[GIT PATCH] UIO patches for 2.6.21

[GIT PATCH] UIO patches for 2.6.21

[Greg KH]

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Here is another round of the updated UIO (Userspace I/O driver framework)
patches for 2.6.21.

All of the issues raised from the last time the patches were posted
(last week) have been fixed in this version.

Many thanks for all of the review comments from everyone who took the
time to read over the code.

These patches include full documentation, are self-contained from the
rest of the kernel, and have been in the -mm tree for the past few
months with no complaints.

Please pull from:
	master.kernel.org:/pub/scm/linux/kernel/git/gregkh/uio-2.6.git/

Patches will be sent as a follow-on to this message to lkml for people
to see.

thanks,

greg k-h



 Documentation/DocBook/kernel-api.tmpl |    4 
 Documentation/DocBook/uio-howto.tmpl  |  611 +++++++++++++++++++++++++++++
 drivers/Kconfig                       |    1 
 drivers/Makefile                      |    1 
 drivers/uio/Kconfig                   |   27 +
 drivers/uio/Makefile                  |    2 
 drivers/uio/uio.c                     |  701 ++++++++++++++++++++++++++++++++++
 drivers/uio/uio_cif.c                 |  156 +++++++
 include/linux/uio_driver.h            |   91 ++++
 9 files changed, 1594 insertions(+)

---------------

Hans J. Koch (2):
      UIO: Add the User IO core code
      UIO: Documentation

Hans-Jürgen Koch (1):
      UIO: Hilscher CIF card driver

[PATCH 1/3] UIO: Add the User IO core code

[Greg Kroah-Hartman]

From: Hans J. Koch <hjk@linutronix.de>

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>
---
 drivers/Kconfig            |    1 +
 drivers/Makefile           |    1 +
 drivers/uio/Kconfig        |   14 +
 drivers/uio/Makefile       |    1 +
 drivers/uio/uio.c          |  701 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/uio_driver.h |   91 ++++++
 6 files changed, 809 insertions(+), 0 deletions(-)
 create mode 100644 drivers/uio/Kconfig
 create mode 100644 drivers/uio/Makefile
 create mode 100644 drivers/uio/uio.c
 create mode 100644 include/linux/uio_driver.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 050323f..325a108 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -84,4 +84,5 @@ source "drivers/auxdisplay/Kconfig"
 
 source "drivers/kvm/Kconfig"
 
+source "drivers/uio/Kconfig"
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 26ca903..1e2974c 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_SCSI)		+= scsi/
 obj-$(CONFIG_ATA)		+= ata/
 obj-$(CONFIG_FUSION)		+= message/
 obj-$(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..8fcef21
--- /dev/null
+++ b/drivers/uio/Kconfig
@@ -0,0 +1,14 @@
+menu "Userspace I/O"
+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..865f32b
--- /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_ */
-- 
1.5.1.3

[PATCH 2/3] UIO: Documentation

[Greg Kroah-Hartman]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 22500 bytes --]

From: Hans J. Koch <hjk@linutronix.de>

Documentation for the UIO interface

From: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 Documentation/DocBook/kernel-api.tmpl |    4 +
 Documentation/DocBook/uio-howto.tmpl  |  611 +++++++++++++++++++++++++++++++++
 2 files changed, 615 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/DocBook/uio-howto.tmpl

diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index b61dfc7..4b7b2fd 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -402,6 +402,10 @@ X!Edrivers/pnp/system.c
 !Edrivers/pnp/manager.c
 !Edrivers/pnp/support.c
      </sect1>
+     <sect1><title>Userspace IO devices</title>
+!Edrivers/uio/uio.c
+!Iinclude/linux/uio_driver.h
+     </sect1>
   </chapter>
 
