
| kobject_put(&mem->map->kobj); |
| } |
| kobject_put(idev->map_dir); |
| |
| for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { |
| port = &idev->info->port[i]; |
| if (port->size == 0) |
| break; |
| kobject_put(&port->portio->kobj); |
| } |
| kobject_put(idev->portio_dir); |
| } |
| |
| static int uio_get_minor(struct uio_device *idev) |
| { |
| int retval = -ENOMEM; |
| |
| mutex_lock(&minor_lock); |
| retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); |
| if (retval >= 0) { |
| idev->minor = retval; |
| retval = 0; |
| } else if (retval == -ENOSPC) { |
| dev_err(idev->dev, "too many uio devices\n"); |
| retval = -EINVAL; |
| } |
| mutex_unlock(&minor_lock); |
| return retval; |
| } |
| |
| static void uio_free_minor(struct uio_device *idev) |
| { |
| mutex_lock(&minor_lock); |
| idr_remove(&uio_idr, idev->minor); |
| mutex_unlock(&minor_lock); |
| } |
| |
| /** |
| * uio_event_notify - trigger an interrupt event |
| * @info: UIO device capabilities |
| */ |
| void uio_event_notify(struct uio_info *info) |
| { |
| struct uio_device *idev = info->uio_dev; |
| |
| atomic_inc(&idev->event); |
| wake_up_interruptible(&idev->wait); |
| kill_fasync(&idev->async_queue, SIGIO, POLL_IN); |
| } |
| EXPORT_SYMBOL_GPL(uio_event_notify); |
| |
| /** |
| * uio_interrupt - hardware interrupt handler |
| * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer |
| * @dev_id: Pointer to the devices uio_device structure |
| */ |
| static irqreturn_t uio_interrupt(int irq, void *dev_id) |
| { |
| struct uio_device *idev = (struct uio_device *)dev_id; |
| irqreturn_t ret = idev->info->handler(irq, idev->info); |
| |
| if (ret == IRQ_HANDLED) |
| uio_event_notify(idev->info); |
| |
| return ret; |
| } |
| |
| struct uio_listener { |
| struct uio_device *dev; |
| s32 event_count; |
| }; |
| |
| static int uio_open(struct inode *inode, struct file *filep) |
| { |
| struct uio_device *idev; |
| struct uio_listener *listener; |
| int ret = 0; |
| |
| mutex_lock(&minor_lock); |
| idev = idr_find(&uio_idr, iminor(inode)); |
| mutex_unlock(&minor_lock); |
| if (!idev) { |
| ret = -ENODEV; |
| goto out; |
| } |
| |
| if (!try_module_get(idev->owner)) { |
| ret = -ENODEV; |
| goto out; |
| } |
| |
| listener = kmalloc(sizeof(*listener), GFP_KERNEL); |
| if (!listener) { |
| ret = -ENOMEM; |
| goto err_alloc_listener; |
| } |
| |
| listener->dev = idev; |
| listener->event_count = atomic_read(&idev->event); |
| filep->private_data = listener; |
| |
| if (idev->info->open) { |
| ret = idev->info->open(idev->info, inode); |
| if (ret) |
| goto err_infoopen; |
| } |
| return 0; |
| |
| err_infoopen: |
| kfree(listener); |
| |
| err_alloc_listener: |
| module_put(idev->owner); |
| |
| out: |
| return ret; |
| } |
| |
| static int uio_fasync(int fd, struct file *filep, int on) |
| { |
| struct uio_listener *listener = filep->private_data; |
| struct uio_device *idev = listener->dev; |
| |
| return fasync_helper(fd, filep, on, &idev->async_queue); |
| } |
| |
| static int uio_release(struct inode *inode, struct file *filep) |
| { |
| int ret = 0; |
| struct uio_listener *listener = filep->private_data; |
| struct uio_device *idev = listener->dev; |
| |
| if (idev->info->release) |
| ret = idev->info->release(idev->info, inode); |
| |
| module_put(idev->owner); |
| kfree(listener); |
| return ret; |
| } |
| |
