kmscon/src/uterm_video_drm.c

/*
 * uterm - Linux User-Space Terminal
 *
 * Copyright (c) 2011-2012 David Herrmann <dh.herrmann@googlemail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * DRM Video backend
 */

#define EGL_EGLEXT_PROTOTYPES
#define GL_GLEXT_PROTOTYPES

#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <errno.h>
#include <fcntl.h>
#include <gbm.h>
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <inttypes.h>
#include <libudev.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <xf86drm.h>
/* #include <xf86drmMode.h> TODO: missing header protection */
#include "eloop.h"
#include "log.h"
#include "uterm.h"
#include "uterm_internal.h"

#define LOG_SUBSYSTEM "video_drm"

static const char *mode_get_name(const struct uterm_mode *mode)
{
	return mode->drm.info.name;
}

static unsigned int mode_get_width(const struct uterm_mode *mode)
{
	return mode->drm.info.hdisplay;
}

static unsigned int mode_get_height(const struct uterm_mode *mode)
{
	return mode->drm.info.vdisplay;
}

static int init_rb(struct uterm_display *disp, struct drm_rb *rb)
{
	unsigned int stride, handle;
	int ret;
	struct uterm_video *video = disp->video;

	rb->bo = gbm_bo_create(video->drm.gbm,
				disp->current_mode->drm.info.hdisplay,
				disp->current_mode->drm.info.vdisplay,
				GBM_BO_FORMAT_XRGB8888,
				GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
	if (!rb->bo) {
		log_err("cannot create gbm-bo");
		return -EFAULT;
	}

	stride = gbm_bo_get_pitch(rb->bo);
	handle = gbm_bo_get_handle(rb->bo).u32;

	/* TODO: how can we choose 24/32 dynamically? */
	ret = drmModeAddFB(video->drm.fd,
					disp->current_mode->drm.info.hdisplay,
					disp->current_mode->drm.info.vdisplay,
					24, 32, stride, handle, &rb->fb);
	if (ret) {
		log_err("cannot add drm-fb");
		ret = -EFAULT;
		goto err_gbm;
	}

	rb->image = eglCreateImageKHR(video->drm.disp, NULL,
					EGL_NATIVE_PIXMAP_KHR, rb->bo, NULL);
	if (!rb->image) {
		log_err("cannot create egl image");
		ret = -EFAULT;
		goto err_fb;
	}

	glGenRenderbuffers(1, &rb->rb);
	glBindRenderbuffer(GL_RENDERBUFFER, rb->rb);
	glEGLImageTargetRenderbufferStorageOES(GL_RENDERBUFFER, rb->image);

	return 0;

err_fb:
	drmModeRmFB(video->drm.fd, rb->fb);
err_gbm:
	gbm_bo_destroy(rb->bo);
	return ret;
}

static void destroy_rb(struct uterm_display *disp, struct drm_rb *rb)
{
	glBindRenderbuffer(GL_RENDERBUFFER, 0);
	glDeleteRenderbuffers(1, &rb->rb);
	eglDestroyImageKHR(disp->video->drm.disp, rb->image);
	drmModeRmFB(disp->video->drm.fd, rb->fb);
	gbm_bo_destroy(rb->bo);
}

static int find_crtc(struct uterm_video *video, drmModeRes *res,
							drmModeEncoder *enc)
{
	int i, crtc;
	struct uterm_display *iter;

	for (i = 0; i < res->count_crtcs; ++i) {
		if (enc->possible_crtcs & (1 << i)) {
			crtc = res->crtcs[i];
			for (iter = video->displays; iter; iter = iter->next) {
				if (iter->drm.crtc_id == crtc)
					break;
			}
			if (!iter)
				return crtc;
		}
	}

	return -1;
}

static int display_activate(struct uterm_display *disp, struct uterm_mode *mode)
{
	struct uterm_video *video = disp->video;
	int ret, crtc, i;
	drmModeRes *res;
	drmModeConnector *conn;
	drmModeEncoder *enc;

	if (!video || !video_is_awake(video) || !mode)
		return -EINVAL;
	if (display_is_online(disp))
		return 0;

