Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 967 insertions, 0 deletions

diff --git a/Documentation/ioctl/cdrom.txt b/Documentation/ioctl/cdrom.txt
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+		Summary of CDROM ioctl calls.
+		============================
+
+		Edward A. Falk <efalk@google.com>
+
+		November, 2004
+
+This document attempts to describe the ioctl(2) calls supported by
+the CDROM layer.  These are by-and-large implemented (as of Linux 2.6)
+in drivers/cdrom/cdrom.c and drivers/block/scsi_ioctl.c
+
+ioctl values are listed in <linux/cdrom.h>.  As of this writing, they
+are as follows:
+
+	CDROMPAUSE		Pause Audio Operation
+	CDROMRESUME		Resume paused Audio Operation
+	CDROMPLAYMSF		Play Audio MSF (struct cdrom_msf)
+	CDROMPLAYTRKIND		Play Audio Track/index (struct cdrom_ti)
+	CDROMREADTOCHDR		Read TOC header (struct cdrom_tochdr)
+	CDROMREADTOCENTRY	Read TOC entry (struct cdrom_tocentry)
+	CDROMSTOP		Stop the cdrom drive
+	CDROMSTART		Start the cdrom drive
+	CDROMEJECT		Ejects the cdrom media
+	CDROMVOLCTRL		Control output volume (struct cdrom_volctrl)
+	CDROMSUBCHNL		Read subchannel data (struct cdrom_subchnl)
+	CDROMREADMODE2		Read CDROM mode 2 data (2336 Bytes)
+					   (struct cdrom_read)
+	CDROMREADMODE1		Read CDROM mode 1 data (2048 Bytes)
+					   (struct cdrom_read)
+	CDROMREADAUDIO		(struct cdrom_read_audio)
+	CDROMEJECT_SW		enable(1)/disable(0) auto-ejecting
+	CDROMMULTISESSION	Obtain the start-of-last-session
+				  address of multi session disks
+				  (struct cdrom_multisession)
+	CDROM_GET_MCN		Obtain the "Universal Product Code"
+				   if available (struct cdrom_mcn)
+	CDROM_GET_UPC		Deprecated, use CDROM_GET_MCN instead.
+	CDROMRESET		hard-reset the drive
+	CDROMVOLREAD		Get the drive's volume setting
+					  (struct cdrom_volctrl)
+	CDROMREADRAW		read data in raw mode (2352 Bytes)
+					   (struct cdrom_read)
+	CDROMREADCOOKED		read data in cooked mode
+	CDROMSEEK		seek msf address
+	CDROMPLAYBLK		scsi-cd only, (struct cdrom_blk)
+	CDROMREADALL		read all 2646 bytes
+	CDROMGETSPINDOWN	return 4-bit spindown value
+	CDROMSETSPINDOWN	set 4-bit spindown value
+	CDROMCLOSETRAY		pendant of CDROMEJECT
+	CDROM_SET_OPTIONS	Set behavior options
+	CDROM_CLEAR_OPTIONS	Clear behavior options
+	CDROM_SELECT_SPEED	Set the CD-ROM speed
+	CDROM_SELECT_DISC	Select disc (for juke-boxes)
+	CDROM_MEDIA_CHANGED	Check is media changed
+	CDROM_DRIVE_STATUS	Get tray position, etc.
+	CDROM_DISC_STATUS	Get disc type, etc.
+	CDROM_CHANGER_NSLOTS	Get number of slots
+	CDROM_LOCKDOOR		lock or unlock door
+	CDROM_DEBUG		Turn debug messages on/off
+	CDROM_GET_CAPABILITY	get capabilities
+	CDROMAUDIOBUFSIZ	set the audio buffer size
+	DVD_READ_STRUCT		Read structure
+	DVD_WRITE_STRUCT	Write structure
+	DVD_AUTH		Authentication
+	CDROM_SEND_PACKET	send a packet to the drive
+	CDROM_NEXT_WRITABLE	get next writable block
+	CDROM_LAST_WRITTEN	get last block written on disc
+
+
+The information that follows was determined from reading kernel source
+code.  It is likely that some corrections will be made over time.
+
+
+
+
+
+
+
+General:
+
+	Unless otherwise specified, all ioctl calls return 0 on success
+	and -1 with errno set to an appropriate value on error.  (Some
+	ioctls return non-negative data values.)
