modprobe -v spidev prints nothing and module is not loaded. Kernel is stock, so it has SPI support compiled in. Module spi_7sun (nor any other sun*-spi) is not available although it's enabled in config:
$ zgrep CONFIG_SPI /proc/config.gz
CONFIG_SPI=y
# CONFIG_SPI_DEBUG is not set
CONFIG_SPI_MASTER=y
# CONFIG_SPI_ALTERA is not set
# CONFIG_SPI_BITBANG is not set
# CONFIG_SPI_BUTTERFLY is not set
# CONFIG_SPI_CADENCE is not set
# CONFIG_SPI_GPIO is not set
# CONFIG_SPI_LM70_LLP is not set
# CONFIG_SPI_FSL_SPI is not set
# CONFIG_SPI_OC_TINY is not set
# CONFIG_SPI_PXA2XX_PCI is not set
# CONFIG_SPI_ROCKCHIP is not set
# CONFIG_SPI_SC18IS602 is not set
CONFIG_SPI_SUN4I=y
CONFIG_SPI_SUN6I=y
# CONFIG_SPI_XCOMM is not set
# CONFIG_SPI_XILINX is not set
# CONFIG_SPI_DESIGNWARE is not set
CONFIG_SPI_SPIDEV=y
# CONFIG_SPI_TLE62X0 is not set
I specifically need newer kernel because of docker>=1.6.2 requirement.