Handling LDAC for the AD5541 using the ad5446.c driver

From looking at the Linux 4.15 kernel, it appears that the AD5541A DAC is controlled using the drivers/iio./dac/ad5446.c driver.  Looking through the source code, I see that I can handle the device using a standard SPI device.  What I don't see is any way to manipulate the LDAC signal.  

Does the ad5446.c driver make provisions for the LDAC signal?  (Does it assume that the signal is pulled low?) 

Since this is a platform device for my application, how do I spec out the ad5541 in the device tree? 

Thanks,

Doug Bailey