[PATCH 4.19 33/34] clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue

Greg Kroah-Hartman
2021-07-09T13:22:25Z

From: Tony Lindgren <tony@atomide.com>

commit 3efe7a878a11c13b5297057bfc1e5639ce1241ce upstream.

There is a timer wrap issue on dra7 for the ARM architected timer.
In a typical clock configuration the timer fails to wrap after 388 days.

To work around the issue, we need to use timer-ti-dm timers instead.

Let's prepare for adding support for percpu timers by adding a common
dmtimer_clkevt_init_common() and call it from __omap_sync32k_timer_init().
This patch makes no intentional functional changes.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Tero Kristo <kristo@kernel.org>
[tony@atomide.com: backported to 4.19.y]
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm/mach-omap2/timer.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -368,18 +368,21 @@ void tick_broadcast(const struct cpumask
}
#endif

-static void __init omap2_gp_clockevent_init(int gptimer_id,
- const char *fck_source,
- const char *property)
+static void __init dmtimer_clkevt_init_common(struct dmtimer_clockevent *clkevt,
+ int gptimer_id,
+ const char *fck_source,
+ unsigned int features,
+ const struct cpumask *cpumask,
+ const char *property,
+ int rating, const char *name)
{
- struct dmtimer_clockevent *clkevt = &clockevent;
struct omap_dm_timer *timer = &clkevt->timer;
int res;

timer->id = gptimer_id;
timer->errata = omap_dm_timer_get_errata();
- clkevt->dev.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
- clkevt->dev.rating = 300;
+ clkevt->dev.features = features;
+ clkevt->dev.rating = rating;
clkevt->dev.set_next_event = omap2_gp_timer_set_next_event;
clkevt->dev.set_state_shutdown = omap2_gp_timer_shutdown;
clkevt->dev.set_state_periodic = omap2_gp_timer_set_periodic;
@@ -397,19 +400,15 @@ static void __init omap2_gp_clockevent_i
&clkevt->dev.name, OMAP_TIMER_POSTED);
BUG_ON(res);

- clkevt->dev.cpumask = cpu_possible_mask;
+ clkevt->dev.cpumask = cpumask;
clkevt->dev.irq = omap_dm_timer_get_irq(timer);

- if (request_irq(timer->irq, omap2_gp_timer_interrupt,
- IRQF_TIMER | IRQF_IRQPOLL, "gp_timer", clkevt))
- pr_err("Failed to request irq %d (gp_timer)\n", timer->irq);
+ if (request_irq(clkevt->dev.irq, omap2_gp_timer_interrupt,
+ IRQF_TIMER | IRQF_IRQPOLL, name, clkevt))
+ pr_err("Failed to request irq %d (gp_timer)\n", clkevt->dev.irq);

__omap_dm_timer_int_enable(timer, OMAP_TIMER_INT_OVERFLOW);

- clockevents_config_and_register(&clkevt->dev, timer->rate,
- 3, /* Timer internal resynch latency */
- 0xffffffff);
-
if (soc_is_am33xx() || soc_is_am43xx()) {
clkevt->dev.suspend = omap_clkevt_idle;
clkevt->dev.resume = omap_clkevt_unidle;
@@ -559,7 +558,12 @@ static void __init __omap_sync32k_timer_
{
omap_clk_init();
omap_dmtimer_init();
- omap2_gp_clockevent_init(clkev_nr, clkev_src, clkev_prop);
+ dmtimer_clkevt_init_common(&clockevent, clkev_nr, clkev_src,
+ CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ cpu_possible_mask, clkev_prop, 300, "clockevent");
+ clockevents_config_and_register(&clockevent.dev, clockevent.timer.rate,
+ 3, /* Timer internal resynch latency */
+ 0xffffffff);

/* Enable the use of clocksource="gp_timer" kernel parameter */
if (use_gptimer_clksrc || gptimer)