[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / uio / uio.c

/*
 * 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 kobject		*map_dir;
};

static int uio_major;
static DEFINE_IDR(uio_idr);
static const struct file_operations uio_fops;

/* UIO class infrastructure */
static struct uio_class {
	struct kref kref;
	struct class *class;
} *uio_class;

/*
 * attributes
 */

struct uio_map {
	struct kobject kobj;
	struct uio_mem *mem;
};
#define to_map(map) container_of(map, struct uio_map, kobj)

static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
{
	return sprintf(buf, "0x%lx\n", mem->addr);
}

static ssize_t map_size_show(struct uio_mem *mem, char *buf)
{
	return sprintf(buf, "0x%lx\n", mem->size);
}

struct uio_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct uio_mem *, char *);
	ssize_t (*store)(struct uio_mem *, const char *, size_t);
};

static struct uio_sysfs_entry addr_attribute =
	__ATTR(addr, S_IRUGO, map_addr_show, NULL);
static struct uio_sysfs_entry size_attribute =
	__ATTR(size, S_IRUGO, map_size_show, NULL);

static struct attribute *attrs[] = {
	&addr_attribute.attr,
	&size_attribute.attr,
	NULL,	/* need to NULL terminate the list of attributes */
};

static void map_release(struct kobject *kobj)
{
	struct uio_map *map = to_map(kobj);
	kfree(map);
}

static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
			     char *buf)
{
	struct uio_map *map = to_map(kobj);
	struct uio_mem *mem = map->mem;
	struct uio_sysfs_entry *entry;

	entry = container_of(attr, struct uio_sysfs_entry, attr);

	if (!entry->show)
		return -EIO;

	return entry->show(mem, buf);
}

static struct sysfs_ops uio_sysfs_ops = {
	.show = map_type_show,
};

static struct kobj_type map_attr_type = {
	.release	= map_release,
	.sysfs_ops	= &uio_sysfs_ops,
	.default_attrs	= 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;
	struct uio_map *map;

	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;
			idev->map_dir = kobject_create_and_add("maps",
							&idev->dev->kobj);
			if (!idev->map_dir)
				goto err;
		}
		map = kzalloc(sizeof(*map), GFP_KERNEL);
		if (!map)
			goto err;
		kobject_init(&map->kobj, &map_attr_type);
		map->mem = mem;
		mem->map = map;
		ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
		if (ret)
			goto err;
		ret = kobject_uevent(&map->kobj, KOBJ_ADD);
		if (ret)
			goto err;
	}

	return 0;

err:
	for (mi--; mi>=0; mi--) {
		mem = &idev->info->mem[mi];
		map = mem->map;
		kobject_put(&map->kobj);
	}
	kobject_put(idev->map_dir);
	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_put(&mem->map->kobj);
	}
	kobject_put(idev->map_dir);
	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 int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct uio_device *idev = vma->vm_private_data;
	struct page *page;

	int mi = uio_find_mem_index(vma);
	if (mi < 0)
		return VM_FAULT_SIGBUS;

	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);
	vmf->page = page;
	return 0;
}

static struct vm_operations_struct uio_vm_ops = {
	.open = uio_vma_open,
	.close = uio_vma_close,
	.fault = uio_vma_fault,
};

