videodev.c

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/*
 * 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, <[e-mail]> (version 1)
 *              Mauro Carvalho Chehab <[e-mail]> (version 2)
 *
 * Fixes:	20000516  Claudio Matsuoka <[e-mail]>
 *		- Added procfs support
 */

#define dbgarg(cmd, fmt, arg...) \
		if (vfd->debug & V4L2_DEBUG_IOCTL_ARG) {		\
			printk (KERN_DEBUG "%s: ",  vfd->name);		\
			v4l_printk_ioctl(cmd);				\
			printk (KERN_DEBUG "%s: " fmt, vfd->name, ## arg); \
		}

#define dbgarg2(fmt, arg...) \
		if (vfd->debug & V4L2_DEBUG_IOCTL_ARG)			\
			printk (KERN_DEBUG "%s: " fmt, vfd->name, ## arg);

#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 <asm/uaccess.h>
#include <asm/system.h>

#define __OLD_VIDIOC_ /* To allow fixing old calls*/
#include <linux/videodev2.h>

#ifdef CONFIG_VIDEO_V4L1
#include <linux/videodev.h>
#endif
#include <media/v4l2-common.h>

#define VIDEO_NUM_DEVICES	256
#define VIDEO_NAME              "video4linux"

/*
 *	sysfs stuff
 */

static ssize_t show_name(struct device *cd,
			 struct device_attribute *attr, 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);
}

struct video_device *video_device_alloc(void)
{
	struct video_device *vfd;

	vfd = kzalloc(sizeof(*vfd),GFP_KERNEL);
	return vfd;
}

void video_device_release(struct video_device *vfd)
{
	kfree(vfd);
}

static void video_release(struct 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 device_attribute video_device_attrs[] = {
	__ATTR(name, S_IRUGO, show_name, NULL),
	__ATTR_NULL
};

static struct class video_class = {
	.name    = VIDEO_NAME,
	.dev_attrs = video_device_attrs,
	.dev_release = video_release,
};

/*
 *	Active devices
 */

static struct video_device *video_device[VIDEO_NUM_DEVICES];
static DEFINE_MUTEX(videodev_lock);

struct video_device* video_devdata(struct file *file)
{
	return video_device[iminor(file->f_path.dentry->d_inode)];
}

/*
 *	Open a video device - FIXME: Obsoleted
 */
static int video_open(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode);
	int err = 0;
	struct video_device *vfl;
	const struct file_operations *old_fops;

	if(minor>=VIDEO_NUM_DEVICES)
		return -ENODEV;
	mutex_lock(&videodev_lock);
	vfl=video_device[minor];
	if(vfl==NULL) {
		mutex_unlock(&videodev_lock);
		request_module("char-major-%d-%d", VIDEO_MAJOR, minor);
		mutex_lock(&videodev_lock);
		vfl=video_device[minor];
		if (vfl==NULL) {
			mutex_unlock(&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);
	mutex_unlock(&videodev_lock);
	return err;
}

/*
 * helper function -- handles userspace copying for ioctl arguments
 */

#ifdef __OLD_VIDIOC_
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;
}
#endif

/*
 * Obsolete usercopy function - Should be removed soon
 */
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;
	int     is_ext_ctrl;
	size_t  ctrls_size = 0;
	void __user *user_ptr = NULL;

#ifdef __OLD_VIDIOC_
	cmd = video_fix_command(cmd);
#endif
	is_ext_ctrl = (cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_G_EXT_CTRLS ||
		       cmd == VIDIOC_TRY_EXT_CTRLS);

	/*  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;
	}
	if (is_ext_ctrl) {
		struct v4l2_ext_controls *p = parg;

		/* In case of an error, tell the caller that it wasn't
		   a specific control that caused it. */
		p->error_idx = p->count;
		user_ptr = (void __user *)p->controls;
		if (p->count) {
			ctrls_size = sizeof(struct v4l2_ext_control) * p->count;
			/* Note: v4l2_ext_controls fits in sbuf[] so mbuf is still NULL. */
			mbuf = kmalloc(ctrls_size, GFP_KERNEL);
			err = -ENOMEM;
			if (NULL == mbuf)
				goto out_ext_ctrl;
			err = -EFAULT;
			if (copy_from_user(mbuf, user_ptr, ctrls_size))
				goto out_ext_ctrl;
			p->controls = mbuf;
		}
	}

