t1040 IFC flash driver Extended Chip Select

[Scott Wood]

On 07/07/2016 06:48 PM, Daniel Walker wrote:
> On 07/07/2016 03:37 PM, Scott Wood wrote:
>> On 07/07/2016 05:01 PM, Daniel Walker wrote:
>>> On 07/07/2016 02:59 PM, Scott Wood wrote:
>>>> On 07/07/2016 04:49 PM, Daniel Walker wrote:
>>>>> On 07/07/2016 02:23 PM, Scott Wood wrote:
>>>>>> I suspect that add the usage of cspr_ext into the driver would fix the
>>>>>> issue we have. It reads like you would find that acceptable ?
>>>>>> What specifically is the problem you're having?  Is it that CSPR_EXT is
>>>>>> not getting written to, and thus the device does not appear at the
>>>>>> address that it should?
>>>>>>
>>>>>> Or is the driver matching incorrectly?  The only way the driver's lack
>>>>>> of using CSPR_EXT to match would be a problem would be if you have
>>>>>> multiple chipselects with the same address in the lower 32 bits, and
>>>>>> only CSPR_EXT distinguishing them.  Since you proposed a device tree
>>>>>> binding that assumes all devices have the same CSPR_EXT, I doubt that's
>>>>>> the case, so I doubt adding CSPR_EXT matching to the driver will solve
>>>>>> your problem.
>>>>>>
>>>>>> -Scott
>>>>>>
>>>>> I didn't do the debug on this. From my perspective it's either flash
>>>>> works, or it doesn't work. We need the code below for it to work,
>>>> Adding CSPR_EXT matching to the driver will not accomplish the same
>>>> thing as that code.
>>>>
>>> So from u-boot perspective, the values in the device tree under "ranges"
>>> or parts of it, are place into the cspr and cspr_ext ? Is that how it's
>>> suppose to work ?
>> U-Boot writes values that are hardcoded in the board config header.
>> These values (as well as the area covered by the IFC LAW) need to match
>> the address in the device tree, but U-Boot doesn't get them from the
>> device tree.
>>
> 
> I was suggesting the values it writes are the same as the ones inside 
> the device tree. So we could have both csrp and csrp_ext written from 
> the driver and the values would
> come from the ranges property.

There's more to CSPR than just the address.  The driver should either be
able to assume that all of CSPR/CSOR has been correctly initialized, or
it should assume none of that has been initialized -- which again,
requires the attribute information to be in the device tree.  If you're
doing something in between, then that's a board quirk rather than a
general solution.

-Scott