[PATCH 3/5] clocksource: h8300: Simplify delta handling

From: Yoshinori Sato
Date: Fri Dec 04 2015 - 00:58:13 EST


Signed-off-by: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
---
drivers/clocksource/h8300_timer8.c | 40 ++++++--------------------------------
1 file changed, 6 insertions(+), 34 deletions(-)

diff --git a/drivers/clocksource/h8300_timer8.c b/drivers/clocksource/h8300_timer8.c
index aa4b2a98..1ba453b 100644
--- a/drivers/clocksource/h8300_timer8.c
+++ b/drivers/clocksource/h8300_timer8.c
@@ -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)
--
2.6.1

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