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Commit 3593f5fe authored by Magnus Damm's avatar Magnus Damm Committed by Paul Mundt
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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: default avatarMagnus Damm <damm@opensource.se>
Acked-by: default avatarJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 31705e21

drivers/clocksource/sh_cmt.c

+7 −12
Original line number Diff line number Diff line
@@ -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;

}