wiringPi on 4th version of RaspberryPi is not working

Question

I have an RPi4.

Based on this link I need to have a version 2.52 of gpio to work properly on this device.

I have done this:

# cd /tmp
# wget https://project-downloads.drogon.net/wiringpi-latest.deb
# sudo dpkg -i wiringpi-latest.deb
# gpio -v
  gpio version: 2.46

Also, writing to GPIO is not working, all ports are logic 1 after booting.

And git.drogon.net is unavailable.

What can I do now if I need to compile a software which relies on this library..?

UPDATE

I have cloned this repository as stevieb recommended. It also has a pull request for supporting PI4 boards.

However even after applying that patch I'm not able to control the output pins of the PI4:

First get the current states of the pins:

# gpio readall
 +-----+-----+---------+------+---+---Pi 4+--+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 1 | 11 || 12 | 1 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 1 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 1 | 15 || 16 | 1 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 1 | ALT0 | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 1 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 1 | 21 || 22 | 1 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 1 | 23 || 24 | 1 | ALT4 | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 1 | ALT5 | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 1 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 1 | 35 || 36 | 1 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 1 | 37 || 38 | 1 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 1 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 4+--+---+------+---------+-----+-----+

Then set pin7 to output and check the result:

# gpio mode 7 out
# gpio readall
 +-----+-----+---------+------+---+---Pi 4+--+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |  OUT | 1 |  7 || 8  | 1 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 1 | 11 || 12 | 1 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 1 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 1 | 15 || 16 | 1 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 1 | ALT0 | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 1 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 1 | 21 || 22 | 1 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 1 | 23 || 24 | 1 | ALT4 | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 1 | ALT5 | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 1 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 1 | 35 || 36 | 1 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 1 | 37 || 38 | 1 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 1 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 4+--+---+------+---------+-----+-----+

Then write 0 to pin7 and check the result:

# gpio write 7 0
# gpio readall
 +-----+-----+---------+------+---+---Pi 4+--+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |   IN | 1 |  3 || 4  |   |      | 5v      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |  OUT | 1 |  7 || 8  | 1 | IN   | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | IN   | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 1 | 11 || 12 | 1 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 1 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 1 | 15 || 16 | 1 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 1 | ALT0 | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 1 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 1 | 21 || 22 | 1 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 1 | 23 || 24 | 1 | ALT4 | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 1 | ALT5 | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 1 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 1 | 35 || 36 | 1 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 1 | 37 || 38 | 1 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 1 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 4+--+---+------+---------+-----+-----+

As you can see every pin is at logic state 1. Measuring it with a voltage meter also confirms this. Does anyone has any idea on how can I modify the wiringPi library to be able to set the output values correctly?

Thanks

Answer 1

Gordon abandoned the Open Source side of wiringPi some time ago, and removed access to it completely.

I have reached out several times to him since then and I've yet to receive a response. I even went as far as to request paid access to his changes so that my own wrapper software can continue to work.

Apparently, you'll have to get access to the older source code and modify it yourself. There's this 'fork' of v2.46 that you could base the changes off of.

Answer 2

Do what Gordon says in this link and it works again:

cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb

Answer 3

Version 2.52 of wiringPi for Raspberry 4 (and the equivalent GPIO shell commands) helps a lot, but it does not properly implement pullUpDnControl(). As a result input-pins cannot be set to use internal pull-up/pull-down resistors.

Tested with GPIO/BCM pin 26 using

sudo raspi-gpio get | grep "GPIO 26"

shell command.

Tried to set pull-up/pull-down using:

pullUpDnControl(26, PUD_DOWN);

and

pullUpDnControl(26, PUD_UP);

under

wiringPiSetupGpio();

wiringPi setup in C.

No change reported using the "raspi-gpio" shell command.

Since the issue was a static setup failure for me, rather than give up on wiringPi completely I implemented a kludge work around. Since I could not get the equivalent GPIO shell command to work (for the same reason (as it is part of the wiringPi suite)), but Python has been maintained and works, I imbedded equivalent Python pin setup code in C, and thought it might be useful for someone (to keep wiringPi working through Raspberry Pi 4).

