linux-kernel - Re: [PATCH v2] leds: ledtrig-morse: send out morse code

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Message-ID: <CAMuHMdXE3MdCQRq6Y5sEu+B8668b5mEEfNT=5qva4AzxWFyijA@mail.gmail.com>
Date:   Fri, 6 Jul 2018 09:22:46 +0200
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Willy Tarreau <w@....eu>
Cc:     Andy Shevchenko <andy.shevchenko@...il.com>,
        Andreas Klinger <ak@...klinger.de>,
        Jacek Anaszewski <jacek.anaszewski@...il.com>,
        Pavel Machek <pavel@....cz>,
        Ben Whitten <ben.whitten@...il.com>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Philippe Ombredanne <pombredanne@...b.com>,
        Greg KH <gregkh@...uxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-leds@...r.kernel.org
Subject: Re: [PATCH v2] leds: ledtrig-morse: send out morse code

Hi Willy,

On Wed, Jul 4, 2018 at 4:41 AM Willy Tarreau <w@....eu> wrote:
> On Tue, Jul 03, 2018 at 09:43:06PM +0300, Andy Shevchenko wrote:
> Well, in this case it's even possible to go further and avoid storing
> 36 strings. Indeed, no representation is longer than 5 symbols, so you
> can use 5 bits for the encoding (0=".", 1="-") and 3 bits for the
> length, it gives you a single byte per character instead of a pointer
> to a string plus 6 chars. Then in order to make it readable, 5 macros
> can be provided to emit the code :

And using the scheme from
https://plus.google.com/u/0/117536210417097546339/posts/hvctn17WUZu
you can store up to 7 symbols in a single byte, which you need when going
beyond plain alphanumeric:

-0111111
--011111
---01111
----0111
-----011
------01
-------0

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-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