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authorRalf Baechle <ralf@linux-mips.org>1997-12-06 23:51:34 +0000
committerRalf Baechle <ralf@linux-mips.org>1997-12-06 23:51:34 +0000
commit230e5ab6a084ed50470f101934782dbf54b0d06b (patch)
tree5dd821c8d33f450470588e7a543f74bf74306e9e /drivers/char/videodev.c
parentc9b1c8a64c6444d189856f1e26bdcb8b4cd0113a (diff)
Merge with Linux 2.1.67.
Diffstat (limited to 'drivers/char/videodev.c')
-rw-r--r--drivers/char/videodev.c264
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/char/videodev.c b/drivers/char/videodev.c
new file mode 100644
index 000000000..71e88f04c
--- /dev/null
+++ b/drivers/char/videodev.c
@@ -0,0 +1,264 @@
+/*
+ * 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@cymru.net>
+ *
+ * Fixes:
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/videodev.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+
+#define VIDEO_NUM_DEVICES 256
+
+/*
+ * Active devices
+ */
+
+static struct video_device *video_device[VIDEO_NUM_DEVICES];
+
+/*
+ * Initialiser list
+ */
+
+struct video_init
+{
+ char *name;
+ int (*init)(struct video_init *);
+};
+
+extern int init_bttv_cards(struct video_init *);
+
+static struct video_init video_init_list[]={
+#ifdef CONFIG_VIDEO_BT848
+ {"bttv", init_bttv_cards},
+#endif
+#ifdef CONFIG_VIDEO_BWQCAM
+ {"bttv", init_bw_qcams},
+#endif
+#ifdef CONFIG_VIDEO_PMS
+ {"bttv", init_pms_cards},
+#endif
+ {"end", NULL}
+};
+
+
+/*
+ * Read will do some smarts later on. Buffer pin etc.
+ */
+
+static ssize_t video_read(struct file *file,
+ char *buf, size_t count, loff_t *ppos)
+{
+ int err;
+ struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
+ return vfl->read(vfl, buf, count, file->f_flags&O_NONBLOCK);
+}
+
+/*
+ * Write for now does nothing. No reason it shouldnt do overlay setting
+ * for some boards I guess..
+ */
+
+static ssize_t video_write(struct file *file, const char *buf,
+ size_t count, loff_t *ppos)
+{
+ int err;
+ struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
+ return vfl->write(vfl, buf, count, file->f_flags&O_NONBLOCK);
+}
+
+/*
+ * Open a video device.
+ */
+
+static int video_open(struct inode *inode, struct file *file)
+{
+ unsigned int minor = MINOR(inode->i_rdev);
+ int err;
+ struct video_device *vfl;
+
+ if(minor>=VIDEO_NUM_DEVICES)
+ return -ENODEV;
+
+ vfl=video_device[minor];
+ if(vfl==NULL)
+ return -ENODEV;
+ if(vfl->busy)
+ return -EBUSY;
+ vfl->busy=1; /* In case vfl->open sleeps */
+
+ if(vfl->open)
+ {
+ err=vfl->open(vfl,0); /* Tell the device it is open */
+ if(err)
+ {
+ vfl->busy=0;
+ return err;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Last close of a video for Linux device
+ */
+
+static int video_release(struct inode *inode, struct file *file)
+{
+ struct video_device *vfl=video_device[MINOR(inode->i_rdev)];
+ if(vfl->close)
+ vfl->close(vfl);
+ vfl->busy=0;
+ return 0;
+}
+
+/*
+ * Question: Should we be able to capture and then seek around the
+ * image ?
+ */
+
+static long long video_lseek(struct file * file,
+ long long offset, int origin)
+{
+ return -ESPIPE;
+}
+
+
+static int video_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct video_device *vfl=video_device[MINOR(inode->i_rdev)];
+ int err=vfl->ioctl(vfl, cmd, (void *)arg);
+
+ if(err!=-ENOIOCTLCMD)
+ return err;
+
+ switch(cmd)
+ {
+ default:
+ return -EINVAL;
+ }
+}
+
+/*
+ * We need to do MMAP support
+ */
+
+/*
+ * Video For Linux device drivers request registration here.
+ */
+
+int video_register_device(struct video_device *vfd)
+{
+ int i=0;
+ int base=0;
+ int err;
+
+ for(i=base;i<base+VIDEO_NUM_DEVICES;i++)
+ {
+ if(video_device[i]==NULL)
+ {
+ video_device[i]=vfd;
+ vfd->minor=i;
+ /* The init call may sleep so we book the slot out
+ then call */
+ MOD_INC_USE_COUNT;
+ err=vfd->initialize(vfd);
+ if(err<0)
+ {
+ video_device[i]=NULL;
+ MOD_DEC_USE_COUNT;
+ return err;
+ }
+ return 0;
+ }
+ }
+ return -ENFILE;
+}
+
+/*
+ * Unregister an unused video for linux device
+ */
+
+void video_unregister_device(struct video_device *vfd)
+{
+ if(video_device[vfd->minor]!=vfd)
+ panic("vfd: bad unregister");
+ video_device[vfd->minor]=NULL;
+ MOD_DEC_USE_COUNT;
+}
+
+
+static struct file_operations video_fops=
+{
+ video_lseek,
+ video_read,
+ video_write,
+ NULL, /* readdir */
+ NULL, /* poll */
+ video_ioctl,
+ NULL, /* mmap */
+ video_open,
+ video_release
+};
+
+/*
+ * Initialise video for linux
+ */
+
+int videodev_init(void)
+{
+ struct video_init *vfli = video_init_list;
+
+ printk(KERN_INFO "Linux video capture interface: v0.01 ALPHA\n");
+ if(register_chrdev(VIDEO_MAJOR,"video_capture", &video_fops))
+ {
+ printk("video_dev: unable to get major %d\n", VIDEO_MAJOR);
+ return -EIO;
+ }
+
+ /*
+ * Init kernel installed video drivers
+ */
+
+ while(vfli->init!=NULL)
+ {
+ vfli->init(vfli);
+ vfli++;
+ }
+ return 0;
+}
+
+
+int init_module(void)
+{
+ return videodev_init();
+}
+
+void cleanup_module(void)
+{
+ unregister_chrdev(VIDEO_MAJOR, "video_capture");
+}
+
+EXPORT_SYMBOL(video_register_device);
+EXPORT_SYMBOL(video_unregister_device);