+
+	Unless otherwise specified, all ioctl calls return -1 and set
+	errno to EFAULT on a failed attempt to copy data to or from user
+	address space.
+
+	Individual drivers may return error codes not listed here.
+
+	Unless otherwise specified, all data structures and constants
+	are defined in <linux/cdrom.h>
+
+
+
+
+CDROMPAUSE			Pause Audio Operation
+
+	usage:
+
+	  ioctl(fd, CDROMPAUSE, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+
+CDROMRESUME			Resume paused Audio Operation
+
+	usage:
+
+	  ioctl(fd, CDROMRESUME, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+
+CDROMPLAYMSF			Play Audio MSF (struct cdrom_msf)
+
+	usage:
+
+	  struct cdrom_msf msf;
+	  ioctl(fd, CDROMPLAYMSF, &msf);
+
+	inputs:
+	  cdrom_msf structure, describing a segment of music to play
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+	notes:
+	  MSF stands for minutes-seconds-frames
+	  LBA stands for logical block address
+
+	  Segment is described as start and end times, where each time
+	  is described as minutes:seconds:frames.  A frame is 1/75 of
+	  a second.
+
+
+CDROMPLAYTRKIND			Play Audio Track/index (struct cdrom_ti)
+
+	usage:
+
+	  struct cdrom_ti ti;
+	  ioctl(fd, CDROMPLAYTRKIND, &ti);
+
+	inputs:
+	  cdrom_ti structure, describing a segment of music to play
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+	notes:
+	  Segment is described as start and end times, where each time
+	  is described as a track and an index.
+
+
+
+CDROMREADTOCHDR			Read TOC header (struct cdrom_tochdr)
+
+	usage:
+
+	  cdrom_tochdr header;
+	  ioctl(fd, CDROMREADTOCHDR, &header);
+
+	inputs:
+	  cdrom_tochdr structure
+
+	outputs:
+	  cdrom_tochdr structure
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+
+
+CDROMREADTOCENTRY		Read TOC entry (struct cdrom_tocentry)
+
+	usage:
+
+	  struct cdrom_tocentry entry;
+	  ioctl(fd, CDROMREADTOCENTRY, &entry);
+
+	inputs:
+	  cdrom_tocentry structure
+
+	outputs:
+	  cdrom_tocentry structure
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+	  EINVAL	entry.cdte_format not CDROM_MSF or CDROM_LBA
+	  EINVAL	requested track out of bounds
+	  EIO		I/O error reading TOC
+
+	notes:
+	  TOC stands for Table Of Contents
+	  MSF stands for minutes-seconds-frames
+	  LBA stands for logical block address
+
+
+
+CDROMSTOP			Stop the cdrom drive
+
+	usage:
+
+	  ioctl(fd, CDROMSTOP, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+	notes:
+	  Exact interpretation of this ioctl depends on the device,
+	  but most seem to spin the drive down.
+
+
+CDROMSTART			Start the cdrom drive
+
+	usage:
+
+	  ioctl(fd, CDROMSTART, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+	notes:
+	  Exact interpretation of this ioctl depends on the device,
+	  but most seem to spin the drive up and/or close the tray.
+	  Other devices ignore the ioctl completely.
+
+
+CDROMEJECT			Ejects the cdrom media
+
+	usage:
+
+	  ioctl(fd, CDROMEJECT, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error returns:
+	  ENOSYS	cd drive not capable of ejecting
+	  EBUSY		other processes are accessing drive, or door is locked
+
+	notes:
+	  See CDROM_LOCKDOOR, below.
+
+
+
+CDROMCLOSETRAY			pendant of CDROMEJECT
+
+	usage:
+
+	  ioctl(fd, CDROMCLOSETRAY, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error returns:
+	  ENOSYS	cd drive not capable of closing the tray
+	  EBUSY		other processes are accessing drive, or door is locked
+
+	notes:
+	  See CDROM_LOCKDOOR, below.
+
+
+
+CDROMVOLCTRL			Control output volume (struct cdrom_volctrl)
+
+	usage:
+
+	  struct cdrom_volctrl volume;
+	  ioctl(fd, CDROMVOLCTRL, &volume);
+
+	inputs:
+	  cdrom_volctrl structure containing volumes for up to 4
+	  channels.
