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Diffstat (limited to 'drivers/media/video/videodev.c')
-rw-r--r--drivers/media/video/videodev.c436
1 files changed, 436 insertions, 0 deletions
diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c
new file mode 100644
index 000000000000..06df15f75de9
--- /dev/null
+++ b/drivers/media/video/videodev.c
@@ -0,0 +1,436 @@
+/*
+ * Video capture interface for Linux
+ *
+ * A generic video device interface for the LINUX operating system
+ * using a set of device structures/vectors for low level operations.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Author: Alan Cox, <alan@redhat.com>
+ *
+ * Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com>
+ * - Added procfs support
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/devfs_fs_kernel.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/semaphore.h>
+
+#include <linux/videodev.h>
+
+#define VIDEO_NUM_DEVICES 256
+#define VIDEO_NAME "video4linux"
+
+/*
+ * sysfs stuff
+ */
+
+static ssize_t show_name(struct class_device *cd, char *buf)
+{
+ struct video_device *vfd = container_of(cd, struct video_device, class_dev);
+ return sprintf(buf,"%.*s\n",(int)sizeof(vfd->name),vfd->name);
+}
+
+static CLASS_DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+struct video_device *video_device_alloc(void)
+{
+ struct video_device *vfd;
+
+ vfd = kmalloc(sizeof(*vfd),GFP_KERNEL);
+ if (NULL == vfd)
+ return NULL;
+ memset(vfd,0,sizeof(*vfd));
+ return vfd;
+}
+
+void video_device_release(struct video_device *vfd)
+{
+ kfree(vfd);
+}
+
+static void video_release(struct class_device *cd)
+{
+ struct video_device *vfd = container_of(cd, struct video_device, class_dev);
+
+#if 1 /* needed until all drivers are fixed */
+ if (!vfd->release)
+ return;
+#endif
+ vfd->release(vfd);
+}
+
+static struct class video_class = {
+ .name = VIDEO_NAME,
+ .release = video_release,
+};
+
+/*
+ * Active devices
+ */
+
+static struct video_device *video_device[VIDEO_NUM_DEVICES];
+static DECLARE_MUTEX(videodev_lock);
+
+struct video_device* video_devdata(struct file *file)
+{
+ return video_device[iminor(file->f_dentry->d_inode)];
+}
+
+/*
+ * Open a video device.
+ */
+static int video_open(struct inode *inode, struct file *file)
+{
+ unsigned int minor = iminor(inode);
+ int err = 0;
+ struct video_device *vfl;
+ struct file_operations *old_fops;
+
+ if(minor>=VIDEO_NUM_DEVICES)
+ return -ENODEV;
+ down(&videodev_lock);
+ vfl=video_device[minor];
+ if(vfl==NULL) {
+ up(&videodev_lock);
+ request_module("char-major-%d-%d", VIDEO_MAJOR, minor);
+ down(&videodev_lock);
+ vfl=video_device[minor];
+ if (vfl==NULL) {
+ up(&videodev_lock);
+ return -ENODEV;
+ }
+ }
+ old_fops = file->f_op;
+ file->f_op = fops_get(vfl->fops);
+ if(file->f_op->open)
+ err = file->f_op->open(inode,file);
+ if (err) {
+ fops_put(file->f_op);
+ file->f_op = fops_get(old_fops);
+ }
