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-rw-r--r--util/flashrom/udelay.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/util/flashrom/udelay.c b/util/flashrom/udelay.c
new file mode 100644
index 0000000000..30b8dde261
--- /dev/null
+++ b/util/flashrom/udelay.c
@@ -0,0 +1,37 @@
+#include <sys/time.h>
+#include <stdio.h>
+
+// count to a billion. Time it. If it's < 1 sec, count to 10B, etc.
+unsigned long micro = 1;
+
+void myusec_delay(int time)
+{
+ volatile unsigned long i;
+ for (i = 0; i < time * micro; i++);
+}
+
+void myusec_calibrate_delay()
+{
+ int count = 1000;
+ unsigned long timeusec;
+ struct timeval start, end;
+ int ok = 0;
+
+ printf("Setting up microsecond timing loop\n");
+ while (!ok) {
+ gettimeofday(&start, 0);
+ myusec_delay(count);
+ gettimeofday(&end, 0);
+ timeusec = 1000000 * (end.tv_sec - start.tv_sec) +
+ (end.tv_usec - start.tv_usec);
+ count *= 2;
+ if (timeusec < 1000000 / 4)
+ continue;
+ ok = 1;
+ }
+
+ // compute one microsecond. That will be count / time
+ micro = count / timeusec;
+
+ fprintf(stderr, "%ldM loops per second\n", (unsigned long) micro);
+}