| static unsigned int uio_poll(struct file *filep, poll_table *wait) |
| { |
| struct uio_listener *listener = filep->private_data; |
| struct uio_device *idev = listener->dev; |
| |
| if (!idev->info->irq) |
| return -EIO; |
| |
| poll_wait(filep, &idev->wait, wait); |
| if (listener->event_count != atomic_read(&idev->event)) |
| return POLLIN | POLLRDNORM; |
| return 0; |
| } |
| |
| static ssize_t uio_read(struct file *filep, char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct uio_listener *listener = filep->private_data; |
| struct uio_device *idev = listener->dev; |
| DECLARE_WAITQUEUE(wait, current); |
| ssize_t retval; |
| s32 event_count; |
| |
| if (!idev->info->irq) |
| return -EIO; |
| |
| if (count != sizeof(s32)) |
| return -EINVAL; |
| |
| add_wait_queue(&idev->wait, &wait); |
| |
| do { |
| set_current_state(TASK_INTERRUPTIBLE); |
| |
| event_count = atomic_read(&idev->event); |
| if (event_count != listener->event_count) { |
| if (copy_to_user(buf, &event_count, count)) |
| retval = -EFAULT; |
| else { |
| listener->event_count = event_count; |
| retval = count; |
| } |
| break; |
| } |
| |
| if (filep->f_flags & O_NONBLOCK) { |
| retval = -EAGAIN; |
| break; |
| } |
| |
| if (signal_pending(current)) { |
| retval = -ERESTARTSYS; |
| break; |
| } |
| schedule(); |
| } while (1); |
| |
| __set_current_state(TASK_RUNNING); |
| remove_wait_queue(&idev->wait, &wait); |
| |
| return retval; |
| } |
| |
| static ssize_t uio_write(struct file *filep, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct uio_listener *listener = filep->private_data; |
| struct uio_device *idev = listener->dev; |
| ssize_t retval; |
| s32 irq_on; |
| |
| if (!idev->info->irq) |
| return -EIO; |
| |
| if (count != sizeof(s32)) |
| return -EINVAL; |
| |
| if (!idev->info->irqcontrol) |
| return -ENOSYS; |
| |
| if (copy_from_user(&irq_on, buf, count)) |
| return -EFAULT; |
| |
| retval = idev->info->irqcontrol(idev->info, irq_on); |
| |
| return retval ? retval : sizeof(s32); |
| } |
| |
| static int uio_find_mem_index(struct vm_area_struct *vma) |
| { |
| struct uio_device *idev = vma->vm_private_data; |
| |
| if (vma->vm_pgoff < MAX_UIO_MAPS) { |
| if (idev->info->mem[vma->vm_pgoff].size == 0) |
| return -1; |
| return (int)vma->vm_pgoff; |
| } |
| return -1; |
| } |
| |
| static void uio_vma_open(struct vm_area_struct *vma) |
| { |
| struct uio_device *idev = vma->vm_private_data; |
| idev->vma_count++; |
| } |
| |
| static void uio_vma_close(struct vm_area_struct *vma) |
| { |
| struct uio_device *idev = vma->vm_private_data; |
| idev->vma_count--; |
| } |
| |
| static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
| { |
| struct uio_device *idev = vma->vm_private_data; |
| struct page *page; |
| unsigned long offset; |
| |
| int mi = uio_find_mem_index(vma); |
| if (mi < 0) |
| return VM_FAULT_SIGBUS; |
| |
| /* |
| * We need to subtract mi because userspace uses offset = N*PAGE_SIZE |
| * to use mem[N]. |
| */ |
| offset = (vmf->pgoff - mi) << PAGE_SHIFT; |
| |
| if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) |
| page = virt_to_page(idev->info->mem[mi].addr + offset); |
| else |
| page = vmalloc_to_page((void *)(unsigned long)idev->info->mem[mi].addr + offset); |
| get_page(page); |
| vmf->page = page; |
| return 0; |
| } |
| |
| static const struct vm_operations_struct uio_logical_vm_ops = { |
