From 4e53aa2fde4124878fc6b2183d6e8ec46e12ceb0 Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Mon, 6 Feb 2017 22:12:02 +0100 Subject: clocksource: em_sti: Compute rate before registration With the upcoming NTP correction related rate adjustments to be implemented in the clockevents core, the latter needs to get informed about every rate change of a clockevent device made after its registration. Currently, em_sti violates this requirement in that it registers its clockevent device with a dummy rate and sets its final rate through clockevents_config() called from its ->set_state_oneshot(). This patch moves the setting of the clockevent device's rate to its registration. I checked all current em_sti users in arch/arm/mach-shmobile and right now, none of them changes any rate in any clock tree relevant to em_sti after their respective time_init(). Since all em_sti instances are created after time_init(), none of them should ever observe any clock rate changes. - Determine the ->rate value in em_sti_probe() at device probing rather than at first usage. - Set the clockevent device's rate at its registration. - Although not strictly necessary for the upcoming clockevent core changes, set the clocksource's rate at its registration for consistency. Signed-off-by: Nicolai Stange Signed-off-by: John Stultz --- drivers/clocksource/em_sti.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'drivers/clocksource/em_sti.c') diff --git a/drivers/clocksource/em_sti.c b/drivers/clocksource/em_sti.c index 6c0955a92f24..bc48cbf6a795 100644 --- a/drivers/clocksource/em_sti.c +++ b/drivers/clocksource/em_sti.c @@ -84,9 +84,6 @@ static int em_sti_enable(struct em_sti_priv *p) return ret; } - /* configure channel, periodic mode and maximum timeout */ - p->rate = clk_get_rate(p->clk); - /* reset the counter */ em_sti_write(p, STI_SET_H, 0x40000000); em_sti_write(p, STI_SET_L, 0x00000000); @@ -205,13 +202,9 @@ static u64 em_sti_clocksource_read(struct clocksource *cs) static int em_sti_clocksource_enable(struct clocksource *cs) { - int ret; struct em_sti_priv *p = cs_to_em_sti(cs); - ret = em_sti_start(p, USER_CLOCKSOURCE); - if (!ret) - __clocksource_update_freq_hz(cs, p->rate); - return ret; + return em_sti_start(p, USER_CLOCKSOURCE); } static void em_sti_clocksource_disable(struct clocksource *cs) @@ -240,8 +233,7 @@ static int em_sti_register_clocksource(struct em_sti_priv *p) dev_info(&p->pdev->dev, "used as clock source\n"); - /* Register with dummy 1 Hz value, gets updated in ->enable() */ - clocksource_register_hz(cs, 1); + clocksource_register_hz(cs, p->rate); return 0; } @@ -263,7 +255,6 @@ static int em_sti_clock_event_set_oneshot(struct clock_event_device *ced) dev_info(&p->pdev->dev, "used for oneshot clock events\n"); em_sti_start(p, USER_CLOCKEVENT); - clockevents_config(&p->ced, p->rate); return 0; } @@ -294,8 +285,7 @@ static void em_sti_register_clockevent(struct em_sti_priv *p) dev_info(&p->pdev->dev, "used for clock events\n"); - /* Register with dummy 1 Hz value, gets updated in ->set_state_oneshot() */ - clockevents_config_and_register(ced, 1, 2, 0xffffffff); + clockevents_config_and_register(ced, p->rate, 2, 0xffffffff); } static int em_sti_probe(struct platform_device *pdev) @@ -344,6 +334,15 @@ static int em_sti_probe(struct platform_device *pdev) return ret; } + ret = clk_enable(p->clk); + if (ret < 0) { + dev_err(&p->pdev->dev, "cannot enable clock\n"); + clk_unprepare(p->clk); + return ret; + } + p->rate = clk_get_rate(p->clk); + clk_disable(p->clk); + raw_spin_lock_init(&p->lock); em_sti_register_clockevent(p); em_sti_register_clocksource(p); -- cgit