sketch uio

kernel_module/user/uio_read.c

@@ -0,0 +1,46 @@
+/*
+Adapted from: https://yurovsky.github.io/2014/10/10/linux-uio-gpio-interrupt/
+
+    modprobe uio_pdrv_genirq
+
+TODO get working.
+
+Handle interrupts from userland and print a message to stdout.
+*/
+
+#define _XOPEN_SOURCE 700
+#include <fcntl.h> /* open */
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h> /* write */
+
+int main(int argc, char **argv)
+{
+
+    char *dev;
+    if (argc < 2) {
+    }
+    int fd = open("/dev/uio", O_RDWR);
+    if (fd < 0) {
+        perror("open");
+        exit(EXIT_FAILURE);
+    }
+    while (1) {
+        uint32_t info = 1;
+        size_t nb = write(fd, &info, sizeof(info));
+        if (nb < sizeof(info)) {
+            perror("write");
+            close(fd);
+            exit(EXIT_FAILURE);
+        }
+        nb = read(fd, &info, sizeof(info));
+        if (nb == sizeof(info)) {
+            printf("Interrupt #%u\n", info);
+        }
+    }
+    close(fd);
+    exit(EXIT_SUCCESS);
+}