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+
+
+CDROMVOLREAD			Get the drive's volume setting
+					  (struct cdrom_volctrl)
+
+	usage:
+
+	  struct cdrom_volctrl volume;
+	  ioctl(fd, CDROMVOLREAD, &volume);
+
+	inputs:		none
+
+	outputs:
+	  The current volume settings.
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+
+
+
+CDROMSUBCHNL			Read subchannel data (struct cdrom_subchnl)
+
+	usage:
+
+	  struct cdrom_subchnl q;
+	  ioctl(fd, CDROMSUBCHNL, &q);
+
+	inputs:
+	  cdrom_subchnl structure
+
+	outputs:
+	  cdrom_subchnl structure
+
+	error return:
+	  ENOSYS	cd drive not audio-capable.
+	  EINVAL	format not CDROM_MSF or CDROM_LBA
+
+	notes:
+	  Format is converted to CDROM_MSF or CDROM_LBA
+	  as per user request on return
+
+
+
+CDROMREADRAW			read data in raw mode (2352 Bytes)
+					   (struct cdrom_read)
+
+	usage:
+
+	  union {
+	    struct cdrom_msf msf;		/* input */
+	    char buffer[CD_FRAMESIZE_RAW];	/* return */
+	  } arg;
+	  ioctl(fd, CDROMREADRAW, &arg);
+
+	inputs:
+	  cdrom_msf structure indicating an address to read.
+	  Only the start values are significant.
+
+	outputs:
+	  Data written to address provided by user.
+
+	error return:
+	  EINVAL	address less than 0, or msf less than 0:2:0
+	  ENOMEM	out of memory
+
+	notes:
+	  As of 2.6.8.1, comments in <linux/cdrom.h> indicate that this
+	  ioctl accepts a cdrom_read structure, but actual source code
+	  reads a cdrom_msf structure and writes a buffer of data to
+	  the same address.
+
+	  MSF values are converted to LBA values via this formula:
+
+	    lba = (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_MSF_OFFSET;
+
+
+
+
+CDROMREADMODE1			Read CDROM mode 1 data (2048 Bytes)
+					   (struct cdrom_read)
+
+	notes:
+	  Identical to CDROMREADRAW except that block size is
+	  CD_FRAMESIZE (2048) bytes
+
+
+
+CDROMREADMODE2			Read CDROM mode 2 data (2336 Bytes)
+					   (struct cdrom_read)
+
+	notes:
+	  Identical to CDROMREADRAW except that block size is
+	  CD_FRAMESIZE_RAW0 (2336) bytes
+
+
+
+CDROMREADAUDIO			(struct cdrom_read_audio)
+
+	usage:
+
+	  struct cdrom_read_audio ra;
+	  ioctl(fd, CDROMREADAUDIO, &ra);
+
+	inputs:
+	  cdrom_read_audio structure containing read start
+	  point and length
+
+	outputs:
+	  audio data, returned to buffer indicated by ra
+
+	error return:
+	  EINVAL	format not CDROM_MSF or CDROM_LBA
+	  EINVAL	nframes not in range [1 75]
+	  ENXIO		drive has no queue (probably means invalid fd)
+	  ENOMEM	out of memory
+
+
+CDROMEJECT_SW			enable(1)/disable(0) auto-ejecting
+
+	usage:
+
+	  int val;
+	  ioctl(fd, CDROMEJECT_SW, val);
+
+	inputs:
+	  Flag specifying auto-eject flag.
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	Drive is not capable of ejecting.
+	  EBUSY		Door is locked
+
+
+
+
+CDROMMULTISESSION		Obtain the start-of-last-session
+				  address of multi session disks
+				  (struct cdrom_multisession)
+	usage:
+
+	  struct cdrom_multisession ms_info;
+	  ioctl(fd, CDROMMULTISESSION, &ms_info);
+
+	inputs:
+	  cdrom_multisession structure containing desired
+	  format.
+
+	outputs:
+	  cdrom_multisession structure is filled with last_session
+	  information.
+
+	error return:
+	  EINVAL	format not CDROM_MSF or CDROM_LBA
+
+
+CDROM_GET_MCN			Obtain the "Universal Product Code"
+				   if available (struct cdrom_mcn)
+
+	usage:
+
+	  struct cdrom_mcn mcn;
+	  ioctl(fd, CDROM_GET_MCN, &mcn);
+
+	inputs:		none
+
+	outputs:
+	  Universal Product Code
+
+	error return:
+	  ENOSYS	Drive is not capable of reading MCN data.
