Building driver for Silicon Labs CP2200 Ethernet chip

[Chris Johns]

Arnout Vandecappelle wrote:
> Chris Johns wrote:
>> Many thanks for this driver. I have a couple of questions, one of
>> which is more generic than specific to this driver.
>>
>> When does a user need to use CP220X_DO_SHUTDOWN ? I cannot see any
>> documentation about this define.
>  Oops, indeed I forgot to document that.
> 
>  The board I was using had a hardware bug, due to which it was unable to
> issue a reset of the CP2200 chip.  Therefore, once the chip was shut
> down it was impossible to start it again.  I therefore had to remove the
> shutdown from the driver.
> 
>  Probably a better option would be to record this in the driver
> configuration, so it can be set from the BSP or from the application... 
> However, I discovered this problem only at the last minute, so I didn't
> implement it that way.
> 
>  Actually, perhaps it's best to simply remove the #ifdefs: on any
> working board, they shouldn't be needed and shutdown should always be
> used.  Of course, I never tested that code...
> 

Is the shutdown needed ?

Can the device be reinitialised with the driver if it needs to be ?

If do I would leave the the defines and add a comment at the top to

>> I see the driver has printf and being based on the cs8900 I am the
>> source of this. Should we have these driver use printf or should they
>> use printk now it exists ?
> 
>  I'm not sure what exactly the difference is between printf and printk,
> except that printk can be called from interrupt context.  Since none of
> the prints are from interrupt context, and since with printk my terminal
> tended to drop newlines, I went for printf...  I'm sure these are not
> good reasons :-)
> 

I used printf because printk did not exist then. The reason is to support a 
tiny RTEMS for small memory targets. On targets that support printf the printk 
call should map to stdout.

Regards
Chris