> And, I also realize that writing documentation requires effort. For Apple's hardware, the documentation exists. It's comprehensive. It's just not being relea

> And, I also realize that writing documentation requires effort. For Apple's hardware, the documentation exists. It's comprehensive. It's just not being released. (This is not the case for software.) Source: Apple employee. But this attitude is common in the hardware industry. This particular situation is a bit unusual because most of the time, Linux drivers either are developed with no support from the hardware vendor (something which wouldn't have been possible here due to secure boot) or are developed by the hardware vendor itself. But in the second case, it's common for no documentation to be released along with the driver, leaving independent parties to glean what they can from register names and other definitions in the source code. Or if documentation is released, it only covers the parts that drivers are supposed to access, excluding what would be needed to, say, write a custom firmware to replace the included blob.