| .open = uio_vma_open, |
| .close = uio_vma_close, |
| .fault = uio_vma_fault, |
| }; |
| |
| static int uio_mmap_logical(struct vm_area_struct *vma) |
| { |
| vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
| vma->vm_ops = &uio_logical_vm_ops; |
| uio_vma_open(vma); |
| return 0; |
| } |
| |
| static const struct vm_operations_struct uio_physical_vm_ops = { |
| #ifdef CONFIG_HAVE_IOREMAP_PROT |
| .access = generic_access_phys, |
| #endif |
| }; |
| |
| static int uio_mmap_physical(struct vm_area_struct *vma) |
| { |
| struct uio_device *idev = vma->vm_private_data; |
| int mi = uio_find_mem_index(vma); |
| struct uio_mem *mem; |
| if (mi < 0) |
| return -EINVAL; |
| mem = idev->info->mem + mi; |
| |
| if (vma->vm_end - vma->vm_start > mem->size) |
| return -EINVAL; |
| |
| vma->vm_ops = &uio_physical_vm_ops; |
| vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| |
| /* |
| * We cannot use the vm_iomap_memory() helper here, |
| * because vma->vm_pgoff is the map index we looked |
| * up above in uio_find_mem_index(), rather than an |
| * actual page offset into the mmap. |
| * |
| * So we just do the physical mmap without a page |
| * offset. |
| */ |
| return remap_pfn_range(vma, |
| vma->vm_start, |
| mem->addr >> PAGE_SHIFT, |
| vma->vm_end - vma->vm_start, |
| vma->vm_page_prot); |
| } |
| |
| static int uio_mmap(struct file *filep, struct vm_area_struct *vma) |
| { |
| struct uio_listener *listener = filep->private_data; |
| struct uio_device *idev = listener->dev; |
| int mi; |
| unsigned long requested_pages, actual_pages; |
| int ret = 0; |
| |
| if (vma->vm_end < vma->vm_start) |
| return -EINVAL; |
| |
| vma->vm_private_data = idev; |
| |
| mi = uio_find_mem_index(vma); |
| if (mi < 0) |
| return -EINVAL; |
| |
| requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; |
| actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) |
| + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; |
| if (requested_pages > actual_pages) |
| return -EINVAL; |
| |
| if (idev->info->mmap) { |
| ret = idev->info->mmap(idev->info, vma); |
| return ret; |
| } |
| |
| switch (idev->info->mem[mi].memtype) { |
| case UIO_MEM_PHYS: |
| return uio_mmap_physical(vma); |
| case UIO_MEM_LOGICAL: |
| case UIO_MEM_VIRTUAL: |
| return uio_mmap_logical(vma); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static const struct file_operations uio_fops = { |
| .owner = THIS_MODULE, |
| .open = uio_open, |
| .release = uio_release, |
| .read = uio_read, |
| .write = uio_write, |
| .mmap = uio_mmap, |
| .poll = uio_poll, |
| .fasync = uio_fasync, |
| .llseek = noop_llseek, |
| }; |
| |
| static int uio_major_init(void) |
| { |
| static const char name[] = "uio"; |
| struct cdev *cdev = NULL; |
| dev_t uio_dev = 0; |
| int result; |
| |
| result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); |
| if (result) |
| goto out; |
| |
| result = -ENOMEM; |
| cdev = cdev_alloc(); |
| if (!cdev) |
| goto out_unregister; |
| |
| cdev->owner = THIS_MODULE; |
| cdev->ops = &uio_fops; |
| kobject_set_name(&cdev->kobj, "%s", name); |
| |
| result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); |
| if (result) |
| goto out_put; |
| |
| uio_major = MAJOR(uio_dev); |
| uio_cdev = cdev; |
| return 0; |
| out_put: |
| kobject_put(&cdev->kobj); |
| out_unregister: |
| unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); |