+ fops_put(old_fops);
+ up(&videodev_lock);
+ return err;
+}
+
+/*
+ * helper function -- handles userspace copying for ioctl arguments
+ */
+
+static unsigned int
+video_fix_command(unsigned int cmd)
+{
+ switch (cmd) {
+ case VIDIOC_OVERLAY_OLD:
+ cmd = VIDIOC_OVERLAY;
+ break;
+ case VIDIOC_S_PARM_OLD:
+ cmd = VIDIOC_S_PARM;
+ break;
+ case VIDIOC_S_CTRL_OLD:
+ cmd = VIDIOC_S_CTRL;
+ break;
+ case VIDIOC_G_AUDIO_OLD:
+ cmd = VIDIOC_G_AUDIO;
+ break;
+ case VIDIOC_G_AUDOUT_OLD:
+ cmd = VIDIOC_G_AUDOUT;
+ break;
+ case VIDIOC_CROPCAP_OLD:
+ cmd = VIDIOC_CROPCAP;
+ break;
+ }
+ return cmd;
+}
+
+int
+video_usercopy(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg,
+ int (*func)(struct inode *inode, struct file *file,
+ unsigned int cmd, void *arg))
+{
+ char sbuf[128];
+ void *mbuf = NULL;
+ void *parg = NULL;
+ int err = -EINVAL;
+
+ cmd = video_fix_command(cmd);
+
+ /* Copy arguments into temp kernel buffer */
+ switch (_IOC_DIR(cmd)) {
+ case _IOC_NONE:
+ parg = NULL;
+ break;
+ case _IOC_READ:
+ case _IOC_WRITE:
+ case (_IOC_WRITE | _IOC_READ):
+ if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
+ parg = sbuf;
+ } else {
+ /* too big to allocate from stack */
+ mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
+ if (NULL == mbuf)
+ return -ENOMEM;
+ parg = mbuf;
+ }
+
+ err = -EFAULT;
+ if (_IOC_DIR(cmd) & _IOC_WRITE)
+ if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
+ goto out;
+ break;
+ }
+
+ /* call driver */
+ err = func(inode, file, cmd, parg);
+ if (err == -ENOIOCTLCMD)
+ err = -EINVAL;
+ if (err < 0)
+ goto out;
+
+ /* Copy results into user buffer */
+ switch (_IOC_DIR(cmd))
+ {
+ case _IOC_READ:
+ case (_IOC_WRITE | _IOC_READ):
+ if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
+ err = -EFAULT;
+ break;
+ }
+
+out:
+ if (mbuf)
+ kfree(mbuf);
+ return err;
+}
+
+/*
+ * open/release helper functions -- handle exclusive opens
+ */
+int video_exclusive_open(struct inode *inode, struct file *file)
+{
+ struct video_device *vfl = video_devdata(file);
+ int retval = 0;
+
+ down(&vfl->lock);
+ if (vfl->users) {
+ retval = -EBUSY;
+ } else {
+ vfl->users++;
+ }
+ up(&vfl->lock);
+ return retval;
+}
+
+int video_exclusive_release(struct inode *inode, struct file *file)
+{
+ struct video_device *vfl = video_devdata(file);
+
+ vfl->users--;
+ return 0;
+}
+
+static struct file_operations video_fops;
+
+/**
+ * video_register_device - register video4linux devices
+ * @vfd: video device structure we want to register
+ * @type: type of device to register
+ * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
+ * -1 == first free)
+ *
+ * The registration code assigns minor numbers based on the type
+ * requested. -ENFILE is returned in all the device slots for this
+ * category are full. If not then the minor field is set and the
+ * driver initialize function is called (if non %NULL).
+ *
+ * Zero is returned on success.
