diff options
Diffstat (limited to 'drivers/uio/uio.c')
| -rw-r--r-- | drivers/uio/uio.c | 701 |
1 files changed, 701 insertions, 0 deletions
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c new file mode 100644 index 000000000000..865f32b63b5c --- /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"); |