For those who might find this useful, here's test code. A 3-LED Cylon. LEDs attached to (resistor-buffered (200OHM)) ground on one end and each to a different pin (16, 20, and 21) on the other). A switch to ground on one end and pin 26 on the other. When the switch is pressed, the Cylon display turns into a glare from all 3 LEDs until the switch is released. Pin numbers are in the BCM series, shown by the shell command "gpio readall".

/* 3-LED Cylon testbed. Embedded Python GPIO pin setup code
 * as a workaround to wiringPi v2.52 pullUpDnControl() bug.
 * Send setup code to Python's stdin, as a short-lived child process.
 * Sends Python equivalent to pullUpDnControl(26, PUD_UP); keeping
 * the pin number (26) as a C #define.
 * Use as needed.
 * Alen Shapiro June 2020
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <wiringPi.h>

/* on */
#define FIX_GPIO    1   // replace pullUpDnControl on Raspberry Pi 4. Use Python as GPIO in the shell fails too */

#define MICRO_SLEEP (100*1000) /* 100 microseconds */
#define LOW         0
#define HIGH        1

     /*   BCM: gpio -g // wPi // Phys: gpio -1 */
#define LED1        16 // 27  // 36
#define LED2        20 // 28  // 38
#define LED3        21 // 29  // 40
#define PRESS       26 // 25  // 37

#if defined(FIX_GPIO)
struct fixGPIO {
    char *pyLine;
    int pin;
} fixGPIO[] = { // feed a three-argument fprintf() to popen() (so #define pins can be passed (one per line))
    { "import RPi.GPIO as GPIO\n", 0},
    { "GPIO.setmode(GPIO.BCM)\n", 0},
    { "GPIO.setwarnings(False)\n", 0},
    { "GPIO.setup(%d, GPIO.IN, pull_up_down=GPIO.PUD_UP)\n", PRESS},
    { (char *)NULL, 0}
};
FILE *pythonStream;
#endif /* defined(FIX_GPIO) */

int
main(void) {
    int i;

    wiringPiSetupGpio();
    //wiringPiSetupPhys();

    printf("Raspberry Pi 4 - direct Cylon Test\n");
    pinMode(LED1, OUTPUT);
    pinMode(LED2, OUTPUT);
    pinMode(LED3, OUTPUT);
    pinMode(PRESS, INPUT);
#if defined(FIX_GPIO)
    if((pythonStream=popen("python", "w")) == NULL) {
        fprintf(stderr, "Can't run python to set pin mode\n");
        exit(1);
    }
    for(i=0 ; fixGPIO[i].pyLine ; i++)
        fprintf(pythonStream, fixGPIO[i].pyLine, fixGPIO[i].pin);
    pclose(pythonStream);
#else /* defined(FIX_GPIO) */
    pullUpDnControl(PRESS, PUD_UP); /* fails on RPi-4 (as does shell GPIO) */
#endif /* defined(FIX_GPIO) */

    while(1) {
        if(digitalRead(PRESS) == LOW) { // Glaring Cylon
            digitalWrite(LED1, HIGH);
            digitalWrite(LED2, HIGH);
            digitalWrite(LED3, HIGH);
            usleep(MICRO_SLEEP);
        }
        else { // Happy Cylon
            digitalWrite(LED1, HIGH);
            digitalWrite(LED2, LOW);
            digitalWrite(LED3, LOW);
            usleep(MICRO_SLEEP);

            digitalWrite(LED1, LOW);
            digitalWrite(LED2, HIGH);
            //digitalWrite(LED3, LOW);
            usleep(MICRO_SLEEP);

            //digitalWrite(LED1, LOW);
            digitalWrite(LED2, LOW);
            digitalWrite(LED3, HIGH);
            usleep(MICRO_SLEEP);

            //digitalWrite(LED1, LOW);
            digitalWrite(LED2, HIGH);
            digitalWrite(LED3, LOW);
            usleep(MICRO_SLEEP);
        }
    }
}

Compiled with this Makefile:

CC=gcc
CLIBS= -lwiringPi

cylon: cylon.o
    $(CC) -o cylon cylon.o $(CLIBS)

Here's a short live-photo of the Cylon testbed in action, ignore the Arduino which is just monitoring GPIO pin voltages (thanks John in Canada):

https://i.stack.imgur.com/IuoUV.jpg

ASIDE: Gordon... I'm sorry you've been put through the wringer by the lower end of a Gaussian Curve of people (just a tail, honest), and hope you're coming out the other end with sanity and health intact.