	log_info("activating display %p to %ux%u", disp,
			mode->drm.info.hdisplay, mode->drm.info.vdisplay);

	res = drmModeGetResources(video->drm.fd);
	if (!res) {
		log_err("cannot get resources for display %p", disp);
		return -EFAULT;
	}
	conn = drmModeGetConnector(video->drm.fd, disp->drm.conn_id);
	if (!conn) {
		log_err("cannot get connector for display %p", disp);
		drmModeFreeResources(res);
		return -EFAULT;
	}

	crtc = -1;
	for (i = 0; i < conn->count_encoders; ++i) {
		enc = drmModeGetEncoder(video->drm.fd, conn->encoders[i]);
		if (!enc)
			continue;
		crtc = find_crtc(video, res, enc);
		drmModeFreeEncoder(enc);
		if (crtc >= 0)
			break;
	}

	drmModeFreeConnector(conn);
	drmModeFreeResources(res);

	if (crtc < 0) {
		log_warn("cannot find crtc for new display");
		return -ENODEV;
	}

	disp->drm.crtc_id = crtc;
	disp->drm.current_rb = 0;
	disp->current_mode = mode;
	disp->drm.saved_crtc = drmModeGetCrtc(video->drm.fd,
							disp->drm.crtc_id);

	ret = init_rb(disp, &disp->drm.rb[0]);
	if (ret)
		goto err_saved;

	ret = init_rb(disp, &disp->drm.rb[1]);
	if (ret)
		goto err_rb;

	glGenFramebuffers(1, &disp->drm.fb);
	glBindFramebuffer(GL_FRAMEBUFFER, disp->drm.fb);
	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
					GL_RENDERBUFFER, disp->drm.rb[1].rb);
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) !=
						GL_FRAMEBUFFER_COMPLETE) {
		log_err("cannot create gl-framebuffer");
		ret = -EFAULT;
		goto err_fb;
	}

	ret = drmModeSetCrtc(video->drm.fd, disp->drm.crtc_id,
			disp->drm.rb[0].fb, 0, 0, &disp->drm.conn_id, 1,
						&disp->current_mode->drm.info);
	if (ret) {
		log_err("cannot set drm-crtc");
		ret = -EFAULT;
		goto err_fb;
	}

	disp->flags |= DISPLAY_ONLINE;
	return 0;

err_fb:
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glDeleteFramebuffers(1, &disp->drm.fb);
	destroy_rb(disp, &disp->drm.rb[1]);
err_rb:
	destroy_rb(disp, &disp->drm.rb[0]);
err_saved:
	disp->current_mode = NULL;
	if (disp->drm.saved_crtc) {
		drmModeFreeCrtc(disp->drm.saved_crtc);
		disp->drm.saved_crtc = NULL;
	}
	return ret;
}

static void display_deactivate(struct uterm_display *disp)
{
	if (!display_is_online(disp))
		return;

	if (disp->drm.saved_crtc) {
		if (disp->video->flags & VIDEO_AWAKE) {
			drmModeSetCrtc(disp->video->drm.fd,
					disp->drm.saved_crtc->crtc_id,
					disp->drm.saved_crtc->buffer_id,
					disp->drm.saved_crtc->x,
					disp->drm.saved_crtc->y,
					&disp->drm.conn_id,
					1,
					&disp->drm.saved_crtc->mode);
		}
		drmModeFreeCrtc(disp->drm.saved_crtc);
		disp->drm.saved_crtc = NULL;
	}

	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	glDeleteFramebuffers(1, &disp->drm.fb);
	destroy_rb(disp, &disp->drm.rb[1]);
	destroy_rb(disp, &disp->drm.rb[0]);
	disp->current_mode = NULL;
	disp->flags &= ~(DISPLAY_ONLINE | DISPLAY_VSYNC);
	log_info("deactivating display %p", disp);
}

static int display_set_dpms(struct uterm_display *disp, int state)
{
	int i, ret, set;
	drmModeConnector *conn;
	drmModePropertyRes *prop;

	if (!display_is_conn(disp) || !video_is_awake(disp->video))
		return -EINVAL;

