summaryrefslogtreecommitdiff
path: root/arch/arm/plat-omap/common.c
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2010-02-17 06:09:29 (GMT)
committerDavid S. Miller <davem@davemloft.net>2010-02-17 06:09:29 (GMT)
commit2bb4646fce8d09916b351d1a62f98db7cec6fc41 (patch)
treec1f0d002e69868606eca9d1b919835f422892063 /arch/arm/plat-omap/common.c
parent6836b9bdd98e3b500cd49512484df68f46e14659 (diff)
parentb0483e78e5c4c9871fc5541875b3bc006846d46b (diff)
downloadlinux-fsl-qoriq-2bb4646fce8d09916b351d1a62f98db7cec6fc41.tar.xz
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Diffstat (limited to 'arch/arm/plat-omap/common.c')
-rw-r--r--arch/arm/plat-omap/common.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c
index bf1eaf3..dddc027 100644
--- a/arch/arm/plat-omap/common.c
+++ b/arch/arm/plat-omap/common.c
@@ -172,6 +172,32 @@ unsigned long long sched_clock(void)
clocksource_32k.mult, clocksource_32k.shift);
}
+/**
+ * read_persistent_clock - Return time from a persistent clock.
+ *
+ * Reads the time from a source which isn't disabled during PM, the
+ * 32k sync timer. Convert the cycles elapsed since last read into
+ * nsecs and adds to a monotonically increasing timespec.
+ */
+static struct timespec persistent_ts;
+static cycles_t cycles, last_cycles;
+void read_persistent_clock(struct timespec *ts)
+{
+ unsigned long long nsecs;
+ cycles_t delta;
+ struct timespec *tsp = &persistent_ts;
+
+ last_cycles = cycles;
+ cycles = clocksource_32k.read(&clocksource_32k);
+ delta = cycles - last_cycles;
+
+ nsecs = clocksource_cyc2ns(delta,
+ clocksource_32k.mult, clocksource_32k.shift);
+
+ timespec_add_ns(tsp, nsecs);
+ *ts = *tsp;
+}
+
static int __init omap_init_clocksource_32k(void)
{
static char err[] __initdata = KERN_ERR