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 const 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");
Commit	Line	Data
beafc54c HK	1	/*
	2	* drivers/uio/uio.c
	3	*
	4	* Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
	5	* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
	6	* Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
	7	* Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
	8	*
	9	* Userspace IO
	10	*
	11	* Base Functions
	12	*
	13	* Licensed under the GPLv2 only.
	14	*/
	15
	16	#include <linux/module.h>
	17	#include <linux/init.h>
	18	#include <linux/poll.h>
	19	#include <linux/device.h>
	20	#include <linux/mm.h>
	21	#include <linux/idr.h>
	22	#include <linux/string.h>
	23	#include <linux/kobject.h>
	24	#include <linux/uio_driver.h>
	25
	26	#define UIO_MAX_DEVICES 255
	27
	28	struct uio_device {
	29	struct module *owner;
	30	struct device *dev;
	31	int minor;
	32	atomic_t event;
	33	struct fasync_struct *async_queue;
	34	wait_queue_head_t wait;
	35	int vma_count;
	36	struct uio_info *info;
81e7c6a6	37	struct kobject *map_dir;
beafc54c HK	38	};
	39
	40	static int uio_major;
	41	static DEFINE_IDR(uio_idr);
4f014691	42	static const struct file_operations uio_fops;
beafc54c HK	43
	44	/* UIO class infrastructure */
	45	static struct uio_class {
	46	struct kref kref;
	47	struct class *class;
	48	} *uio_class;
	49
	50	/*
	51	* attributes
	52	*/
	53
81e7c6a6 GKH	54	struct uio_map {
	55	struct kobject kobj;
	56	struct uio_mem *mem;
beafc54c	57	};
81e7c6a6	58	#define to_map(map) container_of(map, struct uio_map, kobj)
beafc54c	59
4f808bcd	60	static ssize_t map_addr_show(struct uio_mem mem, char buf)
beafc54c	61	{
4f808bcd BP	62	return sprintf(buf, "0x%lx\n", mem->addr);
4f808bcd BP	63	}
beafc54c	64
4f808bcd BP	65	static ssize_t map_size_show(struct uio_mem mem, char buf)
	66	{
	67	return sprintf(buf, "0x%lx\n", mem->size);
beafc54c HK	68	}
beafc54c HK	69
4f808bcd BP	70	struct uio_sysfs_entry {
	71	struct attribute attr;
	72	ssize_t (show)(struct uio_mem , char *);
	73	ssize_t (store)(struct uio_mem , const char *, size_t);
	74	};
	75
	76	static struct uio_sysfs_entry addr_attribute =
	77	__ATTR(addr, S_IRUGO, map_addr_show, NULL);
	78	static struct uio_sysfs_entry size_attribute =
	79	__ATTR(size, S_IRUGO, map_size_show, NULL);
beafc54c	80
81e7c6a6	81	static struct attribute *attrs[] = {
4f808bcd	82	&addr_attribute.attr,
81e7c6a6 GKH	83	&size_attribute.attr,
81e7c6a6 GKH	84	NULL, /* need to NULL terminate the list of attributes */
beafc54c HK	85	};
beafc54c HK	86
81e7c6a6 GKH	87	static void map_release(struct kobject *kobj)
	88	{
	89	struct uio_map *map = to_map(kobj);
	90	kfree(map);
	91	}
	92
4f808bcd BP	93	static ssize_t map_type_show(struct kobject kobj, struct attribute attr,
	94	char *buf)
	95	{
	96	struct uio_map *map = to_map(kobj);
	97	struct uio_mem *mem = map->mem;
	98	struct uio_sysfs_entry *entry;
	99
	100	entry = container_of(attr, struct uio_sysfs_entry, attr);
	101
	102	if (!entry->show)
	103	return -EIO;
	104
	105	return entry->show(mem, buf);
	106	}
	107
	108	static struct sysfs_ops uio_sysfs_ops = {
	109	.show = map_type_show,
	110	};
	111
beafc54c	112	static struct kobj_type map_attr_type = {
81e7c6a6	113	.release = map_release,
4f808bcd	114	.sysfs_ops = &uio_sysfs_ops,
81e7c6a6	115	.default_attrs = attrs,
beafc54c HK	116	};
	117
	118	static ssize_t show_name(struct device *dev,
	119	struct device_attribute attr, char buf)
	120	{
	121	struct uio_device *idev = dev_get_drvdata(dev);
	122	if (idev)
	123	return sprintf(buf, "%s\n", idev->info->name);
	124	else
	125	return -ENODEV;
	126	}
	127	static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
	128
	129	static ssize_t show_version(struct device *dev,