	switch (state) {
	case UTERM_DPMS_ON:
		set = DRM_MODE_DPMS_ON;
		break;
	case UTERM_DPMS_STANDBY:
		set = DRM_MODE_DPMS_STANDBY;
		break;
	case UTERM_DPMS_SUSPEND:
		set = DRM_MODE_DPMS_SUSPEND;
		break;
	case UTERM_DPMS_OFF:
		set = DRM_MODE_DPMS_OFF;
		break;
	default:
		return -EINVAL;
	}

	log_info("setting DPMS of display %p to %s", disp,
			uterm_dpms_to_name(state));

	conn = drmModeGetConnector(disp->video->drm.fd, disp->drm.conn_id);
	if (!conn) {
		log_err("cannot get display connector");
		return -EFAULT;
	}

	for (i = 0; i < conn->count_props; ++i) {
		prop = drmModeGetProperty(disp->video->drm.fd, conn->props[i]);
		if (!prop)
			continue;

		if (!strcmp(prop->name, "DPMS")) {
			ret = drmModeConnectorSetProperty(disp->video->drm.fd,
				disp->drm.conn_id, prop->prop_id, set);
			if (ret) {
				log_info("cannot set DPMS");
				ret = -EFAULT;
			}
			drmModeFreeProperty(prop);
			break;
		}
		drmModeFreeProperty(prop);
	}

	if (i == conn->count_props) {
		ret = 0;
		log_warn("display does not support DPMS");
		state = UTERM_DPMS_UNKNOWN;
	}

	drmModeFreeConnector(conn);
	disp->dpms = state;
	return ret;
}

static int display_use(struct uterm_display *disp)
{
	if (!display_is_online(disp))
		return -EINVAL;

	/* TODO: we need triple buffering as a VSYNC may still be pending */
	glBindFramebuffer(GL_FRAMEBUFFER, disp->drm.fb);
	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
		GL_RENDERBUFFER, disp->drm.rb[disp->drm.current_rb ^ 1].rb);
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) !=
						GL_FRAMEBUFFER_COMPLETE) {
		log_warn("cannot set gl-renderbuffer");
		return -EFAULT;
	}

	return 0;
}

static int display_swap(struct uterm_display *disp)
{
	int ret;

	if (!display_is_conn(disp) || !video_is_awake(disp->video))
		return -EINVAL;
	if (disp->dpms != UTERM_DPMS_ON)
		return -EINVAL;

	/* TODO: is glFlush sufficient here? */
	glFinish();

	errno = 0;
	disp->drm.current_rb ^= 1;
	ret = drmModePageFlip(disp->video->drm.fd, disp->drm.crtc_id,
				disp->drm.rb[disp->drm.current_rb].fb,
				DRM_MODE_PAGE_FLIP_EVENT, disp);
	if (ret) {
		log_warn("page-flip failed %d %d", ret, errno);
		return -EFAULT;
	}
	uterm_display_ref(disp);
	disp->flags |= DISPLAY_VSYNC;

	return 0;
}

static int get_dpms(struct uterm_display *disp, drmModeConnector *conn)
{
	int i, ret;
	drmModePropertyRes *prop;

	for (i = 0; i < conn->count_props; ++i) {
		prop = drmModeGetProperty(disp->video->drm.fd, conn->props[i]);
		if (!prop)
			continue;

		if (!strcmp(prop->name, "DPMS")) {
			switch (conn->prop_values[i]) {
			case DRM_MODE_DPMS_ON:
				ret = UTERM_DPMS_ON;
				break;
			case DRM_MODE_DPMS_STANDBY:
				ret = UTERM_DPMS_STANDBY;
				break;
			case DRM_MODE_DPMS_SUSPEND:
				ret = UTERM_DPMS_SUSPEND;
				break;
			case DRM_MODE_DPMS_OFF:
			default:
				ret = UTERM_DPMS_OFF;
			}

			drmModeFreeProperty(prop);
			return ret;
		}
		drmModeFreeProperty(prop);
	}

	if (i == conn->count_props)
		log_warn("display does not support DPMS");
	return UTERM_DPMS_UNKNOWN;
}

static void bind_display(struct uterm_video *video, drmModeRes *res,
							drmModeConnector *conn)
{
	struct uterm_display *disp;
	struct uterm_mode *mode;
	int ret, i;

	ret = display_new(&disp, &drm_display_ops);
	if (ret)
		return;

	for (i = 0; i < conn->count_modes; ++i) {
		ret = mode_new(&mode, &drm_mode_ops);
		if (ret)
			continue;
		mode->drm.info = conn->modes[i];
		mode->next = disp->modes;
		disp->modes = mode;