| out: |
| return result; |
| } |
| |
| static void uio_major_cleanup(void) |
| { |
| unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); |
| cdev_del(uio_cdev); |
| } |
| |
| static int init_uio_class(void) |
| { |
| int ret; |
| |
| /* This is the first time in here, set everything up properly */ |
| ret = uio_major_init(); |
| if (ret) |
| goto exit; |
| |
| ret = class_register(&uio_class); |
| if (ret) { |
| printk(KERN_ERR "class_register failed for uio\n"); |
| goto err_class_register; |
| } |
| return 0; |
| |
| err_class_register: |
| uio_major_cleanup(); |
| exit: |
| return ret; |
| } |
| |
| static void release_uio_class(void) |
| { |
| class_unregister(&uio_class); |
| uio_major_cleanup(); |
| } |
| |
| /** |
| * uio_register_device - register a new userspace IO device |
| * @owner: module that creates the new device |
| * @parent: parent device |
| * @info: UIO device capabilities |
| * |
| * returns zero on success or a negative error code. |
| */ |
| int __uio_register_device(struct module *owner, |
| struct device *parent, |
| struct uio_info *info) |
| { |
| struct uio_device *idev; |
| int ret = 0; |
| |
| if (!parent || !info || !info->name || !info->version) |
| return -EINVAL; |
| |
| info->uio_dev = NULL; |
| |
| idev = kzalloc(sizeof(*idev), GFP_KERNEL); |
| if (!idev) { |
| ret = -ENOMEM; |
| goto err_kzalloc; |
| } |
| |
| idev->owner = owner; |
| idev->info = info; |
| init_waitqueue_head(&idev->wait); |
| atomic_set(&idev->event, 0); |
| |
| ret = uio_get_minor(idev); |
| if (ret) |
| goto err_get_minor; |
| |
| idev->dev = device_create(&uio_class, parent, |
| MKDEV(uio_major, idev->minor), idev, |
| "uio%d", idev->minor); |
| if (IS_ERR(idev->dev)) { |
| printk(KERN_ERR "UIO: device register failed\n"); |
| ret = PTR_ERR(idev->dev); |
| goto err_device_create; |
| } |
| |
| ret = uio_dev_add_attributes(idev); |
| if (ret) |
| goto err_uio_dev_add_attributes; |
| |
| info->uio_dev = idev; |
| |
| if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { |
| ret = request_irq(info->irq, uio_interrupt, |
| info->irq_flags, info->name, idev); |
| if (ret) |
| goto err_request_irq; |
| } |
| |
| return 0; |
| |
| err_request_irq: |
| uio_dev_del_attributes(idev); |
| err_uio_dev_add_attributes: |
| device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); |
| err_device_create: |
| uio_free_minor(idev); |
| err_get_minor: |
| kfree(idev); |
| err_kzalloc: |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__uio_register_device); |
| |
| /** |
| * uio_unregister_device - unregister a industrial IO device |
| * @info: UIO device capabilities |
| * |
| */ |
| void uio_unregister_device(struct uio_info *info) |
| { |
| struct uio_device *idev; |
| |
| if (!info || !info->uio_dev) |
| return; |
| |
| idev = info->uio_dev; |
| |
| uio_free_minor(idev); |
| |
| if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) |
| free_irq(info->irq, idev); |
| |
| uio_dev_del_attributes(idev); |
| |
| device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); |
| kfree(idev); |
| |
| return; |
| } |
| EXPORT_SYMBOL_GPL(uio_unregister_device); |
| |
| static int __init uio_init(void) |
| { |
| return init_uio_class(); |
| } |
| |
| static void __exit uio_exit(void) |
| { |
| release_uio_class(); |
| } |
| |
| module_init(uio_init) |
| module_exit(uio_exit) |
| MODULE_LICENSE("GPL v2"); |