Re: McSPI3 on the BeagleBoard

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

On Tuesday 17 February 2009, Philip Balister wrote:
> 
> A number of people have tried using the McSPI3 interface with the spidev 
> driver. Running the spidev_test program shows data coming out of the 
> interface, but when we connect the SIMO to SOMI pins, the spidev_test 
> program shows only 0's. Someone tried wiring SOMI to +volts and still 
> only saw 0 read.

I took a quick glance, and the pinmuxing looks sort of OK if
you ignore the names ... use the right balls, not XXX:

+       AE2_3430_MCSPI3_CLK,
+       AG5_3430_MCSPI3_SIMO,
+       AH5_3430_MCSPI3_SOMI,
+       AF4_3430_MCSPI3_CS0,
+       AG4_3430_MCSPI3_CS1,

I suggest you start with a more focussed patch, only setting
up McSPI3.  For one thing, the MMC2 pinmuxing will interfere
with this set of MCSPI3 configurations.

Also, start with a less aggressive bit rate than 48 MHz; that
may be OK on a well designed board, but breadboards tend to
show flakiness at much over 10 MHz.

- Dave