RE: [PATCH v2 3/3] power/supply: Add generic USB charger driver

[Paul Cercueil]

Hi Peter,

Le mar., déc. 17, 2019 at 01:32, Peter Chen <peter.chen@xxxxxxx> a 
écrit :
> >  Le lun., déc. 16, 2019 at 01:24, Peter Chen <peter.chen@xxxxxxx> a 
> > écrit :
> >  >
> >  >>  >>  +
> >  >>  >>  +	desc = &charger->desc;
> >  >>  >>  +	desc->name = "usb-charger";
> >  >>  >>  +	desc->properties = usb_charger_properties;
> >  >>  >>  +	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
> >  >>  >>  +	desc->get_property = usb_charger_get_property;
> >  >>  >>  +	desc->type = POWER_SUPPLY_TYPE_USB;
> >  >>  >
> >  >>  > What's your further plan for this generic USB charger?
> >  >>  > To support BC1.2, we need to know charger type, and how we 
> > could
> >  >> get  > it?
> >  >>  >
> >  >>  > Peter
> >  >>
> >  >>  Well I don't really know. The USB role framework does not give 
> > any
> >  >> info about  what's plugged.
> >  >>
> >  >
> >  > What's the use case for this patch set? How it be used?
> >
> >  My devicetree:
> >
> >  usb_otg: usb@13440000 {
> >  	compatible = "ingenic,jz4770-musb", "simple-mfd";
> >  	reg = <0x13440000 0x10000>;
> >  	[...]
> >
> >  	usb-role-switch;
> >
> >  	connector {
> >  		compatible = "gpio-usb-b-connector", "usb-b-connector";
> >  		label = "mini-USB";
> >  		type = "mini";
> >
> >  		id-gpios = <&gpf 18 GPIO_ACTIVE_HIGH>;
> >  		vbus-gpios = <&gpb 5 GPIO_ACTIVE_HIGH>;
> >  		[...]
> >  	};
> >
> >  	usb_charger: usb-charger {
> >  		compatible = "usb-charger";
> >  	};
> >  };
> >
> >  The new gpio-usb-connector driver uses the ID/VBUS GPIOs to detect 
> > in
> >  which state (device, host, unconnected) a OTG connector is. However,
> >  that means I cannot use the standard gpio-charger driver to detect 
> > the
> >  presence of a charger based on the state of the VBUS gpio, since 
> > it's
> >  already requested here. So the point of this patchset is to provide 
> > an
> >  alternative to gpio-charger that works with OTG controllers 
> > compatible
> >  with 'usb-role-switch'.
>
> Thanks for explaining it.
>
> What's the user for this USB charger,  PMIC or what else? How the 
> user uses
> this USB charger interface?

It's exported as a standard charger, so it can be passed to client 
drivers through devicetree, and its online status can be retrieved from 
sysfs.

-Paul

> >  >>  >
> >  >>  >>  +
> >  >>  >>  +	charger->charger = devm_power_supply_register(dev, desc,
> >  >> &cfg);
> >  >>  >>  +	if (IS_ERR(charger->charger)) {
> >  >>  >>  +		dev_err(dev, "Unable to register charger");
> >  >>  >>  +		return PTR_ERR(charger->charger);
> >  >>  >>  +	}
> >  >>  >>  +
> >  >>  >>  +	err = usb_role_switch_register_notifier(charger->role,
> >  >>  >> &charger->nb);
> >  >>  >>  +	if (err) {
> >  >>  >>  +		dev_err(dev, "Unable to register USB role switch 
> > notifier");
> >  >>  >>  +		return err;
> >  >>  >>  +	}
> >  >>  >>  +
> >  >>  >>  +	return devm_add_action_or_reset(dev, 
> > usb_charger_unregister,
> >  >>  >> charger);
> >  >>  >>  +}
> >  >>  >>  +
> >  >>  >>  +static const struct of_device_id usb_charger_of_match[] = {
> >  >>  >>  +	{ .compatible = "usb-charger" },
> >  >>  >>  +	{ /* sentinel */ },
> >  >>  >>  +};
> >  >>  >>  +MODULE_DEVICE_TABLE(of, usb_charger_of_match);  +  +static
> >  >> struct
> >  >>  >> platform_driver usb_charger_driver = {
> >  >>  >>  +	.driver = {
> >  >>  >>  +		.name = "usb-charger",
> >  >>  >>  +		.of_match_table = of_match_ptr(usb_charger_of_match),
> >  >>  >>  +	},
> >  >>  >>  +	.probe = usb_charger_probe,
> >  >>  >>  +};
> >  >>  >>  +module_platform_driver(usb_charger_driver);
> >  >>  >>  +
> >  >>  >>  +MODULE_DESCRIPTION("Simple USB charger driver");
> >  >>  >> +MODULE_AUTHOR("Paul Cercueil <paul@xxxxxxxxxxxxxxx>");
> >  >>  >> +MODULE_LICENSE("GPL");
> >  >>  >>  --
> >  >>  >>  2.24.0
> >  >>  >>
> >  >>  >
> >  >>  > --
> >  >>  >
> >  >>  > Thanks,
> >  >>  > Peter Chen
> >  >>
> >  >