cooperate with linux parport_pc driver if it is loaded
cooperate with linux parport_pc driver if it is loaded

if parport_pc is loaded, use the linux parport layer to request access to the
underlying port, instead of going through rtapi_request region.  as long as
the port is registered and claimed, linux should prevent other device drivers
from using the same resource.

in addition, when parport_pc is loaded, I/O addresses below 16 are treated
as port indexes.  e.g.,
    loadrt hal_parport cfg="0"
will use the address Linux has detected for parport0.

if parport_pc is not loaded, or the requested port is not known by parport_pc,
then the old rtapi_request_region code is still used.  This means that systems
which block loading of parport_pc will also continue to work.

ikcalB/linuxcnc-mirror,mhaberler/machinekit,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,unseenlaser/machinekit,aschiffler/linuxcnc,unseenlaser/linuxcnc,Cid427/machinekit,bobvanderlinden/machinekit,aschiffler/linuxcnc,yishinli/emc2,bmwiedemann/linuxcnc-mirror,strahlex/machinekit,narogon/linuxcnc,ikcalB/linuxcnc-mirror,cdsteinkuehler/linuxcnc,ArcEye/MK-Qt5,mhaberler/machinekit,yishinli/emc2,EqAfrica/machinekit,RunningLight/machinekit,cdsteinkuehler/MachineKit,ianmcmahon/linuxcnc-mirror,cdsteinkuehler/MachineKit,unseenlaser/linuxcnc,araisrobo/machinekit,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,jaguarcat79/ILC-with-LinuxCNC,bmwiedemann/linuxcnc-mirror,RunningLight/machinekit,cnc-club/linuxcnc,jaguarcat79/ILC-with-LinuxCNC,RunningLight/machinekit,ianmcmahon/linuxcnc-mirror,kinsamanka/machinekit,kinsamanka/machinekit,mhaberler/machinekit,bobvanderlinden/machinekit,aschiffler/linuxcnc,ArcEye/MK-Qt5,RunningLight/machinekit,araisrobo/machinekit,kinsamanka/machinekit,unseenlaser/linuxcnc,bobvanderlinden/machinekit,ArcEye/machinekit-testing,araisrobo/machinekit,cnc-club/linuxcnc,kinsamanka/machinekit,unseenlaser/machinekit,unseenlaser/machinekit,ianmcmahon/linuxcnc-mirror,ArcEye/machinekit-testing,bmwiedemann/linuxcnc-mirror,cnc-club/linuxcnc,bobvanderlinden/machinekit,strahlex/machinekit,ArcEye/MK-Qt5,araisrobo/machinekit,aschiffler/linuxcnc,ArcEye/machinekit-testing,ArcEye/MK-Qt5,unseenlaser/linuxcnc,strahlex/machinekit,ArcEye/machinekit-testing,ArcEye/MK-Qt5,cdsteinkuehler/linuxcnc,unseenlaser/machinekit,aschiffler/linuxcnc,narogon/linuxcnc,EqAfrica/machinekit,ArcEye/machinekit-testing,bobvanderlinden/machinekit,Cid427/machinekit,EqAfrica/machinekit,cdsteinkuehler/MachineKit,araisrobo/machinekit,ikcalB/linuxcnc-mirror,EqAfrica/machinekit,RunningLight/machinekit,cnc-club/linuxcnc,ArcEye/machinekit-testing,Cid427/machinekit,cdsteinkuehler/linuxcnc,strahlex/machinekit,araisrobo/linuxcnc,EqAfrica/machinekit,araisrobo/linuxcnc,cdsteinkuehler/linuxcnc,ArcEye/machinekit-testing,narogon/linuxcnc,unseenlaser/machinekit,araisrobo/machinekit,ianmcmahon/linuxcnc-mirror,narogon/linuxcnc,araisrobo/machinekit,mhaberler/machinekit,yishinli/emc2,RunningLight/machinekit,cnc-club/linuxcnc,kinsamanka/machinekit,cdsteinkuehler/MachineKit,unseenlaser/machinekit,strahlex/machinekit,cdsteinkuehler/MachineKit,cnc-club/linuxcnc,yishinli/emc2,bmwiedemann/linuxcnc-mirror,unseenlaser/linuxcnc,RunningLight/machinekit,Cid427/machinekit,mhaberler/machinekit,unseenlaser/machinekit,ianmcmahon/linuxcnc-mirror,jaguarcat79/ILC-with-LinuxCNC,narogon/linuxcnc,ArcEye/MK-Qt5,ianmcmahon/linuxcnc-mirror,cdsteinkuehler/linuxcnc,strahlex/machinekit,araisrobo/linuxcnc,mhaberler/machinekit,ArcEye/machinekit-testing,EqAfrica/machinekit,araisrobo/linuxcnc,ianmcmahon/linuxcnc-mirror,bobvanderlinden/machinekit,kinsamanka/machinekit,cnc-club/linuxcnc,ArcEye/MK-Qt5,cdsteinkuehler/linuxcnc,Cid427/machinekit,araisrobo/machinekit,ikcalB/linuxcnc-mirror,araisrobo/linuxcnc,araisrobo/machinekit,mhaberler/machinekit,kinsamanka/machinekit,cdsteinkuehler/MachineKit,bmwiedemann/linuxcnc-mirror,mhaberler/machinekit,EqAfrica/machinekit,ArcEye/MK-Qt5,unseenlaser/machinekit,Cid427/machinekit,ikcalB/linuxcnc-mirror,bobvanderlinden/machinekit,EqAfrica/machinekit,strahlex/machinekit,kinsamanka/machinekit,bobvanderlinden/machinekit,RunningLight/machinekit,jaguarcat79/ILC-with-LinuxCNC,jaguarcat79/ILC-with-LinuxCNC,Cid427/machinekit,Cid427/machinekit