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bus_release_resource(9) [freebsd man page]

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

NAME
bus_release_resource -- release resources on a bus SYNOPSIS
#include <sys/param.h> #include <sys/bus.h> #include <machine/bus.h> #include <sys/rman.h> #include <machine/resource.h> int bus_release_resource(device_t dev, int type, int rid, struct resource *r); DESCRIPTION
Free a resource allocated by bus_alloc_resource(9). The resource must not be in use on release, i.e., call an appropriate function before (e.g. bus_teardown_intr(9) for IRQs). dev is the device that owns the resource. type is the type of resource that is released. It must be of the same type you allocated it as before. See bus_alloc_resource(9) for valid types. rid is the resource ID of the resource. The rid value must be the same as the one returned by bus_alloc_resource(9). r is the pointer to struct resource, i.e., the resource itself, returned by bus_alloc_resource(9). RETURN VALUES
EINVAL is returned, if the device dev has no parent, 0 otherwise. The kernel will panic, if it cannot release the resource. EXAMPLES
/* deactivate IRQ */ bus_teardown_intr(dev, foosoftc->irqres, foosoftc->irqid); /* release IRQ resource */ bus_release_resource(dev, SYS_RES_IRQ, foosoftc->irqid, foosoftc->irqres); /* release I/O port resource */ bus_release_resource(dev, SYS_RES_IOPORT, foosoftc->portid, foosoftc->portres); SEE ALSO
bus_alloc_resource(9), device(9), driver(9) AUTHORS
This manual page was written by Alexander Langer <alex@big.endian.de>. BSD
May 18, 2000 BSD

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

NAME
bus_alloc_resource, bus_alloc_resource_any -- allocate resources from a parent bus SYNOPSIS
#include <sys/param.h> #include <sys/bus.h> #include <machine/bus.h> #include <sys/rman.h> #include <machine/resource.h> struct resource * bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end, u_long count, u_int flags); struct resource * bus_alloc_resource_any(device_t dev, int type, int *rid, u_int flags); DESCRIPTION
This is an easy interface to the resource-management functions. It hides the indirection through the parent's method table. This function generally should be called in attach, but (except in some rare cases) never earlier. The bus_alloc_resource_any() function is a convenience wrapper for bus_alloc_resource(). It sets the values for start, end, and count to the default resource (see description of start below). The arguments are as follows: dev is the device that requests ownership of the resource. Before allocation, the resource is owned by the parent bus. type is 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 points to a bus specific handle that identifies the resource being allocated. For ISA this is an index into an array of resources that have been setup for this device by either the PnP mechanism, or via the hints mechanism. For PCCARD, this is an index into the array of resources described by the PC Card's CIS entry. For PCI, the offset into pci config space which has the BAR to use to access the resource. The bus methods are free to change the RIDs that they are given as a parameter. You must not depend on the value you gave it earlier. start and end are the start/end addresses of the resource. If you specify values of 0ul for start and ~0ul for end and 1 for count, the default values for the bus are calculated. count is the size of the resource. For example, the size of an I/O port is usually 1 byte (but some devices override this). If you speci- fied the default values for start and end, then the default value of the bus is used if count is smaller than the default value and count is used, if it is bigger than the default value. flags sets the flags for the resource. You can set one or more of these flags: RF_ALLOCATED resource has been reserved. The resource still needs to be activated with bus_activate_resource(9). RF_ACTIVE activate resource atomically. RF_SHAREABLE resource permits contemporaneous sharing. It should always be set unless you know that the resource cannot be shared. It is the bus driver's task to filter out the flag if the bus does not support sharing. For example, pccard(4) cannot share IRQs while cardbus(4) can. RF_TIMESHARE resource permits time-division sharing. RETURN VALUES
A pointer to struct resource is returned on success, a null pointer otherwise. EXAMPLES
This is some example code that allocates a 32 byte I/O port range and an IRQ. The values of portid and irqid should be saved in the softc of the device after these calls. struct resource *portres, *irqres; int portid, irqid; portid = 0; irqid = 0; portres = bus_alloc_resource(dev, SYS_RES_IOPORT, &portid, 0ul, ~0ul, 32, RF_ACTIVE); irqres = bus_alloc_resource_any(dev, SYS_RES_IRQ, &irqid, RF_ACTIVE | RF_SHAREABLE); SEE ALSO
bus_activate_resource(9), bus_release_resource(9), device(9), driver(9) AUTHORS
This manual page was written by Alexander Langer <alex@big.endian.de> with parts by Warner Losh <imp@FreeBSD.org>. BSD
May 18, 2000 BSD

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