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GPIO_Pi.c
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GPIO_Pi.c
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/*
* Copyright (c) 2017 Shaun Feakes - All rights reserved
*
* You may use redistribute and/or modify this code under the terms of
* the GNU General Public License version 2 as published by the
* Free Software Foundation. For the terms of this license,
* see <http://www.gnu.org/licenses/>.
*
* You are free to use this software under the terms of the GNU General
* Public License, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* https://github.com/sfeakes/GPIO_pi
*/
/********************-> GPIO Pi v1.2 <-********************/
/*
* Note, all referances to pin in this code is the GPIO pin# not the physical pin#
*/
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdarg.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <string.h>
#include <ctype.h>
#include <syslog.h>
#include <errno.h>
#include "GPIO_Pi.h"
#ifndef GPIO_ERR_LOG_DISABELED
//#define LOG_ERROR(fmt, ...) log_message (true, fmt, ##__VA_ARGS__)
#define LOG_ERROR(fmt, ...) log_message (true, "%s: " fmt, _GPIO_pi_NAME_,##__VA_ARGS__)
#else
#define LOG_ERROR(...) {}
#endif
#ifdef GPIO_LOG_ENABLED
//#define LOG_ERROR(fmt, ...) log_message (false, fmt, ##__VA_ARGS__)
#define LOG(fmt, ...) log_message (false, "%s: " fmt, _GPIO_pi_NAME_,##__VA_ARGS__)
#else
#define LOG(...) {}
#endif
#ifdef GPIO_DEBUG
#define DEBUG(fmt, ...) log_message (false, "%s: (%s) " fmt, _GPIO_pi_NAME_,"DEBUG",##__VA_ARGS__)
#else
#define DEBUG(...) {}
#endif
#ifdef GPIO_SYSFS_MODE
#define GPIO_SYSFS_INTERRUPT
#endif
const char *_piModelNames [18] =
{
"Model A", // 0
"Model B", // 1
"Model A+", // 2
"Model B+", // 3
"Pi 2", // 4
"Alpha", // 5
"CM", // 6
"Unknown #07",// 07
"Pi 3b", // 08
"Pi Zero", // 09
"CM3", // 10
"Unknown #11",// 11
"Pi Zero-W", // 12
"Pi 3b+", // 13
"Pi 3a+", // 14
"Unknown #15",// 15
"Pi CM3+", // 16
"Pi 4b", // 17
} ;
static bool _ever = false;
static bool _supressLogging = false;
//static bool _GPIO_setup = false;
static bool _usingGpioMem = false;
/* RPI 4 has different pullup registers - we need to know if we have that type */
static bool _pud_type_rpi4 = false;
//static uint8_t _pud_type_rpi4 = 0;
/* RPI 4 has different pullup operation - make backwards compat */
//static uint8_t _pud_compat_setting = PUD_OFF;
//#define GPIOrunning(X) ((X) <= (GPIO_MAX) ? ( ((X) >= (GPIO_MIN) ? (1) : (0)) ) : (0))
#define GPIOrunning() (_ever)
void gpioDelay (unsigned int howLong);
void log_message(bool critical, char *format, ...)
