drmtest

1 files changed, 208 insertions, 0 deletions

diff --git a/drmtest.c b/drmtest.c
new file mode 100644
index 0000000..dd05f49
--- /dev/null
+++ b/drmtest.c
@@ -0,0 +1,208 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <inttypes.h>
+#include <getopt.h>
+
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+/* ------------------------------------------------------------------ */
+
+/* device */
+static int fd;
+static drmModeConnector *conn = NULL;
+static drmModeEncoder *enc = NULL;
+static drmModeCrtc *scrtc = NULL;
+
+/* dumb fb */
+static struct drm_mode_create_dumb creq;
+static uint32_t fb_id;
+static uint8_t *fbmem;
+
+static void drm_init_dev(int devnr, bool need_dumb, bool need_master)
+{
+    drmModeRes *res;
+    char dev[64];
+    int i, rc;
+    uint64_t has_dumb;
+
+    /* open device */
+    snprintf(dev, sizeof(dev), DRM_DEV_NAME, DRM_DIR_NAME, devnr);
+    fd = open(dev, O_RDWR);
+    if (fd < 0) {
+        fprintf(stderr, "open %s: %s\n", dev, strerror(errno));
+        exit(1);
+    }
+
+    if (need_dumb) {
+        rc = drmGetCap(fd, DRM_CAP_DUMB_BUFFER, &has_dumb);
+        if (rc < 0 || !has_dumb) {
+            fprintf(stderr, "no dumb buffer support\n");
+            exit(1);
+        }
+    }
+    if (need_master) {
+        rc = drmSetMaster(fd);
+        if (rc < 0 || !has_dumb) {
+            fprintf(stderr, "drmSetMaster() failed, X11 running?\n");
+            exit(1);
+        }
+    }
+
+    /* find connector (using first for now) */
+    res = drmModeGetResources(fd);
+    if (res == NULL) {
+        fprintf(stderr, "drmModeGetResources() failed\n");
+        exit(1);
+    }
+    for (i = 0; i < res->count_connectors; i++) {
+        conn = drmModeGetConnector(fd, res->connectors[i]);
+        if (conn &&
+            (conn->connection == DRM_MODE_CONNECTED) &&
+            conn->count_modes)
+            break;
+        drmModeFreeConnector(conn);
+        conn = NULL;
+    }
+    if (!conn) {
+        fprintf(stderr, "no usable connector found\n");
+        exit(1);
+    }
+    enc = drmModeGetEncoder(fd, conn->encoder_id);
+    if (enc == NULL) {
+        fprintf(stderr, "drmModeGetEncoder() failed\n");
+        exit(1);
+    }
+
+    /* save crtc */
+    scrtc = drmModeGetCrtc(fd, enc->crtc_id);
+}
+
+static void drm_fini_dev(void)
+{
+    /* restore crtc */
+    if (scrtc) {
+        drmModeSetCrtc(fd, scrtc->crtc_id, scrtc->buffer_id, scrtc->x, scrtc->y,
+                       &conn->connector_id, 1, &scrtc->mode);
+    }
+}
+
+static void drm_init_dumb_fb(void)
+{
+    struct drm_mode_map_dumb mreq;
+    int rc;
+
+    /* create framebuffer */
+    memset(&creq, 0, sizeof(creq));
+    creq.width = conn->modes[0].hdisplay;
+    creq.height = conn->modes[0].vdisplay;
+    creq.bpp = 32;
+    rc = drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &creq);
+    if (rc < 0) {
+        fprintf(stderr, "DRM_IOCTL_MODE_CREATE_DUMB: %s\n", strerror(errno));
+        exit(1);
+    }
+    rc = drmModeAddFB(fd, creq.width, creq.height, 24, 32, creq.pitch,
+                      creq.handle, &fb_id);
+    if (rc < 0) {
+        fprintf(stderr, "drmModeAddFB() failed\n");
+        exit(1);
+    }
+
+    /* map framebuffer */
+    memset(&mreq, 0, sizeof(mreq));
+    mreq.handle = creq.handle;
+    rc = drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &mreq);
+    if (rc < 0) {
+        fprintf(stderr, "DRM_IOCTL_MODE_MAP_DUMB: %s\n", strerror(errno));
+        exit(1);
+    }
+    fbmem = mmap(0, creq.size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, mreq.offset);
+    if (fbmem == MAP_FAILED) {
+        fprintf(stderr, "framebuffer mmap: %s\n", strerror(errno));
+        exit(1);
+    }
+}
+
+static void drm_draw_dumb_fb(void)
+{
+    int x, y;
+    uint8_t *ptr;
+
+    for (y = 0; y < creq.height; y++) {
+        for (x = 0; x < creq.width; x++) {
+            ptr = fbmem + creq.pitch * y + 4 * x;
+            ptr[0] = 0;         /* blue  */
+            ptr[1] = x & 0xff;  /* green */
+            ptr[2] = y & 0xff;  /* red   */
+            ptr[3] = 0;         /* alpha */
+        }
+    }
+    drmModeDirtyFB(fd, fb_id, 0, 0);
+}
+
+static void drm_show_dumb_fb(void)
+{
+    int rc;
+
+    rc = drmModeSetCrtc(fd, enc->crtc_id, fb_id, 0, 0,
+                        &conn->connector_id, 1,
+                        &conn->modes[0]);
+    if (rc < 0) {
+        fprintf(stderr, "drmModeSetCrtc() failed\n");
+        exit (1);
+    }
+}
+
+/* ------------------------------------------------------------------ */
+
+static void usage(FILE *fp)
+{
+    fprintf(fp,
+            "\n"
+            "usage: drmtest [ options ]\n"
+            "\n"
+            "options:\n"
+            "  -h         print this\n"
+            "  -c <nr>    pick card\n"
+            "\n");
+}
+
+int main(int argc, char **argv)
+{
+    int card = 0;
+    int c;
+
+    for (;;) {
+        c = getopt(argc, argv, "hc:");
+        if (c == -1)
+            break;
+        switch (c) {
+        case 'c':
+            card = atoi(optarg);
+            break;
+        case 'h':
+            usage(stdout);
+            exit(0);
+        default:
+            usage(stderr);
+            exit(1);
+        }
+    }
+
+    drm_init_dev(card, true, true);
+    drm_init_dumb_fb();
+    drm_draw_dumb_fb();
+    drm_show_dumb_fb();
+    sleep(3);
+    drm_fini_dev();
+    return 0;
+}