[PATCH 2/2] clocksource: sprd: Register one always-on timer to compensate suspend time

From: Baolin Wang
Date: Tue Jul 17 2018 - 03:56:06 EST


Since the clocksource framework has introduced one suspend clocksource to
compensate the suspend time, this patch registers one always-on timer as
the suspend clocksource.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
Changes from RFC v1:
- None.
---
drivers/clocksource/timer-sprd.c | 50 ++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)

diff --git a/drivers/clocksource/timer-sprd.c b/drivers/clocksource/timer-sprd.c
index ef9ebea..430cb99 100644
--- a/drivers/clocksource/timer-sprd.c
+++ b/drivers/clocksource/timer-sprd.c
@@ -156,4 +156,54 @@ static int __init sprd_timer_init(struct device_node *np)
return 0;
}

+static struct timer_of suspend_to = {
+ .flags = TIMER_OF_BASE | TIMER_OF_CLOCK,
+};
+
+static u64 sprd_suspend_timer_read(struct clocksource *cs)
+{
+ return ~(u64)readl_relaxed(timer_of_base(&suspend_to) +
+ TIMER_VALUE_SHDW_LO) & cs->mask;
+}
+
+static int sprd_suspend_timer_enable(struct clocksource *cs)
+{
+ sprd_timer_update_counter(timer_of_base(&suspend_to),
+ TIMER_VALUE_LO_MASK);
+ sprd_timer_enable(timer_of_base(&suspend_to), TIMER_CTL_PERIOD_MODE);
+
+ return 0;
+}
+
+static void sprd_suspend_timer_disable(struct clocksource *cs)
+{
+ sprd_timer_disable(timer_of_base(&suspend_to));
+}
+
+static struct clocksource suspend_clocksource = {
+ .name = "sprd_suspend_timer",
+ .rating = 200,
+ .read = sprd_suspend_timer_read,
+ .enable = sprd_suspend_timer_enable,
+ .disable = sprd_suspend_timer_disable,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
+};
+
+static int __init sprd_suspend_timer_init(struct device_node *np)
+{
+ int ret;
+
+ ret = timer_of_init(np, &suspend_to);
+ if (ret)
+ return ret;
+
+ clocksource_register_hz(&suspend_clocksource,
+ timer_of_rate(&suspend_to));
+
+ return 0;
+}
+
TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init);
+TIMER_OF_DECLARE(sc9860_persistent_timer, "sprd,sc9860-suspend-timer",
+ sprd_suspend_timer_init);
--
1.7.9.5