+
+	notes:
+	  Source code comments state:
+
+	    The following function is implemented, although very few
+	    audio discs give Universal Product Code information, which
+	    should just be the Medium Catalog Number on the box.  Note,
+	    that the way the code is written on the CD is /not/ uniform
+	    across all discs!
+
+
+
+
+CDROM_GET_UPC			CDROM_GET_MCN  (deprecated)
+
+	Not implemented, as of 2.6.8.1
+
+
+
+CDROMRESET			hard-reset the drive
+
+	usage:
+
+	  ioctl(fd, CDROMRESET, 0);
+
+	inputs:		none
+
+	outputs:	none
+
+	error return:
+	  EACCES	Access denied:  requires CAP_SYS_ADMIN
+	  ENOSYS	Drive is not capable of resetting.
+
+
+
+
+CDROMREADCOOKED			read data in cooked mode
+
+	usage:
+
+	  u8 buffer[CD_FRAMESIZE]
+	  ioctl(fd, CDROMREADCOOKED, buffer);
+
+	inputs:		none
+
+	outputs:
+	  2048 bytes of data, "cooked" mode.
+
+	notes:
+	  Not implemented on all drives.
+
+
+
+
+CDROMREADALL			read all 2646 bytes
+
+	Same as CDROMREADCOOKED, but reads 2646 bytes.
+
+
+
+CDROMSEEK			seek msf address
+
+	usage:
+
+	  struct cdrom_msf msf;
+	  ioctl(fd, CDROMSEEK, &msf);
+
+	inputs:
+	  MSF address to seek to.
+
+	outputs:	none
+
+
+
+CDROMPLAYBLK			scsi-cd only, (struct cdrom_blk)
+
+	usage:
+
+	  struct cdrom_blk blk;
+	  ioctl(fd, CDROMPLAYBLK, &blk);
+
+	inputs:
+	  Region to play
+
+	outputs:	none
+
+
+
+CDROMGETSPINDOWN
+
+	usage:
+
+	  char spindown;
+	  ioctl(fd, CDROMGETSPINDOWN, &spindown);
+
+	inputs:		none
+
+	outputs:
+	  The value of the current 4-bit spindown value.
+
+
+
+
+CDROMSETSPINDOWN
+
+	usage:
+
+	  char spindown
+	  ioctl(fd, CDROMSETSPINDOWN, &spindown);
+
+	inputs:
+	  4-bit value used to control spindown (TODO: more detail here)
+
+	outputs:	none
+
+
+
+
+
+CDROM_SET_OPTIONS		Set behavior options
+
+	usage:
+
+	  int options;
+	  ioctl(fd, CDROM_SET_OPTIONS, options);
+
+	inputs:
+	  New values for drive options.  The logical 'or' of:
+	    CDO_AUTO_CLOSE	close tray on first open(2)
+	    CDO_AUTO_EJECT	open tray on last release
+	    CDO_USE_FFLAGS	use O_NONBLOCK information on open
+	    CDO_LOCK		lock tray on open files
+	    CDO_CHECK_TYPE	check type on open for data
+
+	outputs:
+	  Returns the resulting options settings in the
+	  ioctl return value.  Returns -1 on error.
+
+	error return:
+	  ENOSYS	selected option(s) not supported by drive.
+
+
+
+
+CDROM_CLEAR_OPTIONS		Clear behavior options
+
+	Same as CDROM_SET_OPTIONS, except that selected options are
+	turned off.
+
+
+
+CDROM_SELECT_SPEED		Set the CD-ROM speed
+
+	usage:
+
+	  int speed;
+	  ioctl(fd, CDROM_SELECT_SPEED, speed);
+
+	inputs:
+	  New drive speed.
+
+	outputs:	none
+
+	error return:
+	  ENOSYS	speed selection not supported by drive.
+
+
+
+CDROM_SELECT_DISC		Select disc (for juke-boxes)
+
+	usage:
+
+	  int disk;
+	  ioctl(fd, CDROM_SELECT_DISC, disk);
+
+	inputs:
+	  Disk to load into drive.
+
+	outputs:	none
+
+	error return:
+	  EINVAL	Disk number beyond capacity of drive
+
+
+
+CDROM_MEDIA_CHANGED		Check is media changed
+
+	usage:
+
+	  int slot;
+	  ioctl(fd, CDROM_MEDIA_CHANGED, slot);
+
+	inputs:
+	  Slot number to be tested, always zero except for jukeboxes.