		/* TODO: more sophisticated default-mode selection */
		if (!disp->default_mode)
			disp->default_mode = mode;
	}

	if (!disp->modes) {
		log_warn("no valid mode for display found");
		uterm_display_unref(disp);
		return;
	}

	disp->video = video;
	disp->drm.conn_id = conn->connector_id;
	disp->flags |= DISPLAY_AVAILABLE;
	disp->next = video->displays;
	video->displays = disp;
	disp->dpms = get_dpms(disp, conn);
	log_info("display %p DPMS is %s", disp,
			uterm_dpms_to_name(disp->dpms));
}

static void unbind_display(struct uterm_display *disp)
{
	if (!display_is_conn(disp))
		return;

	display_deactivate(disp);
	disp->video = NULL;
	disp->flags &= ~DISPLAY_AVAILABLE;
	uterm_display_unref(disp);
}

static int get_id(struct udev_device *dev)
{
	const char *name;
	char *end;
	int devnum;

	name = udev_device_get_sysname(dev);
	if (!name)
		return -ENODEV;
	if (strncmp(name, "card", 4) || !name[4])
		return -ENODEV;

	devnum = strtol(&name[4], &end, 10);
	if (devnum < 0 || *end)
		return -ENODEV;

	return devnum;
}

static void page_flip_handler(int fd, unsigned int frame, unsigned int sec,
						unsigned int usec, void *data)
{
	struct uterm_display *disp = data;

	disp->flags &= ~DISPLAY_VSYNC;
	uterm_display_unref(disp);
}

static void event(struct ev_fd *fd, int mask, void *data)
{
	struct uterm_video *video = data;
	drmEventContext ev;

	if (mask & (EV_HUP | EV_ERR)) {
		log_err("error or hangup on DRM fd");
		ev_eloop_rm_fd(video->drm.efd);
		video->drm.efd = NULL;
		return;
	}

	if (mask & EV_READABLE) {
		memset(&ev, 0, sizeof(ev));
		ev.version = DRM_EVENT_CONTEXT_VERSION;
		ev.page_flip_handler = page_flip_handler;
		drmHandleEvent(video->drm.fd, &ev);
	}
}

static int init_device(struct uterm_video *video, struct udev_device *dev)
{
	const char *node, *ext;
	int ret;
	EGLint major, minor;
	EGLenum api;
	static const EGLint ctx_att[] =
		{ EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE };
	struct drm_video *drm = &video->drm;

	log_info("probing %s", udev_device_get_sysname(dev));

	node = udev_device_get_devnode(dev);
	if (!node)
		return -ENODEV;

	drm->id = get_id(dev);
	if (drm->id < 0) {
		log_err("cannot get device id");
		return -ENODEV;
	}

	drm->fd = open(node, O_RDWR | O_CLOEXEC);
	if (drm->fd < 0) {
		log_err("cannot open drm device %s (%d): %m", node, errno);
		return -EFAULT;
	}
	drmDropMaster(drm->fd);

	drm->gbm = gbm_create_device(drm->fd);
	if (!drm->gbm) {
		log_err("cannot create gbm device for %s (permission denied)",
			node);
		ret = -EFAULT;
		goto err_close;
	}

	drm->disp = eglGetDisplay((EGLNativeDisplayType) drm->gbm);
	if (!drm->disp) {
		log_err("cannot retrieve egl display for %s", node);
		ret = -EFAULT;
		goto err_gbm;
	}

	ret = eglInitialize(drm->disp, &major, &minor);
	if (!ret) {
		log_err("cannot init egl display for %s", node);
		ret = -EFAULT;
		goto err_gbm;
	}

	ext = eglQueryString(drm->disp, EGL_EXTENSIONS);
	if (!ext || !strstr(ext, "EGL_KHR_surfaceless_opengl")) {
		log_err("surfaceless opengl not supported");
		ret = -EFAULT;
		goto err_disp;
	}

	api = EGL_OPENGL_ES_API;
	/* TODO: allow api = EGL_OPENGL_API */
	if (!eglBindAPI(api)) {
		log_err("cannot bind opengl-es api");
		ret = -EFAULT;
		goto err_disp;
	}

	drm->ctx = eglCreateContext(drm->disp, NULL, EGL_NO_CONTEXT, ctx_att);
	if (!drm->ctx) {
		log_err("cannot create egl context");
		ret = -EFAULT;
		goto err_disp;
	}

