update to work on recent kernels. breaks for very old Pi revisions

(v1 and early v2's)

debian/changelog

@@ -1,3 +1,9 @@
+wiringpi (2.70-3) unstable; urgency=low
+
+  * Make it work with recent kernels
+
+ -- Rafael Diniz <rafael@rhizomatica.org>  Fri, 24 Nov 2023 16:01:05 +0000
+
 wiringpi (2.70-2) unstable; urgency=low
 
   * Sync to upstream

wiringPi/wiringPi.c

@@ -748,148 +748,13 @@ static void piGpioLayoutOops (const char *why)
 
 int piGpioLayout (void)
 {
-  FILE *cpuFd ;
-  char line [120] ;
-  char *c ;
   static int  gpioLayout = -1 ;
 
   if (gpioLayout != -1)	// No point checking twice
     return gpioLayout ;
 
-// The "/proc/device-tree/compatible" file consists of a sequence of
-// NUL-terminated strings. We expect to find brcm,bcm283[765] on pi platforms
-
-  if ((cpuFd = fopen ("/proc/device-tree/compatible", "r")) != NULL) {
-    size_t linelen;
-    linelen = fread(line, 1, sizeof(line), cpuFd);
-    fclose(cpuFd);
-    cpuFd = NULL;
-    line[linelen] = '\0';
-    c = line;
-    while ((size_t)(c - line) < linelen) {
-      if ((strncmp(c, "brcm,bcm2837", strlen(c)) == 0) ||
-          (strncmp(c, "brcm,bcm2836", strlen(c)) == 0)) {
-        gpioLayout = 2;
-        if (wiringPiDebug)
-          printf ("piGpioLayoutOops: Returning revision: %d\n", gpioLayout) ;
-        return gpioLayout;
-      }
-      c += strlen(c) + 1;
-    }
-  }
-
-  if ((cpuFd = fopen ("/proc/cpuinfo", "r")) == NULL)
-    piGpioLayoutOops ("Unable to open /proc/device-tree/compatible or /proc/cpuinfo") ;
-
-// Start by looking for the Architecture to make sure we're really running
-//	on a Pi. I'm getting fed-up with people whinging at me because
-//	they can't get it to work on weirdFruitPi boards...
-
-  while (fgets (line, 120, cpuFd) != NULL)
-    if (strncmp (line, "Hardware", 8) == 0)
-      break ;
-
-  if (strncmp (line, "Hardware", 8) != 0)
-    piGpioLayoutOops ("No \"Hardware\" line") ;
-
-  if (wiringPiDebug)
-    printf ("piGpioLayout: Hardware: %s\n", line) ;
-
-// See if it's BCM2708 or BCM2709 or the new BCM2835.
-
-// OK. As of Kernel 4.8,  we have BCM2835 only, regardless of model.
-//	However I still want to check because it will trap the cheapskates and rip-
-//	off merchants who want to use wiringPi on non-Raspberry Pi platforms - which
-//	I do not support so don't email me your bleating whinges about anything
-//	other than a genuine Raspberry Pi.
-
-#ifdef	DONT_CARE_ANYMORE
-  if (! (strstr (line, "BCM2708") || strstr (line, "BCM2709") || strstr (line, "BCM2835")))
-  {
-    fprintf (stderr, "Unable to determine hardware version. I see: %s,\n", line) ;
-    fprintf (stderr, " - expecting BCM2708, BCM2709 or BCM2835.\n") ;
-    fprintf (stderr, "If this is a genuine Raspberry Pi then please report this\n") ;
-    fprintf (stderr, "at GitHub.com/wiringPi/wiringPi. If this is not a Raspberry Pi then you\n") ;
-    fprintf (stderr, "are on your own as wiringPi is designed to support the\n") ;
-    fprintf (stderr, "Raspberry Pi ONLY.\n") ;
-    exit (EXIT_FAILURE) ;
-  }
-#endif
-
-// Actually... That has caused me more than 10,000 emails so-far. Mosty by
-//	people who think they know better by creating a statically linked
-//	version that will not run with a new 4.9 kernel. I utterly hate and
-//	despise those people.
-//
-//	I also get bleats from people running other than Raspbian with another
-//	distros compiled kernel rather than a foundation compiled kernel, so
-//	this might actually help them. It might not - I only have the capacity
-//	to support Raspbian.
-//
-//	However, I've decided to leave this check out and rely purely on the
-//	Revision: line for now. It will not work on a non-pi hardware or weird
-//	kernels that don't give you a suitable revision line.
-
-// So - we're Probably on a Raspberry Pi. Check the revision field for the real
-//	hardware type
-//	In-future, I ought to use the device tree as there are now Pi entries in
-//	/proc/device-tree/ ...
-//	but I'll leave that for the next revision. Or the next.
-
-// Isolate the Revision line
-
-  rewind (cpuFd) ;
-  while (fgets (line, 120, cpuFd) != NULL)
-    if (strncmp (line, "Revision", 8) == 0)
-      break ;
-
-  fclose (cpuFd) ;
-
-  if (strncmp (line, "Revision", 8) != 0)
-    piGpioLayoutOops ("No \"Revision\" line") ;
-
-// Chomp trailing CR/NL
-
-  for (c = &line [strlen (line) - 1] ; (*c == '\n') || (*c == '\r') ; --c)
-    *c = 0 ;
-
-  if (wiringPiDebug)
-    printf ("piGpioLayout: Revision string: %s\n", line) ;
-
-// Scan to the first character of the revision number
-
-  for (c = line ; *c ; ++c)
-    if (*c == ':')
-      break ;
-
-  if (*c != ':')
-    piGpioLayoutOops ("Bogus \"Revision\" line (no colon)") ;
-
-// Chomp spaces
-
-  ++c ;
-  while (isspace (*c))
-    ++c ;
-
-  if (!isxdigit (*c))
-    piGpioLayoutOops ("Bogus \"Revision\" line (no hex digit at start of revision)") ;
-
-// Make sure its long enough
-
-  if (strlen (c) < 4)
-    piGpioLayoutOops ("Bogus revision line (too small)") ;
-
-// Isolate  last 4 characters: (in-case of overvolting or new encoding scheme)
-
-  c = c + strlen (c) - 4 ;
-
-  if (wiringPiDebug)
-    printf ("piGpioLayout: last4Chars are: \"%s\"\n", c) ;
-
-  if ( (strcmp (c, "0002") == 0) || (strcmp (c, "0003") == 0))
-    gpioLayout = 1 ;
-  else
-    gpioLayout = 2 ;	// Covers everything else from the B revision 2 to the B+, the Pi v2, v3, zero and CM's.
+  // set gpioLayout = 1 for very old Pis, like v1 and v2 early revisions
+  gpioLayout = 2 ;
 
   if (wiringPiDebug)
     printf ("piGpioLayoutOops: Returning revision: %d\n", gpioLayout) ;