1 files changed, 427 insertions, 0 deletions

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
new file mode 100644
index 000000000000..ccd6566a515e
--- /dev/null
+++ b/drivers/media/video/v4l2-dev.c
@@ -0,0 +1,427 @@
+/*
+ * Video capture interface for Linux version 2
+ *
+ *      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.
+ *
+ * Authors:     Alan Cox, <alan@redhat.com> (version 1)
+ *              Mauro Carvalho Chehab <mchehab@infradead.org> (version 2)
+ *
+ * Fixes:       20000516  Claudio Matsuoka <claudio@conectiva.com>
+ *              - Added procfs support
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.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/smp_lock.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#include <media/v4l2-common.h>
+
+#define VIDEO_NUM_DEVICES       256
+#define VIDEO_NAME              "video4linux"
+
+/*
+ *      sysfs stuff
+ */
+
+static ssize_t show_index(struct device *cd,
+                         struct device_attribute *attr, char *buf)
+{
+        struct video_device *vfd = container_of(cd, struct video_device, dev);
+
+        return sprintf(buf, "%i\n", vfd->index);
+}
+
+static ssize_t show_name(struct device *cd,
+                         struct device_attribute *attr, char *buf)
+{
+        struct video_device *vfd = container_of(cd, struct video_device, dev);
+
+        return sprintf(buf, "%.*s\n", (int)sizeof(vfd->name), vfd->name);
+}
+
+static struct device_attribute video_device_attrs[] = {
+        __ATTR(name, S_IRUGO, show_name, NULL),
+        __ATTR(index, S_IRUGO, show_index, NULL),
+        __ATTR_NULL
+};
+
+/*
+ *      Active devices
+ */
+static struct video_device *video_device[VIDEO_NUM_DEVICES];
+static DEFINE_MUTEX(videodev_lock);
+static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
+
+struct video_device *video_device_alloc(void)
+{
+        return kzalloc(sizeof(struct video_device), GFP_KERNEL);
+}
+EXPORT_SYMBOL(video_device_alloc);
+
+void video_device_release(struct video_device *vfd)
+{
+        kfree(vfd);
+}
+EXPORT_SYMBOL(video_device_release);
+
+void video_device_release_empty(struct video_device *vfd)
+{
+        /* Do nothing */
+        /* Only valid when the video_device struct is a static. */
+}
+EXPORT_SYMBOL(video_device_release_empty);
+
+/* Called when the last user of the character device is gone. */
+static void v4l2_chardev_release(struct kobject *kobj)
+{
+        struct video_device *vfd = container_of(kobj, struct video_device, cdev.kobj);
+
+        mutex_lock(&videodev_lock);
+        if (video_device[vfd->minor] != vfd) {
+                mutex_unlock(&videodev_lock);
+                BUG();
+                return;
+        }
+
+        /* Free up this device for reuse */
+        video_device[vfd->minor] = NULL;
+        clear_bit(vfd->num, video_nums[vfd->vfl_type]);
+        mutex_unlock(&videodev_lock);
+
+        /* Release the character device */
+        vfd->cdev_release(kobj);
+        /* Release video_device and perform other
+           cleanups as needed. */
+        if (vfd->release)
+                vfd->release(vfd);
+}
+
+/* The new kobj_type for the character device */
+static struct kobj_type v4l2_ktype_cdev_default = {
+        .release = v4l2_chardev_release,
+};
+
+static void video_release(struct device *cd)
+{
+        struct video_device *vfd = container_of(cd, struct video_device, dev);
+
+        /* It's now safe to delete the char device.
+           This will either trigger the v4l2_chardev_release immediately (if
+           the refcount goes to 0) or later when the last user of the
+           character device closes it. */
+        cdev_del(&vfd->cdev);
+}
+
+static struct class video_class = {
+        .name = VIDEO_NAME,
+        .dev_attrs = video_device_attrs,
+        .dev_release = video_release,
+};
+
+struct video_device *video_devdata(struct file *file)
+{
+        return video_device[iminor(file->f_path.dentry->d_inode)];
+}
+EXPORT_SYMBOL(video_devdata);
+
+/**
+ * get_index - assign stream number based on parent device
+ * @vdev: video_device to assign index number to, vdev->dev should be assigned
+ * @num: -1 if auto assign, requested number otherwise
+ *
+ *
+ * returns -ENFILE if num is already in use, a free index number if
+ * successful.
+ */
+static int get_index(struct video_device *vdev, int num)
+{
+        u32 used = 0;
+        const int max_index = sizeof(used) * 8 - 1;
+        int i;
+
+        /* Currently a single v4l driver instance cannot create more than
+           32 devices.
+           Increase to u64 or an array of u32 if more are needed. */
+        if (num > max_index) {
+                printk(KERN_ERR "videodev: %s num is too large\n", __func__);
+                return -EINVAL;
+        }
+
+        for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
+                if (video_device[i] != NULL &&
+                    video_device[i] != vdev &&
+                    video_device[i]->parent == vdev->parent) {
+                        used |= 1 << video_device[i]->index;
+                }
+        }
+
+        if (num >= 0) {
+                if (used & (1 << num))
+                        return -ENFILE;
+                return num;
+        }
+
+        i = ffz(used);
+        return i > max_index ? -ENFILE : i;
+}
+
+static const struct file_operations video_fops;
+
+int video_register_device(struct video_device *vfd, int type, int nr)
+{
+        return video_register_device_index(vfd, type, nr, -1);
+}
+EXPORT_SYMBOL(video_register_device);
+
+/**
+ *      video_register_device_index - 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)
+ *      @index: stream number based on parent device;
+ *              -1 if auto assign, requested number otherwise
+ *
+ *      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_index(struct video_device *vfd, int type, int nr,
+                                        int index)
+{
+        int i = 0;
+        int ret;
+        int minor_offset = 0;
+        int minor_cnt = VIDEO_NUM_DEVICES;
+        const char *name_base;
+        void *priv = video_get_drvdata(vfd);
+
+        /* the release callback MUST be present */
+        BUG_ON(!vfd->release);
+
+        if (vfd == NULL)
+                return -EINVAL;
+
+        switch (type) {
+        case VFL_TYPE_GRABBER:
+                name_base = "video";
+                break;
+        case VFL_TYPE_VTX:
+                name_base = "vtx";
+                break;
+        case VFL_TYPE_VBI:
+                name_base = "vbi";
+                break;
+        case VFL_TYPE_RADIO:
+                name_base = "radio";
+                break;
+        default:
+                printk(KERN_ERR "%s called with unknown type: %d\n",
+                       __func__, type);
+                return -EINVAL;
+        }
+
+        vfd->vfl_type = type;
+
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+        /* Keep the ranges for the first four types for historical
+         * reasons.
