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Hook into the watchdog device, if present. Also, turn off the

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watchdog timer stuff when we boot because the boot blocks are turning
it on...
This commit is contained in:
Warner Losh 2006-08-09 20:58:55 +00:00
parent 00cbc48be6
commit 27e13f2b3e
1 changed files with 41 additions and 4 deletions
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45
sys/arm/at91/at91_st.c
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@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$");
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
@ -48,7 +49,8 @@ __FBSDID("$FreeBSD$");
static struct at91st_softc {
bus_space_tag_t sc_st;
bus_space_handle_t sc_sh;
device_t dev;
device_t sc_dev;
eventhandler_tag sc_wet; /* watchdog event handler tag */
} *timer_softc;
#define RD4(off) \
@ -56,6 +58,8 @@ static struct at91st_softc {
#define WR4(off, val) \
bus_space_write_4(timer_softc->sc_st, timer_softc->sc_sh, (off), (val))
static void at91st_watchdog(void *, u_int, int *);
static inline int
st_crtr(void)
{
@ -97,7 +101,7 @@ at91st_attach(device_t dev)
timer_softc = device_get_softc(dev);
timer_softc->sc_st = sc->sc_st;
timer_softc->dev = dev;
timer_softc->sc_dev = dev;
if (bus_space_subregion(sc->sc_st, sc->sc_sh, AT91RM92_ST_BASE,
AT91RM92_ST_SIZE, &timer_softc->sc_sh) != 0)
panic("couldn't subregion timer registers");
@ -108,6 +112,13 @@ at91st_attach(device_t dev)
WR4(ST_RTMR, 1);
/* Disable all interrupts */
WR4(ST_IDR, 0xffffffff);
/* disable watchdog timer */
WR4(ST_WDMR, 0);
timer_softc->sc_wet = EVENTHANDLER_REGISTER(watchdog_list,
at91st_watchdog, dev, 0);
device_printf(dev,
"watchdog registered, timeout intervall max. 64 sec\n");
return (0);
}
@ -140,6 +151,33 @@ at91st_get_timecount(struct timecounter *tc)
#endif
}
/*
* t below is in a weird unit. The watchdog is set to 2^t
* nanoseconds. Since our watchdog timer can't really do that too
* well, we approximate it by assuming that the timeout interval for
* the lsb is 2^22 ns, which is 4.194ms. This is an overestimation of
* the actual time (3.906ms), but close enough for watchdogging.
* These approximations, though a violation of the spec, improve the
* performance of the application which typically specifies things as
* WD_TO_32SEC. In that last case, we'd wait 32s before the wdog
* reset. The spec says we should wait closer to 34s, but given how
* it is likely to be used, and the extremely coarse nature time
* interval, I think this is the best solution.
*/
static void
at91st_watchdog(void *argp, u_int cmd, int *error)
{
uint32_t wdog;
int t;
wdog = 0;
t = cmd & WD_INTERVAL;
if (cmd != 0 && t >= 22 && t <= 37)
wdog = (1 << (t - 22)) | ST_WDMR_RSTEN;
WR4(ST_WDMR, wdog);
WR4(ST_CR, ST_CR_WDRST);
}
static void
clock_intr(void *arg)
{
@ -161,7 +199,7 @@ cpu_initclocks(void)
struct resource *irq;
int rid = 0;
void *ih;
device_t dev = timer_softc->dev;
device_t dev = timer_softc->sc_dev;
if (32768 % hz) {
printf("Cannot get %d Hz clock; using 128Hz\n", hz);
@ -229,4 +267,3 @@ void
cpu_stopprofclock(void)
{
}