1 files changed, 31 insertions, 0 deletions
diff --git a/i915-watt.c b/i915-watt.c
new file mode 100644
index 0000000..bfbb64b
--- /dev/null
+++ b/i915-watt.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+	FILE *f;
+	uint64_t this_microjoules, last_microjoules = ~UINT64_C(0);
+
+	setbuf(stdout, NULL);
+	f = fopen("/sys/kernel/debug/dri/0/i915_energy_uJ", "r");
+	if (!f) {
+		perror("fopen(/sys/kernel/debug/dri/0/i915_energy_uJ)");
+		return 1;
+	}
+
+	printf("Measuring...");
+	for (;;) {
+		if (fscanf(f, "%" PRIu64, &this_microjoules) != 1) {
+			perror("fscanf");
+			return 1;
+		}
+		rewind(f);
+		if (last_microjoules != ~UINT64_C(0))
+			printf("\x1b[0G\x1b[0K%.2f W", (double)(this_microjoules - last_microjoules) / 1000000.0);
+		last_microjoules = this_microjoules;
+		sleep(1);
+	}
+	return 0;
+}