TPM_TIMEOUT_US_LOW
usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
usleep_range(TPM_TIMEOUT_US_LOW, TPM_TIMEOUT_US_HI);
#define TPM_TIMEOUT_US_HI (TPM_TIMEOUT_US_LOW + 2000)