========================  ===============================================
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_TIMED_MEDIA_CHANGE  Check if media changed
			  since given time
			  (struct cdrom_timed_media_change_info)
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
========================  ===============================================

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>

usage::

  ioctl(fd, CDROMPAUSE, 0);


inputs:
	none


outputs:
	none


error return:
  - ENOSYS	cd drive not audio-capable.

usage::

  ioctl(fd, CDROMRESUME, 0);


inputs:
	none


outputs:
	none


error return:
  - ENOSYS	cd drive not audio-capable.

(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.

(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.

(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.

(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

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.

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.

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.

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.

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.

(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.

(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

(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;

(struct cdrom_read)

notes:
	Identical to CDROMREADRAW except that block size is
	CD_FRAMESIZE (2048) bytes

(struct cdrom_read)

notes:
	Identical to CDROMREADRAW except that block size is
	CD_FRAMESIZE_RAW0 (2336) bytes

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

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

(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

(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!

Not implemented, as of 2.6.8.1

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.

usage::

  u8 buffer[CD_FRAMESIZE]

  ioctl(fd, CDROMREADCOOKED, buffer);

inputs:
	none


outputs:
	2048 bytes of data, "cooked" mode.


notes:
	Not implemented on all drives.

Same as CDROMREADCOOKED, but reads 2646 bytes.

usage::

  struct cdrom_msf msf;

  ioctl(fd, CDROMSEEK, &msf);

inputs:
	MSF address to seek to.


outputs:
	none

(struct cdrom_blk)


usage::

  struct cdrom_blk blk;

  ioctl(fd, CDROMPLAYBLK, &blk);

inputs:
	Region to play


outputs:
	none

usage::

  char spindown;

  ioctl(fd, CDROMGETSPINDOWN, &spindown);

inputs:
	none


outputs:
	The value of the current 4-bit spindown value.

usage::

  char spindown

  ioctl(fd, CDROMSETSPINDOWN, &spindown);

inputs:
	4-bit value used to control spindown (TODO: more detail here)


outputs:
	none

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.

Same as CDROM_SET_OPTIONS, except that selected options are
turned off.

usage::

  int speed;

  ioctl(fd, CDROM_SELECT_SPEED, speed);

inputs:
	New drive speed.


outputs:
	none


error return:
  - ENOSYS	speed selection not supported by drive.

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

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

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

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

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

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

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

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.

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.

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

Not implemented, as of 2.6.8.1

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.

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

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.

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.