check kernel version before enabling the gipo 3 chipenable pins

slsDetectorServers/slsDetectorServer/include/blackfin.h

@@ -105,3 +105,7 @@ uint32_t *Blackfin_getBaseAddress();
  * Map FPGA
  */
 int mapCSP0(void);
+
+/** check kernel version against expected version string (complain if too old)
+ * @returns OK or FAIL */
+int blackfin_checkKernelVersion(char *expectedVersion);

slsDetectorServers/slsDetectorServer/src/blackfin.c

@@ -3,11 +3,14 @@
 #include "blackfin.h"
 #include "RegisterDefs.h"
 #include "clogger.h"
+#include "common.h"
 #include "sls/ansi.h"
 #include "sls/sls_detector_defs.h"
 
-#include <fcntl.h>    // open
+#include <fcntl.h> // open
-#include <sys/mman.h> // mmap
+#include <string.h>
+#include <sys/mman.h>    // mmap
+#include <sys/utsname.h> // uname
 
 /* global variables */
 u_int32_t *csp0base = 0;
@@ -127,3 +130,49 @@ int mapCSP0(void) {
 }
 
 uint32_t *Blackfin_getBaseAddress() { return csp0base; }
+
+int blackfin_checkKernelVersion(char *expectedVersion) {
+    // extract kernel date string
+    struct utsname buf;
+    if (uname(&buf) == -1) {
+        LOG(logERROR, ("Could not get kernel version\n"));
+        return FAIL;
+    }
+
+    // remove first word (#version number)
+    const char *ptr = strchr(buf.version, ' ');
+    if (ptr == NULL) {
+        LOG(logERROR, ("Could not parse kernel version\n"));
+        return FAIL;
+    }
+    char output[256];
+    memset(output, 0, 256);
+    strcpy(output, buf.version + (ptr - buf.version + 1));
+
+    // convert kernel date string into time
+    time_t kernelDate;
+    if (GetTimeFromString(output, &kernelDate) == FAIL) {
+        LOG(logERROR, ("Could not parse retrieved kernel date, %s\n", output));
+        return FAIL;
+    }
+
+    // convert expected date into time
+    time_t expDate;
+    if (GetTimeFromString(expectedVersion, &expDate) == FAIL) {
+        LOG(logERROR,
+            ("Could not parse expected kernel date, %s\n", expectedVersion));
+        return FAIL;
+    }
+
+    // compare if kernel time is older than expected time
+    if (kernelDate < expDate) {
+        LOG(logERROR, ("Kernel Version Incompatible (too old)! Expected: [%s], "
+                       "Got [%s]\n",
+                       expectedVersion, output));
+        return FAIL;
+    }
+
+    LOG(logINFOBLUE, ("Kernel Version Compatible: %s [min.: %s]\n", output,
+                      expectedVersion));
+    return OK;
+}

slsDetectorServers/slsDetectorServer/src/programFpgaBlackfin.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: LGPL-3.0-or-other
 // Copyright (C) 2021 Contributors to the SLS Detector Package
 #include "programFpgaBlackfin.h"
+#include "blackfin.h"
 #include "clogger.h"
 #include "common.h"
 #include "sls/ansi.h"
@@ -24,21 +25,33 @@ int gpioDefined = 0;
 
 extern int executeCommand(char *command, char *result, enum TLogLevel level);
 
+int latestKernelVerified = -1;
+#define KERNEL_DATE_VRSN "Fri Oct 29 13:58:38 CEST 2021"
+
 void defineGPIOpins() {
 #ifdef VIRTUAL
     return;
 #endif
+    if (latestKernelVerified == -1) {
+        latestKernelVerified =
+            ((OK == blackfin_checkKernelVersion(KERNEL_DATE_VRSN)) ? 1 : 0);
+    }
     if (!gpioDefined) {
         // define the gpio pins
         system("echo 7 > /sys/class/gpio/export");
         system("echo 9 > /sys/class/gpio/export");
-        // gpio 3 = not chip enable
+
-        system("echo 3 > /sys/class/gpio/export");
         // define their direction
         system("echo in  > /sys/class/gpio/gpio7/direction");
         system("echo out > /sys/class/gpio/gpio9/direction");
-        system("echo out > /sys/class/gpio/gpio3/direction");
         LOG(logINFO, ("gpio pins defined\n"));
+
+        if (latestKernelVerified == 1) {
+            // gpio 3 = not chip enable
+            system("echo 3 > /sys/class/gpio/export");
+            system("echo out > /sys/class/gpio/gpio3/direction");
+            LOG(logINFO, ("gpio pin for !ChipEnable defined\n"));
+        }
         gpioDefined = 1;
     } else
         LOG(logDEBUG1, ("gpio pins already defined earlier\n"));