ref: 15d1425b276495a82621a8d075176a59a512cdf3
dir: /sys/src/9/bcm/gpio.c/
/* * Raspberry Pi GPIO support */ #include "u.h" #include "../port/lib.h" #include "../port/error.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #define GPIOREGS (VIRTIO+0x200000) /* GPIO regs */ enum { Fsel0 = 0x00>>2, FuncMask= 0x7, Set0 = 0x1c>>2, Clr0 = 0x28>>2, Lev0 = 0x34>>2, Evds0 = 0x40>>2, Redge0 = 0x4C>>2, Fedge0 = 0x58>>2, Hpin0 = 0x64>>2, Lpin0 = 0x70>>2, ARedge0 = 0x7C>>2, AFedge0 = 0x88>>2, PUD = 0x94>>2, Off = 0x0, Pulldown= 0x1, Pullup = 0x2, PudMask = 0x3, PUDclk0 = 0x98>>2, PUDclk1 = 0x9c>>2, /* BCM2711 only */ PUPPDN0 = 0xe4>>2, PUPPDN1 = 0xe8>>2, PUPPDN2 = 0xec>>2, PUPPDN3 = 0xf0>>2, }; static u32int *regs = (u32int*)GPIOREGS; void gpiosel(uint pin, int func) { int shift = (pin % 10) * 3; u32int *reg = ®s[Fsel0 + pin/10]; func &= FuncMask; *reg = (*reg & ~(FuncMask<<shift)) | (func<<shift); } void gpiopull(uint pin, int func) { u32int *reg; func &= PudMask; if(regs[PUPPDN3] == 0x6770696f){ /* BCM2835, BCM2836, BCM2837 */ u32int mask = 1 << (pin % 32); reg = ®s[PUDclk0 + pin/32]; regs[PUD] = func; microdelay(1); *reg = mask; microdelay(1); *reg = 0; } else { /* BCM2711 */ int shift = 2*(pin % 16); static u32int map[PudMask+1] = {0x00,0x02,0x01}; reg = ®s[PUPPDN0 + pin/16]; *reg = (*reg & ~(3<<shift)) | (map[func] << shift); } } void gpiopulloff(uint pin) { gpiopull(pin, Off); } void gpiopullup(uint pin) { gpiopull(pin, Pullup); } void gpiopulldown(uint pin) { gpiopull(pin, Pulldown); } void gpioout(uint pin, int set) { regs[(set? Set0: Clr0) + pin/32] = 1 << (pin % 32); } int gpioin(uint pin) { return (regs[Lev0 + pin/32] & (1 << (pin % 32))) != 0; } void gpioselevent(uint pin, int falling, int enable) { u32int *reg = ®s[(falling? Fedge0: Redge0) + pin/32]; *reg = (*reg & ~(1<<pin)) | ((enable != 0)<<pin); } int gpiogetevent(uint pin) { u32int *reg, val; reg = ®s[Evds0 + pin/32]; val = *reg & (1 << (pin % 32)); *reg |= val; return val != 0; } void gpiomeminit(void) { Physseg seg; memset(&seg, 0, sizeof seg); seg.attr = SG_PHYSICAL | SG_DEVICE | SG_NOEXEC; seg.name = "gpio"; seg.pa = (GPIOREGS - soc.virtio) + soc.physio; seg.size = BY2PG; addphysseg(&seg); }