SPI enabled in device tree, but I can't use it

Question

I am trying to use SPI interface on Raspberry Pi 1 B (OS: Raspbian July 2017, kerenl 4.9.5). To do this, I am using wiringPi. I confirmed that wiringPi works via gpio readall

To load SPI:

gpio load spi

But this gives me an error:

gpio: Unable to load/unload modules as this Pi has the device tree enabled.
  You need to run the raspi-config program (as root) and select the
  modules (SPI or I2C) that you wish to load/unload there and reboot.
  There is more information here:
      https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=97314

Strangely, spidev exists is under /dev (Does it mean SPI is loaded?)

ls /dev/spi*
/dev/spidev0.0  /dev/spidev0.1

Anyway, to fix the problem, the link in the error message tells me to:

1. Run [sudo] raspi-config and enable SPI: I did it and reboot Rpi
   • Did it, but didn't solve the problem.
2. If (1) did not work, edit /boot/config.txt and add dtparam=spi=on.
   • Did it, but didn't solve the problem.

And the official device tree document says one can disable device tree by editing /boot/config.txt to have

device_tree=

But when it is done and reboot, only Rainbow splash appears and boot process never go further.

Can anyone give me an advice what I am missing?

Answer 1

I doubt you can disable device tree anymore, that was intended to be a temporary directive to smooth the introduction of device tree.

Just add the device tree SPI entry. Do not use gpio load spi. That is deprecated.

As long as there /dev/spidev* entries you can use SPI.

To summarise

1. remove device_tree= from /boot/config.txt
2. add dtparam=spi=on to /boot/config.txt
3. do not use gpio load spi