ARM: at91: rm9200: switch back to clockevents_config_and_register

The timer code for at91rm9200 was already converted some time ago by
Shawn Guo in commit 838a2ae8 (ARM: use clockevents_config_and_register()
where possible) but because of a rounding issue in the timer core this
resulted in an easily reproducible oops. So it was reverted (commit
b7a8ca51 (ARM: at91: rm9200 fix time support)) which stopped the oops
from happening because min_delta_ns is increased by one in arch code
which stopped from problem from happening.

Now that the timer core problem is fixed (commit a4578ea (clockevents:
Sanitize ticks to nsec conversion)), we can switch back to the
clockevents_config_and_register helper.
Tested-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

arch/arm/mach-at91/at91rm9200_time.c

@@ -174,7 +174,6 @@ clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev)
 static struct clock_event_device clkevt = {
 	.name		= "at91_tick",
 	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-	.shift		= 32,
 	.rating		= 150,
 	.set_next_event	= clkevt32k_next_event,
 	.set_mode	= clkevt32k_mode,
@@ -265,11 +264,9 @@ void __init at91rm9200_timer_init(void)
 	at91_st_write(AT91_ST_RTMR, 1);
 
 	/* Setup timer clockevent, with minimum of two ticks (important!!) */
-	clkevt.mult = div_sc(AT91_SLOW_CLOCK, NSEC_PER_SEC, clkevt.shift);
-	clkevt.max_delta_ns = clockevent_delta2ns(AT91_ST_ALMV, &clkevt);
-	clkevt.min_delta_ns = clockevent_delta2ns(2, &clkevt) + 1;
 	clkevt.cpumask = cpumask_of(0);
-	clockevents_register_device(&clkevt);
+	clockevents_config_and_register(&clkevt, AT91_SLOW_CLOCK,
+					2, AT91_ST_ALMV);
 
 	/* register clocksource */
 	clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK);