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Belated commit of code to calculate the delay constant used by delay().

This commit is contained in:
scw 2002-09-22 20:57:23 +00:00
parent f9c02a8bd0
commit 9393fbe941
1 changed files with 21 additions and 1 deletions
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22
sys/arch/sh5/dev/tmu.c
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@ -1,4 +1,4 @@
/* $NetBSD: tmu.c,v 1.3 2002/09/04 15:18:14 scw Exp $ */
/* $NetBSD: tmu.c,v 1.4 2002/09/22 20:57:23 scw Exp $ */
/*
* Copyright 2002 Wasabi Systems, Inc.
@ -112,6 +112,7 @@ tmuattach(struct device *parent, struct device *self, void *args)
{
struct pbridge_attach_args *pa = args;
struct tmu_softc *sc;
u_int32_t tcnt;
int i;
tmu_sc = sc = (struct tmu_softc *)self;
@ -148,6 +149,25 @@ tmuattach(struct device *parent, struct device *self, void *args)
printf(": Timer Unit\n");
printf("%s: Tick period: %d nS\n", sc->sc_dev.dv_xname, sc->sc_period);
/*
* Calculate the delay constant.
*/
_sh5_delay_constant = 1;
bus_space_write_4(sc->sc_bust, sc->sc_bush, TMU_REG_TCNT(0),
0xffffffff);
bus_space_write_2(sc->sc_bust, sc->sc_bush, TMU_REG_TCR(0),
TMU_TCR_TPSC_PDIV4);
bus_space_write_1(sc->sc_bust, sc->sc_bush, TMU_REG_TSTR, TMU_TSTR(0));
delay(100000);
tcnt = 0 - bus_space_read_4(sc->sc_bust, sc->sc_bush, TMU_REG_TCNT(0));
bus_space_write_1(sc->sc_bust, sc->sc_bush, TMU_REG_TSTR, 0);
/* How many nanoseconds per loop iteration */
tcnt = (tcnt * sc->sc_period) / 100000;
_sh5_delay_constant = 1000 / tcnt;
printf("%s: Delay constant: %d\n", sc->sc_dev.dv_xname,
_sh5_delay_constant);
/*
* Attach to the common clock back-end
*/