NAME

TC, tc_intr_establish, tc_intr_disestablish, tc_intr_evcnt. tc_mb, tc_wmb, tc_syncbus, tc_badaddr, TC_DENSE_TO_SPARSE, TC_PHYS_TO_UNCACHED — TURBOchannel bus

SYNOPSIS

#include <sys/bus.h>
#include <dev/tc/tcvar.h>
#include <dev/tc/tcdevs.h>

void
tc_intr_establish(struct device *dev, void *cookie, int level, int (*handler)(void *), void *arg);

void
tc_intr_disestablish(struct device *dev, void *cookie);

const struct evcnt *
tc_intr_evcnt(struct device *dev, void *cookie);

void
tc_mb();

void
tc_wmb();

void
tc_syncbus();

int
tc_badaddr(tc_addr_t tcaddr);

tc_addr_t
TC_DENSE_TO_SPARSE(tc_addr_t addr);

tc_addr_t
TC_PHYS_TO_UNCACHED(tc_addr_t addr);

DESCRIPTION

The TC device provides support for the DEC TURBOchannel bus found on all DEC TURBOchannel machines with MIPS (DECstation 5000 series, excluding the 5000/200) and Alpha (3000-series) systems. TURBOchannel is a 32-bit wide synchronous DMA-capable bus, running at 25 MHz on higher-end machines and at 12.5 MHz on lower-end machines.

DATA TYPES

Drivers for devices attached to the TURBOchannel bus will make use of the following data types:

struct tc_attach_args

A structure use to inform the driver of TURBOchannel bus properties. It contains the following members:

	bus_space_tag_t	ta_memt;
	bus_dma_tag_t	ta_dmat;
	char		ta_modname[TC_ROM_LLEN+1];
	u_int		ta_slot;
	tc_offset_t	ta_offset;
	tc_addr_t	ta_addr;
	void		*ta_cookie;
	u_int		ta_busspeed;

The ta_busspeed member specifies the TURBOchannel bus speed and is useful for time-related functions. Values values are TC_SPEED_12_5_MHZ for the 12.5 MHz bus and TC_SPEED_25_MHZ for the 50 MHz bus.

FUNCTIONS

tc_intr_establish(dev, cookie, level, handler, arg): Establish an interrupt handler with device dev for the interrupt described completely by cookie, the value passed to the driver in the ta_cookie member of the tc_attach_args structure. The priority of the interrupt is specified by level. When the interrupt occurs the function handler is called with argument arg.
tc_intr_disestablish(dev, cookie): Dis-establish the interrupt handler with device dev for the interrupt described completely cookie.
tc_intr_evcnt(dev, cookie): Do interrupt event counting with device dev for the event described completely by cookie.
tc_mb(): A read/write memory barrier. Any CPU-to-memory reads/writes before the barrier must complete before any CPU-to-memory reads/writes after it.
tc_wmb(): A write memory barrier. Any CPU-to-memory writes before the barrier must complete before any CPU-to-memory writes after it.
tc_syncbus(): Synchronise writes on the TURBOchannel bus by ensuring CPU writes are propagated across the TURBOchannel bus.
tc_badaddr(tcaddr): Returns non-zero if the given address tcaddr is invalid.
TC_DENSE_TO_SPARSE(addr): Convert the given physical address addr in TURBOchannel dense space to the corresponding address in TURBOchannel sparse space.
TC_PHYS_TO_UNCACHED(addr): Convert the given system memory physical address addr to the physical address of the corresponding region that is not cached.

AUTOCONFIGURATION

The TURBOchannel bus is a direct-connection bus. During autoconfiguration, the parent specifies the name of the found TURBOchannel module into the ta_modname member of the tc_attach_args structure. Drivers should match on this name.

DMA SUPPORT

The TURBOchannel bus supports 32-bit, bidirectional DMA transfers. Support is provided by the standard bus_dma(9) interface.

CODE REFERENCES

The TURBOchannel subsystem itself is implemented within the file sys/dev/tc/tc_subr.c. Machine-dependent portions can be found in sys/arch/<arch>/tc/tcbus.c.