linux man page for pciconfig_read

PCICONFIG_READ(2)					     Linux Programmer's Manual						 PCICONFIG_READ(2)

NAME
       pciconfig_read, pciconfig_write, pciconfig_iobase - pci device information handling

SYNOPSIS
       #include <pci.h>

       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 kernel 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 physical 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 pciconfig_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 3.27 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)