   <chapter id="blkdev">
diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
new file mode 100644
index 0000000..e3bb29a
--- /dev/null
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -0,0 +1,611 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" []>
+
+<book id="index">
+<bookinfo>
+<title>The Userspace I/O HOWTO</title>
+
+<author>
+      <firstname>Hans-Jürgen</firstname>
+      <surname>Koch</surname>
+      <authorblurb><para>Linux developer, Linutronix</para></authorblurb>
+	<affiliation>
+	<orgname>
+		<ulink url="http://www.linutronix.de">Linutronix</ulink>
+	</orgname>
+
+	<address>
+	   <email>hjk@linutronix.de</email>
+	</address>
+    </affiliation>
+</author>
+
+<pubdate>2006-12-11</pubdate>
+
+<abstract>
+	<para>This HOWTO describes concept and usage of Linux kernel's
+		Userspace I/O system.</para>
+</abstract>
+
+<revhistory>
+	<revision>
+	<revnumber>0.3</revnumber>
+	<date>2007-04-29</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Added section about userspace drivers.</revremark>
+	</revision>
+	<revision>
+	<revnumber>0.2</revnumber>
+	<date>2007-02-13</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Update after multiple mappings were added.</revremark>
+	</revision>
+	<revision>
+	<revnumber>0.1</revnumber>
+	<date>2006-12-11</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>First draft.</revremark>
+	</revision>
+</revhistory>
+</bookinfo>
+
+<chapter id="aboutthisdoc">
+<?dbhtml filename="about.html"?>
+<title>About this document</title>
+
+<sect1 id="copyright">
+<?dbhtml filename="copyright.html"?>
+<title>Copyright and License</title>
+<para>
+      Copyright (c) 2006 by Hans-Jürgen Koch.</para>
+<para>
+This documentation is Free Software licensed under the terms of the
+GPL version 2.
+</para>
+</sect1>
+
+<sect1 id="translations">
+<?dbhtml filename="translations.html"?>
+<title>Translations</title>
+
+<para>If you know of any translations for this document, or you are
+interested in translating it, please email me
+<email>hjk@linutronix.de</email>.
+</para>
+</sect1>
+
+<sect1 id="preface">
+<title>Preface</title>
+	<para>
+	For many types of devices, creating a Linux kernel driver is
+	overkill.  All that is really needed is some way to handle an
+	interrupt and provide access to the memory space of the
+	device.  The logic of controlling the device does not
+	necessarily have to be within the kernel, as the device does
+	not need to take advantage of any of other resources that the
+	kernel provides.  One such common class of devices that are
+	like this are for industrial I/O cards.
+	</para>
+	<para>
+	To address this situation, the userspace I/O system (UIO) was
+	designed.  For typical industrial I/O cards, only a very small
+	kernel module is needed. The main part of the driver will run in
+	user space. This simplifies development and reduces the risk of
+	serious bugs within a kernel module.
+	</para>
+</sect1>
+
+<sect1 id="thanks">
+<title>Acknowledgments</title>
+	<para>I'd like to thank Thomas Gleixner and Benedikt Spranger of
+	Linutronix, who have not only written most of the UIO code, but also
+	helped greatly writing this HOWTO by giving me all kinds of background
+	information.</para>
+</sect1>
+
+<sect1 id="feedback">
+<title>Feedback</title>
+	<para>Find something wrong with this document? (Or perhaps something
+	right?) I would love to hear from you. Please email me at
+	<email>hjk@linutronix.de</email>.</para>
+</sect1>
+</chapter>
+
+<chapter id="about">
+<?dbhtml filename="about.html"?>
+<title>About UIO</title>
+
+<para>If you use UIO for your card's driver, here's what you get:</para>
+
+<itemizedlist>
+<listitem>
+	<para>only one small kernel module to write and maintain.</para>
+</listitem>
+<listitem>
+	<para>develop the main part of your driver in user space,
+	with all the tools and libraries you're used to.</para>
+</listitem>
+<listitem>
+	<para>bugs in your driver won't crash the kernel.</para>
+</listitem>
+<listitem>
+	<para>updates of your driver can take place without recompiling
+	the kernel.</para>
+</listitem>
+<listitem>
+	<para>if you need to keep some parts of your driver closed source,
+	you can do so without violating the GPL license on the kernel.</para>
+</listitem>
+</itemizedlist>
+
+<sect1 id="how_uio_works">
+<title>How UIO works</title>
+	<para>
+	Each UIO device is accessed through a device file and several
+	sysfs attribute files. The device file will be called
+	<filename>/dev/uio0</filename> for the first device, and
+	<filename>/dev/uio1</filename>, <filename>/dev/uio2</filename>
+	and so on for subsequent devices.
+	</para>
+
+	<para><filename>/dev/uioX</filename> is used to access the
+	address space of the card. Just use
+	<function>mmap()</function> to access registers or RAM
+	locations of your card.
+	</para>
+
+	<para>
+	Interrupts are handled by reading from
+	<filename>/dev/uioX</filename>. A blocking
+	<function>read()</function> from
+	<filename>/dev/uioX</filename> will return as soon as an
+	interrupt occurs. You can also use
+	<function>select()</function> on
+	<filename>/dev/uioX</filename> to wait for an interrupt. The
+	integer value read from <filename>/dev/uioX</filename>
+	represents the total interrupt count. You can use this number
+	to figure out if you missed some interrupts.
+	</para>
+
+	<para>
+	To handle interrupts properly, your custom kernel module can
