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/**
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <alloca.h>
#ifndef O_CLOEXEC
#define O_CLOEXEC 02000000
#endif
/* Requires video group */
#include <xf86drm.h>
#include <xf86drmMode.h>
/**
* File descriptor for the DRM connection
*/
static int drm_fd;
/**
* DRM mode resources
*/
static drmModeRes* drm_res = NULL;
/**
* Get the number of cards present on the system
*
* @return The number of cards present on the system
*/
int blueshift_drm_card_count()
{
long maxlen = strlen(DRM_DIR_NAME) + strlen(DRM_DEV_NAME) + 10;
char* pathname = alloca(maxlen * sizeof(char));
int count = 0;
struct stat attr;
for (;;)
{
sprintf(pathname, DRM_DEV_NAME, DRM_DIR_NAME, count);
if (stat(pathname, &attr))
break;
count++;
}
return count;
}
/**
* Open connection to a graphics card
*
* @param card The index of the graphics card
* @return Zero on success
*/
int blueshift_drm_open(int card)
{
long maxlen = strlen(DRM_DIR_NAME) + strlen(DRM_DEV_NAME) + 10;
char* pathname = alloca(maxlen * sizeof(char));
sprintf(pathname, DRM_DEV_NAME, DRM_DIR_NAME, card);
drm_fd = open(pathname, O_RDWR | O_CLOEXEC);
if (drm_fd < 0)
{
perror("open");
return 1;
}
return 0;
}
/**
* Close connection to the graphics card
*/
void blueshift_drm_close()
{
drmModeFreeResources(drm_res);
close(drm_fd);
}
/**
* Update the resource, required after `blueshift_drm_open`
*/
void blueshift_drm_update()
{
if (drm_res)
drmModeFreeResources(drm_res);
drm_res = drmModeGetResources(drm_fd);
}
/**
* Return the number of CRTC:s on the opened card
*
* @return The number of CRTC:s on the opened card
*/
int blueshift_drm_crtc_count()
{
return drm_res->count_crtcs;
}
/**
* Return the number of connectors on the opened card
*
* @return The number of connectors on the opened card
*/
int blueshift_drm_connector_count()
{
return drm_res->count_connectors;
}
int main(int argc, char** argv)
{
(void) argc;
(void) argv;
printf("Card count: %i\n", blueshift_drm_card_count());
blueshift_drm_open(0);
blueshift_drm_update();
printf("CRTC count: %i\n", blueshift_drm_crtc_count());
printf("Connector count: %i\n", blueshift_drm_connector_count());
blueshift_drm_close();
return 0;
}
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