[Gta04-owner] [PATCH] mfd: twl4030-power: Fix poweroff with PM configuration enabled
tony at atomide.com
Sat Nov 22 00:37:10 CET 2014
* NeilBrown <neilb at suse.de> [141118 19:45]:
> On Wed, 12 Nov 2014 16:31:54 -0600 Felipe Balbi <balbi at ti.com> wrote:
> > this is actually what the USB Battery Charging spec requires us to
> > implement. If Linux is doing differently, it's a bug on Linux which
> > should be fixed :-)
> > No host is allowed to source more then one unit load (100mA in LS/FS/HS,
> > 150mA in SS) until the device is fully enumerated. Host are also
> > required to drop max current budget to 8mA (IIRC) if the device doesn't
> > enumerate for however many minutes (I guess it was a pretty long
> > threshold, something like half an hour or so. My memory fails me right
> > now).
> I think the twl4030 driver does do the "right" thing unless the "allow_usb"
> module parameter is set, in which case it enables charging at a higher rate
> which is 600mA (default value of BCIIREF1).
> It would be nice if the driver could check if a charger was plugged in and
> act accordingly.
> The charger I have for my openmoko is identified by a 47K resistor between ID
> and ground. The twl4030 can detect that easily enough, but it isn't very
Sounds doable to me, feel free to patch it up since you guys are using
the twl4030 charger :)
> The standard is of course to have D+ and D- shorted, but I don't know if the
> twl4030 can detect that? If it can, then getting some very early code to
> check for the short (or the 47k resistor) and quickly enabling charging might
> be a sufficient solution.
I guess. Note that there's also the USB BC1.2 spec that is more
complicated than having the data lines shorted.
More information about the Gta04-owner