+	provide its own interrupt handler. It will automatically be
+	called by the built-in handler.
+	</para>
+
+	<para>
+	For cards that don't generate interrupts but need to be
+	polled, there is the possibility to set up a timer that
+	triggers the interrupt handler at configurable time intervals.
+	See <filename>drivers/uio/uio_dummy.c</filename> for an
+	example of this technique.
+	</para>
+
+	<para>
+	Each driver provides attributes that are used to read or write
+	variables. These attributes are accessible through sysfs
+	files.  A custom kernel driver module can add its own
+	attributes to the device owned by the uio driver, but not added
+	to the UIO device itself at this time.  This might change in the
+	future if it would be found to be useful.
+	</para>
+
+	<para>
+	The following standard attributes are provided by the UIO
+	framework:
+	</para>
+<itemizedlist>
+<listitem>
+	<para>
+	<filename>name</filename>: The name of your device. It is
+	recommended to use the name of your kernel module for this.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>version</filename>: A version string defined by your
+	driver. This allows the user space part of your driver to deal
+	with different versions of the kernel module.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>event</filename>: The total number of interrupts
+	handled by the driver since the last time the device node was
+	read.
+	</para>
+</listitem>
+</itemizedlist>
+<para>
+	These attributes appear under the
+	<filename>/sys/class/uio/uioX</filename> directory.  Please
+	note that this directory might be a symlink, and not a real
+	directory.  Any userspace code that accesses it must be able
+	to handle this.
+</para>
+<para>
+	Each UIO device can make one or more memory regions available for
+	memory mapping. This is necessary because some industrial I/O cards
+	require access to more than one PCI memory region in a driver.
+</para>
+<para>
+	Each mapping has its own directory in sysfs, the first mapping
+	appears as <filename>/sys/class/uio/uioX/maps/map0/</filename>.
+	Subsequent mappings create directories <filename>map1/</filename>,
+	<filename>map2/</filename>, and so on. These directories will only
+	appear if the size of the mapping is not 0.
+</para>
+<para>
+	Each <filename>mapX/</filename> directory contains two read-only files
+	that show start address and size of the memory:
+</para>
+<itemizedlist>
+<listitem>
+	<para>
+	<filename>addr</filename>: The address of memory that can be mapped.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>size</filename>: The size, in bytes, of the memory
+	pointed to by addr.
+	</para>
+</listitem>
+</itemizedlist>
+
+<para>
+	From userspace, the different mappings are distinguished by adjusting
+	the <varname>offset</varname> parameter of the
+	<function>mmap()</function> call. To map the memory of mapping N, you
+	have to use N times the page size as your offset:
+</para>
+<programlisting format="linespecific">
+offset = N * getpagesize();
+</programlisting>
+
+</sect1>
+</chapter>
+
+<chapter id="using-uio_dummy" xreflabel="Using uio_dummy">
+<?dbhtml filename="using-uio_dummy.html"?>
+<title>Using uio_dummy</title>
+	<para>
+	Well, there is no real use for uio_dummy. Its only purpose is
+	to test most parts of the UIO system (everything except
+	hardware interrupts), and to serve as an example for the
+	kernel module that you will have to write yourself.
+	</para>
+
+<sect1 id="what_uio_dummy_does">
+<title>What uio_dummy does</title>
+	<para>
+	The kernel module <filename>uio_dummy.ko</filename> creates a
+	device that uses a timer to generate periodic interrupts. The
+	interrupt handler does nothing but increment a counter. The
+	driver adds two custom attributes, <varname>count</varname>
+	and <varname>freq</varname>, that appear under
+	<filename>/sys/devices/platform/uio_dummy/</filename>.
+	</para>
+
+	<para>
+	The attribute <varname>count</varname> can be read and
+	written.  The associated file
+	<filename>/sys/devices/platform/uio_dummy/count</filename>
+	appears as a normal text file and contains the total number of
+	timer interrupts. If you look at it (e.g. using
+	<function>cat</function>), you'll notice it is slowly counting
+	up.
+	</para>
+
+	<para>
+	The attribute <varname>freq</varname> can be read and written.
+	The content of
+	<filename>/sys/devices/platform/uio_dummy/freq</filename>
+	represents the number of system timer ticks between two timer
+	interrupts. The default value of <varname>freq</varname> is
+	the value of the kernel variable <varname>HZ</varname>, which
+	gives you an interval of one second. Lower values will
+	increase the frequency. Try the following:
+	</para>
+<programlisting format="linespecific">
+cd /sys/devices/platform/uio_dummy/
+echo 100 > freq
+</programlisting>
+	<para>
+	Use <function>cat count</function> to see how the interrupt
+	frequency changes.
+	</para>
+</sect1>
+</chapter>
+
+<chapter id="custom_kernel_module" xreflabel="Writing your own kernel module">
+<?dbhtml filename="custom_kernel_module.html"?>
+<title>Writing your own kernel module</title>
+	<para>
+	Please have a look at <filename>uio_dummy.c</filename> as an
+	example. The following paragraphs explain the different
+	sections of this file.
+	</para>
+
+<sect1 id="uio_info">
+<title>struct uio_info</title>
+	<para>
+	This structure tells the framework the details of your driver,
+	Some of the members are required, others are optional.
+	</para>
+
+<itemizedlist>
+<listitem><para>
+<varname>char *name</varname>: Required. The name of your driver as
+it will appear in sysfs. I recommend using the name of your module for this.
+</para></listitem>
+
+<listitem><para>
+<varname>char *version</varname>: Required. This string appears in
+<filename>/sys/class/uio/uioX/version</filename>.
+</para></listitem>
+
+<listitem><para>
+<varname>struct uio_mem mem[ MAX_UIO_MAPS ]</varname>: Required if you
+have memory that can be mapped with <function>mmap()</function>. For each
+mapping you need to fill one of the <varname>uio_mem</varname> structures.
+See the description below for details.
+</para></listitem>
+
+<listitem><para>
+<varname>long irq</varname>: Required. If your hardware generates an
+interrupt, it's your modules task to determine the irq number during
+initialization. If you don't have a hardware generated interrupt but
+want to trigger the interrupt handler in some other way, set
+<varname>irq</varname> to <varname>UIO_IRQ_CUSTOM</varname>. The
+uio_dummy module does this as it triggers the event mechanism in a timer
+routine. If you had no interrupt at all, you could set
+<varname>irq</varname> to <varname>UIO_IRQ_NONE</varname>, though this
+rarely makes sense.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long irq_flags</varname>: Required if you've set
+<varname>irq</varname> to a hardware interrupt number. The flags given
+here will be used in the call to <function>request_irq()</function>.
+</para></listitem>
+
+<listitem><para>
+<varname>int (*mmap)(struct uio_info *info, struct vm_area_struct
+*vma)</varname>: Optional. If you need a special
+<function>mmap()</function> function, you can set it here. If this
+pointer is not NULL, your <function>mmap()</function> will be called
+instead of the built-in one.
+</para></listitem>
+
+<listitem><para>
+<varname>int (*open)(struct uio_info *info, struct inode *inode)
+</varname>: Optional. You might want to have your own
+<function>open()</function>, e.g. to enable interrupts only when your
+device is actually used.
+</para></listitem>
+
+<listitem><para>
+<varname>int (*release)(struct uio_info *info, struct inode *inode)
+</varname>: Optional. If you define your own
+<function>open()</function>, you will probably also want a custom
+<function>release()</function> function.
+</para></listitem>
+</itemizedlist>
+
+<para>
+Usually, your device will have one or more memory regions that can be mapped
+to user space. For each region, you have to set up a
+<varname>struct uio_mem</varname> in the <varname>mem[]</varname> array.
+Here's a description of the fields of <varname>struct uio_mem</varname>:
+</para>
+
+<itemizedlist>
+<listitem><para>
+<varname>int memtype</varname>: Required if the mapping is used. Set this to
+<varname>UIO_MEM_PHYS</varname> if you you have physical memory on your
+card to be mapped. Use <varname>UIO_MEM_LOGICAL</varname> for logical
+memory (e.g. allocated with <function>kmalloc()</function>). There's also
+<varname>UIO_MEM_VIRTUAL</varname> for virtual memory.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long addr</varname>: Required if the mapping is used.
+Fill in the address of your memory block. This address is the one that
+appears in sysfs.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long size</varname>: Fill in the size of the
+memory block that <varname>addr</varname> points to. If <varname>size</varname>
+is zero, the mapping is considered unused. Note that you
+<emphasis>must</emphasis> initialize <varname>size</varname> with zero for
+all unused mappings.
+</para></listitem>
+
+<listitem><para>
+<varname>void *internal_addr</varname>: If you have to access this memory
+region from within your kernel module, you will want to map it internally by
+using something like <function>ioremap()</function>. Addresses
+returned by this function cannot be mapped to user space, so you must not
+store it in <varname>addr</varname>. Use <varname>internal_addr</varname>
+instead to remember such an address.
+</para></listitem>
+</itemizedlist>
+
+<para>
+Please do not touch the <varname>kobj</varname> element of
+<varname>struct uio_mem</varname>! It is used by the UIO framework
+to set up sysfs files for this mapping. Simply leave it alone.
+</para>
+</sect1>
+
+<sect1 id="adding_irq_handler">
+<title>Adding an interrupt handler</title>
+	<para>
+	What you need to do in your interrupt handler depends on your
+	hardware and on how you want to	handle it. You should try to
+	keep the amount of code in your kernel interrupt handler low.
+	If your hardware requires no action that you
+	<emphasis>have</emphasis> to perform after each interrupt,
+	then your handler can be empty.</para> <para>If, on the other
+	hand, your hardware <emphasis>needs</emphasis> some action to
+	be performed after each interrupt, then you
+	<emphasis>must</emphasis> do it in your kernel module. Note
+	that you cannot rely on the userspace part of your driver. Your
+	userspace program can terminate at any time, possibly leaving
+	your hardware in a state where proper interrupt handling is
+	still required.
+	</para>
+
+	<para>
+	There might also be applications where you want to read data
