[U-Boot-Users] Any spport for Dallas 1-wire DS2502-E48

[U-Boot-Users] Any spport for Dallas 1-wire DS2502-E48

[Edward Jubenville]

Has anyone tried to implement a 1-wire driver for Dallas/Maxim 1-Wire
devices, in particular for a DS2502-E48 chip?

We are using a custom board based on the FreeScale Lite5200.  We have added
a DS2502-E48 chip to give us a unique MAC address on each board, instead of
having to buy/manage a block of MAC addresses from IEEE.

I'm considering writing a standalone bit-banging application that u-boot can
run to read and display the MAC address.  The user could then use the
display for the "setenv ethaddr" command.  Would there be any way for the
standalone program to modify the ethaddr environment variable directly?

Thanks,

Ed Jubenville

[U-Boot-Users] Any spport for Dallas 1-wire DS2502-E48

[Stefan Roese]

Hi Ed,

On Friday 28 July 2006 15:44, Edward Jubenville wrote:
> Has anyone tried to implement a 1-wire driver for Dallas/Maxim 1-Wire
> devices, in particular for a DS2502-E48 chip?

Please take a look at the file:

board/esd/cpci405/cpci405.c:

Here you will find an simple implementation to access to an 1-wire device. 
Search for ONE_WIRE_CLEAR...

> We are using a custom board based on the FreeScale Lite5200.  We have added
> a DS2502-E48 chip to give us a unique MAC address on each board, instead of
> having to buy/manage a block of MAC addresses from IEEE.
>
> I'm considering writing a standalone bit-banging application that u-boot
> can run to read and display the MAC address.  The user could then use the
> display for the "setenv ethaddr" command.  Would there be any way for the
> standalone program to modify the ethaddr environment variable directly?

Why not automatically set "ethaddr" to the value from the 1-wire device upon 
startup? This is done in other implementations already (not from 1-wire 
device though). For example:

board/tqm8xx/load_sernum_ethaddr.c

Best regards,
Stefan

[U-Boot-Users] Any spport for Dallas 1-wire DS2502-E48

[Wolfgang Denk]

In message <GPECLCIGPLHEOMGPMCPAEEKEDNAA.edjubenville@adelphia.net> you wrote:
> Has anyone tried to implement a 1-wire driver for Dallas/Maxim 1-Wire
> devices, in particular for a DS2502-E48 chip?

None that I know of.

> I'm considering writing a standalone bit-banging application that u-boot can

Why not a regiular driver that fits into the existing environment.

> run to read and display the MAC address.  The user could then use the
> display for the "setenv ethaddr" command.  Would there be any way for the
> standalone program to modify the ethaddr environment variable directly?

You could export the setenv()  function  for  SA  programs,  but  why
making  all  this  so  complicated?  Implement  a regular driver, and
perform the setting of ethaddr automatically as part  of  your  board
init code.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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