Re: [RFC 00/25] arm64: realtek: Add Xnano X5 and implement TM1628/FD628/AiP1618 LED controllers

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: "Andreas Färber" <afaerber@suse.de>,
	linux-realtek-soc@lists.infradead.org,
	linux-leds@vger.kernel.org, linux-rtc@vger.kernel.org,
	"Alessandro Zummo" <a.zummo@towertech.it>,
	"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	csd@princeton.com.tw,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	sales@fdhisi.com, "Mark Brown" <broonie@kernel.org>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	linux-spi <linux-spi@vger.kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Jacek Anaszewski" <jacek.anaszewski@gmail.com>,
	"Pavel Machek" <pavel@ucw.cz>,
	zypeng@titanmec.com,
	"open list:ARM/Amlogic Meson..."
	<linux-amlogic@lists.infradead.org>,
	"Linux ARM" <linux-arm-kernel@lists.infradead.org>,
	"Dan Murphy" <dmurphy@ti.com>,
	"open list:ARM/Rockchip SoC..."
	<linux-rockchip@lists.infradead.org>
Subject: Re: [RFC 00/25] arm64: realtek: Add Xnano X5 and implement TM1628/FD628/AiP1618 LED controllers
Date: Fri, 13 Dec 2019 15:36:24 +0100	[thread overview]
Message-ID: <CAMuHMdXddQ4v8-by_SmcS09EYykoBZ2G2vcFUpqPadHFaasy7A@mail.gmail.com> (raw)
In-Reply-To: <04e7d7cd-a8bc-621b-9205-1a058521cabe@arm.com>

Hi Robin,

On Fri, Dec 13, 2019 at 3:08 PM Robin Murphy <robin.murphy@arm.com> wrote:
> On 12/12/2019 8:55 pm, Andreas Färber wrote:
> > Am 12.12.19 um 14:14 schrieb Robin Murphy:
> >> and as far as I
> >> could tell the command set appears to derive from (or is at least common
> >> to) some old Holtek VFD controllers.
> >
> > Hmm, HT16515 looks similar and has more lines, RAM and mode bits than I
> > prepared here.
> > https://www.holtek.com/productdetail/-/vg/ht16515
> >
> > So I'd need to make more numbers model-dependent and allocate the
> > Display RAM buffer dynamically.
> >
> > Whereas HT16D35A seems incompatible command-wise, and HT16528 appears to
> > be out of scope, for dot displays and with fancy embedded character map.
> >
> > No Holtek email alias that I can quickly spot.
> >
> > But given that I'm proposing vendor-specific compatibles just in case,
> > the main decisions will be the Kconfig symbol and module name. The
> > driver code itself we could always refactor after merging, and renaming
> > the schema file (as opposed to compatible) should also be possible.
>
> Yeah, I'm not sure that it really matters, as I doubt there are many
> Linux-capable devices with a real VFD anyway; it just seemed like an
> interesting datapoint that fell out of scouring the web trying to find
> any evidence for which the "canonical" 1618 might be (and the Holtek
> connection was actually a coincidence from a misidentification of the
> ARTSCHIP part number).

My Sony Blu-Ray/Home Theatre has a nice one (14-segment!), also driven
by an HT16515.  While the specific model predates the arrival of Linux
in the next stepping of the hardware, it should be sufficiently powerful
to run Linux.

Unfortunately it's in active use, so hacking experiments would be vetoed by
the family ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds