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/*
minimal_gpio.c
2015-02-10
Public Domain
*/
/*
gcc -o minimal_gpio minimal_gpio.c
sudo ./minimal_gpio
*/
#include <stdio.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <math.h>
static volatile uint32_t piModel = 1;
static volatile uint32_t piPeriphBase = 0x20000000;
static volatile uint32_t piBusAddr = 0x40000000;
#define SYST_BASE (piPeriphBase + 0x003000)
#define DMA_BASE (piPeriphBase + 0x007000)
#define CLK_BASE (piPeriphBase + 0x101000)
#define GPIO_BASE (piPeriphBase + 0x200000)
#define UART0_BASE (piPeriphBase + 0x201000)
#define PCM_BASE (piPeriphBase + 0x203000)
#define SPI0_BASE (piPeriphBase + 0x204000)
#define I2C0_BASE (piPeriphBase + 0x205000)
#define PWM_BASE (piPeriphBase + 0x20C000)
#define UART1_BASE (piPeriphBase + 0x215000)
#define I2C1_BASE (piPeriphBase + 0x804000)
#define I2C2_BASE (piPeriphBase + 0x805000)
#define DMA15_BASE (piPeriphBase + 0xE05000)
#define DMA_LEN 0x1000 /* allow access to all channels */
#define CLK_LEN 0xA8
#define GPIO_LEN 0xB4
#define SYST_LEN 0x1C
#define PCM_LEN 0x24
#define PWM_LEN 0x28
#define I2C_LEN 0x1C
#define GPSET0 7
#define GPSET1 8
#define GPCLR0 10
#define GPCLR1 11
#define GPLEV0 13
#define GPLEV1 14
#define GPPUD 37
#define GPPUDCLK0 38
#define GPPUDCLK1 39
#define SYST_CS 0
#define SYST_CLO 1
#define SYST_CHI 2
static volatile uint32_t *gpioReg = MAP_FAILED;
static volatile uint32_t *systReg = MAP_FAILED;
#define PI_BANK (gpio>>5)
#define PI_BIT (1<<(gpio&0x1F))
/* gpio modes. */
#define PI_INPUT 0
#define PI_OUTPUT 1
#define PI_ALT0 4
#define PI_ALT1 5
#define PI_ALT2 6
#define PI_ALT3 7
#define PI_ALT4 3
#define PI_ALT5 2
void gpioSetMode(unsigned gpio, unsigned mode)
{
int reg, shift;
reg = gpio/10;
shift = (gpio%10) * 3;
gpioReg[reg] = (gpioReg[reg] & ~(7<<shift)) | (mode<<shift);
}
int gpioGetMode(unsigned gpio)
{
int reg, shift;
reg = gpio/10;
shift = (gpio%10) * 3;
return (*(gpioReg + reg) >> shift) & 7;
}
/* Values for pull-ups/downs off, pull-down and pull-up. */
#define PI_PUD_OFF 0
#define PI_PUD_DOWN 1
#define PI_PUD_UP 2
void gpioSetPullUpDown(unsigned gpio, unsigned pud)
{
*(gpioReg + GPPUD) = pud;
usleep(20);
*(gpioReg + GPPUDCLK0 + PI_BANK) = PI_BIT;
usleep(20);
*(gpioReg + GPPUD) = 0;
*(gpioReg + GPPUDCLK0 + PI_BANK) = 0;
}
int gpioRead(unsigned gpio)
{
if ((*(gpioReg + GPLEV0 + PI_BANK) & PI_BIT) != 0) return 1;
else return 0;
}
void gpioWrite(unsigned gpio, unsigned level)
{
if (level == 0) *(gpioReg + GPCLR0 + PI_BANK) = PI_BIT;
else *(gpioReg + GPSET0 + PI_BANK) = PI_BIT;
}
void gpioTrigger(unsigned gpio, unsigned pulseLen, unsigned level)
{
if (level == 0) *(gpioReg + GPCLR0 + PI_BANK) = PI_BIT;
else *(gpioReg + GPSET0 + PI_BANK) = PI_BIT;
usleep(pulseLen);
if (level != 0) *(gpioReg + GPCLR0 + PI_BANK) = PI_BIT;
