Re: [PATCH v5 09/11] power: bq24257: Allow input current limit sysfs access

[Sebastian Reichel <sre@kernel.org>]

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On Tue, Sep 22, 2015 at 05:10:45PM -0500, Andreas Dannenberg wrote:
> On Tue, Sep 22, 2015 at 09:16:49PM +0200, Sebastian Reichel wrote:
> > On Fri, Sep 18, 2015 at 04:39:57PM -0500, Andreas Dannenberg wrote:
> > > This patch allows reading (and writing, if the D+/D- USB signal-based
> > > charger type detection is disabled) of the input current limit through
> > > the power supply's input_current_limit sysfs property. This allows
> > > userspace to see what charger was detected and to re-configure the
> > > maximum current drawn from the external supply at runtime based on
> > > system-level knowledge or user input.
> > 
> > Maybe also support writing into input_current_limit in auto mode.
> > Just disable auto detection until "auto" is written into sysfs node.
> 
> Auto-detection was enabled by default in the original driver so I think
> that should be left intact. I added the ability to manually override
> this via DT with a fixed value, and then configure said fixed value
> through sysfs at runtime.
> 
> I'm not 100% clear on the usecase of runtime enabling/disabling auto so
> I'd rather leave the implementation as-is. Either auto mode is enabled
> or not -- and this is directly tied to the DT setting. But if someone
> has a strong usecase for this I can certainly add it.

For some usb power supplies auto-detection doesn't work very well,
resulting in a 100mA default fallback. Users knowing their hardware
could force charging with the correct input current limitation.

-- Sebastian

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