Hi,
On 16-08-17 17:54, Tony Lindgren wrote:
* Hans de Goede <hdegoede@xxxxxxxxxx> [170815 13:06]:
On some devices the USB Type-C port power (USB PD 2.0) negotiation is
done by a separate port-controller IC, while the current limit is
controlled through another (charger) IC.
It has been decided to model this by modelling the external Type-C
power brick (adapter/charger) as a power-supply class device which
supplies the charger-IC, with its voltage-now and current-max representing
the negotiated voltage and max current draw.
This commit adds a power_supply_set_input_current_limit_from_supplier
helper function which charger power-supply drivers can call to get
the max-current from their supplier and have this applied
through their set_property call-back to their input-current-limit.
Hmm so can this also be used for the USB gadget subsystem
to tell charge controller when it's OK to enable 500mA
charging after enumeration?
I'm not sure that that would be best modeled this way. Perhaps
the phy-driver can directly control the gpio you have for that,
that seems better then trying to solve this with cross subsystem
calls which are always tricky.
FYI, that's controlled by the bq24190 pin named OTG that should
be only set high after enumeration. Any ideas how that is wired
on your device? Does it connect to the USB PHY or to a GPIO
line?
I believe it is just hardwired to be logical high all the time
on my board.
Regards,
Hans
