+ static uint32_t timing;
+ if (!timing) {
+ uint32_t tp1, tp2, tp3;
+ /* OTP_TP1 = 1000 / sclk_period (in nanoseconds)
+ * OTP_TP1 = 1000 / (1 / get_sclk() * 10^9)
+ * OTP_TP1 = (1000 * get_sclk()) / 10^9
+ * OTP_TP1 = get_sclk() / 10^6
+ */
+ tp1 = get_sclk() / 1000000;
+ /* OTP_TP2 = 400 / (2 * sclk_period)
+ * OTP_TP2 = 400 / (2 * 1 / get_sclk() * 10^9)
+ * OTP_TP2 = (400 * get_sclk()) / (2 * 10^9)
+ * OTP_TP2 = (2 * get_sclk()) / 10^7
+ */
+ tp2 = (2 * get_sclk() / 10000000) << 8;
+ /* OTP_TP3 = magic constant */
+ tp3 = (0x1401) << 15;
+ timing = tp1 | tp2 | tp3;