diff options
Diffstat (limited to 'Documentation/ioctl-number.txt')
| -rw-r--r-- | Documentation/ioctl-number.txt | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/Documentation/ioctl-number.txt b/Documentation/ioctl-number.txt new file mode 100644 index 00000000000..769f925c852 --- /dev/null +++ b/Documentation/ioctl-number.txt @@ -0,0 +1,196 @@ +Ioctl Numbers +19 October 1999 +Michael Elizabeth Chastain +<mec@shout.net> + +If you are adding new ioctl's to the kernel, you should use the _IO +macros defined in <linux/ioctl.h>: + + _IO an ioctl with no parameters + _IOW an ioctl with write parameters (copy_from_user) + _IOR an ioctl with read parameters (copy_to_user) + _IOWR an ioctl with both write and read parameters. + +'Write' and 'read' are from the user's point of view, just like the +system calls 'write' and 'read'. For example, a SET_FOO ioctl would +be _IOW, although the kernel would actually read data from user space; +a GET_FOO ioctl would be _IOR, although the kernel would actually write +data to user space. + +The first argument to _IO, _IOW, _IOR, or _IOWR is an identifying letter +or number from the table below. Because of the large number of drivers, +many drivers share a partial letter with other drivers. + +If you are writing a driver for a new device and need a letter, pick an +unused block with enough room for expansion: 32 to 256 ioctl commands. +You can register the block by patching this file and submitting the +patch to Linus Torvalds. Or you can e-mail me at <mec@shout.net> and +I'll register one for you. + +The second argument to _IO, _IOW, _IOR, or _IOWR is a sequence number +to distinguish ioctls from each other. The third argument to _IOW, +_IOR, or _IOWR is the type of the data going into the kernel or coming +out of the kernel (e.g. 'int' or 'struct foo'). NOTE! Do NOT use +sizeof(arg) as the third argument as this results in your ioctl thinking +it passes an argument of type size_t. + +Some devices use their major number as the identifier; this is OK, as +long as it is unique. Some devices are irregular and don't follow any +convention at all. + +Following this convention is good because: + +(1) Keeping the ioctl's globally unique helps error checking: + if a program calls an ioctl on the wrong device, it will get an + error rather than some unexpected behaviour. + +(2) The 'strace' build procedure automatically finds ioctl numbers + defined with _IO, _IOW, _IOR, or _IOWR. + +(3) 'strace' can decode numbers back into useful names when the + numbers are unique. + +(4) People looking for ioctls can grep for them more easily when + this convention is used to define the ioctl numbers. + +(5) When following the convention, the driver code can use generic + code to copy the parameters between user and kernel space. + +This table lists ioctls visible from user land for Linux/i386. It contains +most drivers up to 2.3.14, but I know I am missing some. + +Code Seq# Include File Comments +======================================================== +0x00 00-1F linux/fs.h conflict! +0x00 00-1F scsi/scsi_ioctl.h conflict! +0x00 00-1F linux/fb.h conflict! +0x00 00-1F linux/wavefront.h conflict! +0x02 all linux/fd.h +0x03 all linux/hdreg.h +0x04 all linux/umsdos_fs.h +0x06 all linux/lp.h +0x09 all linux/md.h +0x12 all linux/fs.h + linux/blkpg.h +0x1b all InfiniBand Subsystem <http://www.openib.org/> +0x20 all drivers/cdrom/cm206.h +0x22 all scsi/sg.h +'#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem +'1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl + <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> +'6' 00-10 <asm-i386/processor.h> Intel IA32 microcode update driver + <mailto:tigran@veritas.com> +'8' all SNP8023 advanced NIC card + <mailto:mcr@solidum.com> +'A' 