+	  May also be special values CDSL_NONE or CDSL_CURRENT
+
+	outputs:
+	  Ioctl return value is 0 or 1 depending on whether the media
+	  has been changed, or -1 on error.
+
+	error returns:
+	  ENOSYS	Drive can't detect media change
+	  EINVAL	Slot number beyond capacity of drive
+	  ENOMEM	Out of memory
+
+
+
+CDROM_DRIVE_STATUS		Get tray position, etc.
+
+	usage:
+
+	  int slot;
+	  ioctl(fd, CDROM_DRIVE_STATUS, slot);
+
+	inputs:
+	  Slot number to be tested, always zero except for jukeboxes.
+	  May also be special values CDSL_NONE or CDSL_CURRENT
+
+	outputs:
+	  Ioctl return value will be one of the following values
+	  from <linux/cdrom.h>:
+
+	    CDS_NO_INFO		Information not available.
+	    CDS_NO_DISC
+	    CDS_TRAY_OPEN
+	    CDS_DRIVE_NOT_READY
+	    CDS_DISC_OK
+	    -1			error
+
+	error returns:
+	  ENOSYS	Drive can't detect drive status
+	  EINVAL	Slot number beyond capacity of drive
+	  ENOMEM	Out of memory
+
+
+
+
+CDROM_DISC_STATUS		Get disc type, etc.
+
+	usage:
+
+	  ioctl(fd, CDROM_DISC_STATUS, 0);
+
+	inputs:		none
+
+	outputs:
+	  Ioctl return value will be one of the following values
+	  from <linux/cdrom.h>:
+	    CDS_NO_INFO
+	    CDS_AUDIO
+	    CDS_MIXED
+	    CDS_XA_2_2
+	    CDS_XA_2_1
+	    CDS_DATA_1
+
+	error returns:	none at present
+
+	notes:
+	  Source code comments state:
+
+	    Ok, this is where problems start.  The current interface for
+	    the CDROM_DISC_STATUS ioctl is flawed.  It makes the false
+	    assumption that CDs are all CDS_DATA_1 or all CDS_AUDIO, etc.
+	    Unfortunately, while this is often the case, it is also
+	    very common for CDs to have some tracks with data, and some
+	    tracks with audio.	Just because I feel like it, I declare
+	    the following to be the best way to cope.  If the CD has
+	    ANY data tracks on it, it will be returned as a data CD.
+	    If it has any XA tracks, I will return it as that.	Now I
+	    could simplify this interface by combining these returns with
+	    the above, but this more clearly demonstrates the problem
+	    with the current interface.  Too bad this wasn't designed
+	    to use bitmasks...	       -Erik
+
+	    Well, now we have the option CDS_MIXED: a mixed-type CD.
+	    User level programmers might feel the ioctl is not very
+	    useful.
+			---david
+
+
+
+
+CDROM_CHANGER_NSLOTS		Get number of slots
+
+	usage:
+
+	  ioctl(fd, CDROM_CHANGER_NSLOTS, 0);
+
+	inputs:		none
+
+	outputs:
+	  The ioctl return value will be the number of slots in a
+	  CD changer.  Typically 1 for non-multi-disk devices.
+
+	error returns:	none
+
+
+
+CDROM_LOCKDOOR			lock or unlock door
+
+	usage:
+
+	  int lock;
+	  ioctl(fd, CDROM_LOCKDOOR, lock);
+
+	inputs:
+	  Door lock flag, 1=lock, 0=unlock
+
+	outputs:	none
+
+	error returns:
+	  EDRIVE_CANT_DO_THIS	Door lock function not supported.
+	  EBUSY			Attempt to unlock when multiple users
+	  			have the drive open and not CAP_SYS_ADMIN
+
+	notes:
+	  As of 2.6.8.1, the lock flag is a global lock, meaning that
+	  all CD drives will be locked or unlocked together.  This is
+	  probably a bug.
+
+	  The EDRIVE_CANT_DO_THIS value is defined in <linux/cdrom.h>
+	  and is currently (2.6.8.1) the same as EOPNOTSUPP
+
+
+
+CDROM_DEBUG			Turn debug messages on/off
+
+	usage:
+
+	  int debug;
+	  ioctl(fd, CDROM_DEBUG, debug);
+
+	inputs:
+	  Cdrom debug flag, 0=disable, 1=enable
+
+	outputs:
+	  The ioctl return value will be the new debug flag.
