msperl / spi-bcm2835

SPI master driver with DMA support for the Raspberry Pi
16 stars 11 forks source link

implement LoSSI/9-bit mode in spi-bcm2835 #3

Open msperl opened 9 years ago

msperl commented 9 years ago

implement LoSSI/9-bit mode in spi-bcm2835 (its basic form implemented in spi-bcm2708) so that it may become a viable option for the foundation kernel.

msperl commented 9 years ago

note that the implementation of the spi-bcm2708 (done by @notro) is not really complete with regards to the read side of things. This to such an extend that not even notro is using this option in the fbtft drivers he is maintaining

msperl commented 9 years ago

there is this commit: ab3f074, but with the above limitations...

msperl commented 9 years ago

it is untested, as I have no Idea what device could get used to test (and I do not own any). Again: the "read" code is not implemented in a correct manner...

msperl commented 9 years ago

@notro: Any recommendation for devices with which to test this?

notro commented 9 years ago

Just loopback it and send 0x04 which should trigger a 24-bit read, and 0x09 which should trigger a 32-bit read. I have never actually tested LoSSI reading. Ref. page 151, BCM2835 ARM Peripherals