UIO: Add the User IO core code
This interface allows the ability to write the majority of a driver in
userspace with only a very small shell of a driver in the kernel itself.
It uses a char device and sysfs to interact with a userspace process to
process interrupts and control memory accesses.
See the docbook documentation for more details on how to use this
interface.
From: Hans J. Koch <hjk@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 7916f4b..ae01d86 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -84,4 +84,5 @@
source "drivers/kvm/Kconfig"
+source "drivers/uio/Kconfig"
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 6d9d7fa..c34c8ef 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -40,6 +40,7 @@
obj-$(CONFIG_FUSION) += message/
obj-$(CONFIG_FIREWIRE) += firewire/
obj-$(CONFIG_IEEE1394) += ieee1394/
+obj-$(CONFIG_UIO) += uio/
obj-y += cdrom/
obj-y += auxdisplay/
obj-$(CONFIG_MTD) += mtd/
diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
new file mode 100644
index 0000000..6b1a62d
--- /dev/null
+++ b/drivers/uio/Kconfig
@@ -0,0 +1,16 @@
+menu "Userspace I/O"
+ depends on !S390
+
+config UIO
+ tristate "Userspace I/O drivers"
+ default n
+ help
+ Enable this to allow the userspace driver core code to be
+ built. This code allows userspace programs easy access to
+ kernel interrupts and memory locations, allowing some drivers
+ to be written in userspace. Note that a small kernel driver
+ is also required for interrupt handling to work properly.
+
+ If you don't know what to do here, say N.
+
+endmenu
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
new file mode 100644
index 0000000..9b7c830
--- /dev/null
+++ b/drivers/uio/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_UIO) += uio.o
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
new file mode 100644
index 0000000..865f32b6
--- /dev/null
+++ b/drivers/uio/uio.c
@@ -0,0 +1,701 @@
+/*
+ * 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@linutronix.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/mm.h>
+#include <linux/idr.h>
+#include <linux/string.h>
+#include <linux/kobject.h>
+#include <linux/uio_driver.h>
+
+#define UIO_MAX_DEVICES 255
+
+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 kset map_attr_kset;
+};
+
+static int uio_major;
+static DEFINE_IDR(uio_idr);
+static struct file_operations uio_fops;
+
+/* UIO class infrastructure */
+static struct uio_class {
+ struct kref kref;
+ struct class *class;
+} *uio_class;
+
+/*
+ * attributes
+ */
+
+static struct attribute attr_addr = {
+ .name = "addr",
+ .mode = S_IRUGO,
+};
+
+static struct attribute attr_size = {
+ .name = "size",
+ .mode = S_IRUGO,
+};
+
+static struct attribute* map_attrs[] = {
+ &attr_addr, &attr_size, NULL
+};
+
+static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct uio_mem *mem = container_of(kobj, struct uio_mem, kobj);
+
+ if (strncmp(attr->name,"addr",4) == 0)
+ return sprintf(buf, "0x%lx\n", mem->addr);
+
+ if (strncmp(attr->name,"size",4) == 0)
+ return sprintf(buf, "0x%lx\n", mem->size);
+
+ return -ENODEV;
+}
+
+static void map_attr_release(struct kobject *kobj)
+{
+ /* TODO ??? */
+}
+
+static struct sysfs_ops map_attr_ops = {
+ .show = map_attr_show,
+};
+
+static struct kobj_type map_attr_type = {
+ .release = map_attr_release,
+ .sysfs_ops = &map_attr_ops,
+ .default_attrs = map_attrs,
+};
+
+static ssize_t show_name(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct uio_device *idev = dev_get_drvdata(dev);
+ if (idev)
+ return sprintf(buf, "%s\n", idev->info->name);
+ else
+ return -ENODEV;
+}
