Re: [PATCH 2/2] hwmon: ina3221: Get channel names from DT node

[Guenter Roeck]

On 09/21/2018 02:18 AM, Nicolin Chen wrote:
> Hi,
>
> On Thu, Sep 20, 2018 at 06:20:38PM -0700, Nicolin Chen wrote:
> > > So if there are no devicetree entries, the user now gets a sequence of
> > > "unknown" sensors ? I don't think so. Please keep in mind that there are
> > > users of this chip who don't have devicetree systems, and other users
> > > may not want to specify any specific name properties (or they use sensors3.conf
> > > to do it).
> >
> > Being enlightened by your comments below, maybe adding a
> > separate group for channel names by attaching is_visible
> > to it could be acceptable? Then, name nodes can hide from
> > those who don't want to specify.
>   
> > > > +		/* Log connected channels */
> > > > +		ina->attr_group[g++] = &ina3221_group[i];
> > > > +		ina->channel_name[i] = str;
> > > > +		ina->enable[i] = true;
> > >
> > > I also don't see the need for defining the group dynamically. The
> > > is_visible callback is very well suited for handling optional sysfs
> > > attributes.
>
> I tried is_visible but it looks like it won't be that neat to
> implement as some attributes of this driver don't really pass
> the channel index to the store()/show() but some other indexes.

The channel index is not the only means that can be used to determine
the channel index. Many drivers use the position in the attrs[] array
to determine the channel index. I don't see why this would not be
possible here.

> If you are very against the dynamical group, I can drop it to
> leave the sysfs node as it was.
>
> And for the name nodes that I was talking about above, I will
> add an sysfs store() function so non-DT users can set them,
> and I also removed the confusing "unknown" default name.

The label attributes are RO. Please follow the ABI.

temp[1-*]_label Suggested temperature channel label.
                Text string
                Should only be created if the driver has hints about what
                this temperature channel is being used for, and user-space
                doesn't. In all other cases, the label is provided by
                user-space.
                RO

Guenter