David Brownell wrote:
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.
OK, more results:1) I do not intend for this to go into the kernel, well unless there is an outcry from beagle users :)
Steve Sakoman suggested I do the pinmux setup in u-boot and furnished me with a small u-boot patch. Using this patch and removing the pinmux stuff from the kernel patch lead to working spidev_test.
The 48 MHz is the max rate, spidev_test defaults to 500 kHz. (but it appears to work at 48 MHz also.
Thanks for taking a look at this! Philip PS: I love photos: http://www.flickr.com/photos/32615155@N00/3291304854/
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