FAN_PERIOD_TO_RPM  183 drivers/hwmon/adt7462.c #define FAN_PERIOD_TO_RPM(x)	((90000 * 60) / (x))
FAN_PERIOD_TO_RPM  129 drivers/hwmon/adt7470.c #define FAN_PERIOD_TO_RPM(x)	((90000 * 60) / (x))
FAN_PERIOD_TO_RPM   92 drivers/hwmon/ultra45_env.c #define FAN_PERIOD_TO_RPM(x)	((90000 * 60) / (x))