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clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue 

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 dmtimer_clockevent_init().
This patch makes no intentional functional changes.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210323074326.28302-2-tony@atomide.com
This commit is contained in:
Tony Lindgren 2021-03-23 09:43:25 +02:00 committed by Daniel Lezcano
parent 397dc6f7ca
commit 3efe7a878a
1 changed files with 47 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
drivers/clocksource/timer-ti-dm-systimer.c
View File

@ -530,17 +530,17 @@ static void omap_clockevent_unidle(struct clock_event_device *evt)
writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->wakeup);
}
static int __init dmtimer_clockevent_init(struct device_node *np)
static int __init dmtimer_clkevt_init_common(struct dmtimer_clockevent *clkevt,
struct device_node *np,
unsigned int features,
const struct cpumask *cpumask,
const char *name,
int rating)
{
struct dmtimer_clockevent *clkevt;
struct clock_event_device *dev;
struct dmtimer_systimer *t;
int error;
clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
if (!clkevt)
return -ENOMEM;
t = &clkevt->t;
dev = &clkevt->dev;
@ -548,25 +548,23 @@ static int __init dmtimer_clockevent_init(struct device_node *np)
* We mostly use cpuidle_coupled with ARM local timers for runtime,
* so there's probably no use for CLOCK_EVT_FEAT_DYNIRQ here.
*/
dev->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
dev->rating = 300;
dev->features = features;
dev->rating = rating;
dev->set_next_event = dmtimer_set_next_event;
dev->set_state_shutdown = dmtimer_clockevent_shutdown;
dev->set_state_periodic = dmtimer_set_periodic;
dev->set_state_oneshot = dmtimer_clockevent_shutdown;
dev->set_state_oneshot_stopped = dmtimer_clockevent_shutdown;
dev->tick_resume = dmtimer_clockevent_shutdown;
dev->cpumask = cpu_possible_mask;
dev->cpumask = cpumask;
dev->irq = irq_of_parse_and_map(np, 0);
if (!dev->irq) {
error = -ENXIO;
goto err_out_free;
}
if (!dev->irq)
return -ENXIO;
error = dmtimer_systimer_setup(np, &clkevt->t);
if (error)
goto err_out_free;
return error;
clkevt->period = 0xffffffff - DIV_ROUND_CLOSEST(t->rate, HZ);
@ -578,32 +576,54 @@ static int __init dmtimer_clockevent_init(struct device_node *np)
writel_relaxed(OMAP_TIMER_CTRL_POSTED, t->base + t->ifctrl);
error = request_irq(dev->irq, dmtimer_clockevent_interrupt,
IRQF_TIMER, "clockevent", clkevt);
IRQF_TIMER, name, clkevt);
if (error)
goto err_out_unmap;
writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->irq_ena);
writel_relaxed(OMAP_TIMER_INT_OVERFLOW, t->base + t->wakeup);
pr_info("TI gptimer clockevent: %s%lu Hz at %pOF\n",
of_find_property(np, "ti,timer-alwon", NULL) ?
pr_info("TI gptimer %s: %s%lu Hz at %pOF\n",
name, of_find_property(np, "ti,timer-alwon", NULL) ?
"always-on " : "", t->rate, np->parent);
clockevents_config_and_register(dev, t->rate,
3, /* Timer internal resync latency */
0xffffffff);
if (of_machine_is_compatible("ti,am33xx") ||
of_machine_is_compatible("ti,am43")) {
dev->suspend = omap_clockevent_idle;
dev->resume = omap_clockevent_unidle;
}
return 0;
err_out_unmap:
iounmap(t->base);
return error;
}
static int __init dmtimer_clockevent_init(struct device_node *np)
{
struct dmtimer_clockevent *clkevt;
int error;
clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
if (!clkevt)
return -ENOMEM;
error = dmtimer_clkevt_init_common(clkevt, np,
CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
cpu_possible_mask, "clockevent",
300);
if (error)
goto err_out_free;
clockevents_config_and_register(&clkevt->dev, clkevt->t.rate,
3, /* Timer internal resync latency */
0xffffffff);
if (of_machine_is_compatible("ti,am33xx") ||
of_machine_is_compatible("ti,am43")) {
clkevt->dev.suspend = omap_clockevent_idle;
clkevt->dev.resume = omap_clockevent_unidle;
}
return 0;
err_out_free:
kfree(clkevt);