+ *
+ * Valid types are
+ *
+ * %VFL_TYPE_GRABBER - A frame grabber
+ *
+ * %VFL_TYPE_VTX - A teletext device
+ *
+ * %VFL_TYPE_VBI - Vertical blank data (undecoded)
+ *
+ * %VFL_TYPE_RADIO - A radio card
+ */
+
+int video_register_device(struct video_device *vfd, int type, int nr)
+{
+ int i=0;
+ int base;
+ int end;
+ char *name_base;
+
+ switch(type)
+ {
+ case VFL_TYPE_GRABBER:
+ base=0;
+ end=64;
+ name_base = "video";
+ break;
+ case VFL_TYPE_VTX:
+ base=192;
+ end=224;
+ name_base = "vtx";
+ break;
+ case VFL_TYPE_VBI:
+ base=224;
+ end=240;
+ name_base = "vbi";
+ break;
+ case VFL_TYPE_RADIO:
+ base=64;
+ end=128;
+ name_base = "radio";
+ break;
+ default:
+ return -1;
+ }
+
+ /* pick a minor number */
+ down(&videodev_lock);
+ if (nr >= 0 && nr < end-base) {
+ /* use the one the driver asked for */
+ i = base+nr;
+ if (NULL != video_device[i]) {
+ up(&videodev_lock);
+ return -ENFILE;
+ }
+ } else {
+ /* use first free */
+ for(i=base;i<end;i++)
+ if (NULL == video_device[i])
+ break;
+ if (i == end) {
+ up(&videodev_lock);
+ return -ENFILE;
+ }
+ }
+ video_device[i]=vfd;
+ vfd->minor=i;
+ up(&videodev_lock);
+
+ sprintf(vfd->devfs_name, "v4l/%s%d", name_base, i - base);
+ devfs_mk_cdev(MKDEV(VIDEO_MAJOR, vfd->minor),
+ S_IFCHR | S_IRUSR | S_IWUSR, vfd->devfs_name);
+ init_MUTEX(&vfd->lock);
+
+ /* sysfs class */
+ memset(&vfd->class_dev, 0x00, sizeof(vfd->class_dev));
+ if (vfd->dev)
+ vfd->class_dev.dev = vfd->dev;
+ vfd->class_dev.class = &video_class;
+ vfd->class_dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
+ strlcpy(vfd->class_dev.class_id, vfd->devfs_name + 4, BUS_ID_SIZE);
+ class_device_register(&vfd->class_dev);
+ class_device_create_file(&vfd->class_dev,
+ &class_device_attr_name);
+
+#if 1 /* needed until all drivers are fixed */
+ if (!vfd->release)
+ printk(KERN_WARNING "videodev: \"%s\" has no release callback. "
+ "Please fix your driver for proper sysfs support, see "
+ "http://lwn.net/Articles/36850/\n", vfd->name);
+#endif
+ return 0;
+}
+
+/**
+ * video_unregister_device - unregister a video4linux device
+ * @vfd: the device to unregister
+ *
+ * This unregisters the passed device and deassigns the minor
+ * number. Future open calls will be met with errors.
+ */
+
+void video_unregister_device(struct video_device *vfd)
+{
+ down(&videodev_lock);
+ if(video_device[vfd->minor]!=vfd)
+ panic("videodev: bad unregister");
+
+ devfs_remove(vfd->devfs_name);
+ video_device[vfd->minor]=NULL;
+ class_device_unregister(&vfd->class_dev);
+ up(&videodev_lock);
+}
+
+
+static struct file_operations video_fops=
+{
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .open = video_open,
+};
+
+/*
+ * Initialise video for linux
+ */
+
+static int __init videodev_init(void)
+{
+ int ret;
+
+ printk(KERN_INFO "Linux video capture interface: v1.00\n");
+ if (register_chrdev(VIDEO_MAJOR, VIDEO_NAME, &video_fops)) {
+ printk(KERN_WARNING "video_dev: unable to get major %d\n", VIDEO_MAJOR);
+ return -EIO;
+ }
+
+ ret = class_register(&video_class);
+ if (ret < 0) {
+ unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME);
+ printk(KERN_WARNING "video_dev: class_register failed\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void __exit videodev_exit(void)
+{
+ class_unregister(&video_class);
+ unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME);
+}
+
+module_init(videodev_init)
+module_exit(videodev_exit)
+
+EXPORT_SYMBOL(video_register_device);
+EXPORT_SYMBOL(video_unregister_device);
+EXPORT_SYMBOL(video_devdata);
+EXPORT_SYMBOL(video_usercopy);
+EXPORT_SYMBOL(video_exclusive_open);
+EXPORT_SYMBOL(video_exclusive_release);
+EXPORT_SYMBOL(video_device_alloc);
+EXPORT_SYMBOL(video_device_release);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("Device registrar for Video4Linux drivers");
+MODULE_LICENSE("GPL");
+
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-20 22:10:09 +0000