On Thu, Nov 26, 2009 at 12:01 PM, Anton Vorontsov
[off-list ref] wrote:

On Thu, Nov 26, 2009 at 11:50:05AM -0700, Grant Likely wrote:

quoted

On Thu, Nov 26, 2009 at 11:41 AM, Anton Vorontsov
[off-list ref] wrote:

quoted

On Thu, Nov 26, 2009 at 11:16:34AM -0700, Grant Likely wrote:
[...]

quoted

The spi-cs-high property is defined in
Documentation/powerpc/dts-bindings/spi-bus.txt, but it definitely was
a mistake

Yup.

quoted

Currently the spi-cs-high property is parsed in the
of_register_spi_devices() function, but the CS polarity needs to be
known before registering devices. =A0It needs to be factored out into
another utility function callable by spi bus drivers so that it can
get polarity data at probe time.

Untill we have this, Torsten's patch is a real improvement, and
works for non-broken hw/fw.

So I think it should be applied.

I disagree since it only band-aids the problem and uglifies the driver
in the process. =A0In the immediate term the driver needs to be changed
to read the spi-cs-high property out of the child nodes before
registering the devices.

Hm. I thought we agreed that spi-cs-high is not good? Why do you
encourage using it then? We'll have to uglify the driver with
legacy device-tree handling code.

spi-cs-high is definitely not a complete solution, but it isn't
actively evil either.  Plus it is documented and (presumably) in
active use. so support for it should not be dropped.

Regardless, there needs to be a library function for parsing all the
SPI child nodes and returning the active state for each GPIO chip
select.  All the code for parsing the old spi-cs-high properties can
be contained in the same place as a new yet-to-be-defined bus node cs
polarity property.  The rework to the driver itself is not ugly.

g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.