path: root/kmscube.c

/*
 * Copyright (c) 2012 Arvin Schnell <arvin.schnell@gmail.com>
 * Copyright (c) 2012 Rob Clark <rob@ti.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, sub license,
 * 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 (including the
 * next paragraph) 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 NON-INFRINGEMENT. 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.
 */

/* Based on a egl cube test app originally written by Arvin Schnell */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <errno.h>

#include <xf86drm.h>
#include <xf86drmMode.h>

#include <assert.h>

#include "common.h"


#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))

static const struct egl *egl;
static const struct gbm *gbm;

static struct {
	int fd;
	drmModeModeInfo *mode;
	uint32_t crtc_id;
	uint32_t connector_id;
} drm;

struct drm_fb {
	struct gbm_bo *bo;
	uint32_t fb_id;
};

static uint32_t find_crtc_for_encoder(const drmModeRes *resources,
				      const drmModeEncoder *encoder) {
	int i;

	for (i = 0; i < resources->count_crtcs; i++) {
		/* possible_crtcs is a bitmask as described here:
		 * https://dvdhrm.wordpress.com/2012/09/13/linux-drm-mode-setting-api
		 */
		const uint32_t crtc_mask = 1 << i;
		const uint32_t crtc_id = resources->crtcs[i];
		if (encoder->possible_crtcs & crtc_mask) {
			return crtc_id;
		}
	}

	/* no match found */
	return -1;
}

static uint32_t find_crtc_for_connector(const drmModeRes *resources,
					const drmModeConnector *connector) {
	int i;

	for (i = 0; i < connector->count_encoders; i++) {
		const uint32_t encoder_id = connector->encoders[i];
		drmModeEncoder *encoder = drmModeGetEncoder(drm.fd, encoder_id);

		if (encoder) {
			const uint32_t crtc_id = find_crtc_for_encoder(resources, encoder);

			drmModeFreeEncoder(encoder);
			if (crtc_id != 0) {
				return crtc_id;
			}
		}
	}

	/* no match found */
	return -1;
}

static int init_drm(const char *dev)
{
	drmModeRes *resources;
	drmModeConnector *connector = NULL;
	drmModeEncoder *encoder = NULL;
	int i, area;

	drm.fd = open(dev, O_RDWR);

	if (drm.fd < 0) {
		printf("could not open drm device\n");
		return -1;
	}

	resources = drmModeGetResources(drm.fd);
	if (!resources) {
		printf("drmModeGetResources failed: %s\n", strerror(errno));
		return -1;
	}

	/* find a connected connector: */
	for (i = 0; i < resources->count_connectors; i++) {
		connector = drmModeGetConnector(drm.fd, resources->connectors[i]);
		if (connector->connection == DRM_MODE_CONNECTED) {
			/* it's connected, let's use this! */
			break;
		}
		drmModeFreeConnector(connector);
		connector = NULL;
	}

	if (!connector) {
		/* we could be fancy and listen for hotplug events and wait for
		 * a connector..
		 */
		printf("no connected connector!\n");
		return -1;
	}

	/* find prefered mode or the highest resolution mode: */
	for (i = 0, area = 0; i < connector->count_modes; i++) {
		drmModeModeInfo *current_mode = &connector->modes[i];

		if (current_mode->type & DRM_MODE_TYPE_PREFERRED) {
			drm.mode = current_mode;
		}

		int current_area = current_mode->hdisplay * current_mode->vdisplay;
		if (current_area > area) {
			drm.mode = current_mode;
			area = current_area;
		}
	}

	if (!drm.mode) {
		printf("could not find mode!\n");
		return -1;
	}

	/* find encoder: */
	for (i = 0; i < resources->count_encoders; i++) {
		encoder = drmModeGetEncoder(drm.fd, resources->encoders[i]);
		if (encoder->encoder_id == connector->encoder_id)
			break;
		drmModeFreeEncoder(encoder);
		encoder = NULL;
	}

	if (encoder) {
		drm.crtc_id = encoder->crtc_id;
	} else {
		uint32_t crtc_id = find_crtc_for_connector(resources, connector);
		if (crtc_id == 0) {
			printf("no crtc found!\n");
			return -1;
		}

		drm.crtc_id = crtc_id;
	}

	drm.connector_id = connector->connector_id;

	return 0;
}

static void
drm_fb_destroy_callback(struct gbm_bo *bo, void *data)
{
	struct drm_fb *fb = data;
	struct gbm_device *gbm = gbm_bo_get_device(bo);

	if (fb->fb_id)
		drmModeRmFB(drm.fd, fb->fb_id);