	/* call driver */
	err = func(inode, file, cmd, parg);
	if (err == -ENOIOCTLCMD)
		err = -EINVAL;
	if (is_ext_ctrl) {
		struct v4l2_ext_controls *p = parg;

		p->controls = (void *)user_ptr;
		if (p->count && err == 0 && copy_to_user(user_ptr, mbuf, ctrls_size))
			err = -EFAULT;
		goto out_ext_ctrl;
	}
	if (err < 0)
		goto out;

out_ext_ctrl:
	/*  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:
	kfree(mbuf);
	return err;
}

/*
 * open/release helper functions -- handle exclusive opens
 * Should be removed soon
 */
int video_exclusive_open(struct inode *inode, struct file *file)
{
	struct  video_device *vfl = video_devdata(file);
	int retval = 0;

	mutex_lock(&vfl->lock);
	if (vfl->users) {
		retval = -EBUSY;
	} else {
		vfl->users++;
	}
	mutex_unlock(&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 char *v4l2_memory_names[] = {
	[V4L2_MEMORY_MMAP]    = "mmap",
	[V4L2_MEMORY_USERPTR] = "userptr",
	[V4L2_MEMORY_OVERLAY] = "overlay",
};


/* FIXME: Those stuff are replicated also on v4l2-common.c */
static char *v4l2_type_names_FIXME[] = {
	[V4L2_BUF_TYPE_VIDEO_CAPTURE]      = "video-cap",
	[V4L2_BUF_TYPE_VIDEO_OVERLAY]      = "video-over",
	[V4L2_BUF_TYPE_VIDEO_OUTPUT]       = "video-out",
	[V4L2_BUF_TYPE_VBI_CAPTURE]        = "vbi-cap",
	[V4L2_BUF_TYPE_VBI_OUTPUT]         = "vbi-out",
	[V4L2_BUF_TYPE_SLICED_VBI_OUTPUT]  = "sliced-vbi-out",
	[V4L2_BUF_TYPE_SLICED_VBI_CAPTURE] = "sliced-vbi-capture",
	[V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY] = "video-out-over",
	[V4L2_BUF_TYPE_PRIVATE]            = "private",
};

static char *v4l2_field_names_FIXME[] = {
	[V4L2_FIELD_ANY]        = "any",
	[V4L2_FIELD_NONE]       = "none",
	[V4L2_FIELD_TOP]        = "top",
	[V4L2_FIELD_BOTTOM]     = "bottom",
	[V4L2_FIELD_INTERLACED] = "interlaced",
	[V4L2_FIELD_SEQ_TB]     = "seq-tb",
	[V4L2_FIELD_SEQ_BT]     = "seq-bt",
	[V4L2_FIELD_ALTERNATE]  = "alternate",
	[V4L2_FIELD_INTERLACED_TB] = "interlaced-tb",
	[V4L2_FIELD_INTERLACED_BT] = "interlaced-bt",
};

#define prt_names(a,arr) (((a)>=0)&&((a)<ARRAY_SIZE(arr)))?arr[a]:"unknown"

static void dbgbuf(unsigned int cmd, struct video_device *vfd,
					struct v4l2_buffer *p)
{
	struct v4l2_timecode *tc=&p->timecode;

	dbgarg (cmd, "%02ld:%02d:%02d.%08ld index=%d, type=%s, "
		"bytesused=%d, flags=0x%08d, "
		"field=%0d, sequence=%d, memory=%s, offset/userptr=0x%08lx, length=%d\n",
			(p->timestamp.tv_sec/3600),
			(int)(p->timestamp.tv_sec/60)%60,
			(int)(p->timestamp.tv_sec%60),
			p->timestamp.tv_usec,
			p->index,
			prt_names(p->type,v4l2_type_names_FIXME),
			p->bytesused,p->flags,
			p->field,p->sequence,
			prt_names(p->memory,v4l2_memory_names),
			p->m.userptr, p->length);
	dbgarg2 ("timecode= %02d:%02d:%02d type=%d, "
		"flags=0x%08d, frames=%d, userbits=0x%08x\n",
			tc->hours,tc->minutes,tc->seconds,
			tc->type, tc->flags, tc->frames, *(__u32 *) tc->userbits);
}

