add prime.c

1 files changed, 96 insertions, 0 deletions

diff --git a/prime.c b/prime.c
new file mode 100644
index 0000000..8a11656
--- /dev/null
+++ b/prime.c
@@ -0,0 +1,96 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <inttypes.h>
+#include <getopt.h>
+#include <fcntl.h>
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include <gbm.h>
+
+/* ------------------------------------------------------------------ */
+
+int drm_init_dev(const char *devname)
+{
+    uint64_t prime, dumb;
+    int fd, rc;
+
+    /* open device */
+    fd = open(devname, O_RDWR);
+    if (fd < 0) {
+        fprintf(stderr, "open %s: %s\n", devname, strerror(errno));
+        exit(1);
+    }
+
+    rc = drmGetCap(fd, DRM_CAP_DUMB_BUFFER, &dumb);
+    if (rc < 0) {
+        fprintf(stderr, "drmGetCap(DRM_CAP_DUMB_BUFFER): %s\n", strerror(errno));
+        exit(1);
+    }
+    rc = drmGetCap(fd, DRM_CAP_PRIME, &prime);
+    if (rc < 0) {
+        fprintf(stderr, "drmGetCap(DRM_CAP_PRIME): %s\n", strerror(errno));
+        exit(1);
+    }
+
+    fprintf(stderr, "%s:\n", devname);
+    fprintf(stderr, "    dumb buffers: %s\n",
+            dumb ? "yes" : "no");
+    fprintf(stderr, "    prime import: %s\n",
+            prime & DRM_PRIME_CAP_IMPORT ? "yes" : "no");
+    fprintf(stderr, "    prime export: %s\n",
+            prime & DRM_PRIME_CAP_EXPORT ? "yes" : "no");
+
+    return fd;
+}
+
+/* ------------------------------------------------------------------ */
+
+static void usage(FILE *fp)
+{
+    fprintf(fp,
+            "\n"
+            "usage: prime [ options ]\n"
+            "\n"
+            "options:\n"
+            "  -h         print this\n"
+            "\n");
+}
+
+int main(int argc, char **argv)
+{
+    char devname[64];
+    int card, c, i;
+
+    for (;;) {
+        c = getopt(argc, argv, "h");
+        if (c == -1)
+            break;
+        switch (c) {
+        case 'h':
+            usage(stdout);
+            exit(0);
+        default:
+            usage(stderr);
+            exit(1);
+        }
+    }
+
+    for (i = 0;; i++) {
+        snprintf(devname, sizeof(devname), DRM_DEV_NAME, DRM_DIR_NAME, i);
+        if (access(devname, R_OK | W_OK) != 0)
+            break;
+        card = drm_init_dev(devname);
+        close(card);
+    }
+
+    return 0;
+}