On Fri, Feb 27, 2015 at 08:48:40AM +0000, Schmid, Carsten wrote: > I have had a look into the spec (USB PD), but it does not explicitly > explain whether the negotiation is done in hardware (by dedicated > charger chips) or driver software (which then assigns higher allowed > current to the ports). > > We are planning for new devices to be designed, where we want to > support charging smartphones etc. and we want to know if there has to > be done something for this in the USB drivers, and from which kernel > on the PD will be supported. > Actually it seems that the negotiation is a job for the charger chips > and they signal their state via GPIOs to CPU/SoC. How are the GPIOs defined? How is the CPU supposed to know where they are? Through ACPI? > However, I think that the USB team should have an eye on the USB PD > spec. and keep it in mind. The USB-IF has been actively hostile toward Linux and the Linux community, going out of their way to make things difficult for us, so keeping track of their new specifications is very low on my priority list. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
