SPI module on Raspberry Pi B+

Hello,

I just switched from Buildroot 2015.08.1 to 2015.11.1, and tried to keep the same configuration. SPI was working well, before the switch.

Now, I am having some trouble with the SPI driver, namely spi_bcm2835 :
when I insert the module, there is no log in dmesg output, and nothing is created in /sys/bus/spi/devices.

I could make it work by loading spi_bcm2708 instead, despite the deprecated warning. In this case, I get some logging messages and /sys/bus/spi/devices/spi0.0 and /sys/bus/spi/devices/spi0.1 appear.

Any idea ?

David.

------------------
Board : Raspberry Pi B+
Buildroot : 2015.11.1
SPI peripheral : Adafruit PiTFT 2.8"

Hello David,

Did you try with a fresh build using the 2015.11.1 configs/raspberrypi_defconfig?

Did you enable spi support (on the target SD card) in the config.txt file?

I use the following for hifiberry-dac+ support (and Adafruit PiTFT):

diff -u config.txt_orig config.txt
@@ -18,3 +18,30 @@
 gpu_mem_256=100
 gpu_mem_512=100
 gpu_mem_1024=100
+
+#
+# from https://www.raspberrypi.org/documentation/configuration/device-tree.md
+#
+dtdebug=1
+
+# Uncomment some or all of these to enable the optional hardware interfaces
+dtparam=i2c_arm=on
+dtparam=i2s=on
+dtparam=spi=on
+dtoverlay=hifiberry-dacplus

Regards,
Peter