tests/periph_pm: add command to display current blockers

tests/periph_pm/main.c

@@ -185,6 +185,17 @@ static int cmd_unblock(int argc, char **argv)
     return 0;
 }
 
+static int cmd_pm(int argc, char **argv)
+{
+    (void)argc;
+    (void)argv;
+
+    for (unsigned i = 0; i < PM_NUM_MODES; i++) {
+        printf("mode %d blockers: %d \n", i, pm_blocker.val_u8[i]);
+    }
+    return 0;
+}
+
 #ifdef MODULE_PERIPH_RTC
 static int cmd_unblock_rtc(int argc, char **argv)
 {
@@ -228,6 +239,7 @@ static const shell_command_t shell_commands[] = {
     { "off", "turn off", cmd_off },
     { "reboot", "reboot", cmd_reboot },
 #ifdef MODULE_PM_LAYERED
+    { "pm", "display current blockers for each power mode", cmd_pm },
     { "block", "block power mode", cmd_block },
     { "set", "set power mode", cmd_set },
     { "unblock", "unblock power mode", cmd_unblock },