static inline void dbgrect(struct video_device *vfd, char *s,
							struct v4l2_rect *r)
{
	dbgarg2 ("%sRect start at %dx%d, size= %dx%d\n", s, r->left, r->top,
						r->width, r->height);
};

static inline void v4l_print_pix_fmt (struct video_device *vfd,
						struct v4l2_pix_format *fmt)
{
	dbgarg2 ("width=%d, height=%d, format=%c%c%c%c, field=%s, "
		"bytesperline=%d sizeimage=%d, colorspace=%d\n",
		fmt->width,fmt->height,
		(fmt->pixelformat & 0xff),
		(fmt->pixelformat >>  8) & 0xff,
		(fmt->pixelformat >> 16) & 0xff,
		(fmt->pixelformat >> 24) & 0xff,
		prt_names(fmt->field,v4l2_field_names_FIXME),
		fmt->bytesperline,fmt->sizeimage,fmt->colorspace);
};


static int check_fmt (struct video_device *vfd, enum v4l2_buf_type type)
{
	switch (type) {
	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
		if (vfd->vidioc_try_fmt_cap)
			return (0);
		break;
	case V4L2_BUF_TYPE_VIDEO_OVERLAY:
		if (vfd->vidioc_try_fmt_overlay)
			return (0);
		break;
	case V4L2_BUF_TYPE_VBI_CAPTURE:
		if (vfd->vidioc_try_fmt_vbi)
			return (0);
		break;
	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
		if (vfd->vidioc_try_fmt_vbi_output)
			return (0);
		break;
	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
		if (vfd->vidioc_try_fmt_vbi_capture)
			return (0);
		break;
	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
		if (vfd->vidioc_try_fmt_video_output)
			return (0);
		break;
	case V4L2_BUF_TYPE_VBI_OUTPUT:
		if (vfd->vidioc_try_fmt_vbi_output)
			return (0);
		break;
	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
		if (vfd->vidioc_try_fmt_output_overlay)
			return (0);
		break;
	case V4L2_BUF_TYPE_PRIVATE:
		if (vfd->vidioc_try_fmt_type_private)
			return (0);
		break;
	}
	return (-EINVAL);
}

static int __video_do_ioctl(struct inode *inode, struct file *file,
		unsigned int cmd, void *arg)
{
	struct video_device *vfd = video_devdata(file);
	void                 *fh = file->private_data;
	int                  ret = -EINVAL;

	if ( (vfd->debug & V4L2_DEBUG_IOCTL) &&
				!(vfd->debug & V4L2_DEBUG_IOCTL_ARG)) {
		v4l_print_ioctl(vfd->name, cmd);
	}

#ifdef CONFIG_VIDEO_V4L1_COMPAT
	/***********************************************************
	 Handles calls to the obsoleted V4L1 API
	 Due to the nature of VIDIOCGMBUF, each driver that supports
	 V4L1 should implement its own handler for this ioctl.
	 ***********************************************************/

	/* --- streaming capture ------------------------------------- */
	if (cmd == VIDIOCGMBUF) {
		struct video_mbuf *p=arg;

		memset(p, 0, sizeof(*p));

		if (!vfd->vidiocgmbuf)
			return ret;
		ret=vfd->vidiocgmbuf(file, fh, p);
		if (!ret)
			dbgarg (cmd, "size=%d, frames=%d, offsets=0x%08lx\n",
						p->size, p->frames,
						(unsigned long)p->offsets);
		return ret;
	}

	/********************************************************
	 All other V4L1 calls are handled by v4l1_compat module.
	 Those calls will be translated into V4L2 calls, and
	 __video_do_ioctl will be called again, with one or more
	 V4L2 ioctls.
	 ********************************************************/
	if (_IOC_TYPE(cmd)=='v')
		return v4l_compat_translate_ioctl(inode,file,cmd,arg,
						__video_do_ioctl);
#endif

	switch(cmd) {
	/* --- capabilities ------------------------------------------ */
	case VIDIOC_QUERYCAP:
	{
		struct v4l2_capability *cap = (struct v4l2_capability*)arg;
		memset(cap, 0, sizeof(*cap));

		if (!vfd->vidioc_querycap)
			break;

		ret=vfd->vidioc_querycap(file, fh, cap);
		if (!ret)
			dbgarg (cmd, "driver=%s, card=%s, bus=%s, "
					"version=0x%08x, "
					"capabilities=0x%08x\n",
					cap->driver,cap->card,cap->bus_info,
					cap->version,
					cap->capabilities);
		break;
	}

