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-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAlz8fAYeHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiG1asH/3ySguxqtqL1MCBa 4/SZ37PHeWKMerfX6ZyJdgEqK3B+PWlmuLiOMNK5h2bPLzeQQQAmHU/mfKmpXqgB dHwUbG9yNnyUtTfsfRqAnCA6vpuw9Yb1oIzTCVQrgJLSWD0j7scBBvmzYqguOkto ThwigLUq3AILr8EfR4rh+GM+5Dn9OTEFAxwil9fPHQo7QoczwZxpURhScT6Co9TB DqLA3fvXbBvLs/CZy/S5vKM9hKzC+p39ApFTURvFPrelUVnythAM0dPDJg3pIn5u g+/+gDxDFa+7ANxvxO2ng1sJPDqJMeY/xmjJYlYyLpA33B7zLNk2vDHhAP06VTtr XCMhQ9s= =cb80 -----END PGP SIGNATURE----- Merge tag 'v5.2-rc4' into media/master There are some conflicts due to SPDX changes. We also have more patches being merged via media tree touching them. So, let's merge back from upstream and address those. Linux 5.2-rc4 * tag 'v5.2-rc4': (767 commits) Linux 5.2-rc4 MAINTAINERS: Karthikeyan Ramasubramanian is MIA i2c: xiic: Add max_read_len quirk lockref: Limit number of cmpxchg loop retries uaccess: add noop untagged_addr definition x86/insn-eval: Fix use-after-free access to LDT entry kbuild: use more portable 'command -v' for cc-cross-prefix s390/unwind: correct stack switching during unwind block, bfq: add weight symlink to the bfq.weight cgroup parameter cgroup: let a symlink too be created with a cftype file drm/nouveau/secboot/gp10[2467]: support newer FW to fix SEC2 failures on some boards drm/nouveau/secboot: enable loading of versioned LS PMU/SEC2 ACR msgqueue FW drm/nouveau/secboot: split out FW version-specific LS function pointers drm/nouveau/secboot: pass max supported FW version to LS load funcs drm/nouveau/core: support versioned firmware loading drm/nouveau/core: pass subdev into nvkm_firmware_get, rather than device block: free sched's request pool in blk_cleanup_queue pktgen: do not sleep with the thread lock held. net: mvpp2: Use strscpy to handle stat strings net: rds: fix memory leak in rds_ib_flush_mr_pool ... Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
329 lines
8.3 KiB
C
329 lines
8.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Media device node
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*
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* Copyright (C) 2010 Nokia Corporation
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*
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* Based on drivers/media/video/v4l2_dev.c code authored by
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* Mauro Carvalho Chehab <mchehab@kernel.org> (version 2)
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* Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
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*
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* Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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* Sakari Ailus <sakari.ailus@iki.fi>
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*
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* --
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*
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* Generic media device node infrastructure to register and unregister
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* character devices using a dynamic major number and proper reference
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* counting.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/kmod.h>
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#include <linux/slab.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/uaccess.h>
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#include <media/media-devnode.h>
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#include <media/media-device.h>
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#define MEDIA_NUM_DEVICES 256
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#define MEDIA_NAME "media"
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static dev_t media_dev_t;
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/*
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* Active devices
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*/
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static DEFINE_MUTEX(media_devnode_lock);
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static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES);
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/* Called when the last user of the media device exits. */
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static void media_devnode_release(struct device *cd)
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{
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struct media_devnode *devnode = to_media_devnode(cd);
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mutex_lock(&media_devnode_lock);
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/* Mark device node number as free */
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clear_bit(devnode->minor, media_devnode_nums);
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mutex_unlock(&media_devnode_lock);
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/* Release media_devnode and perform other cleanups as needed. */
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if (devnode->release)
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devnode->release(devnode);
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kfree(devnode);
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pr_debug("%s: Media Devnode Deallocated\n", __func__);
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}
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static struct bus_type media_bus_type = {
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.name = MEDIA_NAME,
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};
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static ssize_t media_read(struct file *filp, char __user *buf,
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size_t sz, loff_t *off)
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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if (!devnode->fops->read)
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return -EINVAL;
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if (!media_devnode_is_registered(devnode))
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return -EIO;
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return devnode->fops->read(filp, buf, sz, off);
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}
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static ssize_t media_write(struct file *filp, const char __user *buf,
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size_t sz, loff_t *off)
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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if (!devnode->fops->write)
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return -EINVAL;
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if (!media_devnode_is_registered(devnode))
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return -EIO;
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return devnode->fops->write(filp, buf, sz, off);
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}
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static __poll_t media_poll(struct file *filp,
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struct poll_table_struct *poll)
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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if (!media_devnode_is_registered(devnode))
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return EPOLLERR | EPOLLHUP;
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if (!devnode->fops->poll)
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return DEFAULT_POLLMASK;
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return devnode->fops->poll(filp, poll);
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}
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static long
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__media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg,
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long (*ioctl_func)(struct file *filp, unsigned int cmd,
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unsigned long arg))
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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if (!ioctl_func)
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return -ENOTTY;
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if (!media_devnode_is_registered(devnode))
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return -EIO;
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return ioctl_func(filp, cmd, arg);
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}
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static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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return __media_ioctl(filp, cmd, arg, devnode->fops->ioctl);
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}
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#ifdef CONFIG_COMPAT
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static long media_compat_ioctl(struct file *filp, unsigned int cmd,
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unsigned long arg)
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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return __media_ioctl(filp, cmd, arg, devnode->fops->compat_ioctl);
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}
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#endif /* CONFIG_COMPAT */
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/* Override for the open function */
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static int media_open(struct inode *inode, struct file *filp)
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{
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struct media_devnode *devnode;
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int ret;
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/* Check if the media device is available. This needs to be done with
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* the media_devnode_lock held to prevent an open/unregister race:
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* without the lock, the device could be unregistered and freed between
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* the media_devnode_is_registered() and get_device() calls, leading to
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* a crash.
