VME(9)

NAME
VME, vme_probe, vme_space_map, vme_space_unmap, vme_intr_map, vme_intr_establish, vme_intr_disestablish, vme_intr_evcnt, vme_dmamap_create, vme_dmamap_destroy, vme_dmamem_alloc, vme_dmamem_free, vme_space_alloc, vme_space_free, vme_space_get - Versa Module Euroboard bus

SYNOPSIS
#include <sys/bus.h>
#include <dev/vme/vmereg.h>
#include <dev/vme/vmevar.h>
int
vme_probe(void *vc, vme_addr_t vmeaddr, vme_size_t len, vme_am_t am, vme_datasize_t datasize, int (*callback)(), void *arg);
int
vme_space_map(void *vc, vme_addr_t vmeaddr, vme_size_t len, vme_am_t am, vme_datasize_t datasize, vme_swap_t swap, bus_space_tag_t *tag, bus_space_handle_t *handle, vme_mapresc_t *resc);
void
vme_space_unmap(void *vc, vme_mapresc_t resc);
int
vme_intr_map(void *vc, int level, int vector, vme_intr_handle_t *handlep);
void *
vme_intr_establish(void *vc, vme_intr_handle_t handle, int prio, int (*func)(void *), void *arg);
void
vme_intr_disestablish(void *vc, void *cookie);
const struct evcnt *
vme_intr_evcnt(void *vc, vme_intr_handle_t handle);
int
vme_dmamap_create(void *vc, vme_size_t size, vme_am_t am, vme_datasize_t datasize, vme_swap_t swap, int nsegs, vme_size_t segsz, vme_addr_t bound, int flags, bus_dmamap_t *map);
void
vme_dmamap_destroy(void *vc, bus_dmamap_t map);
int
vme_dmamem_alloc(void *vc, vme_size_t size, vme_am_t am, vme_datasize_t datasize, vme_swap_t swap, bus_dma_segment_t *segs, int nsegs, int *rsegs, int flags);
void
vme_dmamem_free(void *vc, bus_dma_segment_t *segs, int nsegs);
int
vme_space_alloc(struct vmebus_softc *tag, vme_addr_t addr, vme_size_t size, vme_am_t ams);
void
vme_space_free(void *vc, vme_addr_t addr, vme_size_t size, vme_am_t ams);
int
vme_space_get(void *vc, vme_size_t size, vme_am_t ams, u_long align, vme_addr_t *addr);

DESCRIPTION
The VME bus provides support for VME devices. The VME bus is a high-performance backplane bus for use in computer systems. It is based on the VMEbus specification initially released by the VMEbus International Trade Association (VITA) in August of 1982. It has since undergone IEC and IEEE standardisation.

The VME bus supports 8, 16, and 32-bit transfers over non-multiplexed 32-bit data and address paths. The latest revisions allow 64-bit, multiplexed transfers. It supports asynchronous, fully handshaken transfers at speeds up to 80 MB/sec. It has a master-slave architecture, encouraging multiprocessing and supports up to seven interrupt levels.

DATA TYPES
Drivers attached to the VME bus will make use of the following data types:

vme_chipset_tag_t
    An opaque type identifying the bus controller.

vme_addr_t
    Addresses on the bus.

vme_am_t
    Address modifiers. Valid values are VME_AM_A32, VME_AM_A16, VME_AM_A24, VME_AM_USERDEF (user/vendor definable), VME_AM_MBO, VME_AM_SUPER, VME_AM_USER, VME_AM_DATA, VME_AM_PRG, VME_AM_BLT32 and VME_AM_BLT64.

vme_datasize_t
    The datasize of the address space. Valid values are VME_D8, VME_D16, and VME_D32.

vme_mapresc_t
    Generic placeholder for any resources needed for a mapping.

vme_intr_handle_t
    An opaque type describing an interrupt mapping.

vme_swap_t
    Hardware swap capabilities for controlling data endianness. Valid values have not been specified yet.

struct vme_range
    A structure used to describe an address range on the VME bus. It contains the following members:

        	vme_addr_t offset;
        	vme_size_t size;
        	vme_am_t am;

struct vme_attach_args
    A structure used to inform the driver of the device properties. It contains the following members:

        	vme_chipset_tag_t va_vct;
        	bus_dma_tag_t va_bdt;
        	int ivector;
        	int ilevel;
        	int numcfranges;
        	struct vme_range r[VME_MAXCFRANGES];

