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:
+ */