	130	struct device_attribute attr, char buf)
	131	{
	132	struct uio_device *idev = dev_get_drvdata(dev);
	133	if (idev)
	134	return sprintf(buf, "%s\n", idev->info->version);
	135	else
	136	return -ENODEV;
	137	}
	138	static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
	139
	140	static ssize_t show_event(struct device *dev,
	141	struct device_attribute attr, char buf)
	142	{
	143	struct uio_device *idev = dev_get_drvdata(dev);
	144	if (idev)
	145	return sprintf(buf, "%u\n",
	146	(unsigned int)atomic_read(&idev->event));
	147	else
	148	return -ENODEV;
	149	}
	150	static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
	151
	152	static struct attribute *uio_attrs[] = {
	153	&dev_attr_name.attr,
	154	&dev_attr_version.attr,
	155	&dev_attr_event.attr,
	156	NULL,
	157	};
	158
	159	static struct attribute_group uio_attr_grp = {
	160	.attrs = uio_attrs,
	161	};
	162
	163	/*
	164	* device functions
	165	*/
	166	static int uio_dev_add_attributes(struct uio_device *idev)
	167	{
	168	int ret;
	169	int mi;
	170	int map_found = 0;
	171	struct uio_mem *mem;
81e7c6a6	172	struct uio_map *map;
beafc54c HK	173
	174	ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
	175	if (ret)
	176	goto err_group;
	177
	178	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
	179	mem = &idev->info->mem[mi];
	180	if (mem->size == 0)
	181	break;
	182	if (!map_found) {
	183	map_found = 1;
81e7c6a6 GKH	184	idev->map_dir = kobject_create_and_add("maps",
	185	&idev->dev->kobj);
	186	if (!idev->map_dir)
	187	goto err;
beafc54c	188	}
81e7c6a6 GKH	189	map = kzalloc(sizeof(*map), GFP_KERNEL);
	190	if (!map)
	191	goto err;
f9cb074b	192	kobject_init(&map->kobj, &map_attr_type);
81e7c6a6 GKH	193	map->mem = mem;
81e7c6a6 GKH	194	mem->map = map;
b2d6db58	195	ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
81e7c6a6 GKH	196	if (ret)
	197	goto err;
	198	ret = kobject_uevent(&map->kobj, KOBJ_ADD);
beafc54c	199	if (ret)
81e7c6a6	200	goto err;
beafc54c HK	201	}
	202
	203	return 0;
	204
81e7c6a6	205	err:
beafc54c HK	206	for (mi--; mi>=0; mi--) {
beafc54c HK	207	mem = &idev->info->mem[mi];
81e7c6a6	208	map = mem->map;
c10997f6	209	kobject_put(&map->kobj);
beafc54c	210	}
c10997f6	211	kobject_put(idev->map_dir);
beafc54c HK	212	sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
	213	err_group:
	214	dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
	215	return ret;
	216	}
	217
	218	static void uio_dev_del_attributes(struct uio_device *idev)
	219	{
	220	int mi;
	221	struct uio_mem *mem;
	222	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
	223	mem = &idev->info->mem[mi];
	224	if (mem->size == 0)
	225	break;
c10997f6	226	kobject_put(&mem->map->kobj);
beafc54c	227	}
c10997f6	228	kobject_put(idev->map_dir);
beafc54c HK	229	sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
	230	}
	231
	232	static int uio_get_minor(struct uio_device *idev)
	233	{
	234	static DEFINE_MUTEX(minor_lock);
	235	int retval = -ENOMEM;
	236	int id;
	237
	238	mutex_lock(&minor_lock);
	239	if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
	240	goto exit;
	241
	242	retval = idr_get_new(&uio_idr, idev, &id);
	243	if (retval < 0) {
	244	if (retval == -EAGAIN)
	245	retval = -ENOMEM;
	246	goto exit;
	247	}
	248	idev->minor = id & MAX_ID_MASK;
	249	exit:
	250	mutex_unlock(&minor_lock);
	251	return retval;
	252	}
	253
	254	static void uio_free_minor(struct uio_device *idev)
	255	{
	256	idr_remove(&uio_idr, idev->minor);
	257	}
	258
	259	/**
	260	* uio_event_notify - trigger an interrupt event
	261	* @info: UIO device capabilities
	262	*/
	263	void uio_event_notify(struct uio_info *info)
	264	{
	265	struct uio_device *idev = info->uio_dev;
	266
	267	atomic_inc(&idev->event);
	268	wake_up_interruptible(&idev->wait);
