From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/media/media-devnode.c | 346 +++++++++++++++++++++++++++++++++++ 1 file changed, 346 insertions(+) create mode 100644 kernel/drivers/media/media-devnode.c (limited to 'kernel/drivers/media/media-devnode.c') diff --git a/kernel/drivers/media/media-devnode.c b/kernel/drivers/media/media-devnode.c new file mode 100644 index 000000000..ebf9626e5 --- /dev/null +++ b/kernel/drivers/media/media-devnode.c @@ -0,0 +1,346 @@ +/* + * Media device node + * + * Copyright (C) 2010 Nokia Corporation + * + * Based on drivers/media/video/v4l2_dev.c code authored by + * Mauro Carvalho Chehab (version 2) + * Alan Cox, (version 1) + * + * Contacts: Laurent Pinchart + * Sakari Ailus + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * -- + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#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 *mdev = to_media_devnode(cd); + + mutex_lock(&media_devnode_lock); + + /* Delete the cdev on this minor as well */ + cdev_del(&mdev->cdev); + + /* Mark device node number as free */ + clear_bit(mdev->minor, media_devnode_nums); + + mutex_unlock(&media_devnode_lock); + + /* Release media_devnode and perform other cleanups as needed. */ + if (mdev->release) + mdev->release(mdev); +} + +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 *mdev = media_devnode_data(filp); + + if (!mdev->fops->read) + return -EINVAL; + if (!media_devnode_is_registered(mdev)) + return -EIO; + return mdev->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 *mdev = media_devnode_data(filp); + + if (!mdev->fops->write) + return -EINVAL; + if (!media_devnode_is_registered(mdev)) + return -EIO; + return mdev->fops->write(filp, buf, sz, off); +} + +static unsigned int media_poll(struct file *filp, + struct poll_table_struct *poll) +{ + struct media_devnode *mdev = media_devnode_data(filp); + + if (!media_devnode_is_registered(mdev)) + return POLLERR | POLLHUP; + if (!mdev->fops->poll) + return DEFAULT_POLLMASK; + return mdev->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 *mdev = media_devnode_data(filp); + + if (!ioctl_func) + return -ENOTTY; + + if (!media_devnode_is_registered(mdev)) + return -EIO; + + return ioctl_func(filp, cmd, arg); +} + +static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct media_devnode *mdev = media_devnode_data(filp); + + return __media_ioctl(filp, cmd, arg, mdev->fops->ioctl); +} + +#ifdef CONFIG_COMPAT + +static long media_compat_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct media_devnode *mdev = media_devnode_data(filp); + + return __media_ioctl(filp, cmd, arg, mdev->fops->compat_ioctl); +} + +#endif /* CONFIG_COMPAT */ + +/* Override for the open function */ +static int media_open(struct inode *inode, struct file *filp) +{ + struct media_devnode *mdev; + 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); + mdev = 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(mdev)) { + mutex_unlock(&media_devnode_lock); + return -ENXIO; + } + /* and increase the device refcount */ + get_device(&mdev->dev); + mutex_unlock(&media_devnode_lock); + + filp->private_data = mdev; + + if (mdev->fops->open) { + ret = mdev->fops->open(filp); + if (ret) { + put_device(&mdev->dev); + return ret; + } + } + + return 0; +} + +/* Override for the release function */ +static int media_release(struct inode *inode, struct file *filp) +{ + struct media_devnode *mdev = media_devnode_data(filp); + + if (mdev->fops->release) + mdev->fops->release(filp); + + /* decrease the refcount unconditionally since the release() + return value is ignored. */ + put_device(&mdev->dev); + filp->private_data = NULL; + 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, +}; + +/** + * media_devnode_register - register a media device node + * @mdev: media device node structure we want to register + * + * The registration code assigns minor numbers and registers the new device node + * with the kernel. An error is returned if no free minor number can be found, + * or if the registration of the device node fails. + * + * Zero is returned on success. + * + * Note that if the media_devnode_register call fails, the release() callback of + * the media_devnode structure is *not* called, so the caller is responsible for + * freeing any data. + */ +int __must_check media_devnode_register(struct media_devnode *mdev, + 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"); + return -ENFILE; + } + + set_bit(minor, media_devnode_nums); + mutex_unlock(&media_devnode_lock); + + mdev->minor = minor; + + /* Part 2: Initialize and register the character device */ + cdev_init(&mdev->cdev, &media_devnode_fops); + mdev->cdev.owner = owner; + + ret = cdev_add(&mdev->cdev, MKDEV(MAJOR(media_dev_t), mdev->minor), 1); + if (ret < 0) { + pr_err("%s: cdev_add failed\n", __func__); + goto error; + } + + /* Part 3: Register the media device */ + mdev->dev.bus = &media_bus_type; + mdev->dev.devt = MKDEV(MAJOR(media_dev_t), mdev->minor); + mdev->dev.release = media_devnode_release; + if (mdev->parent) + mdev->dev.parent = mdev->parent; + dev_set_name(&mdev->dev, "media%d", mdev->minor); + ret = device_register(&mdev->dev); + if (ret < 0) { + pr_err("%s: device_register failed\n", __func__); + goto error; + } + + /* Part 4: Activate this minor. The char device can now be used. */ + set_bit(MEDIA_FLAG_REGISTERED, &mdev->flags); + + return 0; + +error: + cdev_del(&mdev->cdev); + clear_bit(mdev->minor, media_devnode_nums); + return ret; +} + +/** + * media_devnode_unregister - unregister a media device node + * @mdev: the device node to unregister + * + * This unregisters the passed device. Future open calls will be met with + * errors. + * + * This function can safely be called if the device node has never been + * registered or has already been unregistered. + */ +void media_devnode_unregister(struct media_devnode *mdev) +{ + /* Check if mdev was ever registered at all */ + if (!media_devnode_is_registered(mdev)) + return; + + mutex_lock(&media_devnode_lock); + clear_bit(MEDIA_FLAG_REGISTERED, &mdev->flags); + mutex_unlock(&media_devnode_lock); + device_unregister(&mdev->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 "); +MODULE_DESCRIPTION("Device node registration for media drivers"); +MODULE_LICENSE("GPL"); -- cgit 1.2.3-korg