GPIO changes (RPi5 support)

utility/SPIDEV/gpio.cpp

@@ -1,23 +1,17 @@
 /*
- * https://github.com/mrshu/GPIOlib
- * Copyright (c) 2011, Copyright (c) 2011 mr.Shu
+ *
+ * Copyright (c) 2024, Copyright (c) 2024 TMRh20 & 2bndy5
  * All rights reserved.
  *
- * Modified on 24 June 2012, 11:06 AM
- * File:   gpio.cpp
- * Author: purinda (purinda@gmail.com)
  *
- *  Patched for filedescriptor catching and error control by L Diaz 2018
  */
-
+#include <linux/gpio.h>
 #include "gpio.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <sys/stat.h>
+#include <unistd.h>    // close()
+#include <fcntl.h>     // open()
+#include <sys/ioctl.h> // ioctl()
 
-std::map<int, GPIOfdCache_t> GPIO::cache;
+const char* dev_name = "/dev/gpiochip4";
 
 GPIO::GPIO()
 {
@@ -29,150 +23,80 @@ GPIO::~GPIO()
 
 void GPIO::open(int port, int DDR)
 {
-    FILE* f;
-    f = fopen("/sys/class/gpio/export", "w");
-    if (f == NULL) {
-        throw GPIOException("can't export GPIO pin .check access rights");
-    }
-    fprintf(f, "%d\n", port);
-    fclose(f);
-
-    int counter = 0;
-    char file[128];
-    sprintf(file, "/sys/class/gpio/gpio%d/direction", port);
-
-    while ((f = fopen(file, "w")) == NULL) { //Wait 10 seconds for the file to be accessible if not open on first attempt
-        sleep(1);
-        counter++;
-        if (counter > 10) {
-            throw GPIOException("can't access /sys/class/gpio/gpio%d/direction GPIO pin. check access rights");
-            /*perror("Could not open /sys/class/gpio/gpio%d/direction");
-            exit(0); */
-        }
-    }
-    int l = (DDR == 0) ? fprintf(f, "in\n") : fprintf(f, "out\n");
-    if (!(l == 3 || l == 4)) {
-        fclose(f);
-        throw GPIOException("can't set direction on GPIO pin. check access rights");
-    }
-    /*
-    if (DDR == 0)
-        fprintf(f, "in\n");
-    else
-        printf(f, "out\n");
-    */
-    fclose(f);
-
-    // Caches the GPIO descriptor;
-    sprintf(file, "/sys/class/gpio/gpio%d/value", port);
-    int flags = (DDR == 0) ? O_RDONLY : O_WRONLY;
-    int fd = ::open(file, flags);
-    if (fd < 0) {
-        throw GPIOException("Can't open the GPIO");
+    int fd;
+    fd = ::open(dev_name, O_RDONLY);
+    if (fd >= 0) {
+        ::close(fd);
     }
     else {
-        cache[port] = fd; // cache the fd;
-        lseek(fd, SEEK_SET, 0);
+        dev_name = "/dev/gpiochip0";
+        fd = ::open(dev_name, O_RDONLY);
+        if (fd >= 0) {
+            ::close(fd);
+        }
+        else {
+            throw GPIOException("can't open /dev/gpiochip");
+        }
     }
 }
 
 void GPIO::close(int port)
 {
-    std::map<int, GPIOfdCache_t>::iterator i;
-    i = cache.find(port);
-    if (i != cache.end()) {
-        close(i->second); // close the cached fd
-        cache.erase(i);   // Delete cache entry
-    }
-    // Do unexport
-    FILE* f;
-    f = fopen("/sys/class/gpio/unexport", "w");
-    if (f != NULL) {
-        fprintf(f, "%d\n", port);
-        fclose(f);
-    }
 }
 