{
if (_supressLogging && !critical)
return;
va_list arglist;
va_start( arglist, format );
// if terminal don't log to syslod
if ( ! isatty(1) ) {
openlog(_GPIO_pi_NAME_, LOG_NDELAY, LOG_DAEMON);
vsyslog(critical?LOG_ERR:LOG_INFO, format, arglist);
closelog();
} else if (critical == false) {
vfprintf(stdout, format, arglist );
fflush(stdout);
}
// Always send critical errors to stderr
if (critical) {
vfprintf(stderr, format, arglist );
}
va_end( arglist );
}
void printVersionInformation()
{
#ifdef GPIO_SYSFS_MODE
LOG ("(sysfs) v%s\n",_GPIO_pi_VERSION_);
#else
LOG ("v%s\n",_GPIO_pi_VERSION_);
#endif
}
void gpioDelay (unsigned int howLong) // Microseconds (1000000 = 1 second)
{
struct timespec sleeper, dummy ;
sleeper.tv_sec = (time_t)(howLong / 1000) ;
sleeper.tv_nsec = (long)(howLong % 1000) * 1000000 ;
nanosleep (&sleeper, &dummy) ;
}
#ifndef GPIO_SYSFS_MODE
static volatile uint32_t * _gpioReg = MAP_FAILED;
int piBoardId ()
{
FILE *cpuFd ;
char line [120] ;
char *c ;
unsigned int revision ;
//int bRev, bType, bProc, bMfg, bMem, bWarranty;
int bType;
if ((cpuFd = fopen ("/proc/cpuinfo", "r")) == NULL)
LOG_ERROR ( "Unable to open /proc/cpuinfo") ;
while (fgets (line, 120, cpuFd) != NULL)
if (strncmp (line, "Revision", 8) == 0)
break ;
fclose (cpuFd) ;
if (strncmp (line, "Revision", 8) != 0)
LOG_ERROR ( "Unable to determin pi Board \"Revision\" line") ;
// Chomp trailing CR/NL
for (c = &line [strlen (line) - 1] ; (*c == '\n') || (*c == '\r') ; --c)
*c = 0 ;
DEBUG ( "pi Board Revision string: %s\n", line) ;
// Scan to the first character of the revision number
for (c = line ; *c ; ++c)
if (*c == ':')
break ;
if (*c != ':')
LOG_ERROR ( "Unknown pi Board \"Revision\" line (no colon)") ;
// Chomp spaces
++c ;
while (isspace (*c))
++c ;
if (!isxdigit (*c))
LOG_ERROR ( "Unknown pi Board \"Revision\" line (no hex digit at start of revision)") ;
revision = (unsigned int)strtol (c, NULL, 16) ; // Hex number with no leading 0x
if ((revision & (1 << 23)) != 0) // New way
{
/*
bRev = (revision & (0x0F << 0)) >> 0 ;*/
bType = (revision & (0xFF << 4)) >> 4 ;
/*
bProc = (revision & (0x0F << 12)) >> 12 ; // Not used for now.
bMfg = (revision & (0x0F << 16)) >> 16 ;
bMem = (revision & (0x07 << 20)) >> 20 ;
bWarranty = (revision & (0x03 << 24)) != 0 ;
*/
LOG ("pi Board Model: %s\n", _piModelNames[bType]) ;
return bType;
}
LOG_ERROR ( "pi Board Model: UNKNOWN\n");
return PI_MODEL_UNKNOWN;
}
bool gpioSetup() {
int fd;
unsigned int piGPIObase = 0;
unsigned int piGPIOlen = GPIO_LEN;
printVersionInformation();
switch ( piBoardId() )
{
case PI_MODEL_A:
case PI_MODEL_B:
case PI_MODEL_AP:
case PI_MODEL_BP:
case PI_ALPHA:
case PI_MODEL_CM:
case PI_MODEL_ZERO:
case PI_MODEL_ZERO_W:
//case PI_MODEL_UNKNOWN:
piGPIObase = (GPIO_BASE_P1 + GPIO_OFFSET);
piGPIOlen = GPIO_LEN;
break ;
case PI_MODEL_4B:
piGPIObase = (GPIO_BASE_P4 + GPIO_OFFSET);
piGPIOlen = GPIO_LEN_P4;
_pud_type_rpi4 = 1;
break ;
default: // Pi 2 and 3
piGPIObase = (GPIO_BASE_P2 + GPIO_OFFSET);
piGPIOlen = GPIO_LEN;
break ;
}
//fd = open("/dev/mem", O_RDWR | O_SYNC);
if ((fd = open ("/dev/mem", O_RDWR | O_SYNC | O_CLOEXEC)) < 0)
{
//LOG_ERROR ( "Failed to open '/dev/mem' for GPIO access (are we root?)\n");
//return false;
// Something odd going on with writes on /dev/gpiomem, need to fix this.
if ((fd = open ("/dev/gpiomem", O_RDWR | O_SYNC | O_CLOEXEC) ) >= 0) // We're using gpiomem
{
piGPIObase = 0 ;
_usingGpioMem = true ;
LOG ("Using /dev/gpiomem!\n");
} else {
LOG_ERROR ( "Failed to open '/dev/mem' or '/dev/gpiomem' for GPIO access (are we root?)\n");
return false;
}
}
_gpioReg = mmap
(
0,
piGPIOlen,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_SHARED|MAP_LOCKED,
fd,
piGPIObase);
close(fd);
_ever = true;
//_GPIO_setup = true;
return true;
}
int pinMode(unsigned int gpio, unsigned int mode) {
int reg, shift;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! GPIOrunning())
return GPIO_ERR_NOT_SETUP;
if (mode < INPUT || mode > IO_ALT3)
return GPIO_NOT_IO_MODE;
reg = gpio / 10;
shift = (gpio % 10) * 3;
_gpioReg[reg] = (_gpioReg[reg] & ~(7 << shift)) | (mode << shift);
return GPIO_OK;
}
int getPinMode(unsigned int gpio) {
int reg, shift;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! GPIOrunning())
return GPIO_ERR_NOT_SETUP;
reg = gpio / 10;
shift = (gpio % 10) * 3;
//DEBUG("getPinMode read %d from GPIO %d\n",(*(_gpioReg + reg) >> shift) & 7,gpio);
return (*(_gpioReg + reg) >> shift) & 7;
}
int digitalRead(unsigned int gpio) {
unsigned int bank, bit;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! GPIOrunning())
return GPIO_ERR_NOT_SETUP;
bank = gpio >> 5;
bit = (1 << (gpio & 0x1F));
if ((*(_gpioReg + GPLEV0 + bank) & bit) != LOW)
return HIGH;
else
return LOW;
}
int digitalWrite(unsigned int gpio, unsigned int level) {
unsigned int bank, bit;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! GPIOrunning())
return GPIO_ERR_NOT_SETUP;
bank = gpio >> 5;
bit = (1 << (gpio & 0x1F));
DEBUG("Writing %d to GPIO %d\n",level==LOW?0:1,gpio);
if (level == LOW)
*(_gpioReg + GPCLR0 + bank) = bit;
else
*(_gpioReg + GPSET0 + bank) = bit;
return GPIO_OK;
}
int setPullUpDown_Pi4(unsigned int gpio, unsigned int pud)
{
if( _pud_type_rpi4 )
{
unsigned int pull, bit;
LOG("Pi4 setPullUpDown() expermental support!");
switch (pud)
{
case PUD_OFF: pull = 0; break;
case PUD_UP: pull = 1; break;
case PUD_DOWN: pull = 2; break;
default:
return GPIO_ERR_GENERAL;
break;
}
int shift = (gpio & 0xf) << 1;
bit = *(_gpioReg + GPPUPPDN0 + (gpio>>4));
bit &= ~(3 << shift);
bit |= (pull << shift);
*(_gpioReg + GPPUPPDN0 + (gpio>>4)) = bit;
return GPIO_OK;
}
return GPIO_ERR_GENERAL;
}
int setPullUpDown(unsigned int gpio, unsigned int pud)
{
unsigned int bank, bit;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! GPIOrunning())
return GPIO_ERR_NOT_SETUP;
if (pud > PUD_UP || pud < PUD_OFF)
return GPIO_ERR_GENERAL;
if( _pud_type_rpi4 ) {
return setPullUpDown_Pi4(gpio, pud);
}
bank = gpio >> 5;
bit = (1 << (gpio & 0x1F));
*(_gpioReg + GPPUD) = pud;
gpioDelay(1);
*(_gpioReg + GPPUDCLK0 + bank) = bit;
gpioDelay(1);
*(_gpioReg + GPPUD) = 0;
*(_gpioReg + GPPUDCLK0 + bank) = 0;
return GPIO_OK;
}
#else // If GPIO_SYSFS_MODE
// There is no need to setup GPIO memory in sysfs mode, so simply set setup state.