+         * Newer devices (not yet in place) should use the range
+         * of 128-191 and just pick the first free minor there
+         * (new style). */
+        switch (type) {
+        case VFL_TYPE_GRABBER:
+                minor_offset = 0;
+                minor_cnt = 64;
+                break;
+        case VFL_TYPE_RADIO:
+                minor_offset = 64;
+                minor_cnt = 64;
+                break;
+        case VFL_TYPE_VTX:
+                minor_offset = 192;
+                minor_cnt = 32;
+                break;
+        case VFL_TYPE_VBI:
+                minor_offset = 224;
+                minor_cnt = 32;
+                break;
+        default:
+                minor_offset = 128;
+                minor_cnt = 64;
+                break;
+        }
+#endif
+
+        /* Initialize the character device */
+        cdev_init(&vfd->cdev, vfd->fops);
+        vfd->cdev.owner = vfd->fops->owner;
+        /* pick a minor number */
+        mutex_lock(&videodev_lock);
+        nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr);
+        if (nr == minor_cnt)
+                nr = find_first_zero_bit(video_nums[type], minor_cnt);
+        if (nr == minor_cnt) {
+                printk(KERN_ERR "could not get a free kernel number\n");
+                mutex_unlock(&videodev_lock);
+                return -ENFILE;
+        }
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+        /* 1-on-1 mapping of kernel number to minor number */
+        i = nr;
+#else
+        /* The kernel number and minor numbers are independent */
+        for (i = 0; i < VIDEO_NUM_DEVICES; i++)
+                if (video_device[i] == NULL)
+                        break;
+        if (i == VIDEO_NUM_DEVICES) {
+                mutex_unlock(&videodev_lock);
+                printk(KERN_ERR "could not get a free minor\n");
+                return -ENFILE;
+        }
+#endif
+        vfd->minor = i + minor_offset;
+        vfd->num = nr;
+        set_bit(nr, video_nums[type]);
+        BUG_ON(video_device[vfd->minor]);
+        video_device[vfd->minor] = vfd;
+
+        ret = get_index(vfd, index);
+        vfd->index = ret;
+
+        mutex_unlock(&videodev_lock);
+
+        if (ret < 0) {
+                printk(KERN_ERR "%s: get_index failed\n", __func__);
+                goto fail_minor;
+        }
+
+        ret = cdev_add(&vfd->cdev, MKDEV(VIDEO_MAJOR, vfd->minor), 1);
+        if (ret < 0) {
+                printk(KERN_ERR "%s: cdev_add failed\n", __func__);
+                goto fail_minor;
+        }
+        /* sysfs class */
+        memset(&vfd->dev, 0, sizeof(vfd->dev));
+        /* The memset above cleared the device's drvdata, so
+           put back the copy we made earlier. */
+        video_set_drvdata(vfd, priv);
+        vfd->dev.class = &video_class;
+        vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
+        if (vfd->parent)
+                vfd->dev.parent = vfd->parent;
+        sprintf(vfd->dev.bus_id, "%s%d", name_base, nr);
+        ret = device_register(&vfd->dev);
+        if (ret < 0) {
+                printk(KERN_ERR "%s: device_register failed\n", __func__);
+                goto del_cdev;
+        }
+        /* Remember the cdev's release function */
+        vfd->cdev_release = vfd->cdev.kobj.ktype->release;
+        /* Install our own */
+        vfd->cdev.kobj.ktype = &v4l2_ktype_cdev_default;
+        return 0;
+
+del_cdev:
+        cdev_del(&vfd->cdev);
+
+fail_minor:
+        mutex_lock(&videodev_lock);
+        video_device[vfd->minor] = NULL;
+        clear_bit(vfd->num, video_nums[type]);
+        mutex_unlock(&videodev_lock);
+        vfd->minor = -1;
+        return ret;
+}
+EXPORT_SYMBOL(video_register_device_index);
+
+/**
+ *      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)
+{
+        device_unregister(&vfd->dev);
+}
+EXPORT_SYMBOL(video_unregister_device);
+
+/*
+ *      Initialise video for linux
+ */
+static int __init videodev_init(void)
+{
+        dev_t dev = MKDEV(VIDEO_MAJOR, 0);
+        int ret;
+
+        printk(KERN_INFO "Linux video capture interface: v2.00\n");
+        ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
+        if (ret < 0) {
+                printk(KERN_WARNING "videodev: unable to get major %d\n",
+                                VIDEO_MAJOR);
+                return ret;
+        }
+
+        ret = class_register(&video_class);
+        if (ret < 0) {
+                unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
+                printk(KERN_WARNING "video_dev: class_register failed\n");
+                return -EIO;
+        }
+
+        return 0;
+}
+
+static void __exit videodev_exit(void)
+{
+        dev_t dev = MKDEV(VIDEO_MAJOR, 0);
+
+        class_unregister(&video_class);
+        unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
+}
+
+module_init(videodev_init)
+module_exit(videodev_exit)
+
+MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
+MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
+MODULE_LICENSE("GPL");
+
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */