nuclear@0: #include <stdio.h>
nuclear@1: #include <string.h>
nuclear@0: #include <signal.h>
nuclear@1: #include <errno.h>
nuclear@0: #include <unistd.h>
nuclear@0: #include <fcntl.h>
nuclear@0: #include <sys/mman.h>
nuclear@0: #include "bcm_host.h"
nuclear@0: 
nuclear@1: #define REG_GPIO_BASE		0x200000
nuclear@1: #define REG_GPFSEL_BASE		0x200000
nuclear@1: #define REG_GPSET_BASE		0x20001c
nuclear@1: #define REG_GPCLR_BASE		0x200028
nuclear@1: #define REG_GPLEV_BASE		0x200034
nuclear@1: #define REG_GPPUD			0x200094
nuclear@1: #define REG_GPPUDCLK_BASE	0x200098
nuclear@0: 
nuclear@0: #define FSEL_BITS	3
nuclear@0: #define FSEL_INPUT	0
nuclear@0: #define FSEL_OUTPUT	1
nuclear@0: 
nuclear@0: #define FSEL_SHIFT(i)	(((i) % 10) * 3)
nuclear@0: #define FSEL_MASK(i)	(3 << FSEL_SHIFT(i))
nuclear@0: 
nuclear@0: #define REG(r)	(volatile uint32_t*)((unsigned char*)iomem + (r))
nuclear@0: 
nuclear@0: void *iomem;
nuclear@0: int quit;
nuclear@0: 
nuclear@0: static inline void set_pin_func(int pin, int func);
nuclear@0: static inline void set_pin_state(int pin, int s);
nuclear@0: static inline int get_pin_state(int pin);
nuclear@1: static inline void set_pullup(int pin, int en);
nuclear@1: static inline void set_pulldown(int pin, int en);
nuclear@0: static void sighandler(int s);
nuclear@0: 
nuclear@0: int main(void)
nuclear@0: {
nuclear@0: 	int fd;
nuclear@0: 	int i;
nuclear@1: 	uint32_t io_addr, io_size, mmap_size;
nuclear@1: 	void *mmap_ptr;
nuclear@0: 
nuclear@0: 	signal(SIGINT, sighandler);
nuclear@0: 	signal(SIGQUIT, sighandler);
nuclear@0: 	signal(SIGSEGV, sighandler);
nuclear@0: 	signal(SIGILL, sighandler);
nuclear@0: 	signal(SIGFPE, sighandler);
nuclear@0: 
nuclear@0: 	io_addr = bcm_host_get_peripheral_address();
nuclear@0: 	io_size = bcm_host_get_peripheral_size();
nuclear@0: 	printf("I/O registers\n");
nuclear@0: 	printf("  addr: %x\n", io_addr);
nuclear@0: 	printf("  size: %d\n", io_size);
nuclear@0: 
nuclear@1: 	if((fd = open("/dev/gpiomem", O_RDWR | O_SYNC)) >= 0) {
nuclear@1: 		mmap_size = 0xb4;	/* last gpio reg addr + 4 */
nuclear@1: 		if((mmap_ptr = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == (void*)-1) {
nuclear@1: 			perror("failed to map I/O registers");
nuclear@1: 			return 1;
nuclear@1: 		}
nuclear@1: 		iomem = ((unsigned char*)mmap_ptr) - REG_GPIO_BASE;
nuclear@1: 	} else if((fd = open("/dev/mem", O_RDWR | O_SYNC)) >= 0) {
nuclear@1: 		mmap_size = io_size;
nuclear@1: 		if((mmap_ptr = mmap(0, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, io_addr)) == (void*)-1) {
nuclear@1: 			perror("failed to map I/O registers");
nuclear@1: 			return 1;
nuclear@1: 		}
nuclear@1: 		iomem = mmap_ptr;
nuclear@1: 	} else {
nuclear@0: 		perror("failed to open /dev/mem");
nuclear@0: 		return 1;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	/* configure GPIO pins 4 and 17 as outputs */
nuclear@0: 	set_pin_func(4, FSEL_OUTPUT);
nuclear@0: 	set_pin_func(17, FSEL_OUTPUT);
nuclear@1: 	/* configure GPIO pin 22 as input, and enable it's pulldown resistor */
nuclear@1: 	set_pin_func(22, FSEL_INPUT);
nuclear@1: 	set_pulldown(22, 1);
nuclear@0: 
nuclear@0: 	i = 0;
nuclear@0: 	while(!quit) {
nuclear@1: 		if(get_pin_state(22)) {
nuclear@1: 			set_pin_state(4, 1);
nuclear@1: 			set_pin_state(17, 1);
nuclear@1: 		} else {
nuclear@1: 			set_pin_state(4, i & 1);
nuclear@1: 			set_pin_state(17, (~i) & 1);
nuclear@1: 			++i;
nuclear@1: 		}
nuclear@1: 		usleep(250000);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	set_pin_state(4, 0);
nuclear@0: 	set_pin_state(17, 0);
nuclear@0: 	set_pin_func(4, FSEL_INPUT);
nuclear@0: 	set_pin_func(17, FSEL_INPUT);
nuclear@1: 	set_pulldown(22, 0);
nuclear@0: 
nuclear@1: 	munmap(mmap_ptr, mmap_size);
nuclear@0: 	close(fd);
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: static inline void set_pin_func(int pin, int func)
nuclear@0: {
nuclear@0: 	int reg_addr, val;
nuclear@0: 	reg_addr = REG_GPFSEL_BASE + (pin / 10) * 4;
nuclear@0: 	val = *REG(reg_addr);
nuclear@0: 	*REG(reg_addr) = (val & FSEL_MASK(pin)) | (func << FSEL_SHIFT(pin));
nuclear@0: }
nuclear@0: 
nuclear@0: static inline void set_pin_state(int pin, int s)
nuclear@0: {
nuclear@0: 	int reg_addr;
nuclear@0: 	int regidx = pin / 32;
nuclear@0: 	int bit = pin % 32;
nuclear@0: 
nuclear@0: 	if(s) {
nuclear@0: 		reg_addr = REG_GPSET_BASE + regidx * 4;
nuclear@0: 		*REG(reg_addr) |= 1 << bit;
nuclear@0: 	} else {
nuclear@0: 		reg_addr = REG_GPCLR_BASE + regidx * 4;
nuclear@0: 		*REG(reg_addr) |= 1 << bit;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: static inline int get_pin_state(int pin)
nuclear@0: {
nuclear@0: 	int reg_addr;
nuclear@0: 	int regidx = pin / 32;
nuclear@0: 	int bit = pin % 32;
nuclear@0: 
nuclear@0: 	reg_addr = REG_GPLEV_BASE + regidx * 4;
nuclear@0: 	return (*REG(reg_addr) >> bit) & 1;
nuclear@0: }
nuclear@0: 
nuclear@1: #define delay_cycles(x) \
nuclear@1: 	__asm__ __volatile__ (	\
nuclear@1: 		"mov %0, #150\n"	\
nuclear@1: 		"1:\n\t"	\
nuclear@1: 		"nop\n\t" \
nuclear@1: 		"subs %0, %0, #1\n\t"	\
nuclear@1: 		"bne 1b\n\t"	\
nuclear@1: 		:: "r"(x))
nuclear@1: 
nuclear@1: static inline void set_pull_updown(int pin, int updown)
nuclear@1: {
nuclear@1: 	int regidx = pin / 32;
nuclear@1: 	int bit = pin % 32;
nuclear@1: 	int clk_addr = REG_GPPUDCLK_BASE + regidx * 4;
nuclear@1: 
nuclear@1: 	*REG(REG_GPPUD) = updown;
nuclear@1: 	delay_cycles(150);
nuclear@1: 	*REG(clk_addr) = bit;
nuclear@1: 	delay_cycles(150);
nuclear@1: 	*REG(REG_GPPUD) = 0;
nuclear@1: 	*REG(clk_addr) = 0;
nuclear@1: }
nuclear@1: 
nuclear@1: static inline void set_pullup(int pin, int en)
nuclear@1: {
nuclear@1: 	set_pull_updown(pin, en ? 2 : 0);
nuclear@1: }
nuclear@1: 
nuclear@1: static inline void set_pulldown(int pin, int en)
nuclear@1: {
nuclear@1: 	set_pull_updown(pin, en ? 1 : 0);
nuclear@1: }
nuclear@1: 
nuclear@0: static void sighandler(int s)
nuclear@0: {
nuclear@0: 	quit = 1;
nuclear@0: }