	/*
	 * We allow only one global video object. See uterm_video_new for the
	 * reasons. If we every change this we need proper context-management
	 * and should remove this call here.
	 */
	if (!eglMakeCurrent(drm->disp, EGL_NO_SURFACE, EGL_NO_SURFACE,
								drm->ctx)) {
		log_err("cannot activate egl context");
		ret = -EFAULT;
		goto err_ctx;
	}

	ret = ev_eloop_new_fd(video->eloop, &drm->efd, drm->fd,
				EV_READABLE, event, video);
	if (ret)
		goto err_ctx;

	video->flags |= VIDEO_HOTPLUG;
	log_info("new drm device via %s", node);

	return 0;

err_ctx:
	eglDestroyContext(drm->disp, drm->ctx);
err_disp:
	eglTerminate(drm->disp);
err_gbm:
	gbm_device_destroy(drm->gbm);
err_close:
	close(drm->fd);
	return ret;
}

static int video_init(struct uterm_video *video)
{
	struct udev_enumerate *e;
	struct udev_list_entry *name;
	const char *path;
	struct udev_device *dev;
	int ret;

	ret = udev_monitor_filter_add_match_subsystem_devtype(video->umon,
							"drm", "drm_minor");
	if (ret) {
		log_err("cannot add udev filter (%d): %m", ret);
		return -EFAULT;
	}

	ret = udev_monitor_enable_receiving(video->umon);
	if (ret) {
		log_err("cannot start udev_monitor (%d): %m", ret);
		return -EFAULT;
	}

	e = udev_enumerate_new(video->udev);
	if (!e) {
		log_err("cannot create udev_enumerate object");
		return -EFAULT;
	}

	ret = udev_enumerate_add_match_subsystem(e, "drm");
	if (ret) {
		log_err("cannot add udev match (%d): %m", ret);
		ret = -EFAULT;
		goto err_enum;
	}
	ret = udev_enumerate_add_match_sysname(e, "card[0-9]*");
	if (ret) {
		log_err("cannot add udev match (%d): %m", ret);
		ret = -EFAULT;
		goto err_enum;
	}
	ret = udev_enumerate_scan_devices(e);
	if (ret) {
		log_err("cannot scan udev devices (%d): %m", ret);
		ret = -EFAULT;
		goto err_enum;
	}

	udev_list_entry_foreach(name, udev_enumerate_get_list_entry(e)) {
		path = udev_list_entry_get_name(name);
		if (!path || !*path)
			continue;
		dev = udev_device_new_from_syspath(video->udev, path);
		if (!dev)
			continue;

		/* TODO: more sophisticated device selection */
		ret = init_device(video, dev);
		udev_device_unref(dev);
		if (!ret)
			goto done;
	}

	ret = -ENODEV;
	log_err("no drm device found");
	goto err_enum;

done:
	ret = 0;
err_enum:
	udev_enumerate_unref(e);
	return ret;
}

static void video_destroy(struct uterm_video *video)
{
	struct drm_video *drm = &video->drm;
	struct uterm_display *disp;

	while ((disp = video->displays)) {
		video->displays = disp->next;
		disp->next = NULL;
		unbind_display(disp);
	}

	log_info("free drm device");
	ev_eloop_rm_fd(drm->efd);
	eglDestroyContext(drm->disp, drm->ctx);
	eglTerminate(drm->disp);
	gbm_device_destroy(drm->gbm);
	drmDropMaster(drm->fd);
	close(drm->fd);
}

static int hotplug(struct uterm_video *video)
{
	drmModeRes *res;
	drmModeConnector *conn;
	struct uterm_display *disp, *tmp;
	unsigned int i;