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*/
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mutex_lock(&media_devnode_lock);
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devnode = container_of(inode->i_cdev, struct media_devnode, cdev);
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/* return ENXIO if the media device has been removed
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already or if it is not registered anymore. */
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if (!media_devnode_is_registered(devnode)) {
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mutex_unlock(&media_devnode_lock);
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return -ENXIO;
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}
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/* and increase the device refcount */
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get_device(&devnode->dev);
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mutex_unlock(&media_devnode_lock);
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filp->private_data = devnode;
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if (devnode->fops->open) {
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ret = devnode->fops->open(filp);
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if (ret) {
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put_device(&devnode->dev);
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filp->private_data = NULL;
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return ret;
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}
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}
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return 0;
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}
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/* Override for the release function */
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static int media_release(struct inode *inode, struct file *filp)
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{
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struct media_devnode *devnode = media_devnode_data(filp);
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if (devnode->fops->release)
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devnode->fops->release(filp);
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filp->private_data = NULL;
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/* decrease the refcount unconditionally since the release()
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return value is ignored. */
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put_device(&devnode->dev);
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pr_debug("%s: Media Release\n", __func__);
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return 0;
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}
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static const struct file_operations media_devnode_fops = {
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.owner = THIS_MODULE,
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.read = media_read,
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.write = media_write,
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.open = media_open,
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.unlocked_ioctl = media_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = media_compat_ioctl,
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#endif /* CONFIG_COMPAT */
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.release = media_release,
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.poll = media_poll,
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.llseek = no_llseek,
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};
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int __must_check media_devnode_register(struct media_device *mdev,
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struct media_devnode *devnode,
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struct module *owner)
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{
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int minor;
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int ret;
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/* Part 1: Find a free minor number */
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mutex_lock(&media_devnode_lock);
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minor = find_next_zero_bit(media_devnode_nums, MEDIA_NUM_DEVICES, 0);
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if (minor == MEDIA_NUM_DEVICES) {
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mutex_unlock(&media_devnode_lock);
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pr_err("could not get a free minor\n");
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kfree(devnode);
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return -ENFILE;
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}
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set_bit(minor, media_devnode_nums);
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mutex_unlock(&media_devnode_lock);
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devnode->minor = minor;
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devnode->media_dev = mdev;
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/* Part 1: Initialize dev now to use dev.kobj for cdev.kobj.parent */
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devnode->dev.bus = &media_bus_type;
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devnode->dev.devt = MKDEV(MAJOR(media_dev_t), devnode->minor);
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devnode->dev.release = media_devnode_release;
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if (devnode->parent)
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devnode->dev.parent = devnode->parent;
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dev_set_name(&devnode->dev, "media%d", devnode->minor);
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device_initialize(&devnode->dev);
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/* Part 2: Initialize the character device */
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cdev_init(&devnode->cdev, &media_devnode_fops);
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devnode->cdev.owner = owner;
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kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
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/* Part 3: Add the media and char device */
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ret = cdev_device_add(&devnode->cdev, &devnode->dev);
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if (ret < 0) {
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pr_err("%s: cdev_device_add failed\n", __func__);
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goto cdev_add_error;
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}
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/* Part 4: Activate this minor. The char device can now be used. */
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set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
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return 0;
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cdev_add_error:
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mutex_lock(&media_devnode_lock);
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clear_bit(devnode->minor, media_devnode_nums);
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devnode->media_dev = NULL;
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mutex_unlock(&media_devnode_lock);
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put_device(&devnode->dev);
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return ret;
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}
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void media_devnode_unregister_prepare(struct media_devnode *devnode)
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{
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/* Check if devnode was ever registered at all */
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if (!media_devnode_is_registered(devnode))
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return;
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mutex_lock(&media_devnode_lock);
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clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
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mutex_unlock(&media_devnode_lock);
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}
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void media_devnode_unregister(struct media_devnode *devnode)
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{
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mutex_lock(&media_devnode_lock);
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/* Delete the cdev on this minor as well */
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cdev_device_del(&devnode->cdev, &devnode->dev);
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devnode->media_dev = NULL;
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mutex_unlock(&media_devnode_lock);
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put_device(&devnode->dev);
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}
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/*
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* Initialise media for linux
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*/
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static int __init media_devnode_init(void)
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{
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int ret;
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pr_info("Linux media interface: v0.10\n");
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ret = alloc_chrdev_region(&media_dev_t, 0, MEDIA_NUM_DEVICES,
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MEDIA_NAME);
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if (ret < 0) {
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pr_warn("unable to allocate major\n");
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return ret;
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}
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ret = bus_register(&media_bus_type);
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if (ret < 0) {
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unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
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pr_warn("bus_register failed\n");
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return -EIO;
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}
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return 0;
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}
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static void __exit media_devnode_exit(void)
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{
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bus_unregister(&media_bus_type);
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unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
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}
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subsys_initcall(media_devnode_init);
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module_exit(media_devnode_exit)
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MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
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MODULE_DESCRIPTION("Device node registration for media drivers");
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MODULE_LICENSE("GPL");
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