On 6 August 2015 at 12:22, Russell King - ARM Linux
[off-list ref] wrote:

On Thu, Aug 06, 2015 at 12:01:37PM +0200, Michal Suchanek wrote:

quoted

Disclaimer: I am not familiar with the hardware for which this patch
adds support.

However, I am familiar m25p80.c and as I understand it the controller
is basically supposed to implement m25p80.c in hardware when this flag
is set.

That, to me, sounds like what you have is:

---m25p80 specific interface--->SPI bus--->m25p80 device

Where the m25p80 specific interface does not expose direct access to the
SPI bus?

The m25p80 specific hardware interface is presumably optional so you
can use it or not. The description is a bit vague, though.

In fsl-qspi the driver does not make it optional. I am not sure that
controller can be used for non-m25p80 slaves.

If that's the case, then maybe you should consider whether using the SPI
bus infrastructure is really the best way forward.  Would it make more
sense instead to adopt a different software structure, something more
high-level like:

     +-------------------------------------------+
     |          m25p80 high-level driver      =spi-nor   |
     +----------------------+--------------------+
     |   SPI m25p80 driver  |                    |
     +----------------------+                    |
     |      SPI layer       |  Special driver    =fsl-qspi|
     +----------------------+                    |
     |    SPI bus driver    |                    |
     +----------------------+--------------------+
     |     SPI hardware     |  Special hardware  |
     +----------------------+--------------------+

Thanks

Michal