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clocksource/drivers/h8300: Simplify delta handling

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Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Yoshinori Sato 2015-12-05 02:48:16 +09:00 committed by Daniel Lezcano
parent 2f445e0aa0
commit f37632d1e9
1 changed files with 6 additions and 34 deletions
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40
drivers/clocksource/h8300_timer8.c
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@ -36,57 +36,29 @@ struct timer8_priv {
unsigned int tcora;
};
static unsigned long timer8_get_counter(struct timer8_priv *p)
{
unsigned long v1, v2, v3;
int o1, o2;
o1 = readb(p->mapbase + _8TCSR) & 0x20;
/* Make sure the timer value is stable. Stolen from acpi_pm.c */
do {
o2 = o1;
v1 = readw(p->mapbase + _8TCNT);
v2 = readw(p->mapbase + _8TCNT);
v3 = readw(p->mapbase + _8TCNT);
o1 = readb(p->mapbase + _8TCSR) & 0x20;
} while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
|| (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
v2 |= o1 << 10;
return v2;
}
static irqreturn_t timer8_interrupt(int irq, void *dev_id)
{
struct timer8_priv *p = dev_id;
writeb(readb(p->mapbase + _8TCSR) & ~0x40,
p->mapbase + _8TCSR);
writew(p->tcora, p->mapbase + TCORA);
if (clockevent_state_oneshot(&p->ced))
writew(0x0000, p->mapbase + _8TCR);
p->ced.event_handler(&p->ced);
writeb(readb(p->mapbase + _8TCSR) & ~0x40,
p->mapbase + _8TCSR);
return IRQ_HANDLED;
}
static void timer8_set_next(struct timer8_priv *p, unsigned long delta)
{
unsigned long now;
if (delta >= 0x10000)
pr_warn("delta out of range\n");
now = timer8_get_counter(p);
p->tcora = delta;
writeb(readb(p->mapbase + _8TCR) & ~0x40, p->mapbase + _8TCR);
writew(0, p->mapbase + _8TCNT);
writew(delta, p->mapbase + TCORA);
writeb(readb(p->mapbase + _8TCR) | 0x40, p->mapbase + _8TCR);
if (delta > now)
writew(delta, p->mapbase + TCORA);
else
writew(now + 1, p->mapbase + TCORA);
}
static int timer8_enable(struct timer8_priv *p)