On 8 April 2016 at 19:27, Jun Li <jun.li@xxxxxxx> wrote: > > >> -----Original Message----- >> From: Baolin Wang [mailto:baolin.wang@xxxxxxxxxx] >> Sent: Friday, April 08, 2016 7:00 PM >> To: Jun Li <jun.li@xxxxxxx> >> Cc: balbi@xxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; sre@xxxxxxxxxx; >> dbaryshkov@xxxxxxxxx; dwmw2@xxxxxxxxxxxxx; peter.chen@xxxxxxxxxxxxx; >> stern@xxxxxxxxxxxxxxxxxxx; r.baldyga@xxxxxxxxxxx; >> yoshihiro.shimoda.uh@xxxxxxxxxxx; lee.jones@xxxxxxxxxx; broonie@xxxxxxxxxx; >> ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx; patches@xxxxxxxxxxxxxxxxxxxxxxxxxxx; >> linux-pm@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; device- >> mainlining@xxxxxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx >> Subject: Re: [PATCH v10 1/4] gadget: Introduce the usb charger framework >> >> Hi Jun, >> >> >> >> +/* >> >> >> + * usb_charger_detect_type() - detect the charger type manually. >> >> >> + * @uchger - usb charger device >> >> >> + * >> >> >> + * Note: You should ensure you need to detect the charger type >> >> >> +manually on your >> >> >> + * platform. >> >> >> + * You should call it at the right gadget state to avoid >> >> >> +affecting gadget >> >> >> + * enumeration. >> >> >> + */ >> >> >> +int usb_charger_detect_type(struct usb_charger *uchger) { >> >> >> + enum usb_charger_type type; >> >> >> + >> >> >> + if (WARN(!uchger->charger_detect, >> >> >> + "charger detection method should not be NULL")) >> >> >> + return -EINVAL; >> >> >> + >> >> >> + type = uchger->charger_detect(uchger); >> >> >> + >> >> >> + mutex_lock(&uchger->lock); >> >> >> + uchger->type = type; >> >> >> + mutex_unlock(&uchger->lock); >> >> >> + >> >> >> + return 0; >> >> >> +} >> >> >> +EXPORT_SYMBOL_GPL(usb_charger_detect_type); >> >> > >> >> > I still recommend have a central place to call >> >> > usb_charger_detect_type() to cover real charger detection instead >> >> > of leaving this question open to diff users. This can be done after >> >> > vbus-on is detected and before do gadget connect. I don't think >> >> > this >> >> will make your framework complicated. >> >> >> >> This API is used for detecting the charger type manually (software >> >> charger detection), so if user's udc driver is needed to do this, >> >> then they can issue it at their right place to make it more flexible. >> >> But let us see other people's suggestion. Thanks. >> > >> > Ok, actually this API can be used for what ever charger detection >> > type, user can implement any method(manual detection, directly read >> > result from some HW...what ever) in uchger->charger_detect(), target >> > is >> >> But reading result from some HW dose not means *detect*, actually is *get*. >> We can not mix them together with the different semantics. > > It doesn’t matter here, you already define the _get_ API for just read > the charger type from the saved value(uchger->type), so we can think > the API to make uchger->type from UNKNOW to ONE KNOWN type is *detect*, > because we don't need 2 separate API one for *get* type from HW and another > one for *detect* from HW, only one API involve HW access is enough. But another issue is some users may need to get the charger type from power supply by "power_supply_get_property()" function, we need to integrate with the power supply things in the usb charger framework, not user to implement that. > > - Detect: (write to and) read from HW to get the charger type, > save to uchger->type; > - Get: read the charger type from uchger->type. > >> >> > to have the charger type and set uchger->type, then you no need to add >> > the comments/description to limit it usage. Also I do see there is >> possible central place to do this. >> > >> >> -- >> Baolin.wang >> Best Regards -- 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
