patch-2.1.67 linux/drivers/char/videodev.c

• Lines: 265
• Date: Sat Nov 29 10:33:19 1997
• Orig file: v2.1.66/linux/drivers/char/videodev.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.66/linux/drivers/char/videodev.c linux/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);