+	from your hardware at each interrupt and buffer it in a piece
+	of kernel memory you've allocated for that purpose.  With this
+	technique you could avoid loss of data if your userspace
+	program misses an interrupt.
+	</para>
+
+	<para>
+	A note on shared interrupts: Your driver should support
+	interrupt sharing whenever this is possible. It is possible if
+	and only if your driver can detect whether your hardware has
+	triggered the interrupt or not. This is usually done by looking
+	at an interrupt status register. If your driver sees that the
+	IRQ bit is actually set, it will perform its actions, and the
+	handler returns IRQ_HANDLED. If the driver detects that it was
+	not your hardware that caused the interrupt, it will do nothing
+	and return IRQ_NONE, allowing the kernel to call the next
+	possible interrupt handler.
+	</para>
+
+	<para>
+	If you decide not to support shared interrupts, your card
+	won't work in computers with no free interrupts. As this
+	frequently happens on the PC platform, you can save yourself a
+	lot of trouble by supporting interrupt sharing.
+	</para>
+</sect1>
+
+</chapter>
+
+<chapter id="userspace_driver" xreflabel="Writing a driver in user space">
+<?dbhtml filename="userspace_driver.html"?>
+<title>Writing a driver in userspace</title>
+	<para>
+	Once you have a working kernel module for your hardware, you can
+	write the userspace part of your driver. You don't need any special
+	libraries, your driver can be written in any reasonable language,
+	you can use floating point numbers and so on. In short, you can
+	use all the tools and libraries you'd normally use for writing a
+	userspace application.
+	</para>
+
+<sect1 id="getting_uio_information">
+<title>Getting information about your UIO device</title>
+	<para>
+	Information about all UIO devices is available in sysfs. The
+	first thing you should do in your driver is check
+	<varname>name</varname> and <varname>version</varname> to
+	make sure your talking to the right device and that its kernel
+	driver has the version you expect.
+	</para>
+	<para>
+	You should also make sure that the memory mapping you need
+	exists and has the size you expect.
+	</para>
+	<para>
+	There is a tool called <varname>lsuio</varname> that lists
+	UIO devices and their attributes. It is available here:
+	</para>
+	<para>
+	<ulink url="http://www.osadl.org/projects/downloads/UIO/user/">
+		http://www.osadl.org/projects/downloads/UIO/user/</ulink>
+	</para>
+	<para>
+	With <varname>lsuio</varname> you can quickly check if your
+	kernel module is loaded and which attributes it exports.
+	Have a look at the manpage for details.
+	</para>
+	<para>
+	The source code of <varname>lsuio</varname> can serve as an
+	example for getting information about an UIO device.
+	The file <filename>uio_helper.c</filename> contains a lot of
+	functions you could use in your userspace driver code.
+	</para>
+</sect1>
+
+<sect1 id="mmap_device_memory">
+<title>mmap() device memory</title>
+	<para>
+	After you made sure you've got the right device with the
+	memory mappings you need, all you have to do is to call
+	<function>mmap()</function> to map the device's memory
+	to userspace.
+	</para>
+	<para>
+	The parameter <varname>offset</varname> of the
+	<function>mmap()</function> call has a special meaning
+	for UIO devices: It is used to select which mapping of
+	your device you want to map. To map the memory of
+	mapping N, you have to use N times the page size as
+	your offset:
+	</para>
+<programlisting format="linespecific">
+	offset = N * getpagesize();
+</programlisting>
+	<para>
+	N starts from zero, so if you've got only one memory
+	range to map, set <varname>offset = 0</varname>.
+	A drawback of this technique is that memory is always
+	mapped beginning with its start address.
+	</para>
+</sect1>
+
+<sect1 id="wait_for_interrupts">
+<title>Waiting for interrupts</title>
+	<para>
+	After you successfully mapped your devices memory, you
+	can access it like an ordinary array. Usually, you will
+	perform some initialization. After that, your hardware
+	starts working and will generate an interrupt as soon
+	as it's finished, has some data available, or needs your
+	attention because an error occured.
+	</para>
+	<para>
+	<filename>/dev/uioX</filename> is a read-only file. A
+	<function>read()</function> will always block until an
+	interrupt occurs. There is only one legal value for the
+	<varname>count</varname> parameter of
+	<function>read()</function>, and that is the size of a
+	signed 32 bit integer (4). Any other value for
+	<varname>count</varname> causes <function>read()</function>
+	to fail. The signed 32 bit integer read is the interrupt
+	count of your device. If the value is one more than the value
+	you read the last time, everything is OK. If the difference
+	is greater than one, you missed interrupts.
+	</para>
+	<para>
+	You can also use <function>select()</function> on
+	<filename>/dev/uioX</filename>.
+	</para>
+</sect1>
+
+</chapter>
+
+<appendix id="app1">
+<title>Further information</title>
+<itemizedlist>
+	<listitem><para>
+			<ulink url="http://www.osadl.org">
+				OSADL homepage.</ulink>
+		</para></listitem>
+	<listitem><para>
+		<ulink url="http://www.linutronix.de">
+		 Linutronix homepage.</ulink>
+		</para></listitem>
+</itemizedlist>
+</appendix>
+
+</book>
-- 
1.5.1.3

