diff options
Diffstat (limited to 'drivers/media/media-devnode.c')
| -rw-r--r-- | drivers/media/media-devnode.c | 334 |
1 files changed, 0 insertions, 334 deletions
diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c deleted file mode 100644 index 6b87a721dc49..000000000000 --- a/drivers/media/media-devnode.c +++ /dev/null @@ -1,334 +0,0 @@ -/* - * Media device node - * - * Copyright (C) 2010 Nokia Corporation - * - * Based on drivers/media/video/v4l2_dev.c code authored by - * Mauro Carvalho Chehab <mchehab@kernel.org> (version 2) - * Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1) - * - * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> - * Sakari Ailus <sakari.ailus@iki.fi> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * -- - * - * Generic media device node infrastructure to register and unregister - * character devices using a dynamic major number and proper reference - * counting. - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <linux/errno.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/kernel.h> -#include <linux/kmod.h> -#include <linux/slab.h> -#include <linux/mm.h> -#include <linux/string.h> -#include <linux/types.h> -#include <linux/uaccess.h> - -#include <media/media-devnode.h> -#include <media/media-device.h> - -#define MEDIA_NUM_DEVICES 256 -#define MEDIA_NAME "media" - -static dev_t media_dev_t; - -/* - * Active devices - */ -static DEFINE_MUTEX(media_devnode_lock); -static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES); - -/* Called when the last user of the media device exits. */ -static void media_devnode_release(struct device *cd) -{ - struct media_devnode *devnode = to_media_devnode(cd); - - mutex_lock(&media_devnode_lock); - /* Mark device node number as free */ - clear_bit(devnode->minor, media_devnode_nums); - mutex_unlock(&media_devnode_lock); - - /* Release media_devnode and perform other cleanups as needed. */ - if (devnode->release) - devnode->release(devnode); - - kfree(devnode); - pr_debug("%s: Media Devnode Deallocated\n", __func__); -} - -static struct bus_type media_bus_type = { - .name = MEDIA_NAME, -}; - -static ssize_t media_read(struct file *filp, char __user *buf, - size_t sz, loff_t *off) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - if (!devnode->fops->read) - return -EINVAL; - if (!media_devnode_is_registered(devnode)) - return -EIO; - return devnode->fops->read(filp, buf, sz, off); -} - -static ssize_t media_write(struct file *filp, const char __user *buf, - size_t sz, loff_t *off) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - if (!devnode->fops->write) - return -EINVAL; - if (!media_devnode_is_registered(devnode)) - return -EIO; - return devnode->fops->write(filp, buf, sz, off); -} - -static __poll_t media_poll(struct file *filp, - struct poll_table_struct *poll) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - if (!media_devnode_is_registered(devnode)) - return EPOLLERR | EPOLLHUP; - if (!devnode->fops->poll) - return DEFAULT_POLLMASK; - return devnode->fops->poll(filp, poll); -} - -static long -__media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg, - long (*ioctl_func)(struct file *filp, unsigned int cmd, - unsigned long arg)) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - if (!ioctl_func) - return -ENOTTY; - - if (!media_devnode_is_registered(devnode)) - return -EIO; - - return ioctl_func(filp, cmd, arg); -} - -static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - return __media_ioctl(filp, cmd, arg, devnode->fops->ioctl); -} - -#ifdef CONFIG_COMPAT - -static long media_compat_ioctl(struct file *filp, unsigned int cmd, - unsigned long arg) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - return __media_ioctl(filp, cmd, arg, devnode->fops->compat_ioctl); -} - -#endif /* CONFIG_COMPAT */ - -/* Override for the open function */ -static int media_open(struct inode *inode, struct file *filp) -{ - struct media_devnode *devnode; - int ret; - - /* Check if the media device is available. This needs to be done with - * the media_devnode_lock held to prevent an open/unregister race: - * without the lock, the device could be unregistered and freed between - * the media_devnode_is_registered() and get_device() calls, leading to - * a crash. - */ - mutex_lock(&media_devnode_lock); - devnode = container_of(inode->i_cdev, struct media_devnode, cdev); - /* return ENXIO if the media device has been removed - already or if