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device_numbers(3K)             DG/UX R4.11MU05            device_numbers(3K)


NAME
       devicenumbers: ioallocatedevicenumber,
       iodeallocatedevicenumber, iomapdevicenumber - manage minor
       device numbers

SYNOPSIS
       #include "/usr/src/uts/aviion/ii/iio.h"

       statustype   ioallocatedevicenumber (
           iomajordevicenumbertype     major,        /*READONLY*/
           bit32etype                     handle,       /*READONLY*/
           uint16type                     unit,         /*READONLY*/
           iominordevicenumberptrtype minorptr     /*WRITEONLY*/
                                               )

       void          iodeallocatedevicenumber (
           iodevicenumbertype           devicenumber  /*READONLY*/
                                                 )

       statustype   iomapdevicenumber (
           iodevicenumbertype           devicenumber, /*READONLY*/
           bit32eptrtype                 handleptr,    /*WRITEONLY*/
           uint16ptrtype                 unitptr       /*WRITEONLY*/
                                          )

   where:
       devicenumber      The major and minor device numbers of a device.
       handle             Device handle that identifies the device to its
                          driver.  This is usually a pointer to a structure
                          that contains state information about the devices.
       handleptr         Pointer to location where device handle is re­
                          turned.
       major              The device's major device number.
       minorptr          A pointer to the location where the allocated mi­
                          nor device number is returned.
       unit               The unit number that identifies the device to its
                          controller.
       unitptr           A pointer to the location where the unit number is
                          returned.

DESCRIPTION
       The following device number management routines are described in this
       man page:
       ioallocatedevicenumber
              Assign device a minor device number.  The major device number
              identifies the family of devices to which the device belongs.
       iodeallocatedevicenumber
              Deallocate minor device number, thus terminating the associa­
              tion between a device and its minor device number.
       iomapdevicenumber
              Translate a previously allocated major and minor device number
              pair to a device handle and unit number.
       During device configuration, the system passes to a driver's driv­
       erconfigure routine a major number that identifies the driver's po­
       sition in the kernel's driver lookup table.  The driver must then
       call ioallocatedevicenumber to specify the particular device's lo­
       cation in the kernel's device tables.  This routine returns the next
       available minor number and also puts a parameter supplied by the
       driver into the device table.  Typically, the parameter is a pointer
       to a data structure associated with the device.  The driver can re­
       trieve the stored parameter by calling iomapdevicenumber with the
       major and minor device number as parameters.  At device deconfigura­
       tion time, the minor device number can be returned to the pool of un­
       claimed numbers by calling iodeallocatedevicenumber.
DIAGNOSTICS
   Return Value
       For ioallocatedevicenumber:
              OK     No errors were discovered, so all returned arguments
                     are valid.
              IOENXIOALLMINORNUMBERSINUSE
                     The minor device number table for this major device
                     number contains no unused slots and has grown to the
                     maximum size.

       For iodeallocatedevicenumber:
              None.

       For iomapdevicenumber:
              OK     No errors occurred.
              IOENXIODEVICEISNOTCONFIGURED
                     An attempt was made to map a device that is not config­
                     ured.

   Errors
       None.

   Abort Conditions
       For iodeallocatedevicenumber, panic may be invoked with the fol­
       lowing error codes:
              IOPANICMAJORNUMBEREXCEEDSMAX
                     An invalid major device number was used.
              IOPANICDEVICEISNOTCONFIGURED
                     An attempt was made to deallocate a device that was not
                     configured.
              IOPANICDEVICEISNOTCONFIGURED2
                     An active entry in the minor device number table does
                     not exist at the offset specified by the minor device
                     number argument.

       For iomapdevicenumber, panic may be invoked with the following er­
       ror code:
              IOPANICMAJORNUMBEREXCEEDSMAX
                     The major device number argument exceeds the maximum
                     specified by cfiodevicedrivercount.
              IOPANICMAJORNUMBEREXCEEDSMAX2
                     The major device number argument exceeds the maximum
                     specified by cfiomajornumbercount.

SEE ALSO
       deviceconfiguration(3K).
       Programming in the DG/UX Kernel Environment.


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