	269	kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
	270	}
	271	EXPORT_SYMBOL_GPL(uio_event_notify);
	272
	273	/**
	274	* uio_interrupt - hardware interrupt handler
	275	* @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
	276	* @dev_id: Pointer to the devices uio_device structure
	277	*/
	278	static irqreturn_t uio_interrupt(int irq, void *dev_id)
	279	{
	280	struct uio_device idev = (struct uio_device )dev_id;
	281	irqreturn_t ret = idev->info->handler(irq, idev->info);
	282
	283	if (ret == IRQ_HANDLED)
	284	uio_event_notify(idev->info);
	285
	286	return ret;
	287	}
	288
	289	struct uio_listener {
	290	struct uio_device *dev;
	291	s32 event_count;
	292	};
293
294	static int uio_open(struct inode inode, struct file filep)
295	{
296	struct uio_device *idev;
297	struct uio_listener *listener;
298	int ret = 0;
299
300	idev = idr_find(&uio_idr, iminor(inode));
301	if (!idev)
302	return -ENODEV;
303
304	listener = kmalloc(sizeof(*listener), GFP_KERNEL);
305	if (!listener)
306	return -ENOMEM;
307
308	listener->dev = idev;
309	listener->event_count = atomic_read(&idev->event);
310	filep->private_data = listener;
311
312	if (idev->info->open) {
313	if (!try_module_get(idev->owner))
314	return -ENODEV;
315	ret = idev->info->open(idev->info, inode);
316	module_put(idev->owner);
317	}
318
319	if (ret)
320	kfree(listener);
321
322	return ret;
323	}
324
325	static int uio_fasync(int fd, struct file *filep, int on)
326	{
327	struct uio_listener *listener = filep->private_data;
328	struct uio_device *idev = listener->dev;
329
330	return fasync_helper(fd, filep, on, &idev->async_queue);
331	}
332
333	static int uio_release(struct inode inode, struct file filep)
334	{
335	int ret = 0;
336	struct uio_listener *listener = filep->private_data;
337	struct uio_device *idev = listener->dev;
338
339	if (idev->info->release) {
340	if (!try_module_get(idev->owner))
341	return -ENODEV;
342	ret = idev->info->release(idev->info, inode);
343	module_put(idev->owner);
344	}
345	if (filep->f_flags & FASYNC)
346	ret = uio_fasync(-1, filep, 0);
347	kfree(listener);
348	return ret;
349	}
350
351	static unsigned int uio_poll(struct file filep, poll_table wait)
352	{
353	struct uio_listener *listener = filep->private_data;
354	struct uio_device *idev = listener->dev;
355
356	if (idev->info->irq == UIO_IRQ_NONE)
357	return -EIO;
358
359	poll_wait(filep, &idev->wait, wait);
360	if (listener->event_count != atomic_read(&idev->event))
361	return POLLIN \| POLLRDNORM;
362	return 0;
363	}
364
365	static ssize_t uio_read(struct file filep, char __user buf,
366	size_t count, loff_t *ppos)
367	{
368	struct uio_listener *listener = filep->private_data;
369	struct uio_device *idev = listener->dev;
370	DECLARE_WAITQUEUE(wait, current);
371	ssize_t retval;
372	s32 event_count;
373
374	if (idev->info->irq == UIO_IRQ_NONE)
375	return -EIO;
376
377	if (count != sizeof(s32))
378	return -EINVAL;
379
380	add_wait_queue(&idev->wait, &wait);
381
382	do {
383	set_current_state(TASK_INTERRUPTIBLE);
384
385	event_count = atomic_read(&idev->event);
386	if (event_count != listener->event_count) {
387	if (copy_to_user(buf, &event_count, count))
388	retval = -EFAULT;
389	else {
390	listener->event_count = event_count;
391	retval = count;
392	}
393	break;
394	}
395
396	if (filep->f_flags & O_NONBLOCK) {
397	retval = -EAGAIN;
398	break;
399	}
400
401	if (signal_pending(current)) {
402	retval = -ERESTARTSYS;
403	break;
404	}
405	schedule();
406	} while (1);
407
408	__set_current_state(TASK_RUNNING);
409	remove_wait_queue(&idev->wait, &wait);
410
411	return retval;
412	}
413
414	static int uio_find_mem_index(struct vm_area_struct *vma)
415	{
416	int mi;
417	struct uio_device *idev = vma->vm_private_data;
418