it is not registered anymore. */ - if (!media_devnode_is_registered(devnode)) { - mutex_unlock(&media_devnode_lock); - return -ENXIO; - } - /* and increase the device refcount */ - get_device(&devnode->dev); - mutex_unlock(&media_devnode_lock); - - filp->private_data = devnode; - - if (devnode->fops->open) { - ret = devnode->fops->open(filp); - if (ret) { - put_device(&devnode->dev); - filp->private_data = NULL; - return ret; - } - } - - return 0; -} - -/* Override for the release function */ -static int media_release(struct inode *inode, struct file *filp) -{ - struct media_devnode *devnode = media_devnode_data(filp); - - if (devnode->fops->release) - devnode->fops->release(filp); - - filp->private_data = NULL; - - /* decrease the refcount unconditionally since the release() - return value is ignored. */ - put_device(&devnode->dev); - - pr_debug("%s: Media Release\n", __func__); - return 0; -} - -static const struct file_operations media_devnode_fops = { - .owner = THIS_MODULE, - .read = media_read, - .write = media_write, - .open = media_open, - .unlocked_ioctl = media_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = media_compat_ioctl, -#endif /* CONFIG_COMPAT */ - .release = media_release, - .poll = media_poll, - .llseek = no_llseek, -}; - -int __must_check media_devnode_register(struct media_device *mdev, - struct media_devnode *devnode, - struct module *owner) -{ - int minor; - int ret; - - /* Part 1: Find a free minor number */ - mutex_lock(&media_devnode_lock); - minor = find_next_zero_bit(media_devnode_nums, MEDIA_NUM_DEVICES, 0); - if (minor == MEDIA_NUM_DEVICES) { - mutex_unlock(&media_devnode_lock); - pr_err("could not get a free minor\n"); - kfree(devnode); - return -ENFILE; - } - - set_bit(minor, media_devnode_nums); - mutex_unlock(&media_devnode_lock); - - devnode->minor = minor; - devnode->media_dev = mdev; - - /* Part 1: Initialize dev now to use dev.kobj for cdev.kobj.parent */ - devnode->dev.bus = &media_bus_type; - devnode->dev.devt = MKDEV(MAJOR(media_dev_t), devnode->minor); - devnode->dev.release = media_devnode_release; - if (devnode->parent) - devnode->dev.parent = devnode->parent; - dev_set_name(&devnode->dev, "media%d", devnode->minor); - device_initialize(&devnode->dev); - - /* Part 2: Initialize the character device */ - cdev_init(&devnode->cdev, &media_devnode_fops); - devnode->cdev.owner = owner; - - /* Part 3: Add the media and char device */ - ret = cdev_device_add(&devnode->cdev, &devnode->dev); - if (ret < 0) { - pr_err("%s: cdev_device_add failed\n", __func__); - goto cdev_add_error; - } - - /* Part 4: Activate this minor. The char device can now be used. */ - set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); - - return 0; - -cdev_add_error: - mutex_lock(&media_devnode_lock); - clear_bit(devnode->minor, media_devnode_nums); - devnode->media_dev = NULL; - mutex_unlock(&media_devnode_lock); - - put_device(&devnode->dev); - return ret; -} - -void media_devnode_unregister_prepare(struct media_devnode *devnode) -{ - /* Check if devnode was ever registered at all */ - if (!media_devnode_is_registered(devnode)) - return; - - mutex_lock(&media_devnode_lock); - clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); - mutex_unlock(&media_devnode_lock); -} - -void media_devnode_unregister(struct media_devnode *devnode) -{ - mutex_lock(&media_devnode_lock); - /* Delete the cdev on this minor as well */ - cdev_device_del(&devnode->cdev, &devnode->dev); - mutex_unlock(&media_devnode_lock); - devnode->media_dev = NULL; - put_device(&devnode->dev); -} - -/* - * Initialise media for linux - */ -static int __init media_devnode_init(void) -{ - int ret; - - pr_info("Linux media interface: v0.10\n"); - ret = alloc_chrdev_region(&media_dev_t, 0, MEDIA_NUM_DEVICES, - MEDIA_NAME); - if (ret < 0) { - pr_warn("unable to allocate major\n"); - return ret; - } - - ret = bus_register(&media_bus_type); - if (ret < 0) { - unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES); - pr_warn("bus_register failed\n"); - return -EIO; - } - - return 0; -} - -static void __exit media_devnode_exit(void) -{ - bus_unregister(&media_bus_type); - unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES); -} - -subsys_initcall(media_devnode_init); -module_exit(media_devnode_exit) - -MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); -MODULE_DESCRIPTION("Device node registration for media drivers"); -MODULE_LICENSE("GPL"); |