SPI driver for RPi

[fabiodive]

pardon…the autocorrector…
should I use "device spi" 
thank you
f.



On Aug 22, 2013, at 2:57 PM, Luiz Otavio O Souza <loos.br at gmail.com> wrote:

> Hello,
> 
> Here is a SPI driver for RPi.
> 
> It has been tested with a hardware loopback (MOSI wired to MISO) and with a s25fl032 spansion flash (removed from a wr941nd router).
> 
> I've tested the reading from the flash up to 10Mhz of clock and surprisingly my (simple) wiring support it without any fail.
> 
> At boot the SPI clock is set to 500Khz, not fast and not too slow (as the 3.814Khz default):
> 
> # dd if=/dev/flash/spi0 of=flash-wr941nd-2 bs=64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 75.632316 secs (55457 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2
> # sysctl dev.spi.0.clock=1000000
> dev.spi.0.clock: 500000 -> 1000000
> # dd if=/dev/flash/spi0 of=flash-wr941nd-2 bs=64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 37.896805 secs (110677 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2             
> # sysctl dev.spi.0.clock=2000000                 
> dev.spi.0.clock: 1000000 -> 2016129
> # dd if=/dev/flash/spi0 of=flash-wr941nd-2 bs=64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 18.879980 secs (222156 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2             
> # sysctl dev.spi.0.clock=4000000                 
> dev.spi.0.clock: 2016129 -> 4032258
> # dd if=/dev/flash/spi0 of=flash-wr941nd-2 bs=64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 9.642490 secs (434981 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2             
> # sysctl dev.spi.0.clock=10000000                
> dev.spi.0.clock: 4032258 -> 10416666
> # dd if=/dev/flash/spi0 of=flash-wr941nd-2 bs=64k
> 64+0 records in
> 64+0 records out
> 4194304 bytes transferred in 4.317743 secs (971411 bytes/sec)
> # diff flash-wr941nd flash-wr941nd-2             
> 
> 
> It export a few handy sysctl knobs:
> 
> # sysctl dev.spi
> dev.spi.0.%desc: BCM2708/2835 SPI controller
> dev.spi.0.%driver: spi
> dev.spi.0.%parent: simplebus0
> dev.spi.0.clock: 500000
> dev.spi.0.cpol: 0
> dev.spi.0.cpha: 0
> dev.spi.0.cspol0: 0
> dev.spi.0.cspol1: 0
> 
> 
> About the patches:
> 
> - bcm2835_spi.diff implements the SPI driver, the dts and kernel changes;
> 
> - ofw_spibus.diff adds the OFW SPI bus glue to attach the SPI children as described in the FDT.
> 
> - mx25l-fdt-intr.diff adds the support for FDT and configure a intr hook so the device identification runs only when the interrupts are active (the SPI driver is interrupt based);
> 
> - rpi-mx25l-dts.diff the change i did to add my mx25l on the rpi dts (only as reference).
> 
> 
> Luiz
> 
> 
> 
> 
> <bcm2835_spi.diff><ofw_spibus.diff><mx25l-fdt-intr.diff><rpi-mx25l-dts.diff>_______________________________________________
> freebsd-arm at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-arm
> To unsubscribe, send any mail to "freebsd-arm-unsubscribe at freebsd.org"