 int GPIO::read(int port)
 {
-    std::map<int, GPIOfdCache_t>::iterator i;
-    int fd;
-    i = cache.find(port);
-    if (i == cache.end()) { // Fallback to open the gpio
-        GPIO::open(port, GPIO::DIRECTION_IN);
-        i = cache.find(port);
-        if (i == cache.end()) {
-            throw GPIOException("can't access to GPIO");
+
+    struct gpiohandle_request rq;
+    struct gpiohandle_data data;
+    int fd, ret;
+    fd = ::open(dev_name, O_RDONLY);
+    if (fd >= 0) {
+        rq.lineoffsets[0] = port;
+        rq.flags = GPIOHANDLE_REQUEST_INPUT;
+        rq.lines = 1;
+        ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &rq);
+        if (ret == -1) {
+            throw GPIOException("Can't get line handle from IOCTL");
+            return ret;
         }
-        else {
-            fd = i->second;
+        ::close(fd);
+        ret = ioctl(rq.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
+        if (ret == -1) {
+            throw GPIOException("Can't get line value from IOCTL");
+            return ret;
         }
+        ::close(rq.fd);
+        return data.values[0];
     }
-    else {
-        fd = i->second;
-    }
-
-    char c;
-    if (lseek(fd, 0, SEEK_SET) == 0 && ::read(fd, &c, 1) == 1) {
-        return (c == '0') ? 0 : 1;
-    }
-    else {
-        throw GPIOException("can't access to GPIO");
-    }
-
-    /*
-    FILE *f;
-
-    char file[128];
-    sprintf(file, "/sys/class/gpio/gpio%d/value", port);
-    f = fopen(file, "r");
-
-    int i;
-    fscanf(f, "%d", &i);
-    fclose(f);
-    return i;
-    */
+    return -1;
 }
 
 void GPIO::write(int port, int value)
 {
-    std::map<int, GPIOfdCache_t>::iterator i;
-    int fd;
-    i = cache.find(port);
-    if (i == cache.end()) { // Fallback to open the gpio
-        GPIO::open(port, GPIO::DIRECTION_OUT);
-        i = cache.find(port);
-        if (i == cache.end()) {
-            throw GPIOException("can't access to GPIO");
-        }
-        else {
-            fd = i->second;
-        }
-    }
-    else {
-        fd = i->second;
-    }
 
-    if (lseek(fd, 0, SEEK_SET) != 0) {
-        throw GPIOException("can't access to GPIO");
+    struct gpiohandle_request rq;
+    struct gpiohandle_data data;
+    int fd, ret;
+    fd = ::open(dev_name, O_RDONLY);
+    if (fd < 0) {
+        throw GPIOException("Can't open dev");
+        return;
     }
-    int l = (value == 0) ? ::write(fd, "0\n", 2) : ::write(fd, "1\n", 2);
-    if (l != 2) {
-        throw GPIOException("can't access to GPIO");
+    rq.lineoffsets[0] = port;
+    rq.flags = GPIOHANDLE_REQUEST_OUTPUT;
+    rq.lines = 1;
+    ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &rq);
+    if (ret == -1) {
+        throw GPIOException("Can't get line handle from IOCTL");
+        return;
     }
-
-    /*
-    FILE *f;
-
-    char file[128];
-    sprintf(file, "/sys/class/gpio/gpio%d/value", port);
-    f = fopen(file, "w");
-
-    if (value == 0)
-        fprintf(f, "0\n");
-    else
-        fprintf(f, "1\n");
-
-    fclose(f);
-    */
+    ::close(fd);
+    data.values[0] = value;
+    ret = ioctl(rq.fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, &data);
+    if (ret == -1) {
+        throw GPIOException("Can't set line value from IOCTL");
+        return;
+    }
+    ::close(rq.fd);
 }

utility/SPIDEV/gpio.h

@@ -52,8 +52,6 @@ class GPIO
     virtual ~GPIO();
 
 private:
-    /* fd cache */
-    static std::map<int, GPIOfdCache_t> cache;
 };
 
 #endif // RF24_UTILITY_SPIDEV_GPIO_H_