[U-Boot] [PATCH] ARM: mvebu: db-88f6820-amc: enable SPI_FLASH_BAR

[Vignesh Raghavendra]

Hi Stefan,

On 02-Mar-19 3:56 PM, Stefan Roese wrote:
> Hi Chris,
> Hi Vignesh,
> 
> On 02.03.19 09:36, Vignesh Raghavendra wrote:
>>
>>
>> On 02-Mar-19 1:15 PM, Chris Packham wrote:
>>> This board uses Micron N25Q256A SPI flash. Enable SPI_FLASH_BAR to allow
>>> us to access the whole chip.
>>>
>>> Signed-off-by: Chris Packham <judge.packham at gmail.com>
>>> Cc: Vignesh R <vigneshr at ti.com>
>>> ---
>>>
>>
>> Could add imply SPI_FLASH_BAR to KIRKWOOD_SPI instead? So that we don't
>> have to fix every defconfig that using kirkwood_spi.c.
> 
> Did you use BAR before the newly introduced SPI NOR restructuring?
> If not, then I would rather oppose to using it now, since option
> should only be used by those platforms that used it earlier as well.

configs/db-88f6820-amc_defconfig did use SPI_FLASH_BAR before SPI NOR
re-work

> BAR mode is not supported by Linux and an U-Boot special.
>   
>> Looks like kernel driver does support 3/4 byte addressing, but U-Boot
>> version of the driver doesn't.
> 
> Could you please double check, if and how addressing of the whole
> 32MiB was done before? And perhaps its possible to enhance the SPI
> driver to support 3 and 4 byte addressing instead.
> 

It would be great if driver could be modified to support 3 and 4 byte
addressing modes.