Re: [PATCH 0/3] ARM: OMAP: SPI edge selection [was Re: Edge selecton on SPI bus]

[Tony Lindgren <tony@atomide.com>]

* David Brownell <david-b@pacbell.net> [060517 11:50]:
> 
> > I think the devices worked so far with this buggy logic since I suspect
> > a complementary problem in the TRM for the read edge selection HW flag.
> > I checked this against devices that are known to be using a given SPI
> > mode.
> 
> Hmm, I hope the attached GIF makes it through ... it shows the data
> and clock signals and their variations pretty clearly, though you need
> to understand that "out" means MOSI.
> 
> Agreed, the TRM is a bit opaque there.  There are three bits to
> cover two basic protocol options:  sample edge (2x) which seems
> to encode CPHA, and clock polarity which sure ought to be CPOL.  
> 
> 
> > Also at least the ads7846 was using incorrectly SPI mode 0, since it's
> > expecting writes on the falling / reads on the rising edge which maps to
> > mode 1.
> 
> Seems right ... does that give you more consistent sample readings?
> 
> 
> > I'm posting 3 patches to solve these issues.
> 
> They look OK to me.  I'd say to merge them to the OMAP tree; if no
> problems turn up, I'll push the ads7846 patch along soonish.

Pushed all 3 patches.

Tony