Answer 4

Although WiringPi is discontinued, there was an unofficial patch.

(Open-source is hard to kill, others will continue it.)

Tested, and GPIO worked great on my RaspberryPi4 after applying that.

Patch:

diff -ruN wiringPi/wiringPi.c wiringPi/wiringPi.c
--- wiringPi/wiringPi.c
+++ wiringPi/wiringPi.c
@@ -215,6 +215,7 @@ volatile unsigned int *_wiringPiTimerIrqRaw ;
 
 #define    GPIO_PERI_BASE_OLD  0x20000000
 #define    GPIO_PERI_BASE_NEW  0x3F000000
+#define    GPIO_PERI_BASE_RP4  0xFE000000
 
 static volatile unsigned int piGpioBase = 0 ;
 
@@ -547,6 +548,10 @@ static uint8_t gpioToPUDCLK [] =
   39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,39,
 } ;
 
+#define PULLUPDN_OFFSET_2711_0      57
+#define PULLUPDN_OFFSET_2711_1      58
+#define PULLUPDN_OFFSET_2711_2      59
+#define PULLUPDN_OFFSET_2711_3      60
 
 // gpioToPwmALT
 // the ALT value to put a GPIO pin into PWM mode
@@ -814,7 +819,7 @@ int piGpioLayout (void)
 
   for (c = &line [strlen (line) - 1] ; (*c == '\n') || (*c == '\r') ; --c)
     *c = 0 ;
-  
+
   if (wiringPiDebug)
     printf ("piGpioLayout: Revision string: %s\n", line) ;
 
@@ -883,7 +888,7 @@ int piBoardRev (void)
  * So the distinction between boards that I can see is:
  *
  *     0000 - Error
- *     0001 - Not used 
+ *     0001 - Not used
  *
  * Original Pi boards:
  *     0002 - Model B,  Rev 1,   256MB, Egoman
@@ -955,6 +960,30 @@ void piBoardId (int *model, int *rev, int *mem, int *maker, int *warranty)
   if ((cpuFd = fopen ("/proc/cpuinfo", "r")) == NULL)
     piGpioLayoutOops ("Unable to open /proc/cpuinfo") ;
 
+  char buffer[12] ;
+  const char *ranges_file = "/proc/device-tree/soc/ranges" ;
+  int info_fd = open(ranges_file, O_RDONLY) ;
+
+  if (info_fd < 0) {
+    fprintf(stderr, "cannot open: %s", ranges_file) ;
+    exit (EXIT_FAILURE) ;
+  }
+
+  ssize_t n = read(info_fd, buffer, sizeof(buffer)) ;
+  close(info_fd) ;
+
+  if (n < 8) {
+    fprintf(stderr, "cannot read base address: %s", ranges_file) ;
+    exit (EXIT_FAILURE) ;
+  }
+
+  uint32_t gpio_base =  (buffer[4] << 24) + (buffer[5] << 16) + (buffer[6] << 8) + (buffer[7] << 0) ;
+
+  if (!gpio_base)
+  {
+    gpio_base = (buffer[8] << 24) + (buffer[9] << 16) + (buffer[10] << 8) + (buffer[11] << 0) ;
+  }
+
   while (fgets (line, 120, cpuFd) != NULL)
     if (strncmp (line, "Revision", 8) == 0)
       break ;
@@ -968,7 +997,7 @@ void piBoardId (int *model, int *rev, int *mem, int *maker, int *warranty)
 
   for (c = &line [strlen (line) - 1] ; (*c == '\n') || (*c == '\r') ; --c)
     *c = 0 ;
-  
+
   if (wiringPiDebug)
     printf ("piBoardId: Revision string: %s\n", line) ;
 
