Re: [spi-devel-general] [PATCH v2] spi: Add support for the OpenCores SPI controller.

[David Brownell <david-b@pacbell.net>]

On Tuesday 28 April 2009, Thierry Reding wrote:
> This second version is pretty much a rewrite.

That happens sometimes...


> Some notes about the most 
> important changes:
> 
>   * uses per-chip states to allow more slaves to use the controller
>     concurrently
>   * rejects invalid device configurations during setup
>   * rejects invalid per-message and per-transfer options
>   * queues messages so that they can be processed one after another
>       - this also provides for a way to handle power-management
>   * omits the spioc.h (and with it the platform data structure):
>       - uses the platform_device.id for the bus number
>       - always uses 8 chipselects because that's the maximum that the core
>         supports

All that sounds good.

 
> I couldn't really find a way to implement per-transfer overrides for the
> word size because the controller simply has no concept of word sizes. Is it
> in such cases still necessary to hardwire the word size to 8 bits?

Is this the http://www.opencores.org/?do=project&who=spi core?
Its summary says "Variable length of transfer word up to 32 bits";
does that mean "configurable when core is synthesized" instead of
truly "variable"?