Re: [PATCH RESEND 0/5] dt-bindings: support Ethernet devices as LED triggers

From: Ansuel Smith <ansuelsmth@gmail.com>
To: "Rafał Miłecki" <zajec5@gmail.com>
Cc: "Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Pavel Machek" <pavel@ucw.cz>,
	"David S . Miller" <davem@davemloft.net>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	"Hauke Mehrtens" <hauke@hauke-m.de>,
	"Jacek Anaszewski" <jacek.anaszewski@gmail.com>,
	devicetree@vger.kernel.org, netdev@vger.kernel.org,
	linux-leds@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	bcm-kernel-feedback-list@broadcom.com, andrew@lunn.ch,
	vivien.didelot@gmail.com, "Vladimir Oltean" <olteanv@gmail.com>,
	"Jonathan Corbet" <corbet@lwn.net>,
	"John Crispin" <john@phrozen.org>,
	linux-doc@vger.kernel.org, "Rafał Miłecki" <rafal@milecki.pl>
Subject: Re: [PATCH RESEND 0/5] dt-bindings: support Ethernet devices as LED triggers
Date: Thu, 5 May 2022 16:30:30 +0200	[thread overview]
Message-ID: <6273df88.1c69fb81.1757e.5347@mx.google.com> (raw)
In-Reply-To: <b9ef7ce4-2a9d-9ecb-0aee-3f671c25d13f@gmail.com>

On Thu, May 05, 2022 at 04:21:33PM +0200, Rafał Miłecki wrote:
> On 5.05.2022 16:02, Ansuel Smith wrote:
> > On Thu, May 05, 2022 at 03:55:07PM +0200, Rafał Miłecki wrote:
> > > From: Rafał Miłecki <rafal@milecki.pl>
> > > 
> > > Some LEDs are designed to represent a state of another device. That may
> > > be USB port, Ethernet interface, CPU, hard drive and more.
> > > 
> > > We already have support for LEDs that are designed to indicate USB port
> > > (e.g. light on when USB device gets connected). There is DT binding for
> > > that and Linux implementation in USB trigger.
> > > 
> > > This patchset adds support for describing LEDs that should react to
> > > Ethernet interface status. That is commonly used in routers. They often
> > > have LED to display state and activity of selected physical port. It's
> > > also common to have multiple LEDs, each reacting to a specific link
> > > speed.
> > > 
> > 
> > I notice this is specific to ethernet speed... I wonder if we should
> > expand this also to other thing like duplex state or even rx/tx.
> 
> I didn't see any router with separated Rx/Tx LEDs, but it still sounds
> like a valid case.
>

Not a normal configuration but it's doable. For qca8k you can really set
the led to do whatever you want.

> We could add flags for that in proposed field like:
> trigger-sources = <&port (SPEED_1000 | LINK | TX)>;
> 
> Or add separated field for non-speed flags like:
> trigger-sources = <&port SPEED_1000 (LINK | TX)>;
> 
> Let's see what DT experts say about it.

-- 
	Ansuel