00-1F linux/apm_bios.h +'B' C0-FF advanced bbus + <mailto:maassen@uni-freiburg.de> +'C' all linux/soundcard.h +'D' all asm-s390/dasd.h +'F' all linux/fb.h +'I' all linux/isdn.h +'J' 00-1F drivers/scsi/gdth_ioctl.h +'K' all linux/kd.h +'L' 00-1F linux/loop.h +'L' E0-FF linux/ppdd.h encrypted disk device driver + <http://linux01.gwdg.de/~alatham/ppdd.html> +'M' all linux/soundcard.h conflict! +'M' 00-1F linux/isicom.h conflict! +'N' 00-1F drivers/usb/scanner.h +'P' all linux/soundcard.h +'Q' all linux/soundcard.h +'R' 00-1F linux/random.h +'S' all linux/cdrom.h conflict! +'S' 80-81 scsi/scsi_ioctl.h conflict! +'S' 82-FF scsi/scsi.h conflict! +'T' all linux/soundcard.h conflict! +'T' all asm-i386/ioctls.h conflict! +'U' 00-EF linux/drivers/usb/usb.h +'U' F0-FF drivers/usb/auerswald.c +'V' all linux/vt.h +'W' 00-1F linux/watchdog.h conflict! +'W' 00-1F linux/wanrouter.h conflict! +'X' all linux/xfs_fs.h +'Y' all linux/cyclades.h +'a' all ATM on linux + <http://lrcwww.epfl.ch/linux-atm/magic.html> +'b' 00-FF bit3 vme host bridge + <mailto:natalia@nikhefk.nikhef.nl> +'c' 00-7F linux/comstats.h conflict! +'c' 00-7F linux/coda.h conflict! +'d' 00-FF linux/char/drm/drm/h conflict! +'d' 00-1F linux/devfs_fs.h conflict! +'d' 00-DF linux/video_decoder.h conflict! +'d' F0-FF linux/digi1.h +'e' all linux/digi1.h conflict! +'e' 00-1F linux/video_encoder.h conflict! +'e' 00-1F net/irda/irtty.h conflict! +'f' 00-1F linux/ext2_fs.h +'h' 00-7F Charon filesystem + <mailto:zapman@interlan.net> +'i' 00-3F linux/i2o.h +'j' 00-3F linux/joystick.h +'k' all asm-sparc/kbio.h + asm-sparc64/kbio.h +'l' 00-3F linux/tcfs_fs.h transparent cryptographic file system + <http://mikonos.dia.unisa.it/tcfs> +'l' 40-7F linux/udf_fs_i.h in development: + <http://www.trylinux.com/projects/udf/> +'m' all linux/mtio.h conflict! +'m' all linux/soundcard.h conflict! +'m' all linux/synclink.h conflict! +'m' 00-1F net/irda/irmod.h conflict! +'n' 00-7F linux/ncp_fs.h +'n' E0-FF video/matrox.h matroxfb +'p' 00-3F linux/mc146818rtc.h +'p' 40-7F linux/nvram.h +'p' 80-9F user-space parport + <mailto:tim@cyberelk.net> +'q' 00-1F linux/serio.h +'q' 80-FF Internet PhoneJACK, Internet LineJACK + <http://www.quicknet.net> +'r' 00-1F linux/msdos_fs.h +'s' all linux/cdk.h +'t' 00-7F linux/if_ppp.h +'t' 80-8F linux/isdn_ppp.h +'u' 00-1F linux/smb_fs.h +'v' 00-1F linux/ext2_fs.h conflict! +'v' all linux/videodev.h conflict! +'w' all CERN SCI driver +'y' 00-1F packet based user level communications + <mailto:zapman@interlan.net> +'z' 00-3F CAN bus card + <mailto:hdstich@connectu.ulm.circular.de> +'z' 40-7F CAN bus card + <mailto:oe@port.de> +0x80 00-1F linux/fb.h +0x81 00-1F linux/videotext.h +0x89 00-06 asm-i386/sockios.h +0x89 0B-DF linux/sockios.h +0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range +0x89 F0-FF linux/sockios.h SIOCDEVPRIVATE range +0x8B all linux/wireless.h +0x8C 00-3F WiNRADiO driver + <http://www.proximity.com.au/~brian/winradio/> +0x90 00 drivers/cdrom/sbpcd.h +0x93 60-7F linux/auto_fs.h +0x99 00-0F 537-Addinboard driver + <mailto:buk@buks.ipn.de> +0xA0 all linux/sdp/sdp.h Industrial Device Project + <mailto:kenji@bitgate.com> +0xA3 80-8F Port ACL in development: + <mailto:tlewis@mindspring.com> +0xA3 90-9F linux/dtlk.h +0xAB 00-1F linux/nbd.h +0xAC 00-1F linux/raw.h +0xAD 00 Netfilter device in development: + <mailto:rusty@rustcorp.com.au> +0xB0 all RATIO devices in development: + <mailto:vgo@ratio.de> +0xB1 00-1F PPPoX <mailto:mostrows@styx.uwaterloo.ca> +0xCB 00-1F CBM serial IEC bus in development: + <mailto:michael.klein@puffin.lb.shuttle.de> +0xDD 00-3F ZFCP device driver see drivers/s390/scsi/ + <mailto:aherrman@de.ibm.com> +0xF3 00-3F video/sisfb.h sisfb (in development) + <mailto:thomas@winischhofer.net> |