bus_child_present(9) [debian man page]

BUS_CHILD_PRESENT(9)					   BSD Kernel Developer's Manual				      BUS_CHILD_PRESENT(9)

NAME

     bus_child_present -- ask the bus driver to see if this device is still really present

SYNOPSIS

     #include <sys/param.h>
     #include <sys/bus.h>

     #include <machine/bus.h>
     #include <sys/rman.h>
     #include <machine/resource.h>

     int
     bus_child_present(device_t dev);

DESCRIPTION

     The bus_child_present() function requests that the parent device driver of dev check to see if the hardware represented by dev is still phys-
     ically accessible at this time.  While the notion of accessible varies from bus to bus, generally hardware that is not accessible cannot be
     accessed via the bus_space*() methods that would otherwise be used to access the device.

     This does not ask the question ``does this device have children?'' which can better be answered by device_get_children(9).

RETURN VALUES

     A zero return value indicates that the device is not present in the system.  A non-zero return value indicates that the device is present in
     the system, or that the state of the device cannot be determined.

EXAMPLES

     This is some example code.  It only calls stop when the dc(4) device is actually present.

	   device_t dev;
	   dc_softc *sc;

	   sc = device_get_softc(dev);
	   if (bus_child_present(dev))
		   dc_stop(sc);

SEE ALSO

     device(9), driver(9)

AUTHORS

     This manual page was written by Warner Losh <imp@FreeBSD.org>.

BSD
								  March 27, 2003							       BSD

BUS_ACTIVATE_RESOURCE(9)				   BSD Kernel Developer's Manual				  BUS_ACTIVATE_RESOURCE(9)

NAME

     bus_activate_resource, bus_deactivate_resource -- activate or deactivate a resource

SYNOPSIS

     #include <sys/param.h>
     #include <sys/bus.h>

     #include <machine/bus.h>
     #include <sys/rman.h>
     #include <machine/resource.h>

     int
     bus_activate_resource(device_t dev, int type, int rid, struct resource *r);

     int
     bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r);

DESCRIPTION

     These functions activate or deactivate a previously allocated resource.  In general, resources must be activated before they can be accessed
     by the driver so that the bus driver can map the resource into the devices space.

     The arguments are as follows:

     dev     The device that requests ownership of the resource.  Before allocation, the resource is owned by the parent bus.

     type    The type of resource you want to allocate.  It is one of:

	     SYS_RES_IRQ     for IRQs
	     SYS_RES_DRQ     for ISA DMA lines
	     SYS_RES_IOPORT  for I/O ports
	     SYS_RES_MEMORY  for I/O memory

     rid     A pointer to a bus specific handle that identifies the resource being allocated.

     r	     A pointer to the struct resource returned by bus_alloc_resource(9).

RETURN VALUES

     Zero is returned on success, otherwise an error is returned.

SEE ALSO

     bus_alloc_resource(9), device(9), driver(9)

AUTHORS

     This manual page was written by Warner Losh <imp@FreeBSD.org>.

BSD
								  March 28, 2003							       BSD