Re: [PATCH v9 1/4] gadget: Introduce the usb charger framework

From: Felipe Balbi
Date: Wed Apr 06 2016 - 06:27:43 EST



Hi,

Peter Chen <hzpeterchen@xxxxxxxxx> writes:
> On Wed, Apr 06, 2016 at 11:05:26AM +0300, Felipe Balbi wrote:
>> Peter Chen <hzpeterchen@xxxxxxxxx> writes:
>> > On Wed, Apr 06, 2016 at 10:38:23AM +0300, Felipe Balbi wrote:
>> >> Peter Chen <hzpeterchen@xxxxxxxxx> writes:
>> >> > On Fri, Apr 01, 2016 at 03:21:49PM +0800, Baolin Wang wrote:
>> >> > +
>> >> >> +static struct attribute *usb_charger_attrs[] = {
>> >> >> + &dev_attr_sdp_current.attr,
>> >> >> + &dev_attr_dcp_current.attr,
>> >> >> + &dev_attr_cdp_current.attr,
>> >> >> + &dev_attr_aca_current.attr,
>> >> >> + &dev_attr_charger_type.attr,
>> >> >> + &dev_attr_charger_state.attr,
>> >> >> + NULL
>> >> >> +};
>> >> >
>> >> > The user may only care about current limit, type and state, why they
>> >> > need to care what type's current limit, it is the usb charger
>> >> > framework handles, the framework judge the current according to
>> >> > charger type and USB state (connect/configured/suspended).
>> >>
>> >> it might be useful if we want to know that $this charger doesn't really
>> >> give us as much current as it advertises.
>> >>
>> >
>> > As my understanding, the current limit is dynamic value, it should
>> > report the value the charger supports now, eg, it connects SDP, but
>> > the host is suspended now, then the value should be 2mA.
>>
>> yes, and that's the limit. Now consider we connect to DCP or CDP and
>> limit is 2000mA but we're charging at 1000mA ;-)
>>
>
> The user doesn't need to know the value which spec designs.

because... ?

--
balbi

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