@@ -1007,7 +1036,7 @@ void piBoardId (int *model, int *rev, int *mem, int *maker, int *warranty)
     bMfg      = (revision & (0x0F << 16)) >> 16 ;
     bMem      = (revision & (0x07 << 20)) >> 20 ;
     bWarranty = (revision & (0x03 << 24)) != 0 ;
-    
+
     *model    = bType ;
     *rev      = bRev ;
     *mem      = bMem ;
@@ -1034,7 +1063,7 @@ void piBoardId (int *model, int *rev, int *mem, int *maker, int *warranty)
 // If longer than 4, we'll assume it's been overvolted
 
     *warranty = strlen (c) > 4 ;
-  
+
 // Extract last 4 characters:
 
     c = c + strlen (c) - 4 ;
@@ -1073,8 +1102,11 @@ void piBoardId (int *model, int *rev, int *mem, int *maker, int *warranty)
 
     else                              { *model = 0           ; *rev = 0              ; *mem =   0 ; *maker = 0 ;               }
   }
+  if (gpio_base == GPIO_PERI_BASE_RP4) {
+    *model = PI_MODEL_4;
+  }
 }
- 
+
 
 
 /*
@@ -1205,6 +1237,10 @@ void pwmSetRange (unsigned int range)
 void pwmSetClock (int divisor)
 {
   uint32_t pwm_control ;
+
+  if(piGpioBase == GPIO_PERI_BASE_RP4) {
+    divisor = 540*divisor/192;
+  }
   divisor &= 4095 ;
 
   if ((wiringPiMode == WPI_MODE_PINS) || (wiringPiMode == WPI_MODE_PHYS) || (wiringPiMode == WPI_MODE_GPIO))
@@ -1260,7 +1296,7 @@ void gpioClockSet (int pin, int freq)
     pin = physToGpio [pin] ;
   else if (wiringPiMode != WPI_MODE_GPIO)
     return ;
-  
+
   divi = 19200000 / freq ;
   divr = 19200000 % freq ;
   divf = (int)((double)divr * 4096.0 / 19200000.0) ;
@@ -1504,11 +1540,31 @@ void pullUpDnControl (int pin, int pud)
     else if (wiringPiMode != WPI_MODE_GPIO)
       return ;
 
-    *(gpio + GPPUD)              = pud & 3 ;       delayMicroseconds (5) ;
-    *(gpio + gpioToPUDCLK [pin]) = 1 << (pin & 31) ;   delayMicroseconds (5) ;
-    
-    *(gpio + GPPUD)              = 0 ;         delayMicroseconds (5) ;
-    *(gpio + gpioToPUDCLK [pin]) = 0 ;         delayMicroseconds (5) ;
+    // Check GPIO register
+    int is2711 = *(gpio + PULLUPDN_OFFSET_2711_3) != 0x6770696f;
+    if(is2711) {
+        // Pi 4 Pull-up/down method
+        int pullreg = PULLUPDN_OFFSET_2711_0 + (pin >> 4);
+        int pullshift = (pin & 0xf) << 1;
+        unsigned int pullbits;
+        unsigned int pull = 0; // Turn PUD off by default
+        if (pud == PUD_UP) {
+            pull = 1;
+        } else if (pud == PUD_DOWN) {
+            pull = 2;
+        }
+        pullbits = *(gpio + pullreg);
+        pullbits &= ~(3 << pullshift);
+        pullbits |= (pull << pullshift);
+        *(gpio + pullreg) = pullbits;
+    } else {
+        // Legacy Pull-up/down method
+        *(gpio + GPPUD)              = pud & 3 ;       delayMicroseconds (5) ;
+        *(gpio + gpioToPUDCLK [pin]) = 1 << (pin & 31) ;   delayMicroseconds (5) ;
+
+        *(gpio + GPPUD)              = 0 ;         delayMicroseconds (5) ;
+        *(gpio + gpioToPUDCLK [pin]) = 0 ;         delayMicroseconds (5) ;
+    }
   }
   else                     // Extension module
   {
@@ -1680,7 +1736,7 @@ void pwmWrite (int pin, int value)
 
 /*
  * analogRead:
- * Read the analog value of a given Pin. 
+ * Read the analog value of a given Pin.
  * There is no on-board Pi analog hardware,
  * so this needs to go to a new node.
  *********************************************************************************
@@ -1699,7 +1755,7 @@ int analogRead (int pin)
 