[PATCH 3/3] UIO: Hilscher CIF card driver

[Greg Kroah-Hartman]

From: Hans-Jürgen Koch <hjk@linutronix.de>

this is a patch that adds support for Hilscher CIF DeviceNet and
Profibus cards. I tested it on a Kontron CPX board, and Thomas reviewed
it.

You can find the user space part here:

http://www.osadl.org/projects/downloads/UIO/user/cif-0.1.0.tar.gz

Notes: cif_api.c is the main file you want to look at. It contains the
functions to open, close, mmap and so on. cif_dps.c adds functions
specific to Profibus cards, and cif_dn.c contains functions for
DeviceNet cards.  cif.c is a universal playground, it's just a small
test program.  The user space part of this UIO driver is still work in
progress, and not everything is tested yet. At the moment, the thread in
cif_api.c contains some code that artificially makes the card generate
interrupts, this was added for testing and will be removed later. But
the driver already contains all the functions needed for useful
operation, so it gives a good idea of how such a thing looks like.

For comparison, here's what you get from the manufacturer
(www.hilscher.com) when you ask for a Linux 2.6 driver:

http://www.tglx.de/private/hjk/cif-orig-2.6.tar.bz2

WARNING: Don't look at the code for too long, you might become sick :-)


Signed-off-by: Hans-Jürgen Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/uio/Kconfig   |   13 ++++
 drivers/uio/Makefile  |    3 +-
 drivers/uio/uio_cif.c |  156 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 171 insertions(+), 1 deletions(-)
 create mode 100644 drivers/uio/uio_cif.c

diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 8fcef21..279f26c 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -11,4 +11,17 @@ config UIO
 
 	  If you don't know what to do here, say N.
 
+config UIO_CIF
+	tristate "generic Hilscher CIF Card driver"
+	depends on UIO && PCI
+	default n
+	help
+	  Driver for Hilscher CIF DeviceNet and Profibus cards.  This
+	  driver requires a userspace component that handles all of the
+	  heavy lifting and can be found at:
+	  	http://www.osadl.org/projects/downloads/UIO/user/cif-*
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called uio_cif.
+
 endmenu
diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
index 9b7c830..7fecfb4 100644
--- a/drivers/uio/Makefile
+++ b/drivers/uio/Makefile
@@ -1 +1,2 @@
-obj-$(CONFIG_UIO) += uio.o
+obj-$(CONFIG_UIO)	+= uio.o
+obj-$(CONFIG_UIO_CIF)	+= uio_cif.o
diff --git a/drivers/uio/uio_cif.c b/drivers/uio/uio_cif.c
new file mode 100644
index 0000000..838bae4
--- /dev/null
+++ b/drivers/uio/uio_cif.c
@@ -0,0 +1,156 @@
+/*
+ * UIO Hilscher CIF card driver
+ *
+ * (C) 2007 Hans J. Koch <hjk@linutronix.de>
+ * Original code (C) 2005 Benedikt Spranger <b.spranger@linutronix.de>
+ *
+ * Licensed under GPL version 2 only.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/uio_driver.h>
+
+#include <asm/io.h>
+
+#ifndef PCI_DEVICE_ID_PLX_9030
+#define PCI_DEVICE_ID_PLX_9030	0x9030
+#endif
+
+#define PLX9030_INTCSR		0x4C
+#define INTSCR_INT1_ENABLE	0x01
+#define INTSCR_INT1_STATUS	0x04
+#define INT1_ENABLED_AND_ACTIVE	(INTSCR_INT1_ENABLE | INTSCR_INT1_STATUS)
+
+#define PCI_SUBVENDOR_ID_PEP	0x1518
+#define CIF_SUBDEVICE_PROFIBUS	0x430
+#define CIF_SUBDEVICE_DEVICENET	0x432
+
+
+static irqreturn_t hilscher_handler(int irq, struct uio_info *dev_info)
+{
+	void __iomem *plx_intscr = dev_info->mem[0].internal_addr
+					+ PLX9030_INTCSR;
+
+	if ((ioread8(plx_intscr) & INT1_ENABLED_AND_ACTIVE)
+	    != INT1_ENABLED_AND_ACTIVE)
+		return IRQ_NONE;
+
+	/* Disable interrupt */
+	iowrite8(ioread8(plx_intscr) & ~INTSCR_INT1_ENABLE, plx_intscr);
+	return IRQ_HANDLED;
+}
+
+static int __devinit hilscher_pci_probe(struct pci_dev *dev,
+					const struct pci_device_id *id)
+{
+	struct uio_info *info;
+
+	info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	if (pci_enable_device(dev))
+		goto out_free;
+
+	if (pci_request_regions(dev, "hilscher"))
+		goto out_disable;
+
+	info->mem[0].addr = pci_resource_start(dev, 0);
+	if (!info->mem[0].addr)
+		goto out_release;
+	info->mem[0].internal_addr = ioremap(pci_resource_start(dev, 0),
+					     pci_resource_len(dev, 0));
+	if (!info->mem[0].internal_addr)
+		goto out_release;
+
+	info->mem[0].size = pci_resource_len(dev, 0);
+	info->mem[0].memtype = UIO_MEM_PHYS;
+	info->mem[1].addr = pci_resource_start(dev, 2);
+	info->mem[1].size = pci_resource_len(dev, 2);
+	info->mem[1].memtype = UIO_MEM_PHYS;
+	switch (id->subdevice) {
+		case CIF_SUBDEVICE_PROFIBUS:
+			info->name = "CIF_Profibus";
+			break;
+		case CIF_SUBDEVICE_DEVICENET:
+			info->name = "CIF_Devicenet";
+			break;
+		default:
+			info->name = "CIF_???";
+	}
+	info->version = "0.0.1";
+	info->irq = dev->irq;
+	info->irq_flags = IRQF_DISABLED | IRQF_SHARED;
+	info->handler = hilscher_handler;
+
+	if (uio_register_device(&dev->dev, info))
+		goto out_unmap;
+
+	pci_set_drvdata(dev, info);
+
+	return 0;
+out_unmap:
+	iounmap(info->mem[0].internal_addr);
+out_release:
+	pci_release_regions(dev);
+out_disable:
+	pci_disable_device(dev);
+out_free:
+	kfree (info);
+	return -ENODEV;
+}
+
+static void hilscher_pci_remove(struct pci_dev *dev)
+{
+	struct uio_info *info = pci_get_drvdata(dev);
+
+	uio_unregister_device(info);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+	pci_set_drvdata(dev, NULL);
+	iounmap(info->mem[0].internal_addr);
+
+	kfree (info);
+}
+
+static struct pci_device_id hilscher_pci_ids[] = {
+	{
+		.vendor =	PCI_VENDOR_ID_PLX,
+		.device =	PCI_DEVICE_ID_PLX_9030,
+		.subvendor =	PCI_SUBVENDOR_ID_PEP,
+		.subdevice =	CIF_SUBDEVICE_PROFIBUS,
+	},
+	{
+		.vendor =	PCI_VENDOR_ID_PLX,
+		.device =	PCI_DEVICE_ID_PLX_9030,
+		.subvendor =	PCI_SUBVENDOR_ID_PEP,
+		.subdevice =	CIF_SUBDEVICE_DEVICENET,
+	},
+	{ 0, }
+};
+
+static struct pci_driver hilscher_pci_driver = {
+	.name = "hilscher",
+	.id_table = hilscher_pci_ids,
+	.probe = hilscher_pci_probe,
+	.remove = hilscher_pci_remove,
+};
+
+static int __init hilscher_init_module(void)
+{
+	return pci_register_driver(&hilscher_pci_driver);
+}
+
+static void __exit hilscher_exit_module(void)
+{
+	pci_unregister_driver(&hilscher_pci_driver);
+}
+
+module_init(hilscher_init_module);
+module_exit(hilscher_exit_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Hans J. Koch, Benedikt Spranger");
-- 
1.5.1.3