	free(fb);
}

static struct drm_fb * drm_fb_get_from_bo(struct gbm_bo *bo)
{
	struct drm_fb *fb = gbm_bo_get_user_data(bo);
	uint32_t width, height, stride, handle;
	int ret;

	if (fb)
		return fb;

	fb = calloc(1, sizeof *fb);
	fb->bo = bo;

	width = gbm_bo_get_width(bo);
	height = gbm_bo_get_height(bo);
	stride = gbm_bo_get_stride(bo);
	handle = gbm_bo_get_handle(bo).u32;

	ret = drmModeAddFB(drm.fd, width, height, 24, 32, stride, handle, &fb->fb_id);
	if (ret) {
		printf("failed to create fb: %s\n", strerror(errno));
		free(fb);
		return NULL;
	}

	gbm_bo_set_user_data(bo, fb, drm_fb_destroy_callback);

	return fb;
}

static void page_flip_handler(int fd, unsigned int frame,
		  unsigned int sec, unsigned int usec, void *data)
{
	int *waiting_for_flip = data;
	*waiting_for_flip = 0;
}

static const char *shortopts = "D:";

static const struct option longopts[] = {
	{"device", required_argument, 0, 'D'},
	{0, 0, 0, 0}
};

static void usage(const char *name)
{
	printf("Usage: %s [-D]\n"
			"\n"
			"options:\n"
			"    -D, --device=DEVICE      use the given device\n",
			name);
}

int main(int argc, char *argv[])
{
	fd_set fds;
	drmEventContext evctx = {
			.version = DRM_EVENT_CONTEXT_VERSION,
			.page_flip_handler = page_flip_handler,
	};
	struct gbm_bo *bo;
	struct drm_fb *fb;
	uint32_t i = 0;
	const char *device = "/dev/dri/card0";
	int opt, ret;

	while ((opt = getopt_long_only(argc, argv, shortopts, longopts, NULL)) != -1) {
		switch (opt) {
		case 'D':
			device = optarg;
			break;
		default:
			printf("error: unknown option: %c\n", opt);
			usage(argv[0]);
			return -1;
		}
	}

	ret = init_drm(device);
	if (ret) {
		printf("failed to initialize DRM\n");
		return ret;
	}

	FD_ZERO(&fds);
	FD_SET(0, &fds);
	FD_SET(drm.fd, &fds);

	gbm = init_gbm(drm.fd, drm.mode->hdisplay, drm.mode->vdisplay);
	if (!gbm) {
		printf("failed to initialize GBM\n");
		return -1;
	}

	egl = init_cube_smooth(gbm);
	if (!egl) {
		printf("failed to initialize EGL\n");
		return -1;
	}

	/* clear the color buffer */
	glClearColor(0.5, 0.5, 0.5, 1.0);
	glClear(GL_COLOR_BUFFER_BIT);
	eglSwapBuffers(egl->display, egl->surface);
	bo = gbm_surface_lock_front_buffer(gbm->surface);
	fb = drm_fb_get_from_bo(bo);

	/* set mode: */
	ret = drmModeSetCrtc(drm.fd, drm.crtc_id, fb->fb_id, 0, 0,
			&drm.connector_id, 1, drm.mode);
	if (ret) {
		printf("failed to set mode: %s\n", strerror(errno));
		return ret;
	}

	while (1) {
		struct gbm_bo *next_bo;
		int waiting_for_flip = 1;

		egl->draw(i++);

		eglSwapBuffers(egl->display, egl->surface);
		next_bo = gbm_surface_lock_front_buffer(gbm->surface);
		fb = drm_fb_get_from_bo(next_bo);

		/*
		 * Here you could also update drm plane layers if you want
		 * hw composition
		 */

		ret = drmModePageFlip(drm.fd, drm.crtc_id, fb->fb_id,
				DRM_MODE_PAGE_FLIP_EVENT, &waiting_for_flip);
		if (ret) {
			printf("failed to queue page flip: %s\n", strerror(errno));
			return -1;
		}

		while (waiting_for_flip) {
			ret = select(drm.fd + 1, &fds, NULL, NULL, NULL);
			if (ret < 0) {
				printf("select err: %s\n", strerror(errno));
				return ret;
			} else if (ret == 0) {
				printf("select timeout!\n");
				return -1;
			} else if (FD_ISSET(0, &fds)) {
				printf("user interrupted!\n");
				break;
			}
			drmHandleEvent(drm.fd, &evctx);
		}

		/* release last buffer to render on again: */
		gbm_surface_release_buffer(gbm->surface, bo);
		bo = next_bo;
	}

	return ret;
}