Problem loading environment from spi-nor flash partition since barebox 2017.01.0

[s.hauer at pengutronix.de]

On Fri, Jan 13, 2017 at 05:46:41PM +0000, Trent Piepho wrote:
> On Wed, 2017-01-11 at 09:32 +0100, Sascha Hauer wrote:
> > With (real) SPI this is a little different and works as expected: If the
> > qspi node would be handled by the SPI layer then the SPI core would
> > register the child nodes as devices on a SPI bus. The normal probe
> > mechanism would then bind the device and the driver together.
> > 
> > With the cadence-quadspi driver a device is registered in
> > cqspi_setup_flash(), but there is never a driver attached to it, thus
> > the dev->driver test fails.
> > 
> > The proper way if probably to register the n25q00 device on a qspi bus
> > and to provide a qspi-nor-flash driver which gets probed then.
> > The not-so-proper, faster way could be to just create a dummy driver
> > struct and attach it to the device allocated in cqspi_setup_flash().
> 
> The qspi device is more like an MTD device than a SPI master.  It just
> supports memory devices, not arbitrary SPI slaves that have their own
> drivers.
> 
> But that said, there is sort of a driver for the SPI NOR chips attached
> to the qspi in spi-nor.c, but it is not a real 'struct driver_d' driver.
> Maybe it could be?
> 
> qspi could create a "qspi" or "spi-flash" bus (I don't think it will fit
> well as a generic SPI bus) with the flash devices on it, and then
> spi-nor could bind to them like a normal driver.

Yes, that was what I tried to express in my mail.

> 
> Or spi-nor could have a driver_d that's not registered and make
> nor->dev->driver point to it in spi_nor_scan().

Yes.

> 
> Or spi_nor_scan() could just set nor->dev->driver =
> nor->dev->parent->driver.

Probably not a good idea. I looks wrong.

Sascha

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