stm32_usbphyc_clr_bits
stm32_usbphyc_clr_bits(pll_reg, PLLEN);
stm32_usbphyc_clr_bits(usbphyc->base + STM32_USBPHYC_MISC,
stm32_usbphyc_clr_bits(usbphyc->base + STM32_USBPHYC_PLL, PLLEN);