Re: t1040 IFC flash driver Extended Chip Select

On 07/08/2016 06:12 PM, Scott Wood wrote:

On 07/07/2016 06:48 PM, Daniel Walker wrote:

quoted

On 07/07/2016 03:37 PM, Scott Wood wrote:

quoted

On 07/07/2016 05:01 PM, Daniel Walker wrote:

quoted

On 07/07/2016 02:59 PM, Scott Wood wrote:

quoted

On 07/07/2016 04:49 PM, Daniel Walker wrote:

quoted

On 07/07/2016 02:23 PM, Scott Wood wrote:

quoted

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

It would seems like a good idea to add it then. I think it can be piece 
mail, rather than all or nothing tho. How difficult is adding the other 
part to the driver , v.s. just the cspr_ext ?

Daniel