bool gpioSetup() {
printVersionInformation();
_ever = true;
return true;
}
int setPullUpDown(unsigned int gpio, unsigned int pud) {
LOG_ERROR("setPullUpDown() not supported in sysfs mode");
return GPIO_ERR_GENERAL;
}
int pinMode (unsigned int pin, unsigned int mode)
{
//printVersionInformation();
//static const char s_directions_str[] = "in\0out\0";
if (! validGPIO(pin))
return GPIO_ERR_BAD_PIN;
if (! isExported(pin))
return GPIO_NOT_EXPORTED;
if (mode != INPUT && mode != OUTPUT)
return GPIO_NOT_IO_MODE;
char path[SYSFS_PATH_MAX];
int fd;
/*
if ( pinExport(pin) != true) {
LOG ("start pinMode (pinExport) failed\n");
return false;
}
*/
snprintf(path, SYSFS_PATH_MAX, "/sys/class/gpio/gpio%d/direction", pin);
fd = open(path, O_WRONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open gpio direction for writing!\n");
LOG_ERROR ( "Failed to open gpio '%s' for writing!\n",path);
return GPIO_ERR_IO;
}
//if (-1 == write(fd, &s_directions_str[INPUT == mode ? 0 : 3], INPUT == mode ? 2 : 3)) {
if (-1 == write(fd, (INPUT==mode?"in\n":"out\n"),(INPUT==mode?3:4))) {
//fprintf(stderr, "Failed to set direction!\n");
LOG_ERROR ( "Failed to setup gpio input/output on '%s'!\n",path);
LOG_ERROR ( "Error (%d) - %s\n",errno, strerror (errno));
//displayLastSystemError("");
return GPIO_ERR_IO;
}
close(fd);
return GPIO_OK;
}
int getPinMode(unsigned int gpio) {
char path[SYSFS_PATH_MAX];
char value_str[SYSFS_READ_MAX];
int fd;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! isExported(gpio))
return GPIO_NOT_EXPORTED;
snprintf(path, SYSFS_PATH_MAX, "/sys/class/gpio/gpio%d/direction", gpio);
fd = open(path, O_RDONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open gpio direction for writing!\n");
LOG_ERROR ( "Failed to open gpio '%s' for reading!\n",path);
return GPIO_ERR_IO;
}
if (-1 == read(fd, value_str, SYSFS_READ_MAX)) {
//fprintf(stderr, "Failed to read value!\n");
LOG_ERROR ( "Failed to read value on '%s'!\n",path);
LOG_ERROR ( "Error (%d) - %s\n",errno, strerror (errno));
//displayLastSystemError("");
return GPIO_ERR_IO;
}
close(fd);
if (strncasecmp(value_str, "out", 3)==0)
return OUTPUT;
return INPUT;
}
int digitalRead (unsigned int gpio)
{
char path[SYSFS_PATH_MAX];
char value_str[SYSFS_READ_MAX];
int fd;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! isExported(gpio))
return GPIO_NOT_EXPORTED;
snprintf(path, SYSFS_PATH_MAX, "/sys/class/gpio/gpio%d/value", gpio);
fd = open(path, O_RDONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open gpio value for reading!\n");
LOG_ERROR ( "Failed to open gpio '%s' for reading!\n",path);
return GPIO_ERR_IO;
}
if (-1 == read(fd, value_str, SYSFS_READ_MAX)) {
//fprintf(stderr, "Failed to read value!\n");
LOG_ERROR ( "Failed to read value on '%s'!\n",path);
LOG_ERROR ( "Error (%d) - %s\n",errno, strerror (errno));
//displayLastSystemError("");
return GPIO_ERR_IO;
}
close(fd);
return(atoi(value_str));
}
int digitalWrite (unsigned int gpio, unsigned int value)
{
//static const char s_values_str[] = "01";
char path[SYSFS_PATH_MAX];
int fd;
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! isExported(gpio))
return GPIO_NOT_EXPORTED;
if (getPinMode(gpio) != OUTPUT)
return GPIO_NOT_OUTPUT;
snprintf(path, SYSFS_PATH_MAX, "/sys/class/gpio/gpio%d/value", gpio);
fd = open(path, O_WRONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open gpio value for writing!\n");
LOG_ERROR ( "Failed to open gpio '%s' for writing!\n",path);
