PCICONFIG_READ(2)	   Linux Programmers Manual	    PCICONFIG_READ(2)



NAME
       pciconfig_read, pciconfig_write, pciconfig_iobase - pci device informa
       tion handling

SYNOPSIS
       #include 

       int pciconfig_read(unsigned long bus, unsigned long dfn,
		 unsigned long off, unsigned long len, void *buf);
       int pciconfig_write(unsigned long bus, unsigned long dfn,
		 unsigned long off, unsigned long len, void *buf);
       int pciconfig_iobase(long which, unsigned long bus,
		 unsigned long devfn);

DESCRIPTION
       Most of the interaction with PCI devices is already handled by the ker
       nel  PCI  layer,  and  thus  these calls should not normally need to be
       accessed from userspace.

       pciconfig_read()
	      Reads to buf from device dev at offset off value.

       pciconfig_write()
	      Writes from buf to device dev at offset off value.

       pciconfig_iobase()
	      You pass it a bus/devfn pair and	get  a	physical  address  for
	      either  the  memory  offset  (for  things  like  prep,  this  is
	      0xc0000000), the IO base for PIO cycles, or  the	ISA  holes  if
	      any.

RETURN VALUE
       pciconfig_read()
	      On success zero is returned.  On error, -1 is returned and errno
	      is set appropriately.

       pciconfig_write()
	      On success zero is returned.  On error, -1 is returned and errno
	      is set appropriately.

       pciconfig_iobase()
	      Returns information on locations of various I/O regions in phys
	      ical memory according to the which value.  Values for which are:
	      IOBASE_BRIDGE_NUMBER,  IOBASE_MEMORY,  IOBASE_IO, IOBASE_ISA_IO,
	      IOBASE_ISA_MEM.

ERRORS
       EINVAL len  value  is  invalid.	 This  does  not  apply   to   pcicon
	      fig_iobase().

       EIO    I/O error.

       ENODEV For  pciconfig_iobase(),	"hose"	value  is NULL.  For the other
	      calls, could not find a slot.

       ENOSYS The system has  not  implemented	these  calls  (CONFIG_PCI  not
	      defined).

       EOPNOTSUPP
	      This  return  value is only valid for pciconfig_iobase().  It is
	      returned if the value for which is invalid.

       EPERM  User does not have the CAP_SYS_ADMIN capability.	This does  not
	      apply to pciconfig_iobase().

CONFORMING TO
       These calls are Linux-specific, available since Linux 2.0.26/2.1.11.

SEE ALSO
       capabilities(7)

COLOPHON
       This  page  is  part of release 3.05 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2003-07-14		     PCICONFIG_READ(2)