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static ssize_t show_version(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct uio_device *idev = dev_get_drvdata(dev);
+ if (idev)
+ return sprintf(buf, "%s\n", idev->info->version);
+ else
+ return -ENODEV;
+}
+static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
+
+static ssize_t show_event(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct uio_device *idev = dev_get_drvdata(dev);
+ if (idev)
+ return sprintf(buf, "%u\n",
+ (unsigned int)atomic_read(&idev->event));
+ else
+ return -ENODEV;
+}
+static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
+
+static struct attribute *uio_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_version.attr,
+ &dev_attr_event.attr,
+ NULL,
+};
+
+static struct attribute_group uio_attr_grp = {
+ .attrs = uio_attrs,
+};
+
+/*
+ * device functions
+ */
+static int uio_dev_add_attributes(struct uio_device *idev)
+{
+ int ret;
+ int mi;
+ int map_found = 0;
+ struct uio_mem *mem;
+
+ ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
+ if (ret)
+ goto err_group;
+
+ for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
+ mem = &idev->info->mem[mi];
+ if (mem->size == 0)
+ break;
+ if (!map_found) {
+ map_found = 1;
+ kobject_set_name(&idev->map_attr_kset.kobj,"maps");
+ idev->map_attr_kset.ktype = &map_attr_type;
+ idev->map_attr_kset.kobj.parent = &idev->dev->kobj;
+ ret = kset_register(&idev->map_attr_kset);
+ if (ret)
+ goto err_remove_group;
+ }
+ kobject_init(&mem->kobj);
+ kobject_set_name(&mem->kobj,"map%d",mi);
+ mem->kobj.parent = &idev->map_attr_kset.kobj;
+ mem->kobj.kset = &idev->map_attr_kset;
+ ret = kobject_add(&mem->kobj);
+ if (ret)
+ goto err_remove_maps;
+ }
+
+ return 0;
+
+err_remove_maps:
+ for (mi--; mi>=0; mi--) {
+ mem = &idev->info->mem[mi];
+ kobject_unregister(&mem->kobj);
+ }
+ kset_unregister(&idev->map_attr_kset); /* Needed ? */
+err_remove_group:
+ sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
+err_group:
+ dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
+ return ret;
+}
+
+static void uio_dev_del_attributes(struct uio_device *idev)
+{
+ int mi;
+ struct uio_mem *mem;
+ for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
+ mem = &idev->info->mem[mi];
+ if (mem->size == 0)
+ break;
+ kobject_unregister(&mem->kobj);
+ }
+ kset_unregister(&idev->map_attr_kset);
+ sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
+}
+
+static int uio_get_minor(struct uio_device *idev)
+{
+ static DEFINE_MUTEX(minor_lock);
+ int retval = -ENOMEM;
+ int id;
+
+ mutex_lock(&minor_lock);
+ if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
+ goto exit;
+
+ retval = idr_get_new(&uio_idr, idev, &id);
+ if (retval < 0) {
+ if (retval == -EAGAIN)
+ retval = -ENOMEM;
+ goto exit;
+ }
+ idev->minor = id & MAX_ID_MASK;
+exit:
+ mutex_unlock(&minor_lock);
+ return retval;
+}
+
+static void uio_free_minor(struct uio_device *idev)
+{
+ idr_remove(&uio_idr, idev->minor);
+}
+
+/**
+ * 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;
+
+ idev = idr_find(&uio_idr, iminor(inode));
+ if (!idev)
+ return -ENODEV;
+
+ listener = kmalloc(sizeof(*listener), GFP_KERNEL);
+ if (!listener)
+ return -ENOMEM;
+
+ listener->dev = idev;
+ listener->event_count = atomic_read(&idev->event);
+ filep->private_data = listener;
+
+ if (idev->info->open) {
+ if (!try_module_get(idev->owner))
+ return -ENODEV;
+ ret = idev->info->open(idev->info, inode);
+ module_put(idev->owner);
+ }
+
+ if (ret)
+ kfree(listener);
+
+ 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) {
+ if (!try_module_get(idev->owner))
+ return -ENODEV;
+ ret = idev->info->release(idev->info, inode);
+ module_put(idev->owner);
+ }
+ if (filep->f_flags & FASYNC)
+ ret = uio_fasync(-1, filep, 0);
