* NeilBrown <neilb@xxxxxxx> [141118 19:45]: > On Wed, 12 Nov 2014 16:31:54 -0600 Felipe Balbi <balbi@xxxxxx> 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 > standard. 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. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