FUNCTIONS

vme_probe(vc, vmeaddr, len, am, datasize, callback, arg)
    Probes the VME space managed by controller vc at address vmeaddr, length len, with address modifiers am and datasize datasize for a device. If a VME device is found, the function callback() (if it is not NULL) is called to perform device-specific identification. callback() is called with the argument arg, and the bus-space tag and bus-space handle for accessing the VME space mapping and should return a nonzero positive integer for a positive device match.

vme_space_map(vc, vmeaddr, len, am, datasize, swap, tag, handle, resc)
    Maps the VME space managed by controller vc at address vmeaddr, length len, with address modifiers am, datasize datasize and endianness swap for a device. If the mapping is successful tag contains the bus-space tag and handle contains the bus-space handle for accessing the VME space mapping. resc contains the resources for the mappings. vme_space_map() returns 0 on success, and nonzero on error.

vme_space_unmap(vc, resc)
    Unmaps the VME space mapping managed by controller vc and resources resc.

vme_intr_map(vc, level, vector, handlep)
    Sets handlep to a machine-dependent value which identifies a particular interrupt source at level level and vector vector on the controller vc. vme_intr_map() returns zero on success, and nonzero on failure.

vme_intr_establish(vc, handle, prio, func, arg)
    Establishes the interrupt handler handlep. When the device interrupts, func() will be called with a single argument arg and will run at the interrupt priority level prio. The return value of vme_intr_establish() may be saved and passed to vme_intr_disestablish().

vme_intr_disestablish(vc, cookie)
    Disables the interrupt handler when the driver is no longer interested in interrupts from the device. cookie is the value returned by vme_intr_establish().

vme_intr_evcnt(vc, handle)
    Increment the interrupt event counter for the interrupt specified by handle.

vme_dmamap_create(vc, size, am, datasize, swap, nsegs, segsz, bound, flags, map)
    Allocates a DMA handle and initializes it according to the parameters provided. The VME-specific parameters describe the address-space modifiers am, datasize datasize, and endianness swap. The remaining parameters are described in bus_dma(9).

vme_dmamap_destroy(vc, map)
    Frees all resources associated with a given DMA handle. The parameters are described in bus_dma(9).

vme_dmamem_alloc(vc, size, am, datasize, swap, segs, nsegs, rsegs, flags)
    Allocates memory that is “ DMA safe ” for the VME bus managed by controller vc. The VME-specific parameters describe the address-space modifiers am, datasize datasize, and endianness swap. The remaining parameters are described in bus_dma(9).

vme_dmamem_free(vc, segs, nsegs)
    Frees memory previously allocated by vme_dmamem_alloc() for the VME space managed by controller vc.

vme_space_alloc(tag, addr, size, ams)
    Allocate VME space for the bus-space tag at address addr of size size and address-space modifiers ams. vme_space_alloc() returns EINVAL on invalid inputs.

vme_space_free(vc, addr, size, ams)
    Deallocate VME space for the bus-space tag at address addr of size size and address-space modifiers ams.

vme_space_get(vc, size, ams, align, addr)
    Returns EINVAL on invalid inputs.

AUTOCONFIGURATION
The VME bus is an indirect-connection bus. During autoconfiguration each driver is required to probe the bus for the presence of a device. A VME driver will receive a pointer to a struct vme_attach_args hinting at "locations" (address ranges) on the VME bus where the device may be located. The driver should check the number of address ranges, allocate the address space of these ranges using vme_space_alloc(), and probe the address space for the device using vme_probe().

During driver attach the driver should also map the address ranges using vme_space_map(). The interrupt locators in struct vme_attach_args are used by vme_intr_map() and vme_intr_establish().

DMA SUPPORT
Extensive DMA facilities are provided.

CODE REFERENCES
The VME subsystem itself is implemented within the file sys/dev/vme/vme.c.

SEE ALSO
vme(4), autoconf(9), bus_dma(9), bus_space(9), driver(9)

HISTORY
The machine-independent VME subsystem appeared in NetBSD 1.5.

BUGS
This page is incomplete.