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authorMagnus Damm <damm@opensource.se>2011-04-25 17:32:11 +0400
committerPaul Mundt <lethal@linux-sh.org>2011-05-23 09:33:59 +0400
commit3593f5fe40a13badf6921ccbc3378b02fbf6a532 (patch)
treef2d8710c0e6abfb0f633935003bd532757a27f66 /drivers/clocksource
parent31705e21f9b5a0628c043f88ff4d20488b47b8ab (diff)
downloadlinux-3593f5fe40a13badf6921ccbc3378b02fbf6a532.tar.xz
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>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/sh_cmt.c19
1 files changed, 7 insertions, 12 deletions
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index f975d24890fa..dc7c033ef587 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -416,11 +416,15 @@ static cycle_t sh_cmt_clocksource_read(struct clocksource *cs)
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 @@ static int sh_cmt_register_clocksource(struct sh_cmt_priv *p,
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;
}