/* * 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 . *********************************************************************** */ #include #include #include #include #include #include #include #include #include #define VERSION "1.0" static int wpMode ; char *usage = "Usage: gpio -v\n" " gpio [-g] ...\n" " gpio [-p] ...\n" " gpio ..." ; /* * 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 \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 ; }