55e189eda5
- Add `#include <stdbool.h> to all files previously using the `TRUE`/`FALSE` macros - Replace all instances of `TRUE`/`FALSE` with `true`/`false`, respectively - Definitions of `TRUE`/`FALSE` macros retained in wiringPi.h for compatibility.
111 lines
3.2 KiB
C
111 lines
3.2 KiB
C
/*
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* pseudoPins.c:
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* Extend wiringPi with a number of pseudo pins which can be
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* digitally or analog written/read.
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*
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* Note:
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* Just one set of pseudo pins can exist per Raspberry Pi.
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* These pins are shared between all programs running on
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* that Raspberry Pi. The values are also persistant as
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* they live in shared RAM. This gives you a means for
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* temporary variable storing/sharing between programs,
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* or for other cunning things I've not thought of yet..
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*
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* Copyright (c) 2012-2016 Gordon Henderson
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***********************************************************************
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* This file is part of wiringPi:
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* https://github.com/WiringPi/WiringPi/
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*
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* wiringPi is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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*
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* wiringPi is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with wiringPi.
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* If not, see <http://www.gnu.org/licenses/>.
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***********************************************************************
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*/
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#define SHARED_NAME "wiringPiPseudoPins"
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#define PSEUDO_PINS 64
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#include <stdio.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/mman.h>
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#include <fcntl.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <wiringPi.h>
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#include "pseudoPins.h"
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static int myAnalogRead(struct wiringPiNodeStruct *node, int pin)
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{
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int *ptr = (int *)(intptr_t)node->data0; // Cast to intptr_t to handle pointer-to-integer conversion
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int myPin = pin - node->pinBase;
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return *(ptr + myPin);
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}
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static void myAnalogWrite(struct wiringPiNodeStruct *node, int pin, int value)
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{
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int *ptr = (int *)(intptr_t)node->data0;
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int myPin = pin - node->pinBase;
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*(ptr + myPin) = value;
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}
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/*
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* pseudoPinsSetup:
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* Create a new wiringPi device node for the pseudoPins driver
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*********************************************************************************
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*/
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int pseudoPinsSetup(const int pinBase)
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{
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struct wiringPiNodeStruct *node;
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void *ptr;
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node = wiringPiNewNode(pinBase, PSEUDO_PINS);
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if (node == NULL) {
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fprintf(stderr, "Error creating new wiringPi node");
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return false;
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}
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node->fd = shm_open(SHARED_NAME, O_CREAT | O_RDWR, 0666);
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if (node->fd < 0) {
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perror("Error opening shared memory");
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return false;
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}
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if (ftruncate(node->fd, PSEUDO_PINS * sizeof(int)) < 0) {
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perror("Error resizing shared memory");
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return false;
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}
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ptr = mmap(NULL, PSEUDO_PINS * sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED, node->fd, 0);
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if (ptr == MAP_FAILED) {
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perror("Error mapping shared memory");
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return false;
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}
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node->data0 = (unsigned int)(uintptr_t)ptr;
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node->analogRead = myAnalogRead;
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node->analogWrite = myAnalogWrite;
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return true;
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}
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