wiringPi/gpio/gpio.c

594 lines
13 KiB
C

/*
* gpio.c:
* Set-UID command-line interface to the Raspberry Pi's GPIO
* Copyright (c) 2012 Gordon Henderson
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* wiringPi is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with wiringPi. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
#include <wiringPi.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <fcntl.h>
#define VERSION "1.0"
static int wpMode ;
char *usage = "Usage: gpio -v\n"
" gpio [-g] <read/write/pwm/mode> ...\n"
" gpio [-p] <read/write/mode> ...\n"
" gpio <export/edge/unexport/unexportall/exports> ..." ;
/*
* doExports:
* List all GPIO exports
*********************************************************************************
*/
void doExports (void)
{
int fd ;
int i, l, first ;
char fName [128] ;
char buf [16] ;
// Rather crude, but who knows what others are up to...
for (first = 0, i = 0 ; i < 64 ; ++i)
{
// Try to read the direction
sprintf (fName, "/sys/class/gpio/gpio%d/direction", i) ;
if ((fd = open (fName, O_RDONLY)) == -1)
continue ;
if (first == 0)
{
++first ;
printf ("GPIO Pins exported:\n") ;
}
printf ("%4d: ", i) ;
if ((l = read (fd, buf, 16)) == 0)
sprintf (buf, "%s", "?") ;
buf [l] = 0 ;
if ((buf [strlen (buf) - 1]) == '\n')
buf [strlen (buf) - 1] = 0 ;
printf ("%-3s", buf) ;
close (fd) ;
// Try to Read the value
sprintf (fName, "/sys/class/gpio/gpio%d/value", i) ;
if ((fd = open (fName, O_RDONLY)) == -1)
{
printf ("No Value file (huh?)\n") ;
continue ;
}
if ((l = read (fd, buf, 16)) == 0)
sprintf (buf, "%s", "?") ;
buf [l] = 0 ;
if ((buf [strlen (buf) - 1]) == '\n')
buf [strlen (buf) - 1] = 0 ;
printf (" %s", buf) ;
// Read any edge trigger file
sprintf (fName, "/sys/class/gpio/gpio%d/edge", i) ;
if ((fd = open (fName, O_RDONLY)) == -1)
{
printf ("\n") ;
continue ;
}
if ((l = read (fd, buf, 16)) == 0)
sprintf (buf, "%s", "?") ;
buf [l] = 0 ;
if ((buf [strlen (buf) - 1]) == '\n')
buf [strlen (buf) - 1] = 0 ;
printf (" %-8s\n", buf) ;
close (fd) ;
}
}
/*
* doExport:
* gpio export pin mode
* This uses the /sys/class/gpio device interface.
*********************************************************************************
*/
void doExport (int argc, char *argv [])
{
FILE *fd ;
int pin ;
char *mode ;
char fName [128] ;
uid_t uid ;
gid_t gid ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s export pin mode\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
mode = argv [3] ;
if ((fd = fopen ("/sys/class/gpio/export", "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO export interface: %s\n", argv [0], strerror (errno)) ;
exit (1) ;
}
fprintf (fd, "%d\n", pin) ;
fclose (fd) ;
sprintf (fName, "/sys/class/gpio/gpio%d/direction", pin) ;
if ((fd = fopen (fName, "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO direction interface for pin %d: %s\n", argv [0], pin, strerror (errno)) ;
exit (1) ;
}
/**/ if ((strcasecmp (mode, "in") == 0) || (strcasecmp (mode, "input") == 0))
fprintf (fd, "in\n") ;
else if ((strcasecmp (mode, "out") == 0) || (strcasecmp (mode, "output") == 0))
fprintf (fd, "out\n") ;
else
{
fprintf (stderr, "%s: Invalid mode: %s. Should be in or out\n", argv [1], mode) ;
exit (1) ;
}
fclose (fd) ;
// Change ownership so the current user can actually use it!
uid = getuid () ;
gid = getgid () ;
sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
if (chown (fName, uid, gid) != 0)
{
fprintf (stderr, "%s: Unable to change ownership of the value file: %s\n", argv [1], strerror (errno)) ;
exit (1) ;
}
// Also change ownership of the edge file - if it exists
sprintf (fName, "/sys/class/gpio/gpio%d/edge", pin) ;
if (chown (fName, uid, gid) != 0)
{
if (errno != ENOENT) // Silently ignore File not found - older kernel
{
fprintf (stderr, "%s: Unable to change ownership of the value file: %s\n", argv [1], strerror (errno)) ;
exit (1) ;
}
}
}
/*
* doEdge:
* gpio edge pin mode
* Easy access to changing the edge trigger on a GPIO pin
* This uses the /sys/class/gpio device interface.