+
+	error return:
+	  EACCES	Access denied:  requires CAP_SYS_ADMIN
+
+
+
+CDROM_GET_CAPABILITY		get capabilities
+
+	usage:
+
+	  ioctl(fd, CDROM_GET_CAPABILITY, 0);
+
+	inputs:		none
+
+	outputs:
+	  The ioctl return value is the current device capability
+	  flags.  See CDC_CLOSE_TRAY, CDC_OPEN_TRAY, etc.
+
+
+
+CDROMAUDIOBUFSIZ		set the audio buffer size
+
+	usage:
+
+	  int arg;
+	  ioctl(fd, CDROMAUDIOBUFSIZ, val);
+
+	inputs:
+	  New audio buffer size
+
+	outputs:
+	  The ioctl return value is the new audio buffer size, or -1
+	  on error.
+
+	error return:
+	  ENOSYS	Not supported by this driver.
+
+	notes:
+	  Not supported by all drivers.
+
+
+
+DVD_READ_STRUCT			Read structure
+
+	usage:
+
+	  dvd_struct s;
+	  ioctl(fd, DVD_READ_STRUCT, &s);
+
+	inputs:
+	  dvd_struct structure, containing:
+	    type		specifies the information desired, one of
+	    			DVD_STRUCT_PHYSICAL, DVD_STRUCT_COPYRIGHT,
+				DVD_STRUCT_DISCKEY, DVD_STRUCT_BCA,
+				DVD_STRUCT_MANUFACT
+	    physical.layer_num	desired layer, indexed from 0
+	    copyright.layer_num	desired layer, indexed from 0
+	    disckey.agid
+
+	outputs:
+	  dvd_struct structure, containing:
+	    physical		for type == DVD_STRUCT_PHYSICAL
+	    copyright		for type == DVD_STRUCT_COPYRIGHT
+	    disckey.value	for type == DVD_STRUCT_DISCKEY
+	    bca.{len,value}	for type == DVD_STRUCT_BCA
+	    manufact.{len,valu}	for type == DVD_STRUCT_MANUFACT
+
+	error returns:
+	  EINVAL	physical.layer_num exceeds number of layers
+	  EIO		Received invalid response from drive
+
+
+
+DVD_WRITE_STRUCT		Write structure
+
+	Not implemented, as of 2.6.8.1
+
+
+
+DVD_AUTH			Authentication
+
+	usage:
+
+	  dvd_authinfo ai;
+	  ioctl(fd, DVD_AUTH, &ai);
+
+	inputs:
+	  dvd_authinfo structure.  See <linux/cdrom.h>
+
+	outputs:
+	  dvd_authinfo structure.
+
+	error return:
+	  ENOTTY	ai.type not recognized.
+
+
+
+CDROM_SEND_PACKET		send a packet to the drive
+
+	usage:
+
+	  struct cdrom_generic_command cgc;
+	  ioctl(fd, CDROM_SEND_PACKET, &cgc);
+
+	inputs:
+	  cdrom_generic_command structure containing the packet to send.
+
+	outputs:	none
+	  cdrom_generic_command structure containing results.
+
+	error return:
+	  EIO		command failed.
+	  EPERM		Operation not permitted, either because a
+			write command was attempted on a drive which
+			is opened read-only, or because the command
+			requires CAP_SYS_RAWIO
+	  EINVAL	cgc.data_direction not set
+
+
+
+CDROM_NEXT_WRITABLE		get next writable block
+
+	usage:
+
+	  long next;
+	  ioctl(fd, CDROM_NEXT_WRITABLE, &next);
+
+	inputs:		none
+
+	outputs:
+	  The next writable block.
+
+	notes:
+	  If the device does not support this ioctl directly, the
+	  ioctl will return CDROM_LAST_WRITTEN + 7.
+
+
+
+CDROM_LAST_WRITTEN		get last block written on disc
+
+	usage:
+
+	  long last;
+	  ioctl(fd, CDROM_LAST_WRITTEN, &last);
+
+	inputs:		none
+
+	outputs:
+	  The last block written on disc
+
+	notes:
+	  If the device does not support this ioctl directly, the
+	  result is derived from the disc's table of contents.  If the
+	  table of contents can't be read, this ioctl returns an
+	  error.