Make certain fields read only?

For instance I have the below in the device page config, I would like to be able to set it for Read-only instead of allowing write access to the value.

- label: "'Frequency Lock:'"
  parameter: InternetGatewayDevice.FreqLock.FreqLData.FreqLock_Mode
- label: "'EARFCN Lock:'"
  parameter: InternetGatewayDevice.FreqLock.FreqLData.FreqLock_FreqValue

I tried via permissions too with a separate user and was not able to, I have also tried adding the writable: false below parameter and had no luck either.