else *(gpioReg + GPSET0 + PI_BANK) = PI_BIT;
}
/* Bit (1<<x) will be set if gpio x is high. */
uint32_t gpioReadBank1(void) { return (*(gpioReg + GPLEV0)); }
uint32_t gpioReadBank2(void) { return (*(gpioReg + GPLEV1)); }
/* To clear gpio x bit or in (1<<x). */
void gpioClearBank1(uint32_t bits) { *(gpioReg + GPCLR0) = bits; }
void gpioClearBank2(uint32_t bits) { *(gpioReg + GPCLR1) = bits; }
/* To set gpio x bit or in (1<<x). */
void gpioSetBank1(uint32_t bits) { *(gpioReg + GPSET0) = bits; }
void gpioSetBank2(uint32_t bits) { *(gpioReg + GPSET1) = bits; }
unsigned gpioHardwareRevision(void)
{
static unsigned rev = 0;
FILE * filp;
char buf[512];
char term;
int chars=4; /* number of chars in revision string */
if (rev) return rev;
piModel = 0;
filp = fopen ("/proc/cpuinfo", "r");
if (filp != NULL)
{
while (fgets(buf, sizeof(buf), filp) != NULL)
{
if (piModel == 0)
{
if (!strncasecmp("model name", buf, 10))
{
if (strstr (buf, "ARMv6") != NULL)
{
piModel = 1;
chars = 4;
piPeriphBase = 0x20000000;
piBusAddr = 0x40000000;
}
else if (strstr (buf, "ARMv7") != NULL)
{
piModel = 2;
chars = 6;
piPeriphBase = 0x3F000000;
piBusAddr = 0xC0000000;
}
}
}
if (!strncasecmp("revision", buf, 8))
{
if (sscanf(buf+strlen(buf)-(chars+1),
"%x%c", &rev, &term) == 2)
{
if (term != '\n') rev = 0;
}
}
}
fclose(filp);
}
return rev;
}
/* Returns the number of microseconds after system boot. Wraps around
after 1 hour 11 minutes 35 seconds.
*/
uint32_t gpioTick(void) { return systReg[SYST_CLO]; }
/* Map in registers. */
static uint32_t * initMapMem(int fd, uint32_t addr, uint32_t len)
{
return (uint32_t *) mmap(0, len,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_SHARED|MAP_LOCKED,
fd, addr);
}
int gpioInitialise(void)
{
int fd;
gpioHardwareRevision(); /* sets piModel, needed for peripherals address */
fd = open("/dev/mem", O_RDWR | O_SYNC) ;
if (fd < 0)
{
fprintf(stderr,
"This program needs root privileges. Try using sudo\n");
return -1;
}
gpioReg = initMapMem(fd, GPIO_BASE, GPIO_LEN);
systReg = initMapMem(fd, SYST_BASE, SYST_LEN);
close(fd);
if ((gpioReg == MAP_FAILED) ||
(systReg == MAP_FAILED))
{
fprintf(stderr,
"Bad, mmap failed\n");
return -1;
}
return 0;
}
main()
{
int i;
int j;
int k;
int l;
int m;
int p;
char bitsRead[1000];
if (gpioInitialise() < 0) return 1;
i=5; // which pin
FILE *f1 = fopen("client.data", "wb");
int total;
total = 0;
while (total<5000000) {
for (j=0;j<1000;j++) {
l = 0;
for (k=0;k<8;k++) {
if (k==0) {
m=1;
} else if (k==1) {
m=2;
} else if (k==2) {
m=4;
} else if (k==3) {
m=8;
} else if (k==4) {
m=16;
} else if (k==5) {
m=32;
} else if (k==6) {
m=64;
} else if (k==7) {
m=128;
}
l+=m*gpioRead(i);
}
//printf("%d\n",(int)l);
bitsRead[j]=(char)l;
}
fwrite(bitsRead, sizeof(char), sizeof(bitsRead), f1);
total+=1000;
}
fclose(f1);
}