[U-Boot] [PATCH 1/1] at91: Update MEESC board support

Daniel Gorsulowski Daniel.Gorsulowski at esd.eu
Fri Sep 11 09:03:31 CEST 2009


Dear Wolfgang Denk,

Wolfgang Denk wrote:
> Dear Daniel Gorsulowski,
> 
> In message <4AA90821.1060106 at esd.eu> you wrote:
>>>> -	/* arch number of MEESC-Board */
>>>> -	gd->bd->bi_arch_number = MACH_TYPE_MEESC;
>>>> +	/* initialize ET1100 Controller */
>>>> +	meesc_ethercat_hw_init();
>>> I thought we had agreed not to initialize the Ethernet hardware if it
>>> not used by U-Boot?
>>>
>> We had, but this does not initialize unused hardware. This is needed for
>> detecting hw_type and setting correct arch_number.
> 
> meesc_ethercat_hw_init() "is needed for ... setting correct
> arch_number" ??
> 
> Best regards,
> 
> Wolfgang Denk
> 
Please take a look at function checkboard().
There is a call "hw_type = readb(CONFIG_ET1100_BASE);" to read the ET1100
type register. The read value is used to determine the correct arch_number.
  valid value (ET1100 present)      --> arch_number = MACH_TYPE_MEESC
  invalid value (no ET1100 present) --> arch_number = MACH_TYPE_ETHERCAN2

For accessing the ET1100 type register, it is mandatory to initialize the
memory controller. Thus, meesc_ethercat_hw_init() is needed and does not
initialize unused hardware!


Btw. the function meesc_ethercat_hw_init() is not new in this patch. I
entirely moved the function call.


Best regards,
Daniel Gorsulowski


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