I set /boot/uEnv.txt:
verbosity=7
fdtfile=rockchip/rk3308-rock-pi-s.dtb
console=ttyS0,1500000n8
overlays=rk3308-uart0 rk3308-i2c1 rk3308-spi-spidev
param_spidev_spi_bus=1
rootuuid=513ebcfa-a901-4300-9829-68632c397250
initrdsize=0x64d777
kernelversion=4.4.143-57-rockchip-g4b8d0571d76e
initrdimg=initrd.img-4.4.143-57-rockchip-g4b8d0571d76e
kernelimg=vmlinuz-4.4.143-57-rockchip-g4b8d0571d76e
/**
- Initialise SPI_context without any board configuration, selects a bus and a mux.
- @param bus Bus to use as listed by spidev
- @param cs Chip select to use as listed in spidev ???
-
@return Spi context or NULL
*/
mraa_spi_context mraa_spi_init_raw(unsigned int bus, unsigned int cs);
question:
param cs is the number of bus? or the number of pin? or the number of gpio?