usb: obtain configuration descriptor's bmAttributes and bMaxPower from DT

[jfischer-no]

Currently configuration descriptor's bmAttributes and bMaxPower is hardcoded to SelfPowered and MaxPower of 100mA. Where SelfPowered applies to most boards in the tree except boards like pca10059 for example.

Both SelfPowered and MaxPower should be derived from DT because they are hardware properties.
Note: SelfPowered can not be changed at runtime because there is no API for.

[StefJar]

any news on that feature implementation?

[StefJar]

@galak any news regarding that feature?

[solsbarry]

I also would like this feature. I tired creating a second usb descriptor which is easy enough. But whether the Host even asks for anything but the first descriptor is host dependent. On my host, the first descriptor is used if it can be, so this is not a solution.
All you need to do I think, is make a new kconfig option called CONFIG_USB_MAX_POWER in zephyr/subsys/usb/Kconfig
The defualt could be 0x32
Then in usb_descriptor.c
do .bMaxPower = CONFIG_USB_MAX_POWER;

and something similar for bmAttributes

[solsbarry]

I provided a fix like I described above. I realize the original request asked for a way to configure this at runtime, and my fix is only at build time. But I am not sure there is a practical reason to reconfigure at runtime. But maybe there is.

[jfischer-no]

Where is this "original request" you talking about?

[solsbarry]

@jfischer-phytec-iot I meant your request. But now reading your post closer, I see you were just stating there is no API not asking for one. Sorry for any confusion.

[jfischer-no]

This issue suggests to use device tree not Kconfig. But with #20375, Kconfig could probably be a good solution too.

[StefJar]

I put a request for that some time ago
#19544

[jfischer-no]

resolved by #21461