• https://forum.armbian.com/topic/5951-activate-spidev-on-the-rock64/
  
• https://forum.pine64.org/showthread.php?tid=5409
  

• https://github.com/ayufan-rock64/linux-build/blob/master/recipes/additional-devices.md#use-additional-devices
  

• https://forum.pine64.org/showthread.php?tid=5682 (didn't work)
  
• https://forum.pine64.org/showthread.php?tid=4869 (modprobe did not do the trick for me)
  
• https://forum.pine64.org/showthread.php?tid=5473 (no clue if its related)
  
• https://forum.pine64.org/showthread.php?tid=1297&page=5 (other distro, right?)
  

• https://irc.pine64.uk/?date=2018-07-12T09:57:00.000Z [On Rock64. Didn't help]
  

• If you know a paid service I can ask, I would pay the help out of my own pocket and publish the steps here, since our project  LiquidInvestigations is free and open and I'd rather work on testing elastic search, UI things, ... (things that I'm better at) than hanging in the air because of a seemingly trivial (but only known to a few) piece of information. Narf. 
  
• This is to make https://liquidinvestigations.github.io/ (which uses the rock64) more usable and safer by having a (cheap) display to show codes for the air-gapped rock64 even when it is turned off (hence the use of ePaper)
  
• I can't switch the Linux Distro/Flavour right now, but if /dev/spidev0,0  only available by changing, then its better than scrapping the use of ePaper displays. 
  
• And finally: If someone will tell me "it does not work", then I'll move in the next iteration to another board which can work with existing code. 
  
  [Edit: Removed some snarky remarks.]
  

1. There is only one SPI on rk3328 device with possible 2 chipselects CSN0/CSN1.
   
2. Rockchip chose "pin multiplex 2 for SPI" (check pins *_M2 and spi2_* + grf_con_spi_io_sel in TRM) as default. This is wrong choice because only one chipselect (CSN0) is available on pin (GPIO3_B0 (SPI_CSN0_M2)).
   
3. Chipselect CSN0 is used in Rock64 to activate embedded SPI-NOR flash (GD25Q128) and therefore unavailable to user (I requested RFE to be optional). Internal BOOTROM can boot only from SPI-NOR/CSN0. SPI is already enabled "okay" in DTS but only with embedded SPI-NOR flash.
   
4. Let's enable SPI for user (need set driver "rockchip,spidev") with non-wired CSN1 (dynamically without reboot on ayufan kernel with backported configfs).
   
   Code:

   # cat >spi1.dts <<EOF
/dts-v1/;
/plugin/;

/ {
        compatible = "pine64,rock64";

        fragment@0 {
                target-path = "/spi@ff190000";
                __overlay__ {
                        spidev@1 {
                                compatible="rockchip,spidev";
                                reg=<1>;
                                spi-max-frequency=<10000000>;
                        };
                };
        };
};
EOF
# dtc spi1.dts -o spi1.dtbo
# mkdir /sys/kernel/config/device-tree/overlays/spi1
# cat spi1.dtbo > /sys/kernel/config/device-tree/overlays/spi1/dtbo
# ls /dev/spidev*
/dev/spidev32766.1
5. Connect SPI device:
   • pin 19 (GPIO3_A1 (SPI_TXD_M2)) -> device SI
     
   • pin 21 (GPIO3_A2 (SPI_RXD_M2)) <- device SO (not used in e-paper device)
     
   • pin 24 (GPIO3_A0 (SPI_CLK_M2)) -> device CLK (There is bug in v2.0 hardware that swapped pins 23/24!)
     
   • any other pin (for example 26) -> device CS
     
6. Let's try SPI with python and AT45DB041D SPI-NOR flash . Because CSN1 is unavailable program must simulate CSN1 before any access of SPI transfer functions.
   
   Code:

   # apt install python-pip python-setuptools python-dev
# pip install spidev
# git clone https://github.com/Leapo/Rock64-R64.GPIO.git
# ln -s Rock64-R64.GPIO/R64 .
# ./spi.py
JEDEC: 1f 24 00 00 00 00

run with parameters 'sector' or 'erase' or 'compare file' or 'write file'
# ./spi.py erase
JEDEC: 1f 24 00 00 00 00

chip erase ...
wait  wait  wait  wait  wait  wait  wait  wait  wait  wait  wait  wait  wait  wait  wait  ...  done

# ./spi.py write file
: 1f 24 00 00 00 00

write ...

00000000 size 100: d0 0d fe ed  ...  wait  wait  wait  wait  wait  wait  
00000100 size 100: 00 00 00 4c  ...  wait  wait  wait  wait  wait  wait  
00000200 size 100: 00 00 01 38  ...  wait  wait  wait  wait  wait  wait  
...
# ./spi.py compare file
JEDEC: 1f 24 00 00 00 00

compare ...

• it does sadly not show /dev/spidev0,0 nor other 
  
• If it would work, what would the difference to spidev0,0 vs spidev32766.1 be?
  
• If you read my issue before, what else would I need to modify for the eInk display?
  

• Do all under root ("sudo bash") (Permission denied!). '#' is root prompt, '$' is user prompt.
  
• "dtc" warning are ok.
  
• Yes, you must change device from /dev/spidev0,0 to spidev32766.1 in application. The numbering is platform dependent.
  

• VCC = pin 17 (3.3V)
  
• GND = pin 20 (GND)
  
• DIN <- pin 19 (GPIO3_A1 (SPI_TXD_M2))
  
• CLK <- pin 24 (GPIO3_A0 (SPI_CLK_M2))
  
• CS <- pin 26 GPIO2_B4 (SPI_CSN1_M0)
  
• D/C <- pin 15 GPIO3_A4
  
• RES <- pin 16 GPIO3_A5
  
• BUSY -> pin 18 GPIO3_A6
  

(08-22-2018, 12:22 PM)Kappuchino Wrote: # pip install spidev
  error: invalid command 'bdist_wheel'
When I start main.py, it doesn't complain, but nothing shows on the display ...