*********************************************************************************
*/
void doEdge (int argc, char *argv [])
{
FILE *fd ;
int pin ;
char *mode ;
char fName [128] ;
uid_t uid ;
gid_t gid ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s edge pin mode\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
mode = argv [3] ;
// Export the pin and set direction to input
if ((fd = fopen ("/sys/class/gpio/export", "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO export interface: %s\n", argv [0], strerror (errno)) ;
exit (1) ;
}
fprintf (fd, "%d\n", pin) ;
fclose (fd) ;
sprintf (fName, "/sys/class/gpio/gpio%d/direction", pin) ;
if ((fd = fopen (fName, "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO direction interface for pin %d: %s\n", argv [0], pin, strerror (errno)) ;
exit (1) ;
}
fprintf (fd, "in\n") ;
fclose (fd) ;
sprintf (fName, "/sys/class/gpio/gpio%d/edge", pin) ;
if ((fd = fopen (fName, "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO edge interface for pin %d: %s\n", argv [0], pin, strerror (errno)) ;
exit (1) ;
}
/**/ if (strcasecmp (mode, "none") == 0)
fprintf (fd, "none\n") ;
else if (strcasecmp (mode, "rising") == 0)
fprintf (fd, "rising\n") ;
else if (strcasecmp (mode, "falling") == 0)
fprintf (fd, "falling\n") ;
else if (strcasecmp (mode, "both") == 0)
fprintf (fd, "both\n") ;
else
{
fprintf (stderr, "%s: Invalid mode: %s. Should be none, rising, falling or both\n", argv [1], mode) ;
exit (1) ;
}
// Change ownership so the current user can actually use it!
uid = getuid () ;
gid = getgid () ;
sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
if (chown (fName, uid, gid) != 0)
{
fprintf (stderr, "%s: Unable to change ownership of the value file: %s\n", argv [1], strerror (errno)) ;
exit (1) ;
}
// Also change ownership of the edge file
sprintf (fName, "/sys/class/gpio/gpio%d/edge", pin) ;
if (chown (fName, uid, gid) != 0)
{
fprintf (stderr, "%s: Unable to change ownership of the value file: %s\n", argv [1], strerror (errno)) ;
exit (1) ;
}
fclose (fd) ;
}
/*
* doUnexport:
* gpio unexport pin
* This uses the /sys/class/gpio device interface.
*********************************************************************************
*/
void doUnexport (int argc, char *argv [])
{
FILE *fd ;
int pin ;
if (argc != 3)
{
fprintf (stderr, "Usage: %s unexport pin\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
if ((fd = fopen ("/sys/class/gpio/unexport", "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO export interface\n", argv [0]) ;
exit (1) ;
}
fprintf (fd, "%d\n", pin) ;
fclose (fd) ;
}
/*
* doUnexportAll:
* gpio unexportall
* Un-Export all the GPIO pins.
* This uses the /sys/class/gpio device interface.
*********************************************************************************
*/
void doUnexportall (int argc, char *argv [])
{
FILE *fd ;
int pin ;
for (pin = 0 ; pin < 63 ; ++pin)
{
if ((fd = fopen ("/sys/class/gpio/unexport", "w")) == NULL)
{
fprintf (stderr, "%s: Unable to open GPIO export interface\n", argv [0]) ;
exit (1) ;
}
fprintf (fd, "%d\n", pin) ;
fclose (fd) ;
}
}
/*
* doMode:
* gpio mode pin mode ...