[GIT PATCH] UIO patches for 2.6.22

[Greg KH]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=unknown-8bit, Size: 1827 bytes --]

Here are the UIO (Userspace I/O driver framework) patches for 2.6.22

They have been revamped from the last time you have seen them, and they
include a real driver, the Hilscher CIF DeviceNet and Profibus card
controller, which is being used in production systems with this driver
framework right now.  The kernel driver they replaced was a total mess,
with over 60+ ioctls to try to control the different aspects of the
device.  See the last patch in this series for more details on this
driver.

These patches include full documentation, are self-contained from the
rest of the kernel, and have been in the -mm tree for the past few
months with no complaints.

Please pull from:
	master.kernel.org:/pub/scm/linux/kernel/git/gregkh/uio-2.6.git/

Patches will be sent as a follow-on to this message to lkml for people
to see.

thanks,

greg k-h


 Documentation/DocBook/kernel-api.tmpl |    4 +
 Documentation/DocBook/uio-howto.tmpl  |  611 ++++++++++++++++++++++++++++
 drivers/Kconfig                       |    1 +
 drivers/Makefile                      |    1 +
 drivers/uio/Kconfig                   |   29 ++
 drivers/uio/Makefile                  |    2 +
 drivers/uio/uio.c                     |  701 +++++++++++++++++++++++++++++++++
 drivers/uio/uio_cif.c                 |  156 ++++++++
 include/linux/uio_driver.h            |   91 +++++
 9 files changed, 1596 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/DocBook/uio-howto.tmpl
 create mode 100644 drivers/uio/Kconfig
 create mode 100644 drivers/uio/Makefile
 create mode 100644 drivers/uio/uio.c
 create mode 100644 drivers/uio/uio_cif.c
 create mode 100644 include/linux/uio_driver.h

---------------

Hans J. Koch (2):
      UIO: Add the User IO core code
      UIO: Documentation

Hans-Jürgen Koch (1):
      UIO: Hilscher CIF card driver

[PATCH 1/3] UIO: Add the User IO core code

[Greg Kroah-Hartman]

