[U-Boot-Users] Troubles on my custom keyboard driver in u-boot

Wolfgang Denk wd at denx.de
Wed Apr 7 15:24:21 CEST 2004

In message <20040407112143.80715.qmail at web15201.mail.bjs.yahoo.com> you wrote:
> I had a trouble on coding a custom keyboard driver on
> my custom 8xx board in u-boot.According to README,only
> RBC823 does have a custom keyboard so far.I looked up

This is wrong.

Many systems have a custom keyboard of one kind or another.  See  for
example  LWMON  and  R360  and  TRAB,  which  allow to bind arbitrary
command sequences to arbitrary key combinations.

Or see HMI-10 which uses  a  custom  PS/2  multiplexor  to  attach  a
standard PC keuyboard as input device.

> kbd.c of this board but still some puzzles.In kbd.c,
> RBC823 use SMC1 as serial port to get the input,while
> I mean to implement the input by PCMCIA pins as GPIO.I
> could make a Level 0 interrupt by PCMCIA status change
> to create a character.But how about next step?

What are you going to use the "keyboard" for? To  detect  single  key
presses and to switch functions in U-Boot, like truning on/off of log
,messages, booting a different image and the like? Or as input device
for interactive use?

> 1. RBC823 use DPRAM as keyboard buffer and get
> 2. How come RBC823 uses lcd_disable function and a
> special U-BUS arbitration priority? I did the same on
> 3. Also,when I registered my custom board as RBC823
> did.I found the I/O address of keyboard and LCD had

It makes little sense  to  use  a  configuration  for  one  board  on
completely  different  hardware. You need a detailed understanding of
that hardware, and of your own, and in nearly all cases you will have
to adapt the code. Simpy copying a configuration  is  a  pretty  good
guarantee to run you into problems.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
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Doctor:   "Ah, ah that's a catch question. With a brain your size you
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