linux-kernel - Re: Linux support for a 7 segment LED display

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Message-ID: <20240219151332.GC10170@google.com>
Date: Mon, 19 Feb 2024 15:13:32 +0000
From: Lee Jones <lee@...nel.org>
To: Chris Packham <Chris.Packham@...iedtelesis.co.nz>
Cc: Pavel Machek <pavel@....cz>,
	"linux-leds@...r.kernel.org" <linux-leds@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: Linux support for a 7 segment LED display

On Sun, 11 Feb 2024, Chris Packham wrote:

> Hi Blinkenlight enthusiasts,
> 
> I'm looking for something that I figured must exists but maybe it's so 
> niche that no-one has bothered to upstream a driver for it.
> 
> I have a requirement to support a 7-segment LED display[1] (one that can 
> display a single digit from 0-9). Hardware wise it's just a bunch of 
> individual GPIOs connected to each segment (plus an extra one for a 
> dot). I can't see anything obvious in drivers/leds but maybe I'm looking 
> in the wrong place. Or maybe it's the kind of thing on PC hardware that 
> is just driven by the BIOS without the operating system knowing about it.
> 
> Is there an existing in-kernel driver for such a thing?

Why would LEDs connected to a bunch of GPIOs in a specific fashion
require a hardware driver?  Doesn't drivers/leds/leds-gpio.c already
provide all the support you need?

-- 
Lee Jones [李琼斯]