clocksource: sh_cmt: __clocksource_updatefreq_hz() update
This patch updates the clocksource part of the CMT driver
to make use of the __clocksource_updatefreq_hz() function.
Without this patch the old code uses clocksource_register()
together with a hack that assumes a never changing clock rate
(see clk_enable(), clk_get_rate() and clk_disable()).
The patch uses clocksource_register_hz() with 1 Hz as initial
value, then lets the ->enable() callback update the value
with __clocksource_updatefreq_hz() once the struct clk has
been enabled and the frequency is stable.
Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index f975d24..dc7c033 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -416,11 +416,15 @@
static int sh_cmt_clocksource_enable(struct clocksource *cs)
{
+ int ret;
struct sh_cmt_priv *p = cs_to_sh_cmt(cs);
p->total_cycles = 0;
- return sh_cmt_start(p, FLAG_CLOCKSOURCE);
+ ret = sh_cmt_start(p, FLAG_CLOCKSOURCE);
+ if (!ret)
+ __clocksource_updatefreq_hz(cs, p->rate);
+ return ret;
}
static void sh_cmt_clocksource_disable(struct clocksource *cs)
@@ -448,19 +452,10 @@
cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8);
cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
- /* clk_get_rate() needs an enabled clock */
- clk_enable(p->clk);
- p->rate = clk_get_rate(p->clk) / ((p->width == 16) ? 512 : 8);
- clk_disable(p->clk);
-
- /* TODO: calculate good shift from rate and counter bit width */
- cs->shift = 0;
- cs->mult = clocksource_hz2mult(p->rate, cs->shift);
-
dev_info(&p->pdev->dev, "used as clock source\n");
- clocksource_register(cs);
-
+ /* Register with dummy 1 Hz value, gets updated in ->enable() */
+ clocksource_register_hz(cs, 1);
return 0;
}