419	for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
420	if (idev->info->mem[mi].size == 0)
421	return -1;
422	if (vma->vm_pgoff == mi)
423	return mi;
424	}
425	return -1;
426	}
427
428	static void uio_vma_open(struct vm_area_struct *vma)
429	{
430	struct uio_device *idev = vma->vm_private_data;
431	idev->vma_count++;
432	}
433
434	static void uio_vma_close(struct vm_area_struct *vma)
435	{
436	struct uio_device *idev = vma->vm_private_data;
437	idev->vma_count--;
438	}
439
a18b630d	440	static int uio_vma_fault(struct vm_area_struct vma, struct vm_fault vmf)
beafc54c HK	441	{
beafc54c HK	442	struct uio_device *idev = vma->vm_private_data;
a18b630d	443	struct page *page;
beafc54c HK	444
	445	int mi = uio_find_mem_index(vma);
	446	if (mi < 0)
a18b630d	447	return VM_FAULT_SIGBUS;
beafc54c HK	448
	449	if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
	450	page = virt_to_page(idev->info->mem[mi].addr);
	451	else
	452	page = vmalloc_to_page((void*)idev->info->mem[mi].addr);
	453	get_page(page);
a18b630d NP	454	vmf->page = page;
a18b630d NP	455	return 0;
beafc54c HK	456	}
	457
	458	static struct vm_operations_struct uio_vm_ops = {
	459	.open = uio_vma_open,
	460	.close = uio_vma_close,
a18b630d	461	.fault = uio_vma_fault,
beafc54c HK	462	};
	463
	464	static int uio_mmap_physical(struct vm_area_struct *vma)
	465	{
	466	struct uio_device *idev = vma->vm_private_data;
	467	int mi = uio_find_mem_index(vma);
	468	if (mi < 0)
	469	return -EINVAL;
	470
	471	vma->vm_flags \|= VM_IO \| VM_RESERVED;
	472
	473	return remap_pfn_range(vma,
	474	vma->vm_start,
	475	idev->info->mem[mi].addr >> PAGE_SHIFT,
	476	vma->vm_end - vma->vm_start,
	477	vma->vm_page_prot);
	478	}
	479
	480	static int uio_mmap_logical(struct vm_area_struct *vma)
	481	{
	482	vma->vm_flags \|= VM_RESERVED;
	483	vma->vm_ops = &uio_vm_ops;
	484	uio_vma_open(vma);
	485	return 0;
	486	}
	487
	488	static int uio_mmap(struct file filep, struct vm_area_struct vma)
	489	{
	490	struct uio_listener *listener = filep->private_data;
	491	struct uio_device *idev = listener->dev;
	492	int mi;
	493	unsigned long requested_pages, actual_pages;
	494	int ret = 0;
	495
	496	if (vma->vm_end < vma->vm_start)
	497	return -EINVAL;
	498
	499	vma->vm_private_data = idev;
	500
	501	mi = uio_find_mem_index(vma);
	502	if (mi < 0)
	503	return -EINVAL;
	504
	505	requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
	506	actual_pages = (idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
	507	if (requested_pages > actual_pages)
	508	return -EINVAL;
	509
	510	if (idev->info->mmap) {
	511	if (!try_module_get(idev->owner))
	512	return -ENODEV;
	513	ret = idev->info->mmap(idev->info, vma);
	514	module_put(idev->owner);
	515	return ret;
	516	}
	517
	518	switch (idev->info->mem[mi].memtype) {
	519	case UIO_MEM_PHYS:
	520	return uio_mmap_physical(vma);
	521	case UIO_MEM_LOGICAL:
	522	case UIO_MEM_VIRTUAL:
	523	return uio_mmap_logical(vma);
	524	default:
	525	return -EINVAL;
526	}
527	}
528
4f014691	529	static const struct file_operations uio_fops = {
beafc54c HK	530	.owner = THIS_MODULE,
	531	.open = uio_open,
	532	.release = uio_release,
	533	.read = uio_read,
	534	.mmap = uio_mmap,
	535	.poll = uio_poll,
	536	.fasync = uio_fasync,
	537	};
	538
	539	static int uio_major_init(void)
	540	{
	541	uio_major = register_chrdev(0, "uio", &uio_fops);
	542	if (uio_major < 0)
	543	return uio_major;
	544	return 0;
	545	}
	546
	547	static void uio_major_cleanup(void)
	548	{
	549	unregister_chrdev(uio_major, "uio");
	550	}
	551
	552	static int init_uio_class(void)
	553	{
	554	int ret = 0;
	555
	556	if (uio_class != NULL) {
	557	kref_get(&uio_class->kref);
	558	goto exit;
	559	}
	560
	561	/* This is the first time in here, set everything up properly */
	562	ret = uio_major_init();
	563	if (ret)
	564	goto exit;
	565
	566	uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
	567	if (!uio_class) {
	568	ret = -ENOMEM;
	569	goto err_kzalloc;
	570	}
	571
	572	kref_init(&uio_class->kref);
	573	uio_class->class = class_create(THIS_MODULE, "uio");
	574	if (IS_ERR(uio_class->class)) {
	575	ret = IS_ERR(uio_class->class);
	576	printk(KERN_ERR "class_create failed for uio\n");
	577	goto err_class_create;
	578	}
	579	return 0;
	580
	581	err_class_create:
	582	kfree(uio_class);
	583	uio_class = NULL;
	584	err_kzalloc:
	585	uio_major_cleanup();
	586	exit:
	587	return ret;
	588	}
	589
	590	static void release_uio_class(struct kref *kref)
	591	{
	592	/* Ok, we cheat as we know we only have one uio_class */
	593	class_destroy(uio_class->class);
594	kfree(uio_class);
595	uio_major_cleanup();
596	uio_class = NULL;
597	}
598
599	static void uio_class_destroy(void)
600	{
601	if (uio_class)
602	kref_put(&uio_class->kref, release_uio_class);
603	}
604
605	/**
606	* uio_register_device - register a new userspace IO device
607	* @owner: module that creates the new device
608	* @parent: parent device
609	* @info: UIO device capabilities
610	*
611	* returns zero on success or a negative error code.
612	*/
613	int __uio_register_device(struct module *owner,
614	struct device *parent,
615	struct uio_info *info)
616	{
617	struct uio_device *idev;
618	int ret = 0;
619
620	if (!parent \|\| !info \|\| !info->name \|\| !info->version)
621	return -EINVAL;
622
623	info->uio_dev = NULL;
624
625	ret = init_uio_class();
626	if (ret)
627	return ret;
628
629	idev = kzalloc(sizeof(*idev), GFP_KERNEL);
630	if (!idev) {
631	ret = -ENOMEM;
632	goto err_kzalloc;
633	}
634
635	idev->owner = owner;
636	idev->info = info;
637	init_waitqueue_head(&idev->wait);
638	atomic_set(&idev->event, 0);
639
640	ret = uio_get_minor(idev);
641	if (ret)
642	goto err_get_minor;
643
644	idev->dev = device_create(uio_class->class, parent,
645	MKDEV(uio_major, idev->minor),
646	"uio%d", idev->minor);
647	if (IS_ERR(idev->dev)) {
648	printk(KERN_ERR "UIO: device register failed\n");
649	ret = PTR_ERR(idev->dev);
650	goto err_device_create;
651	}
652	dev_set_drvdata(idev->dev, idev);
653
654	ret = uio_dev_add_attributes(idev);
655	if (ret)
656	goto err_uio_dev_add_attributes;
657
658	info->uio_dev = idev;
659
660	if (idev->info->irq >= 0) {
661	ret = request_irq(idev->info->irq, uio_interrupt,
662	idev->info->irq_flags, idev->info->name, idev);
663	if (ret)
664	goto err_request_irq;
665	}
666
667	return 0;
668
669	err_request_irq:
670	uio_dev_del_attributes(idev);
671	err_uio_dev_add_attributes:
672	device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
673	err_device_create:
674	uio_free_minor(idev);
675	err_get_minor:
676	kfree(idev);
677	err_kzalloc:
678	uio_class_destroy();
679	return ret;
680	}
681	EXPORT_SYMBOL_GPL(__uio_register_device);
682
683	/**
684	* uio_unregister_device - unregister a industrial IO device
685	* @info: UIO device capabilities
686	*
687	*/
688	void uio_unregister_device(struct uio_info *info)
689	{
690	struct uio_device *idev;
691
692	if (!info \|\| !info->uio_dev)
693	return;
694
695	idev = info->uio_dev;
696
697	uio_free_minor(idev);
698
699	if (info->irq >= 0)
700	free_irq(info->irq, idev);
701
702	uio_dev_del_attributes(idev);
703
704	dev_set_drvdata(idev->dev, NULL);
705	device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
706	kfree(idev);
707	uio_class_destroy();
708
709	return;
710	}
711	EXPORT_SYMBOL_GPL(uio_unregister_device);
712
713	static int __init uio_init(void)
714	{
715	return 0;
716	}
717
718	static void __exit uio_exit(void)
719	{
720	}
721
722	module_init(uio_init)
723	module_exit(uio_exit)
724	MODULE_LICENSE("GPL v2");