Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32l1/STM32L152/I2C1/CR2#0x0
CR2
Peripheral clock frequency
Error interrupt enable
Event interrupt enable
Buffer interrupt enable
DMA requests enable
DMA last transfer
https://github.com/modm-io/cmsis-svd-stm32