1 files changed, 108 insertions, 0 deletions
diff --git a/src/x b/src/x
new file mode 100644
index 0000000..9f7de31
--- /dev/null
+++ b/src/x
@@ -0,0 +1,108 @@
+/*
+ * mts-wait-for-cell-reset
+ *
+ * Block signal
+ * If not in reset, exit
+ * Register with mts-io for reset
+ * If not in reset, exit
+ * Suspend process for signal
+ * If signal occurs, exit
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+const char *name = "mts-wait-for-cell-reset";
+const int RST_SIG=SIGUSR2;  // Wait for this signal
+const char *MONITOR="/sys/devices/platform/mts-io/radio-reset-monitor";
+const char *RADIO_DISCOVERY="/sys/devices/platform/mts-io/radio-udev-discovery";
+
+/* Return 0 if Cellular modem is being reset
+ * Return 1 if Cellular modem is not being reset
+ */
+int
+not_reset(const char *attr_name)
+{
+    int not_in_reset, result;
+    char buf[256];
+    int discovery;
+
+    discovery = open(attr_name,O_RDONLY);
+    if (discovery == -1) {
+        fprintf(stderr,"FAILED: %s cannot open attribute %s: %s\n",name,attr_name,strerror(errno));
+        exit(1);
+    }
+    result = read(discovery,buf,sizeof buf);
+    if (result > 0)
+        not_in_reset = atoi(buf);
+    else if (result == 0) {
+        fprintf(stderr,"FAILED: %s attribute %s has no state\n",name,attr_name);
+        exit(1);
+    } else {
+        fprintf(stderr,"FAILED: %s attribute %s error: %s\n",name,attr_name,strerror(errno));
+        exit(1);
+    }
+    close(discovery);
+    return not_in_reset;
+}
+
+void
+handler(int sig)
+{
+    /* Normal way out of this program
+     * exit not safe from signal handler so
+     * use _exit()
+     */
+    _exit(0);
+}
+
+int
+main(int argc, char *argv[])
+{
+    sigset_t blockedset,nullset;
+    int monitor;
+    int result;
+    char buf[128];
+    struct sigaction action;
+
+    memset(&action,0,sizeof action);
+    action.sa_handler = handler;
+    memset(&blockedset,0,sizeof blockedset);
+    sigaddset(&blockedset,RST_SIG);
+    memset(&nullset,0,sizeof nullset);
+
+    sigprocmask(SIG_BLOCK,&blockedset,NULL);  // Blocked RST_SIG
+
+    sigaction(RST_SIG,&action,NULL);
+
+    if (not_reset(RADIO_DISCOVERY))
+        exit(0);  // Not in reset
+    sprintf(buf,"%d %d",getpid(),RST_SIG);
+
+    monitor = open(MONITOR,O_WRONLY);
+    if (monitor == -1) {
+        fprintf(stderr,"FAILED: %s cannot open attribute %s: %s\n",name,MONITOR,strerror(errno));
+        exit(2);
+    }
+    result = write(monitor,buf,strlen(buf));
+    if(result != strlen(buf)) {
+        if (result == -1) {
+            fprintf(stderr,"FAILED: %s attribute %s write error: %s\n",name,MONITOR,strerror(errno));
+            exit(3);
+        }
+        fprintf(stderr,"FAILED: %s attribute %s incomplete write error: %d/%d\n",name,MONITOR,result,(int)strlen(buf));
+        exit(4);
+    }
+    close(monitor);
+    if (not_reset(RADIO_DISCOVERY))
+        exit(0);
+
+    sigsuspend(&nullset); // Allow all signals
+    /* NOTREACHED */
+}