Rask Ingemann Lambertsen wrote: > We've always just bitbanged them, so we can't fully screw it up. Of course > we should try to get the hardware SPI going for efficiency reasons.
I think the background story is that Andy experienced problems with hardware SPI, so he switched to bit-banging. The snags he hit may be one of the niceties I later discovered when working on WLAN SPI: - the receive FIFO is off by one byte. It seems that just the chip revision we're using is blessed with this feature. Someone with exactly the same chip confirmed the problem on linux-arm while someone with a slightly different 2442 reported no problems. - if you go above 12 MHz, reception is off by one bit, even though the signals look perfectly clean. I never figured out how to work around that one. The usual suspects, like changing the SPI mode, didn't yield any improvements. Here's my evil patch that makes SPI work quite reliably up to 12 MHz: http://svn.openmoko.org/developers/werner/wlan-spi/patches/s3c-spi-fix-int-mode.patch - Werner _______________________________________________ gta02-core mailing list [email protected] https://lists.openmoko.org/mailman/listinfo/gta02-core