return GPIO_ERR_IO;
}
//if (1 != write(fd, &s_values_str[LOW == value ? 0 : 1], 1)) {
if (1 != write(fd, (LOW==value?"0":"1"), 1)) {
//fprintf(stderr, "Failed to write value!\n");
LOG_ERROR ( "Failed to write value to '%s'!\n",path);
LOG_ERROR ( "Error (%d) - %s\n",errno, strerror (errno));
//displayLastSystemError("");
return GPIO_ERR_IO;
}
close(fd);
return GPIO_OK;
}
#endif // GPIO_SYSFS_MODE
#ifdef GPIO_SYSFS_INTERRUPT
bool isExported(unsigned int pin)
{
char path[SYSFS_PATH_MAX];
struct stat sb;
snprintf(path, SYSFS_PATH_MAX, "/sys/class/gpio/gpio%d/", pin);
if (stat(path, &sb) == 0 && S_ISDIR(sb.st_mode)) {
return true;
} else {
return false;
}
}
int pinExport(unsigned int pin)
{
char buffer[SYSFS_READ_MAX];
ssize_t bytes_written;
int fd;
if (! validGPIO(pin))
return GPIO_ERR_BAD_PIN;
fd = open("/sys/class/gpio/export", O_WRONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open export for writing!\n");
LOG_ERROR ( "Failed to open '/sys/class/gpio/export' for writing!\n");
return GPIO_ERR_IO;
}
bytes_written = snprintf(buffer, SYSFS_READ_MAX, "%d", pin);
write(fd, buffer, bytes_written);
close(fd);
return GPIO_OK;
}
int pinUnexport(unsigned int pin)
{
char buffer[SYSFS_READ_MAX];
ssize_t bytes_written;
int fd;
if (! validGPIO(pin))
return GPIO_ERR_BAD_PIN;
if (! isExported(pin))
return GPIO_NOT_EXPORTED;
fd = open("/sys/class/gpio/unexport", O_WRONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open unexport for writing!\n");
LOG_ERROR ( "Failed to open '/sys/class/gpio/unexport' for writing!\n");
return GPIO_ERR_IO;
}
bytes_written = snprintf(buffer, SYSFS_READ_MAX, "%d", pin);
write(fd, buffer, bytes_written);
close(fd);
return GPIO_OK;
}
int edgeSetup (unsigned int pin, unsigned int value)
{
//static const char s_values_str[] = "01";
char path[SYSFS_PATH_MAX];
int fd;
if (! validGPIO(pin))
return GPIO_ERR_BAD_PIN;
snprintf(path, SYSFS_PATH_MAX, "/sys/class/gpio/gpio%d/edge", pin);
fd = open(path, O_WRONLY);
if (-1 == fd) {
//fprintf(stderr, "Failed to open gpio value for writing!\n");
LOG_ERROR ( "Failed to open gpio '%s' for writing!\n",path);
return GPIO_ERR_IO;
}
int rtn = 0;
if (value==INT_EDGE_RISING)
rtn = write(fd, "rising", 6);
else if (value==INT_EDGE_FALLING)
rtn = write(fd, "falling", 7);
else if (value==INT_EDGE_BOTH)
rtn = write(fd, "both", 4);
else
rtn = write(fd, "none", 4);
if (rtn <= 0) {
LOG_ERROR ( "Failed to setup edge on '%s'!\n",path);
LOG_ERROR ( "Error (%d) - %s\n",errno, strerror (errno));
//displayLastSystemError("");
return GPIO_ERR_IO;
}
close(fd);
return GPIO_OK;
}
#include <poll.h>
#include <pthread.h>
#include <sys/ioctl.h>
struct threadGPIOinterupt{
void (*function)(void *args);
void *args;
unsigned int pin;
};
static pthread_mutex_t pinMutex ;
#define MAX_FDS 64
static unsigned int _sysFds [MAX_FDS] =
{
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
} ;
void pushSysFds(int fd)
{
int i;
for (i=0; i< MAX_FDS; i++) {
if (_sysFds[i] == -1) {
_sysFds[i] = fd;
return;
}
}
}
void gpioShutdown() {
int i;
_ever = false;
for (i=0; i< MAX_FDS; i++) {
if (_sysFds[i] != -1) {
//printf("Closing fd %d\n",i);
close(_sysFds[i]);
_sysFds[i] = -1;
} else {
break;
}
}
}
int waitForInterrupt (int pin, int mS, int fd)
{
int x;
uint8_t c ;
struct pollfd polls ;
// Setup poll structure
polls.fd = fd ;
polls.events = POLLPRI | POLLERR | POLLHUP | POLLNVAL;
// Wait for something ...
