bcm2835 rpi regulator driver to enable usb

[Noralf Trønnes]

Den 22.10.2015 20:56, skrev Alexander Aring:
> Hi,
>
> I would like to have some mainline solution to enable the power for the
> dwc2 controller inside the raspberry pi. The reason is that I want to boot
> a mainline Raspberry Pi (not from u-boot) and having ethernet support.
>
> I also don't want to add hacks into bootloader which enables the usb
> controller before booting linux.
>
> I just see that the firmware driver is already on the way. So I want to
> ask what the best method is to add such support.
>
> I came up to the idea to add a regulator driver, somewhere in
> "drivers/regulator/raspberrypi.c" (keeping firmware naming convention), which
> supports to enable the usb host controller over the firmware driver.
>
> Is this a mainline acceptable solution?
> Or are there some patches which needs some little cleanups to add such
> support?
> Or is somebody already working on it?

The first[1] version of the firmware driver could do that using power
domains, but this was later removed due to deferred probing issues.
Eric Anholt proposed a solution[2] for this, but it wasn't accepted.

[1] 
http://lists.infradead.org/pipermail/linux-rpi-kernel/2015-April/001638.html
[2] https://lkml.org/lkml/2015/3/11/483


Noralf.