*********************************************************************************
*/
void doMode (int argc, char *argv [])
{
int pin ;
char *mode ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s mode pin mode\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
if ((wpMode == WPI_MODE_PINS) && ((pin < 0) || (pin >= NUM_PINS)))
return ;
mode = argv [3] ;
/**/ if (strcasecmp (mode, "in") == 0)
pinMode (pin, INPUT) ;
else if (strcasecmp (mode, "out") == 0)
pinMode (pin, OUTPUT) ;
else if (strcasecmp (mode, "pwm") == 0)
pinMode (pin, PWM_OUTPUT) ;
else if (strcasecmp (mode, "up") == 0)
pullUpDnControl (pin, PUD_UP) ;
else if (strcasecmp (mode, "down") == 0)
pullUpDnControl (pin, PUD_DOWN) ;
else if (strcasecmp (mode, "tri") == 0)
pullUpDnControl (pin, PUD_OFF) ;
else
{
fprintf (stderr, "%s: Invalid mode: %s. Should be in/out/pwm/up/down/tri\n", argv [1], mode) ;
exit (1) ;
}
}
/*
* doWrite:
* gpio write pin value
*********************************************************************************
*/
void doWrite (int argc, char *argv [])
{
int pin, val ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s write pin value\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
if ((wpMode == WPI_MODE_PINS) && ((pin < 0) || (pin >= NUM_PINS)))
return ;
val = atoi (argv [3]) ;
/**/ if (val == 0)
digitalWrite (pin, LOW) ;
else
digitalWrite (pin, HIGH) ;
}
/*
* doRead:
* Read a pin and return the value
*********************************************************************************
*/
void doRead (int argc, char *argv [])
{
int pin, val ;
if (argc != 3)
{
fprintf (stderr, "Usage: %s read pin\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
if ((wpMode == WPI_MODE_PINS) && ((pin < 0) || (pin >= NUM_PINS)))
{
printf ("0\n") ;
return ;
}
val = digitalRead (pin) ;
printf ("%s\n", val == 0 ? "0" : "1") ;
}
/*
* doPwm:
* Output a PWM value on a pin
*********************************************************************************
*/
void doPwm (int argc, char *argv [])
{
int pin, val ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s pwm <pin> <value>\n", argv [0]) ;
exit (1) ;
}
pin = atoi (argv [2]) ;
if ((wpMode == WPI_MODE_PINS) && ((pin < 0) || (pin >= NUM_PINS)))
return ;
val = atoi (argv [3]) ;
pwmWrite (pin, val) ;
}
/*
* main:
* Start here
*********************************************************************************
*/
int main (int argc, char *argv [])
{
int i ;
if (argc == 1)
{
fprintf (stderr, "%s: %s\n", argv [0], usage) ;
return 1 ;
}
if (geteuid () != 0)
{
fprintf (stderr, "%s: Must be root to run\n", argv [0]) ;
return 1 ;
}
if (strcasecmp (argv [1], "-v") == 0)
{
printf ("gpio version: %s\n", VERSION) ;
printf ("Copyright (c) 2012 Gordon Henderson\n") ;
printf ("This is free software with ABSOLUTELY NO WARRANTY.\n") ;
return 0 ;
}
// Initial test for /sys/class/gpio operations:
/**/ if (strcasecmp (argv [1], "exports" ) == 0)
{ doExports () ; return 0 ; }
else if (strcasecmp (argv [1], "export" ) == 0)
{ doExport (argc, argv) ; return 0 ; }
else if (strcasecmp (argv [1], "edge" ) == 0)
{ doEdge (argc, argv) ; return 0 ; }
else if (strcasecmp (argv [1], "unexportall") == 0)
{ doUnexportall (argc, argv) ; return 0 ; }
else if (strcasecmp (argv [1], "unexport") == 0)
{ doUnexport (argc, argv) ; return 0 ; }
// Check for -g argument
if (strcasecmp (argv [1], "-g") == 0)
{
if (wiringPiSetupGpio () == -1)
{
fprintf (stderr, "%s: Unable to initialise GPIO in GPIO mode.\n", argv [0]) ;
exit (1) ;
}
for (i = 2 ; i < argc ; ++i)
argv [i - 1] = argv [i] ;
--argc ;
wpMode = WPI_MODE_GPIO ;
}
// Check for -p argument for PiFace
else if (strcasecmp (argv [1], "-p") == 0)
{
if (wiringPiSetupPiFaceForGpioProg () == -1)
{
fprintf (stderr, "%s: Unable to initialise PiFace.\n", argv [0]) ;
exit (1) ;
}
for (i = 2 ; i < argc ; ++i)
argv [i - 1] = argv [i] ;
--argc ;
wpMode = WPI_MODE_PIFACE ;
}
// Default to wiringPi mode
else
{
if (wiringPiSetup () == -1)
{
fprintf (stderr, "%s: Unable to initialise GPIO in wiringPi mode\n", argv [0]) ;
exit (1) ;
}
wpMode = WPI_MODE_PINS ;
}
/**/ if (strcasecmp (argv [1], "write" ) == 0)
doWrite (argc, argv) ;
else if (strcasecmp (argv [1], "read" ) == 0)
doRead (argc, argv) ;
else if (strcasecmp (argv [1], "mode" ) == 0)
doMode (argc, argv) ;
else if (strcasecmp (argv [1], "pwm" ) == 0)
doPwm (argc, argv) ;
else
{
fprintf (stderr, "%s: Unknown command: %s. (read/write/pwm/mode expected)\n", argv [0], argv [1]) ;
exit (1) ;
}
return 0 ;
}