	/* --- priority ------------------------------------------ */
	case VIDIOC_G_PRIORITY:
	{
		enum v4l2_priority *p=arg;

		if (!vfd->vidioc_g_priority)
			break;
		ret=vfd->vidioc_g_priority(file, fh, p);
		if (!ret)
			dbgarg(cmd, "priority is %d\n", *p);
		break;
	}
	case VIDIOC_S_PRIORITY:
	{
		enum v4l2_priority *p=arg;

		if (!vfd->vidioc_s_priority)
			break;
		dbgarg(cmd, "setting priority to %d\n", *p);
		ret=vfd->vidioc_s_priority(file, fh, *p);
		break;
	}

	/* --- capture ioctls ---------------------------------------- */
	case VIDIOC_ENUM_FMT:
	{
		struct v4l2_fmtdesc *f = arg;
		enum v4l2_buf_type type;
		unsigned int index;

		index = f->index;
		type  = f->type;
		memset(f,0,sizeof(*f));
		f->index = index;
		f->type  = type;

		switch (type) {
		case V4L2_BUF_TYPE_VIDEO_CAPTURE:
			if (vfd->vidioc_enum_fmt_cap)
				ret=vfd->vidioc_enum_fmt_cap(file, fh, f);
			break;
		case V4L2_BUF_TYPE_VIDEO_OVERLAY:
			if (vfd->vidioc_enum_fmt_overlay)
				ret=vfd->vidioc_enum_fmt_overlay(file, fh, f);
			break;
		case V4L2_BUF_TYPE_VBI_CAPTURE:
			if (vfd->vidioc_enum_fmt_vbi)
				ret=vfd->vidioc_enum_fmt_vbi(file, fh, f);
			break;
		case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
			if (vfd->vidioc_enum_fmt_vbi_output)
				ret=vfd->vidioc_enum_fmt_vbi_output(file,
								fh, f);
			break;
		case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
			if (vfd->vidioc_enum_fmt_vbi_capture)
				ret=vfd->vidioc_enum_fmt_vbi_capture(file,
								fh, f);
			break;
		case V4L2_BUF_TYPE_VIDEO_OUTPUT:
			if (vfd->vidioc_enum_fmt_video_output)
				ret=vfd->vidioc_enum_fmt_video_output(file,
								fh, f);
			break;
		case V4L2_BUF_TYPE_VBI_OUTPUT:
			if (vfd->vidioc_enum_fmt_vbi_output)
				ret=vfd->vidioc_enum_fmt_vbi_output(file,
								fh, f);
			break;
		case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
			if (vfd->vidioc_enum_fmt_output_overlay)
				ret=vfd->vidioc_enum_fmt_output_overlay(file, fh, f);
			break;
		case V4L2_BUF_TYPE_PRIVATE:
			if (vfd->vidioc_enum_fmt_type_private)
				ret=vfd->vidioc_enum_fmt_type_private(file,
								fh, f);
			break;
		}
		if (!ret)
			dbgarg (cmd, "index=%d, type=%d, flags=%d, "
					"pixelformat=%c%c%c%c, description='%s'\n",
					f->index, f->type, f->flags,
					(f->pixelformat & 0xff),
					(f->pixelformat >>  8) & 0xff,
					(f->pixelformat >> 16) & 0xff,
					(f->pixelformat >> 24) & 0xff,
					f->description);
		break;
	}
	case VIDIOC_G_FMT:
	{
		struct v4l2_format *f = (struct v4l2_format *)arg;
		enum v4l2_buf_type type=f->type;

		memset(&f->fmt.pix,0,sizeof(f->fmt.pix));
		f->type=type;

		/* FIXME: Should be one dump per type */
		dbgarg (cmd, "type=%s\n", prt_names(type,
					v4l2_type_names_FIXME));

		switch (type) {
		case V4L2_BUF_TYPE_VIDEO_CAPTURE:
			if (vfd->vidioc_g_fmt_cap)
				ret=vfd->vidioc_g_fmt_cap(file, fh, f);
			if (!ret)
				v4l_print_pix_fmt(vfd,&f->fmt.pix);
			break;
		case V4L2_BUF_TYPE_VIDEO_OVERLAY:
			if (vfd->vidioc_g_fmt_overlay)