x = poll (&polls, 1, mS) ;
// If no error, do a dummy read to clear the interrupt
// A one character read appars to be enough.
if (x > 0)
{
lseek (fd, 0, SEEK_SET) ; // Rewind
(void)read (fd, &c, 1) ; // Read & clear
}
return x ;
}
static void *interruptHandler (void *arg)
{
struct threadGPIOinterupt *stuff = (struct threadGPIOinterupt *) arg;
int pin = stuff->pin;
void (*function)(void *args) = stuff->function;
void *args = stuff->args;
stuff->pin = -1;
char path[SYSFS_PATH_MAX];
int fd, count, i ;
uint8_t c ;
sprintf(path, "/sys/class/gpio/gpio%d/value", pin);
if ((fd = open(path, O_RDONLY)) < 0)
{
LOG_ERROR ( "Failed to open '%s'!\n",path);
return NULL;
}
pushSysFds(fd);
// Clear any initial pending interrupt
ioctl (fd, FIONREAD, &count) ;
for (i = 0 ; i < count ; ++i)
read (fd, &c, 1);
while (_ever == true) {
if (waitForInterrupt (pin, -1, fd) > 0) {
function(args);
} else {
LOG_ERROR ("interruptHandler failed for GPIO %d, resetting\n", pin);
gpioDelay(1);
}
}
LOG("interruptHandler ended for GPIO %d\n", pin);
close(fd);
return NULL ;
}
int registerGPIOinterrupt(unsigned int pin, unsigned int mode, void (*function)(void *args), void *args )
{
pthread_t threadId ;
struct threadGPIOinterupt stuff;
if (! validGPIO(pin))
return false;
// Check it's exported
if (! isExported(pin))
pinExport(pin);
// Setup pin if defined.
if (mode != INT_EDGE_SETUP) {
// if the pin is output, set as input to setup edge then reset to output.
if (getPinMode(pin) == OUTPUT) {
pinMode(pin, INPUT);
edgeSetup(pin, mode);
pinMode(pin, OUTPUT);
} else {
edgeSetup(pin, mode);
}
}
//#endif
stuff.function = function;
stuff.args = args;
stuff.pin = pin;
pthread_mutex_lock (&pinMutex) ;
if (pthread_create (&threadId, NULL, interruptHandler, (void *)&stuff) < 0) {
LOG_ERROR("Failed to start interruptHandler thread\n");
return GPIO_ERR_GENERAL;
} else {
while (stuff.pin == pin)
gpioDelay(1);
}
pthread_mutex_unlock (&pinMutex) ;
return GPIO_OK ;
}
#else // GPIO_SYSFS_INTERRUPT
#include <pthread.h>
struct GPIOinterupt{
void (*function)(void *args);
void *args;
unsigned int pin;
unsigned int bit;
unsigned int bank;
unsigned int lastValue;
unsigned int edge;
bool running;
pthread_t threadId;
pthread_mutex_t mutex;
pthread_cond_t cond;
struct GPIOinterupt *next;
};
#define POLL_DELAY 10
static struct GPIOinterupt *_GPIOinterupts = NULL;
static pthread_t _interruptHandlerThreadId = 0;
static pthread_mutex_t _gpioRegisterMutex;
static void *GPIOinterruptHandler (void *arg)
{
struct GPIOinterupt *data = (struct GPIOinterupt *) arg;
void (*function)(void *args) = data->function;
void *args = data->args;
data->running = true;
DEBUG("Created Thread for GPIO interrupt %d\n",data->pin);
pthread_mutex_lock(&data->mutex);
while (_ever == true && data->running == true) {
//printf("GPIOinterruptHandler() %d wait\n", data->pin);
pthread_cond_wait(&data->cond, &data->mutex);
DEBUG("GPIO interrupt triggered for %d\n",data->pin);
// recheck _ever incase this is a shutdown signal, and running incase we've been told to shutdown
if (_ever == true && data->running == true) {
// Check edge
if ( (data->edge == INT_EDGE_BOTH) ||
(data->edge == INT_EDGE_RISING && data->lastValue == HIGH) ||
(data->edge == INT_EDGE_FALLING && data->lastValue == LOW))
{
//DEBUG("GPIO interrupt triggered for %d\n",data->pin);
function(args);
}
//printf("GPIOinterruptHandler() called gpio %d\n",data->pin);
}
}
pthread_mutex_unlock(&data->mutex);
//printf("GPIOinterruptHandler() stopped gpio %d\n",data->pin);
DEBUG("Stopping thread for GPIO interrupt %d\n",data->pin);
free(arg);
pthread_exit(0);
return NULL;
}
static void *interruptHandler(void *arg)
{
// Use the global var and not one that passed, just incase we change the global pointer in the future
// to redefine starting position.
