I2C_IRQSTATUS
[I2C_IRQSTATUS] = 0x08,
[I2C_IRQSTATUS] = 0x28,
stat = I2C_READ_REG(sc, I2C_IRQSTATUS);
I2C_WRITE_REG(sc, I2C_IRQSTATUS, stat);
I2C_WRITE_REG(sc, I2C_IRQSTATUS,
I2C_READ_REG(sc, I2C_IRQSTATUS));
I2C_WRITE_REG(sc, I2C_IRQSTATUS, stat);