from etm.c:153
#define ETM_COUNTER(i) \
{ ETM_COUNTER_RELOAD_VALUE + (i) - 1, 16, WO, 0x10, \
"ETM_counter_" #i "_reload_value", }, \
{ ETM_COUNTER_ENABLE + (i) - 1, 18, WO, 0x10, \
"ETM_counter_" #i "_enable", }, \
{ ETM_COUNTER_RELOAD_EVENT + (i) - 1, 17, WO, 0x10, \
"ETM_counter_" #i "_reload_event", }, \
{ ETM_COUNTER_VALUE + (i) - 1, 16, RO, 0x10, \
"ETM_counter_" #i "_value", }