1 files changed, 84 insertions, 0 deletions
diff --git a/common/clock.c b/common/clock.c
new file mode 100644
index 0000000000..2e4e9d7dfc
--- /dev/null
+++ b/common/clock.c
@@ -0,0 +1,84 @@
+#include <common.h>
+#include <asm-generic/div64.h>
+#include <clock.h>
+
+static struct clocksource *current_clock;
+static uint64_t time_ns;
+
+/**
+ * get_time_ns - get current timestamp in nanoseconds
+ */
+uint64_t get_time_ns(void)
+{
+	struct clocksource *cs = current_clock;
+        uint64_t cycle_now, cycle_delta;
+        uint64_t ns_offset;
+
+        /* read clocksource: */
+        cycle_now = cs->read();
+
+        /* calculate the delta since the last call: */
+        cycle_delta = (cycle_now - cs->cycle_last) & cs->mask;
+
+        /* convert to nanoseconds: */
+        ns_offset = cyc2ns(cs, cycle_delta);
+
+	cs->cycle_last = cycle_now;
+
+	time_ns += ns_offset;
+        return time_ns;
+}
+
+/**
+ * clocksource_hz2mult - calculates mult from hz and shift
+ * @hz:                 Clocksource frequency in Hz
+ * @shift_constant:     Clocksource shift factor
+ *
+ * Helper functions that converts a hz counter
+ * frequency to a timsource multiplier, given the
+ * clocksource shift value
+ */
+uint32_t clocksource_hz2mult(uint32_t hz, uint32_t shift_constant)
+{
+        /*  hz = cyc/(Billion ns)
+         *  mult/2^shift  = ns/cyc
+         *  mult = ns/cyc * 2^shift
+         *  mult = 1Billion/hz * 2^shift
+         *  mult = 1000000000 * 2^shift / hz
+         *  mult = (1000000000<<shift) / hz
+         */
+        uint64_t tmp = ((uint64_t)1000000000) << shift_constant;
+
+        tmp += hz/2; /* round for do_div */
+        do_div(tmp, hz);
+
+        return (uint32_t)tmp;
+}
+
+int is_timeout(uint64_t start_ns, uint64_t time_offset_ns)
+{
+	if (start_ns + time_offset_ns < get_time_ns())
+		return 1;
+	else
+		return 0;
+}
+
+void udelay(unsigned long usecs)
+{
+	uint64_t start = get_time_ns();
+
+	while(!is_timeout(start, usecs * 1000));
+}
+
+void mdelay(unsigned long msecs)
+{
+	uint64_t start = get_time_ns();
+
+	while(!is_timeout(start, msecs * 1000000));
+}
+
+int init_clock(struct clocksource *cs)
+{
+	current_clock = cs;
+	return 0;
+}