Thanks for the confirmation and link. I already have a UART connected. Perhaps I'll use this to make requests to the master (Beaglebone) to read a frame.
Any thoughts as to why the device files/nodes are created for SPI but the pins aren't listed in pingroups? On Friday, November 3, 2017 at 7:17:23 PM UTC-7, RobertCNelson wrote: > > I don't think this got merged, but yeah spi slave support needs some work. > > > https://lwn.net/Articles/700433/ > > Regards, > > On Nov 3, 2017 9:10 PM, "Kenny Koller" <[email protected] > <javascript:>> wrote: > >> 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] <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/ba30c445-6367-468d-bccd-6a9945844729%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/ba30c445-6367-468d-bccd-6a9945844729%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- 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/dc2ed4df-46cf-49fa-9970-74d7f23b2325%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
