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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 09:47:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 09:47:22 -0700
commited63b9c873601ca113da5c7b1745e3946493e9f3 (patch)
tree94e96db2b79a8d123c0645dd64b3830bc4d20bfe /drivers/media/mc/mc-devnode.c
parent947fbd4ca9fb38f320b076e68cfccab977c5ea01 (diff)
parentf81cbfc4f82a75ca0a2dc181a9c93b88f0e6509d (diff)
downloadtalos-op-linux-ed63b9c873601ca113da5c7b1745e3946493e9f3.tar.gz
talos-op-linux-ed63b9c873601ca113da5c7b1745e3946493e9f3.zip
Merge tag 'media/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab: - new Atmel microship ISC driver - coda has gained support for mpeg2 and mpeg4 - cxusb gained support for analog TV - rockchip staging driver was split into two separate staging drivers - added a new staging driver for Allegro DVT video IP core - added a new staging driver for Amlogic Meson video decoder - lots of improvements and cleanups * tag 'media/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (398 commits) media: allegro: use new v4l2_m2m_ioctl_try_encoder_cmd funcs media: doc-rst: Fix typos media: radio-raremono: change devm_k*alloc to k*alloc media: stv0297: fix frequency range limit media: rc: Prefer KEY_NUMERIC_* for number buttons on remotes media: dvb_frontend: split dvb_frontend_handle_ioctl function media: mceusb: disable "nonsensical irdata" messages media: rc: remove redundant dev_err message media: cec-notifier: add new notifier functions media: cec: add struct cec_connector_info support media: cec-notifier: rename variables, check kstrdup and n->conn_name media: MAINTAINERS: Add maintainers for Media Controller media: staging: media: tegra-vde: Defer dmabuf's unmapping media: staging: media: tegra-vde: Add IOMMU support media: hdpvr: fix locking and a missing msleep media: v4l2: Test type instead of cfg->type in v4l2_ctrl_new_custom() media: atmel: atmel-isc: fix i386 build error media: v4l2-ctrl: Move compound control initialization media: hantro: Use vb2_get_buffer media: pci: cx88: Change the type of 'missed' to u64 ...
Diffstat (limited to 'drivers/media/mc/mc-devnode.c')
-rw-r--r--drivers/media/mc/mc-devnode.c328
1 files changed, 328 insertions, 0 deletions
diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
new file mode 100644
index 000000000000..f11382afe23b
--- /dev/null
+++ b/drivers/media/mc/mc-devnode.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ *
+ * --
+ *
+ * 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;
+ kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
+
+ /* 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);
+ devnode->media_dev = NULL;
+ mutex_unlock(&media_devnode_lock);
+
+ 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");
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