[PATCH 47/69] clocksource/drivers/h8300_timer8: Retrieve the clock rate at init time

Daniel Lezcano
2015-12-18T14:29:21Z

The current code retrieves the rate value when the timer is enabled which
occurs each time a timer is re-armed. Except if the clock frequency has changed
magically I don't see why this should be done each time.

Retrieve the clock rate value at init time only.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
drivers/clocksource/h8300_timer8.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/clocksource/h8300_timer8.c b/drivers/clocksource/h8300_timer8.c
index 24d91b1..187c416 100644
--- a/drivers/clocksource/h8300_timer8.c
+++ b/drivers/clocksource/h8300_timer8.c
@@ -34,7 +34,6 @@ struct timer8_priv {
unsigned long flags;
unsigned int rate;
unsigned int tcora;
- struct clk *pclk;
};

static unsigned long timer8_get_counter(struct timer8_priv *p)
@@ -92,7 +91,6 @@ static void timer8_set_next(struct timer8_priv *p, unsigned long delta)

static int timer8_enable(struct timer8_priv *p)
{
- p->rate = clk_get_rate(p->pclk) / SCALE;
ctrl_outw(0xffff, p->mapbase + TCORA);
ctrl_outw(0x0000, p->mapbase + _8TCNT);
ctrl_outw(0x0c02, p->mapbase + _8TCR);
@@ -102,16 +100,15 @@ static int timer8_enable(struct timer8_priv *p)

static int timer8_start(struct timer8_priv *p)
{
- int ret = 0;
+ int ret;

- if (!(p->flags & FLAG_STARTED))
- ret = timer8_enable(p);
+ if ((p->flags & FLAG_STARTED))
+ return 0;

- if (ret)
- goto out;
- p->flags |= FLAG_STARTED;
+ ret = timer8_enable(p);
+ if (!ret)
+ p->flags |= FLAG_STARTED;

- out:
return ret;
}

@@ -217,7 +214,12 @@ static void __init h8300_8timer_init(struct device_node *node)
}

timer8_priv.mapbase = (unsigned long)base;
- timer8_priv.pclk = clk;
+
+ rate = clk_get_rate(clk) / SCALE;
+ if (!rate) {
+ pr_err("Failed to get rate for the clocksource\n");
+ goto unmap_reg;
+ }

ret = request_irq(irq, timer8_interrupt,
IRQF_TIMER, timer8_priv.ced.name, &timer8_priv);
@@ -225,10 +227,10 @@ static void __init h8300_8timer_init(struct device_node *node)
pr_err("failed to request irq %d for clockevent\n", irq);
goto unmap_reg;
}
- rate = clk_get_rate(clk) / SCALE;
+
clockevents_config_and_register(&timer8_priv.ced, rate, 1, 0x0000ffff);
- return;

+ return;
unmap_reg:
iounmap(base);
free_clk:
--
1.9.1