WinstonF_61 provided a link into an area that's designated for module partner access only.
DHD was our original Linux driver model. Under this model, all updates were delivered by Cypress to module partners who would then integrate into their Linux release and support customers directly. The exception being Murata as they incorporated all DHD updates for their module portfolio into the standard i.MX Linux release.
All of this and the new model which leverages our open source FMAC driver is explained here: Wi-Fi/Bluetooth for Linux
Which module partner are you working with today? Have you reached out to them regarding DHD driver updates?