From: Hans J. Koch <hjk@linutronix.de>

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>
---
 drivers/Kconfig            |    1 +
 drivers/Makefile           |    1 +
 drivers/uio/Kconfig        |   16 +
 drivers/uio/Makefile       |    1 +
 drivers/uio/uio.c          |  701 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/uio_driver.h |   91 ++++++
 6 files changed, 811 insertions(+), 0 deletions(-)
 create mode 100644 drivers/uio/Kconfig
 create mode 100644 drivers/uio/Makefile
 create mode 100644 drivers/uio/uio.c
 create mode 100644 include/linux/uio_driver.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 7916f4b..ae01d86 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -84,4 +84,5 @@ source "drivers/auxdisplay/Kconfig"
 
 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-$(CONFIG_ATA)		+= ata/
 obj-$(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..865f32b
--- /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_ */
-- 
1.5.2.2

[GIT PATCH] UIO patches for 2.6.21

[Greg KH]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=unknown-8bit, Size: 1831 bytes --]

Here are the updated UIO (Userspace I/O driver framework) patches for
2.6.21.

They have been revamped from the last time you have seen them, and they
include a real driver, the Hilscher CIF DeviceNet and Profibus card
controller, which is being used in production systems with this driver
framework right now.  The kernel driver they replaced was a total mess,
with over 60+ ioctls to try to control the different aspects of the
device.  See the last patch in this series for more details on this
driver.

These patches include full documentation, are self-contained from the
rest of the kernel, and have been in the -mm tree for the past few
months with no complaints.

Please pull from:
	master.kernel.org:/pub/scm/linux/kernel/git/gregkh/uio-2.6.git/

Patches will be sent as a follow-on to this message to lkml for people
to see.

thanks,

greg k-h


 Documentation/DocBook/kernel-api.tmpl |    4 +
 Documentation/DocBook/uio-howto.tmpl  |  498 +++++++++++++++++++++++
 drivers/Kconfig                       |    1 +
 drivers/Makefile                      |    1 +
 drivers/uio/Kconfig                   |   27 ++
 drivers/uio/Makefile                  |    2 +
 drivers/uio/uio.c                     |  702 +++++++++++++++++++++++++++++++++
 drivers/uio/uio_cif.c                 |  156 ++++++++
 include/linux/uio_driver.h            |   91 +++++
 9 files changed, 1482 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/DocBook/uio-howto.tmpl
 create mode 100644 drivers/uio/Kconfig
 create mode 100644 drivers/uio/Makefile
 create mode 100644 drivers/uio/uio.c
 create mode 100644 drivers/uio/uio_cif.c
 create mode 100644 include/linux/uio_driver.h

---------------

Hans J. Koch (2):
      UIO: Add the User IO core code
      UIO: Documentation

Hans-Jürgen Koch (1):
      UIO: Hilscher CIF card driver

[PATCH 1/3] UIO: Add the User IO core code

[Greg Kroah-Hartman]

From: Hans J. Koch <hjk@linutronix.de>

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>
---
 drivers/Kconfig            |    1 +
 drivers/Makefile           |    1 +
 drivers/uio/Kconfig        |   14 +
 drivers/uio/Makefile       |    1 +
 drivers/uio/uio.c          |  702 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/uio_driver.h |   91 ++++++
 6 files changed, 810 insertions(+), 0 deletions(-)
 create mode 100644 drivers/uio/Kconfig
 create mode 100644 drivers/uio/Makefile
 create mode 100644 drivers/uio/uio.c
 create mode 100644 include/linux/uio_driver.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 050323f..325a108 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -84,4 +84,5 @@ source "drivers/auxdisplay/Kconfig"
 
 source "drivers/kvm/Kconfig"
 
+source "drivers/uio/Kconfig"
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 920c975..5cf267f 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_SCSI)		+= scsi/
 obj-$(CONFIG_ATA)		+= ata/
 obj-$(CONFIG_FUSION)		+= message/
 obj-$(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..8fcef21
--- /dev/null
+++ b/drivers/uio/Kconfig
@@ -0,0 +1,14 @@
+menu "Userspace I/O"
+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..6ca3379
--- /dev/null
+++ b/drivers/uio/uio.c
@@ -0,0 +1,702 @@
+/*
+ * 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;
+			idev->map_attr_kset.subsys = &uio_class->class->subsys;
+			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
+ * @idev: UIO device where the event occured
+ */
+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;
+	int 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;
+	int event_count;
+
+	if (idev->info->irq == UIO_IRQ_NONE)
+		return -EIO;
+
+	if (count != sizeof(int))
+		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
+ *
+ * @parent:	parent device
+ * @idev:	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;
+
+	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;
+	}
+
+	info->uio_dev = idev;
+	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
+ * @uiodev:	UIO device driver identifier
+ *
+ * returns 0 on success
+ */
+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..13d9f90
--- /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>
+
+/**
+ * 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;
+
+/**
+ * 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_ */
-- 
1.5.1.2