control_reg = readw(i2c->base + OFFSET_CONTROL) &
                        ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
-       if ((i2c->speed_hz > 400000) || (left_num >= 1))
+       if ((i2c->speed_hz > MAX_FS_MODE_SPEED) || (left_num >= 1))
                control_reg |= I2C_CONTROL_RS;
 
        if (i2c->op == I2C_MASTER_WRRD)
        writew(control_reg, i2c->base + OFFSET_CONTROL);
 
        /* set start condition */
-       if (i2c->speed_hz <= 100000)
+       if (i2c->speed_hz <= I2C_DEFAULT_SPEED)
                writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF);
        else
                writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF);