REG_IEN           103 drivers/i2c/busses/i2c-efm32.c #define REG_IEN			0x34
REG_IEN            34 drivers/i2c/busses/i2c-rk3x.c #define REG_IEN        0x18 /* interrupt enable */
REG_IEN            61 drivers/spi/spi-efm32.c #define REG_IEN		0x4c