drm code

2 files changed, 190 insertions, 0 deletions

diff --git a/drmtools.c b/drmtools.c
new file mode 100644
index 0000000..563aa3b
--- /dev/null
+++ b/drmtools.c
@@ -0,0 +1,188 @@
+#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>
+
+#include "gfx.h"
+#include "drmtools.h"
+
+/* ------------------------------------------------------------------ */
+
+/* device */
+static int fd;
+static drmModeConnector *conn = NULL;
+static drmModeEncoder *enc = NULL;
+static drmModeModeInfo *mode = NULL;
+static drmModeCrtc *scrtc = NULL;
+static uint32_t fb_id;
+
+/* dumb fb */
+static struct drm_mode_create_dumb creq;
+static uint8_t *fbmem;
+
+/* ------------------------------------------------------------------ */
+
+static void drm_cleanup_display(void)
+{
+    /* restore crtc */
+    if (scrtc) {
+        drmModeSetCrtc(fd, scrtc->crtc_id, scrtc->buffer_id, scrtc->x, scrtc->y,
+                       &conn->connector_id, 1, &scrtc->mode);
+    }
+}
+
+static int drm_init_dev(const char *dev)
+{
+    drmModeRes *res;
+    int i, rc;
+    uint64_t has_dumb;
+
+    /* open device */
+    fd = open(dev, O_RDWR);
+    if (fd < 0) {
+        fprintf(stderr, "drm: open %s: %s\n", dev, strerror(errno));
+        return -1;
+    }
+
+    rc = drmGetCap(fd, DRM_CAP_DUMB_BUFFER, &has_dumb);
+    if (rc < 0 || !has_dumb) {
+        fprintf(stderr, "drm: no dumb buffer support\n");
+        return -1;
+    }
+
+    /* find connector (using first for now) */
+    res = drmModeGetResources(fd);
+    if (res == NULL) {
+        fprintf(stderr, "drm: drmModeGetResources() failed\n");
+        return -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, "drm: no usable connector found\n");
+        return -1;
+    }
+    mode = &conn->modes[0];
+    enc = drmModeGetEncoder(fd, conn->encoder_id);
+    if (enc == NULL) {
+        fprintf(stderr, "drm: drmModeGetEncoder() failed\n");
+        return -1;
+    }
+
+    /* save crtc */
+    scrtc = drmModeGetCrtc(fd, enc->crtc_id);
+    return 0;
+}
+
+static int drm_init_fb(void)
+{
+    struct drm_mode_map_dumb mreq;
+    int rc;
+
+    /* create framebuffer */
+    memset(&creq, 0, sizeof(creq));
+    creq.width = mode->hdisplay;
+    creq.height = mode->vdisplay;
+    creq.bpp = 32;
+    rc = drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &creq);
+    if (rc < 0) {
+        fprintf(stderr, "drm: DRM_IOCTL_MODE_CREATE_DUMB: %s\n", strerror(errno));
+        return -1;
+    }
+    rc = drmModeAddFB(fd, creq.width, creq.height, 24, 32, creq.pitch,
+                      creq.handle, &fb_id);
+    if (rc < 0) {
+        fprintf(stderr, "drm: drmModeAddFB() failed\n");
+        return -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: DRM_IOCTL_MODE_MAP_DUMB: %s\n", strerror(errno));
+        return -1;
+    }
+    fbmem = mmap(0, creq.size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, mreq.offset);
+    if (fbmem == MAP_FAILED) {
+        fprintf(stderr, "drm: framebuffer mmap: %s\n", strerror(errno));
+        return -1;
+    }
+    return 0;
+}
+
+static int drm_show_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, "drm: drmModeSetCrtc() failed\n");
+        return -1;
+    }
+    return 0;
+}
+
+/* ------------------------------------------------------------------ */
+
+static void drm_restore_display(void)
+{
+    drm_show_fb();
+}
+
+gfxstate *drm_init(const char *dev)
+{
+    gfxstate *gfx;
+
+    if (drm_init_dev(dev) < 0)
+        return NULL;
+    if (drm_init_fb() < 0)
+        return NULL;
+    if (drm_show_fb() < 0)
+        return NULL;
+
+    /* prepare gfx */
+    gfx = malloc(sizeof(*gfx));
+    memset(gfx, 0, sizeof(*gfx));
+
+    gfx->hdisplay        = mode->hdisplay;
+    gfx->vdisplay        = mode->vdisplay;
+    gfx->stride          = creq.pitch;
+    gfx->mem             = fbmem;
+
+    gfx->rlen            =  8;
+    gfx->glen            =  8;
+    gfx->blen            =  8;
+    gfx->tlen            =  8;
+    gfx->roff            = 16;
+    gfx->goff            =  8;
+    gfx->boff            =  0;
+    gfx->toff            = 24;
+    gfx->bits_per_pixel  = 32;
+
+    gfx->restore_display = drm_restore_display;
+    gfx->cleanup_display = drm_cleanup_display;
+
+    return gfx;
+}
diff --git a/drmtools.h b/drmtools.h
new file mode 100644
index 0000000..d778342
--- /dev/null
+++ b/drmtools.h
@@ -0,0 +1,2 @@
+gfxstate *drm_init(const char *dev);
+