[U-Boot-Users] Proposal to add "ispeed" (I2C speed) command

listmember at orkun.us listmember at orkun.us
Thu Mar 4 16:58:29 CET 2004


> Makes sense, but why do you need measuring datas in context of a
> bootloader ?

Well, it is not meant to be full time use. Sort of quick diagnostics and
to do some random device/register access by a technician or to check the
configuration, upload new config etc..

> Hm, I think you should expand the command syntax -- ex.:
>
> ispeed [i2c_bus_speed_in_hz]
>
>
> Without a argument 'ispeed' gets back the current setting.

Good idea.

>> I would also set an environment variable in ispeed command indicating
>> current i2c speed ("i2cspeed") so it could be used in scripts.
>
> Is it really needed ... I don't think so. You can read back the current
> setting with 'ispeed' and save the result into a environment variable of
> your choice. So you can use it again in another or the same script.

This is probably not needed if the output can be saved in a variable in
u-boot. Can you do so using standard u-boot scripting instead of hush?

I am not going to insist much on this. It seemed to be a good idea and we
certainly have a case to use it here (folks here are developing an ASIC
with I2C interface). It might be useful for some people to have the
convenience to switch the i2c speed but I also recognized it might not be
useful for everyone so I proposed to make it conditional.

Best regards,
Tolunay




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