+ 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 == UIO_IRQ_NONE)
+ 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 == UIO_IRQ_NONE)
+ 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 int uio_find_mem_index(struct vm_area_struct *vma)
+{
+ int mi;
+ struct uio_device *idev = vma->vm_private_data;
+
+ for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
+ if (idev->info->mem[mi].size == 0)
+ return -1;
+ if (vma->vm_pgoff == mi)
+ return mi;
+ }
+ 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 struct page *uio_vma_nopage(struct vm_area_struct *vma,
+ unsigned long address, int *type)
+{
+ struct uio_device *idev = vma->vm_private_data;
+ struct page* page = NOPAGE_SIGBUS;
+
+ int mi = uio_find_mem_index(vma);
+ if (mi < 0)
+ return page;
+
+ if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
+ page = virt_to_page(idev->info->mem[mi].addr);
+ else
+ page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
+ get_page(page);
+ if (type)
+ *type = VM_FAULT_MINOR;
+ return page;
+}
+
+static struct vm_operations_struct uio_vm_ops = {
+ .open = uio_vma_open,
+ .close = uio_vma_close,
+ .nopage = uio_vma_nopage,
+};
+
+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);
+ if (mi < 0)
+ return -EINVAL;
+
+ vma->vm_flags |= VM_IO | VM_RESERVED;
+
+ return remap_pfn_range(vma,
+ vma->vm_start,
+ idev->info->mem[mi].addr >> PAGE_SHIFT,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static int uio_mmap_logical(struct vm_area_struct *vma)
+{
+ vma->vm_flags |= VM_RESERVED;
+ vma->vm_ops = &uio_vm_ops;
+ uio_vma_open(vma);
+ return 0;
+}
+
+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].size + PAGE_SIZE -1) >> PAGE_SHIFT;
+ if (requested_pages > actual_pages)
+ return -EINVAL;
+
+ if (idev->info->mmap) {
+ if (!try_module_get(idev->owner))
+ return -ENODEV;
+ ret = idev->info->mmap(idev->info, vma);
+ module_put(idev->owner);
+ 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 struct file_operations uio_fops = {
+ .owner = THIS_MODULE,
+ .open = uio_open,
+ .release = uio_release,
+ .read = uio_read,
+ .mmap = uio_mmap,
+ .poll = uio_poll,
+ .fasync = uio_fasync,
+};
+
+static int uio_major_init(void)
+{
+ uio_major = register_chrdev(0, "uio", &uio_fops);
+ if (uio_major < 0)
+ return uio_major;
+ return 0;
+}
+
+static void uio_major_cleanup(void)
+{
+ unregister_chrdev(uio_major, "uio");
+}
+
+static int init_uio_class(void)
+{
+ int ret = 0;
+
+ if (uio_class != NULL) {
+ kref_get(&uio_class->kref);
+ goto exit;
+ }
+
+ /* This is the first time in here, set everything up properly */
+ ret = uio_major_init();
+ if (ret)
+ goto exit;
+
+ uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
+ if (!uio_class) {
+ ret = -ENOMEM;
+ goto err_kzalloc;
+ }
+
+ kref_init(&uio_class->kref);
+ uio_class->class = class_create(THIS_MODULE, "uio");
+ if (IS_ERR(uio_class->class)) {
+ ret = IS_ERR(uio_class->class);
+ printk(KERN_ERR "class_create failed for uio\n");
+ goto err_class_create;
+ }
+ return 0;
+
+err_class_create:
+ kfree(uio_class);
+ uio_class = NULL;
+err_kzalloc:
+ uio_major_cleanup();
+exit:
+ return ret;
+}
+
+static void release_uio_class(struct kref *kref)
+{
+ /* Ok, we cheat as we know we only have one uio_class */
+ class_destroy(uio_class->class);
+ kfree(uio_class);
+ uio_major_cleanup();
+ uio_class = NULL;
+}
+
+static void uio_class_destroy(void)
+{
+ if (uio_class)
+ kref_put(&uio_class->kref, release_uio_class);
+}
+
+/**
+ * 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;
+
+ ret = init_uio_class();
+ if (ret)
+ return ret;
+
+ 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->class, parent,
+ MKDEV(uio_major, idev->minor),
+ "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;
+ }
+ dev_set_drvdata(idev->dev, idev);
+
+ ret = uio_dev_add_attributes(idev);
+ if (ret)
+ goto err_uio_dev_add_attributes;
+
+ info->uio_dev = idev;
+
+ if (idev->info->irq >= 0) {
+ ret = request_irq(idev->info->irq, uio_interrupt,
+ idev->info->irq_flags, idev->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->class, MKDEV(uio_major, idev->minor));
+err_device_create:
+ uio_free_minor(idev);
+err_get_minor:
+ kfree(idev);
+err_kzalloc:
+ uio_class_destroy();
+ 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 >= 0)
+ free_irq(info->irq, idev);
+
+ uio_dev_del_attributes(idev);
+
+ dev_set_drvdata(idev->dev, NULL);
+ device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
+ kfree(idev);
+ uio_class_destroy();
+
+ return;
+}
+EXPORT_SYMBOL_GPL(uio_unregister_device);
+
+static int __init uio_init(void)
+{
+ return 0;
+}
+
+static void __exit uio_exit(void)
+{
+}
+
+module_init(uio_init)
+module_exit(uio_exit)
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
new file mode 100644
index 0000000..44c28e9
--- /dev/null
+++ b/include/linux/uio_driver.h
@@ -0,0 +1,91 @@
+/*
+ * include/linux/uio_driver.h
+ *
+ * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
+ * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
+ * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
+ *
+ * Userspace IO driver.
+ *
+ * Licensed under the GPLv2 only.
+ */
+
+#ifndef _UIO_DRIVER_H_
+#define _UIO_DRIVER_H_
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+
+/**
+ * struct uio_mem - description of a UIO memory region
+ * @kobj: kobject for this mapping
+ * @addr: address of the device's memory
+ * @size: size of IO
+ * @memtype: type of memory addr points to
+ * @internal_addr: ioremap-ped version of addr, for driver internal use
+ */
+struct uio_mem {
+ struct kobject kobj;
+ unsigned long addr;
+ unsigned long size;
+ int memtype;
+ void __iomem *internal_addr;
+};
+
+#define MAX_UIO_MAPS 5
+
+struct uio_device;
+
+/**
+ * struct uio_info - UIO device capabilities
+ * @uio_dev: the UIO device this info belongs to
+ * @name: device name
+ * @version: device driver version
+ * @mem: list of mappable memory regions, size==0 for end of list
+ * @irq: interrupt number or UIO_IRQ_CUSTOM
+ * @irq_flags: flags for request_irq()
+ * @priv: optional private data
+ * @handler: the device's irq handler
+ * @mmap: mmap operation for this uio device
+ * @open: open operation for this uio device
+ * @release: release operation for this uio device
+ */
+struct uio_info {
+ struct uio_device *uio_dev;
+ char *name;
+ char *version;
+ struct uio_mem mem[MAX_UIO_MAPS];
+ long irq;
+ unsigned long irq_flags;
+ void *priv;
+ irqreturn_t (*handler)(int irq, struct uio_info *dev_info);
+ int (*mmap)(struct uio_info *info, struct vm_area_struct *vma);
+ int (*open)(struct uio_info *info, struct inode *inode);
+ int (*release)(struct uio_info *info, struct inode *inode);
+};
+
+extern int __must_check
+ __uio_register_device(struct module *owner,
+ struct device *parent,
+ struct uio_info *info);
+static inline int __must_check
+ uio_register_device(struct device *parent, struct uio_info *info)
+{
+ return __uio_register_device(THIS_MODULE, parent, info);
+}
+extern void uio_unregister_device(struct uio_info *info);
+extern void uio_event_notify(struct uio_info *info);
+
+/* defines for uio_device->irq */
+#define UIO_IRQ_CUSTOM -1
+#define UIO_IRQ_NONE -2
+
+/* defines for uio_device->memtype */
+#define UIO_MEM_NONE 0
+#define UIO_MEM_PHYS 1
+#define UIO_MEM_LOGICAL 2
+#define UIO_MEM_VIRTUAL 3
+
+#endif /* _LINUX_UIO_DRIVER_H_ */