battery: Add sleep param; make errors fatal in the loop

If you're running the battery command in a loop:

* You may need a sleep so you don't trigger watchdog resets, at least
  if you're running at a low clock frequency.
* You probably want to break on an error.

Make the sleep delay come from a parameter since you might want to
avoid it if you just want to pound on the bus as fast as possible.

BRANCH=pit
BUG=chrome-os-partner:22093
TEST=With all patches together:
- on AP: suspend_stress_test
- on EC: battery 10000 50

Change-Id: I6ae6d818c06f59064e90bd6d23d6d4c782544849
Signed-off-by: Doug Anderson <dianders@chromium.org>
Previous-Reviewed-on: https://chromium-review.googlesource.com/167103
(cherry picked from commit 703ce2abf2e38b0f1434224534c1be505e1244f7)
Reviewed-on: https://chromium-review.googlesource.com/167160
Reviewed-by: Hung-ying Tyan <tyanh@google.com>
Reviewed-by: Rong Chang <rongchang@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

common/smart_battery.c

@@ -229,6 +229,7 @@ static int command_battery(int argc, char **argv)
 	int repeat = 1;
 	int rv = 0;
 	int loop;
+	int sleep_ms = 0;
 	char *e;
 
 	if (argc > 1) {
@@ -239,16 +240,31 @@ static int command_battery(int argc, char **argv)
 		}
 	}
 
-	for (loop = 0; loop < repeat; loop++)
+	if (argc > 2) {
+		sleep_ms = strtoi(argv[2], &e, 0);
+		if (*e) {
+			ccputs("Invalid sleep ms\n");
+			return EC_ERROR_INVAL;
+		}
+	}
+
+	for (loop = 0; loop < repeat; loop++) {
 		rv = print_battery_info();
 
+		if (sleep_ms)
+			msleep(sleep_ms);
+
+		if (rv)
+			break;
+	}
+
 	if (rv)
 		ccprintf("Failed - error %d\n", rv);
 
 	return rv ? EC_ERROR_UNKNOWN : EC_SUCCESS;
 }
 DECLARE_CONSOLE_COMMAND(battery, command_battery,
-			"<repeat_count>",
+			"<repeat_count> <sleep_ms>",
 			"Print battery info",
 			NULL);