//struct GPIOinterupt *GPIOinterupt = (struct GPIOinterupt *) arg;
//unsigned int bank, bit;
struct GPIOinterupt *i_ptr;
while (_ever == true && _GPIOinterupts != NULL) {
for (i_ptr = _GPIOinterupts; i_ptr != NULL; i_ptr = i_ptr->next) {
//DEBUG ("Poll %d\n",i_ptr->pin);
if (i_ptr->threadId <= 0) {
if (pthread_create (&i_ptr->threadId, NULL, GPIOinterruptHandler, (void *)i_ptr) < 0) {
LOG_ERROR("Can't create GPIO interrupt handler for GPIO %d\n",i_ptr->pin);
}
}
if (i_ptr->lastValue != digitalRead(i_ptr->pin))
//if (i_ptr->lastValue != ((*(_gpioReg + GPLEV0 + i_ptr->bank) & i_ptr->bit)==0?LOW:HIGH) )
{
i_ptr->lastValue = !i_ptr->lastValue;
pthread_cond_signal(&i_ptr->cond);
}
}
gpioDelay(POLL_DELAY);
}
// signel so thread can shutdown
for (i_ptr = _GPIOinterupts; i_ptr != NULL; i_ptr = i_ptr->next) {
if (i_ptr->threadId > 0) {
pthread_cond_signal(&i_ptr->cond);
}
}
DEBUG("interruptHandler stopped\n");
_interruptHandlerThreadId = 0;
pthread_exit(0);
return NULL;
}
int registerGPIOinterrupt(unsigned int gpio, unsigned int mode, void (*function)(void *args), void *args )
{
if (! validGPIO(gpio))
return GPIO_ERR_BAD_PIN;
if (! GPIOrunning())
return GPIO_ERR_NOT_SETUP;
if (mode == INT_EDGE_SETUP) {
LOG("INT_EDGE_SETUP is only valid for sysfs mode");
mode = INT_EDGE_BOTH;
}
// Lock the function, this isn't thread safe.
pthread_mutex_lock (&_gpioRegisterMutex);
struct GPIOinterupt *i_ptr;
struct GPIOinterupt *interupt = calloc(1, sizeof(struct GPIOinterupt));
interupt->function = function;
interupt->args = args;
interupt->pin = gpio;
interupt->edge = mode;
interupt->lastValue = digitalRead(gpio);
interupt->threadId = 0;
interupt->running = false;
interupt->next = NULL;
interupt->bank = gpio >> 5;
interupt->bit = (1 << (gpio & 0x1F));
//interupt->lastValue = (*(_gpioReg + GPLEV0 + i_ptr->bank) & i_ptr->bit)==0?0:1)
if (_GPIOinterupts == NULL) {
_GPIOinterupts = interupt;
} else {
for (i_ptr = _GPIOinterupts; i_ptr->next != NULL; i_ptr = i_ptr->next) {} // Simply run to the end of the list