I am reading the SPI docs that came with the kernel source. It looks like this driver only supports being a master and not a slave?
On Friday, November 3, 2017 at 6:51:36 PM UTC-7, Kenny Koller wrote: > > > At the moment our design connects a UART between the Beaglebone and an > STM32F4. I'd like to add support to receive data from the STM32F4 using > SPI. It will require receiving frames of at least 64 kB each second so a 1 > MHz clock should be adequate. I'm using the 3.8.13 kernel. > > Some questions: > > Some search results suggested that the SPI driver was a kernel extension > but I was unable to find a corresponding spidev.ko in my filesystem or see > it listed with lsmod. Does this mean that the device driver has been > compiled in to the kernel? > > If it has been compiled within the kernel am I correct in thinking that > I'll need to rebuild the kernel and adjust the buffer size. I think the > default is 4096 and I would like it to be able to hold an entire > transaction. > > Finally, I'm in the process of verifying the use of SPI0. I've compiled a > device tree file (I'm using the one from ADA Fruit) and it seems to load > properly: > > $ echo ADA-SPI0-01 > /sys/devices/bone_capemgr.9/slots > $ ls /dev/spi* > /dev/spidev1.0 /dev/spidev1.1 > > I downloaded the kernel source and compiled > Documentation/spi/spidev_test.c for 3.8.13. > > I've jumpered pins 18 and 21 but I'm only seeing zeros: > > $ ./spidev_test /dev/spidev1.0 > spi mode: 0 > bits per word: 8 > max speed: 500000 Hz (500 KHz) > > > 00 00 00 00 00 00 > 00 00 00 00 00 00 > 00 00 00 00 00 00 > 00 00 00 00 00 00 > 00 00 00 00 00 00 > 00 00 00 00 00 00 > 00 00 > > I am not see the SPI pins listed in the pingroups as some posts have > suggested: > > cat /sys/kernel/debug/pinctrl/44e10800.pinmux/pingroups > > Is editing uEnv.txt and a reboot required to properly configure things? > When I tried adding the overlay to the kernel parameters the device nodes > were not created. I modified in the following way: > > optargs=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr. > enable_partno=BB-UART5,ADA-SPI0-01 omap_wdt.nowayout=0 > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/ba30c445-6367-468d-bccd-6a9945844729%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
