From: Nicolin Chen <nicoleotsuka@gmail.com>
To: Guenter Roeck <linux@roeck-us.net>
Cc: jdelvare@suse.com, robh+dt@kernel.org, mark.rutland@arm.com,
afd@ti.com, linux-hwmon@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] hwmon: ina3221: Get channel names from DT node
Date: Thu, 20 Sep 2018 18:20:39 -0700 [thread overview]
Message-ID: <20180921012038.GA23354@Asurada-Nvidia.nvidia.com> (raw)
In-Reply-To: <21a6e8f3-c95d-43d0-ca3f-3f91ddfeff07@roeck-us.net>
Hi Guenter,
Thanks for the review.
On Thu, Sep 20, 2018 at 05:41:48PM -0700, Guenter Roeck wrote:
> > Meanwhile, channels could be left unconnected based on
> > the hardware design. So the channel name should support
> > NC so the driver could disable the channel accordingly.
> >
>
> I am not in favor of such indirect settings. If a channel is
> to be disconnected, define a property for it.
OK. I can add a bool property for it instead.
> I am personally also not in favor of using devicetree to define
> channel names like this, much less so for a single driver.
As DT is used to describe hardware, I felt plausible to put
them in since the names are mentioned in the schematics. Do
you have any advise to handle this better?
> > + /* Fetch hardware information from Device Tree */
> > + for (i = 0, g = 0; i < INA3221_NUM_CHANNELS; i++) {
> > + /* Fetch the channel name */
> > + sprintf(prop, "ti,channel%d-name", i + 1);
> > + /* Set a default name on failure */
> > + if (of_property_read_string(np, prop, &str))
> > + str = "unknown";
>
> 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.
> > + /* Ignore unconnected channels */
> > + if (!strcmp(str, INA3221_NOT_CONNECTED))
> > + continue;
>
> Sorry, I won't accept this. I am sure we can come up with some useful means
> to define in devicetree if individual channels of a hardware monitoring chip
> are enabled or not, but a channel name of "NC" won't be it.
I will try the bool property as you mentioned earlier.
> > + /* 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 will add an is_visible callback.
Thanks
Nicolin
next prev parent reply other threads:[~2018-09-21 1:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-21 0:07 [PATCH 0/2] Add an initial DT binding doc for ina3221 Nicolin Chen
2018-09-21 0:07 ` [PATCH 1/2] dt-bindings: hwmon: Add ina3221 documentation Nicolin Chen
2018-09-21 0:45 ` Guenter Roeck
2018-09-21 1:24 ` Nicolin Chen
2018-09-21 0:07 ` [PATCH 2/2] hwmon: ina3221: Get channel names from DT node Nicolin Chen
2018-09-21 0:41 ` Guenter Roeck
2018-09-21 1:20 ` Nicolin Chen [this message]
2018-09-21 9:18 ` Nicolin Chen
2018-09-21 12:56 ` Guenter Roeck
2018-09-21 17:43 ` Nicolin Chen
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