[U-Boot] [PATCH v2] wandboard: Add board revision detection support

[Alexander Holler]

Am 24.05.2015 um 19:29 schrieb Alexander Holler:
> Am 24.05.2015 um 16:27 schrieb Fabio Estevam:
>> Hi Stefano and Alexander,
>>
>> On Sun, May 24, 2015 at 4:43 AM, Stefano Babic <sbabic at denx.de> wrote:
>>
>>>> Wouldn't it be better to just enable CONFIG_CMD_GPIO and then change
>>>> the
>>>> boot-script in the config to something like "if gpio ..." instead of
>>>> adding something special?
>>>>
>>>> Assuming the gpio command works on imx, which I haven't tested or
>>>> looked
>>>> up.
>>>
>>> gpio works - this is really a good idea, moving the check into the
>>> script. Fabio, what do you mind ?
>>
>> I think the idea is good, thanks.
>>
>> I wanted to keep consistency with the mx6cuboxi implementation (which
>> was based on TI's implementation suggested by Tom during the review of
>> the mx6cuboxi patches).
>>
>> Also, the gpio script idea would work fine for selecting the dtb file,
>> but not inside checkboard() function, where I print the board revision
>> name.
>
> Printing the board revision in the script is as easy as selecting the dtb.
>
>> Other aspect I thought is the fact that in case we have another
>> revision of the board in the future, I think that C code is more
>> flexible for handling it.
>
> Not really. Then it it would need again a patch for the C source. Using
> the gpio command one could just change the check even by just changing
> uEnv.txt. Look at how long it now needed until someone did this patch
> (your patch) for u-boot.
>
>> So I like the idea of gpio script, but I would prefer to keep the
>> current implementation if possible due to the reasons stated above.
>
> I would suggest to change the stuff for mx6cuboxi to use the gpio
> command too instead of taking the same (imho wrong) approach.
>
> But enough said from me, I don't really care. ;)

Hmm, just one comment more.

If the gpio command would be enabled, it would even be possible to reset 
the BRCM- WLAN and Bluetooth modules by just adding some stuff to 
uEnv.txt. So at least WLAN would reliable work even after a reboot or 
reset, without the need for the rfkill-driver. Also the 
wandboard-rfkill-driver has more advantages, e.g. the rfkill. ;)

For those which don't know it, currently, without the 
wandboard-rfkill-driver, WLAN works only once after power up, but not 
after the reboot. Thats because the HW doesn't reset the brcm on reset, 
so after a reboot or reset uploading the firmware fails (because it is 
already uploaded due to the missing reset of the module).


> Regards,
>
> Alexander Holler
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