1*c66ec88fSEmmanuel VadotAltera Passive Serial SPI FPGA Manager 2*c66ec88fSEmmanuel Vadot 3*c66ec88fSEmmanuel VadotAltera FPGAs support a method of loading the bitstream over what is 4*c66ec88fSEmmanuel Vadotreferred to as "passive serial". 5*c66ec88fSEmmanuel VadotThe passive serial link is not technically SPI, and might require extra 6*c66ec88fSEmmanuel Vadotcircuits in order to play nicely with other SPI slaves on the same bus. 7*c66ec88fSEmmanuel Vadot 8*c66ec88fSEmmanuel VadotSee https://www.altera.com/literature/hb/cyc/cyc_c51013.pdf 9*c66ec88fSEmmanuel Vadot 10*c66ec88fSEmmanuel VadotRequired properties: 11*c66ec88fSEmmanuel Vadot- compatible: Must be one of the following: 12*c66ec88fSEmmanuel Vadot "altr,fpga-passive-serial", 13*c66ec88fSEmmanuel Vadot "altr,fpga-arria10-passive-serial" 14*c66ec88fSEmmanuel Vadot- reg: SPI chip select of the FPGA 15*c66ec88fSEmmanuel Vadot- nconfig-gpios: config pin (referred to as nCONFIG in the manual) 16*c66ec88fSEmmanuel Vadot- nstat-gpios: status pin (referred to as nSTATUS in the manual) 17*c66ec88fSEmmanuel Vadot 18*c66ec88fSEmmanuel VadotOptional properties: 19*c66ec88fSEmmanuel Vadot- confd-gpios: confd pin (referred to as CONF_DONE in the manual) 20*c66ec88fSEmmanuel Vadot 21*c66ec88fSEmmanuel VadotExample: 22*c66ec88fSEmmanuel Vadot fpga: fpga@0 { 23*c66ec88fSEmmanuel Vadot compatible = "altr,fpga-passive-serial"; 24*c66ec88fSEmmanuel Vadot spi-max-frequency = <20000000>; 25*c66ec88fSEmmanuel Vadot reg = <0>; 26*c66ec88fSEmmanuel Vadot nconfig-gpios = <&gpio4 9 GPIO_ACTIVE_LOW>; 27*c66ec88fSEmmanuel Vadot nstat-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>; 28*c66ec88fSEmmanuel Vadot confd-gpios = <&gpio4 12 GPIO_ACTIVE_LOW>; 29*c66ec88fSEmmanuel Vadot }; 30