	if (!video_is_awake(video) || !video_need_hotplug(video))
		return 0;

	res = drmModeGetResources(video->drm.fd);
	if (!res) {
		log_err("cannot retrieve drm resources");
		return -EACCES;
	}

	for (disp = video->displays; disp; disp = disp->next)
		disp->flags &= ~DISPLAY_AVAILABLE;

	for (i = 0; i < res->count_connectors; ++i) {
		conn = drmModeGetConnector(video->drm.fd, res->connectors[i]);
		if (!conn)
			continue;
		if (conn->connection == DRM_MODE_CONNECTED) {
			for (disp = video->displays; disp; disp = disp->next) {
				if (disp->drm.conn_id == res->connectors[i]) {
					disp->flags |= DISPLAY_AVAILABLE;
					break;
				}
			}
			if (!disp)
				bind_display(video, res, conn);
		}
		drmModeFreeConnector(conn);
	}

	drmModeFreeResources(res);

	while (video->displays) {
		tmp = video->displays;
		if (tmp->flags & DISPLAY_AVAILABLE)
			break;

		video->displays = tmp->next;
		tmp->next = NULL;
		unbind_display(tmp);
	}
	for (disp = video->displays; disp && disp->next; ) {
		tmp = disp->next;
		if (tmp->flags & DISPLAY_AVAILABLE) {
			disp = tmp;
		} else {
			disp->next = tmp->next;
			tmp->next = NULL;
			unbind_display(tmp);
		}
	}

	video->flags &= ~VIDEO_HOTPLUG;
	return 0;
}

static int monitor(struct uterm_video *video)
{
	struct udev_device *dev;
	const char *action, *val;
	unsigned int id;

	dev = udev_monitor_receive_device(video->umon);
	if (!dev) {
		log_warn("cannot receive device from udev_monitor");
		return 0;
	}

	action = udev_device_get_action(dev);
	if (!action)
		goto ignore;
	if (strcmp(action, "change"))
		goto ignore;

	val = udev_device_get_property_value(dev, "HOTPLUG");
	if (strcmp(val, "1"))
		goto ignore;

	id = get_id(dev);
	if (id != video->drm.id)
		goto ignore;

	video->flags |= VIDEO_HOTPLUG;
ignore:
	udev_device_unref(dev);
	return 0;
}

static int video_poll(struct uterm_video *video, int mask)
{
	int ret;

	if (mask & (EV_HUP | EV_ERR)) {
		log_err("udev_monitor closed unexpectedly");
		return -EFAULT;
	}

	if (mask & EV_READABLE) {
		ret = monitor(video);
		if (ret)
			return ret;
	}

	return hotplug(video);
}

static void video_sleep(struct uterm_video *video)
{
	if (!video_is_awake(video))
		return;

	drmDropMaster(video->drm.fd);
	video->flags &= ~VIDEO_AWAKE;
}

static int video_wake_up(struct uterm_video *video)
{
	int ret;

	if (video_is_awake(video))
		return 0;

	ret = drmSetMaster(video->drm.fd);
	if (ret) {
		log_err("cannot set DRM-master");
		return -EACCES;
	}

	video->flags |= VIDEO_AWAKE;
	ret = hotplug(video);
	if (ret) {
		video->flags &= ~VIDEO_AWAKE;
		drmDropMaster(video->drm.fd);
		return ret;
	}

	return 0;
}

const struct mode_ops drm_mode_ops = {
	.init = NULL,
	.destroy = NULL,
	.get_name = mode_get_name,
	.get_width = mode_get_width,
	.get_height = mode_get_height,
};

const struct display_ops drm_display_ops = {
	.init = NULL,
	.destroy = NULL,
	.activate = display_activate,
	.deactivate = display_deactivate,
	.set_dpms = display_set_dpms,
	.use = display_use,
	.swap = display_swap,
};

const struct video_ops drm_video_ops = {
	.init = video_init,
	.destroy = video_destroy,
	.segfault = NULL, /* TODO: reset all saved CRTCs on segfault */
	.poll = video_poll,
	.sleep = video_sleep,
	.wake_up = video_wake_up,
};