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diff --git a/Documentation/ioctl/cdrom.txt b/Documentation/ioctl/cdrom.txt new file mode 100644 index 000000000..59df81c8d --- /dev/null +++ b/Documentation/ioctl/cdrom.txt @@ -0,0 +1,966 @@ + 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 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. |