linux: Don't try to include <sys/io.h> on arm It no longer exists in newer glibc, and didn't work like you'd have hoped on anything but strongarm anyway.
Documentation of the libpciaccess API's can be generated from the sources via the doxygen command. Information about porting Xorg drivers to libpciaccess is located at:
https://www.x.org/wiki/PciReworkHowto
For historical reference, the original proposal for this work is at:
https://www.x.org/wiki/PciReworkProposal
All questions regarding this software should be directed at the Xorg mailing list:
https://lists.x.org/mailman/listinfo/xorg
The master development code repository can be found at:
https://gitlab.freedesktop.org/xorg/lib/libpciaccess
Please submit bug reports and requests to merge patches there.
For patch submission instructions, see:
https://www.x.org/wiki/Development/Documentation/SubmittingPatches