 /*
  * analogWrite:
- * Write the analog value to the given Pin. 
+ * Write the analog value to the given Pin.
  * There is no on-board Pi analog hardware,
  * so this needs to go to a new node.
  *********************************************************************************
@@ -1748,7 +1804,7 @@ void pwmToneWrite (int pin, int freq)
  * Write an 8-bit byte to the first 8 GPIO pins - try to do it as
  * fast as possible.
  * However it still needs 2 operations to set the bits, so any external
- * hardware must not rely on seeing a change as there will be a change 
+ * hardware must not rely on seeing a change as there will be a change
  * to set the outputs bits to zero, then another change to set the 1's
  * Reading is just bit fiddling.
  * These are wiringPi pin numbers 0..7, or BCM_GPIO pin numbers
@@ -1804,7 +1860,7 @@ unsigned int digitalReadByte (void)
       data = (data << 1) | x ;
     }
   }
-  else 
+  else
   {
     raw = *(gpio + gpioToGPLEV [0]) ; // First bank for these pins
     for (pin = 0 ; pin < 8 ; ++pin)
@@ -1861,7 +1917,7 @@ unsigned int digitalReadByte2 (void)
       data = (data << 1) | x ;
     }
   }
-  else 
+  else
     data = ((*(gpio + gpioToGPLEV [0])) >> 20) & 0xFF ; // First bank for these pins
 
   return data ;
@@ -2265,6 +2321,9 @@ int wiringPiSetup (void)
     case PI_MODEL_ZERO:    case PI_MODEL_ZERO_W:
       piGpioBase = GPIO_PERI_BASE_OLD ;
       break ;
+  case PI_MODEL_4:
+      piGpioBase = GPIO_PERI_BASE_RP4 ;
+      break ;
 
     default:
       piGpioBase = GPIO_PERI_BASE_NEW ;
@@ -2273,7 +2332,7 @@ int wiringPiSetup (void)
 
 // Open the master /dev/ memory control device
 // Device strategy: December 2016:
-// Try /dev/mem. If that fails, then 
+// Try /dev/mem. If that fails, then
 // try /dev/gpiomem. If that fails then game over.
 
   if ((fd = open ("/dev/mem", O_RDWR | O_SYNC | O_CLOEXEC)) < 0)
@@ -2311,13 +2370,13 @@ int wiringPiSetup (void)
   pwm = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_PWM) ;
   if (pwm == MAP_FAILED)
     return wiringPiFailure (WPI_ALMOST, "wiringPiSetup: mmap (PWM) failed: %s\n", strerror (errno)) ;
- 
+
 // Clock control (needed for PWM)
 
   clk = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_CLOCK_BASE) ;
   if (clk == MAP_FAILED)
     return wiringPiFailure (WPI_ALMOST, "wiringPiSetup: mmap (CLOCK) failed: %s\n", strerror (errno)) ;
- 
+
 // The drive pads
 
   pads = (uint32_t *)mmap(0, BLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED, fd, GPIO_PADS) ;
@@ -2437,7 +2496,7 @@ int wiringPiSetupSys (void)
 
 // Open and scan the directory, looking for exported GPIOs, and pre-open
 // the 'value' interface to speed things up for later
-  
+
   for (pin = 0 ; pin < 64 ; ++pin)
   {
     sprintf (fName, "/sys/class/gpio/gpio%d/value", pin) ;
diff -ruN wiringPi/wiringPi.h wiringPi/wiringPi.h
--- wiringPi/wiringPi.h
+++ wiringPi/wiringPi.h
@@ -100,6 +100,7 @@
 #define    PI_MODEL_CM3        10
 #define    PI_MODEL_ZERO_W     12
 #define    PI_MODEL_3P         13
+#define    PI_MODEL_4          14
 
 #define    PI_VERSION_1        0
 #define    PI_VERSION_1_1      1

Note that the patch should be executed inside of Wiring-Pi root (outside of it's wiringPi sub-directory).

Also, this is a copy of my other answer on RaspberryPi.StackExchange.com, and is not related to https://github.com/WiringPi/WiringPi (although, they are free to apply this, too).