drm/mode: Unstatic kernel-userspace mode conversion

Move the drm_display_mode <-> drm_mode_modeinfo conversion functions
from drm_crtc.c to drm_modes.c, and make them non-static so that others
can use them.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Tested-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 213b11e..cd74a09 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1405,3 +1405,90 @@
 	return mode;
 }
 EXPORT_SYMBOL(drm_mode_create_from_cmdline_mode);
+
+/**
+ * drm_crtc_convert_to_umode - convert a drm_display_mode into a modeinfo
+ * @out: drm_mode_modeinfo struct to return to the user
+ * @in: drm_display_mode to use
+ *
+ * Convert a drm_display_mode into a drm_mode_modeinfo structure to return to
+ * the user.
+ */
+void drm_mode_convert_to_umode(struct drm_mode_modeinfo *out,
+			       const struct drm_display_mode *in)
+{
+	WARN(in->hdisplay > USHRT_MAX || in->hsync_start > USHRT_MAX ||
+	     in->hsync_end > USHRT_MAX || in->htotal > USHRT_MAX ||
+	     in->hskew > USHRT_MAX || in->vdisplay > USHRT_MAX ||
+	     in->vsync_start > USHRT_MAX || in->vsync_end > USHRT_MAX ||
+	     in->vtotal > USHRT_MAX || in->vscan > USHRT_MAX,
+	     "timing values too large for mode info\n");
+
+	out->clock = in->clock;
+	out->hdisplay = in->hdisplay;
+	out->hsync_start = in->hsync_start;
+	out->hsync_end = in->hsync_end;
+	out->htotal = in->htotal;
+	out->hskew = in->hskew;
+	out->vdisplay = in->vdisplay;
+	out->vsync_start = in->vsync_start;
+	out->vsync_end = in->vsync_end;
+	out->vtotal = in->vtotal;
+	out->vscan = in->vscan;
+	out->vrefresh = in->vrefresh;
+	out->flags = in->flags;
+	out->type = in->type;
+	strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
+	out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
+}
+
+/**
+ * drm_crtc_convert_umode - convert a modeinfo into a drm_display_mode
+ * @out: drm_display_mode to return to the user
+ * @in: drm_mode_modeinfo to use
+ *
+ * Convert a drm_mode_modeinfo into a drm_display_mode structure to return to
+ * the caller.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_mode_convert_umode(struct drm_display_mode *out,
+			   const struct drm_mode_modeinfo *in)
+{
+	int ret = -EINVAL;
+
+	if (in->clock > INT_MAX || in->vrefresh > INT_MAX) {
+		ret = -ERANGE;
+		goto out;
+	}
+
+	if ((in->flags & DRM_MODE_FLAG_3D_MASK) > DRM_MODE_FLAG_3D_MAX)
+		goto out;
+
+	out->clock = in->clock;
+	out->hdisplay = in->hdisplay;
+	out->hsync_start = in->hsync_start;
+	out->hsync_end = in->hsync_end;
+	out->htotal = in->htotal;
+	out->hskew = in->hskew;
+	out->vdisplay = in->vdisplay;
+	out->vsync_start = in->vsync_start;
+	out->vsync_end = in->vsync_end;
+	out->vtotal = in->vtotal;
+	out->vscan = in->vscan;
+	out->vrefresh = in->vrefresh;
+	out->flags = in->flags;
+	out->type = in->type;
+	strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN);
+	out->name[DRM_DISPLAY_MODE_LEN-1] = 0;
+
+	out->status = drm_mode_validate_basic(out);
+	if (out->status != MODE_OK)
+		goto out;
+
+	ret = 0;
+
+out:
+	return ret;
+}
\ No newline at end of file