On 30 March 2016 at 17:19, Peter Chen <hzpeterchen@xxxxxxxxx> wrote: > On Wed, Mar 30, 2016 at 04:40:31PM +0800, Baolin Wang wrote: >> >> > - Third, since composite driver covers 500mA (and more for CDP) after set >> >> > configuration and 2mA after suspend, and vbus handler covers connect >> >> > and disconnect. I can't see any reasons we need to notify gadget state >> >> > for power driver, do we really need to have usb_charger_plug_by_gadget? >> >> >> >> In some solutions, gadget does not negotiate with the current. They >> >> just send out one signal to power driver to set the current when the >> >> gadget state is changed (plugin or not). So we need to check the >> >> charger state by the gadget state to notify the charger IC to set >> >> current. >> >> >> > >> > Would you give some examples? >> >> OK. I explain it in detail. Now charger detection can be from gadget >> itself or PMIC, and we focus on gadget detection. Charger IC (charger >> driver) is separate with gadget. >> When the usb cable is plugin, we need to report the plugin event to >> charger driver to set current after setting configuration for gadget. >> The usb charger is responsible for reporting plugin event to charger >> driver. But how usb charger get the plugin event? It can get the >> plugin event from gadget state (if the gadget state is more than >> 'USB_STATE_ATTACHED', it means one cable plugin). So we need notify >> gadget state to usb charger. >> > > Ok, I see, it only changes current limit at function usb_gadget_vbus_draw > in your patch 2/4. Then, we need to make sure usb_charger_set_cur_limit_by_type > is called before calling usb_gadget_set_state(gadget, USB_STATE_CONFIGURED). That's right. > > It seems you have not implemented usb_charger_plug_by_gadget in your patch set. It is implemented in patch 3/4. > > -- > Best Regards, > Peter Chen -- Baolin.wang Best Regards -- 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
