From: Tony Lindgren <tony@atomide.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: Keerthy <j-keerthy@ti.com>,
linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Tero Kristo <kristo@kernel.org>
Subject: [PATCH 1/2] clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue
Date: Thu, 4 Mar 2021 09:37:36 +0200 [thread overview]
Message-ID: <20210304073737.15810-2-tony@atomide.com> (raw)
In-Reply-To: <20210304073737.15810-1-tony@atomide.com>
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>
---
drivers/clocksource/timer-ti-dm-systimer.c | 72 +++++++++++++++-------
1 file changed, 49 insertions(+), 23 deletions(-)
diff --git a/drivers/clocksource/timer-ti-dm-systimer.c b/drivers/clocksource/timer-ti-dm-systimer.c
--- a/drivers/clocksource/timer-ti-dm-systimer.c
+++ b/drivers/clocksource/timer-ti-dm-systimer.c
@@ -528,17 +528,18 @@ 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;
+ unsigned long irqflags;
int error;
- clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
- if (!clkevt)
- return -ENOMEM;
-
t = &clkevt->t;
dev = &clkevt->dev;
@@ -546,25 +547,23 @@ 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);
@@ -575,33 +574,60 @@ static int __init dmtimer_clockevent_init(struct device_node *np)
*/
writel_relaxed(OMAP_TIMER_CTRL_POSTED, t->base + t->ifctrl);
+ if (dev->cpumask == cpu_possible_mask)
+ irqflags = IRQF_TIMER;
+ else
+ irqflags = IRQF_TIMER | IRQF_NOBALANCING;
+
error = request_irq(dev->irq, dmtimer_clockevent_interrupt,
- IRQF_TIMER, "clockevent", clkevt);
+ irqflags, 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,
+ 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 resynch 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;
+ clkevt->dev.suspend = omap_clockevent_idle;
+ clkevt->dev.resume = omap_clockevent_unidle;
}
return 0;
-err_out_unmap:
- iounmap(t->base);
-
err_out_free:
kfree(clkevt);
--
2.30.1
next prev parent reply other threads:[~2021-03-04 7:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-04 7:37 [PATCH 0/2] Fixes for for dra7 timer wrap errata i940 Tony Lindgren
2021-03-04 7:37 ` Tony Lindgren [this message]
2021-03-22 15:55 ` [PATCH 1/2] clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue Daniel Lezcano
2021-03-22 16:33 ` Tony Lindgren
2021-03-22 18:23 ` Daniel Lezcano
2021-03-23 6:31 ` Tony Lindgren
2021-03-04 7:37 ` [PATCH 2/2] clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940 Tony Lindgren
2021-03-22 10:15 ` Daniel Lezcano
2021-03-22 10:17 ` Tony Lindgren
2021-03-23 7:43 [PATCHv2 0/2] Fixes for for " Tony Lindgren
2021-03-23 7:43 ` [PATCH 1/2] clocksource/drivers/timer-ti-dm: Prepare to handle dra7 timer wrap issue Tony Lindgren
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