/**
* crt-calibrator – Calibration utility for CRT monitors
* 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 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 "drmgamma.h"
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
/**
* Close on exec flag for `open`
*/
#ifndef O_CLOEXEC
# define O_CLOEXEC 02000000
#endif
/**
* The number of elements to allocates to a buffer for a DRM device pathname
*/
#define DRM_DEV_NAME_MAX_LEN \
((sizeof(DRM_DEV_NAME) + sizeof(DRM_DIR_NAME)) / sizeof(char) + 3 * sizeof(int))
/**
* Figure out how many graphics cards there are on the system
*
* @return The number of graphics cards on the system
*/
size_t drm_card_count(void)
{
char buf[DRM_DEV_NAME_MAX_LEN];
size_t count = 0;
for (;; count++)
{
sprintf(buf, DRM_DEV_NAME, DRM_DIR_NAME, (int)count);
if (access(buf, F_OK) < 0)
return count;
}
}
/**
* Acquire access to a graphics card
*
* @param index The index of the graphics card
* @param card Graphics card information to fill in
* @return Zero on success, -1 on error
*/
int drm_card_open(size_t index, drm_card_t* restrict card)
{
char buf[DRM_DEV_NAME_MAX_LEN];
int old_errno;
size_t i, n;
card->fd = -1;
card->res = NULL;
card->connectors = NULL;
card->encoders = NULL;
card->connector_count = 0;
sprintf(buf, DRM_DEV_NAME, DRM_DIR_NAME, (int)index);
card->fd = open(buf, O_RDWR | O_CLOEXEC);
if (card->fd == -1)
goto fail;
card->res = drmModeGetResources(card->fd);
if (card->res == NULL)
goto fail;
card->crtc_count = (size_t)(card->res->count_crtcs);
card->connector_count = (size_t)(card->res->count_connectors);
n = card->connector_count;
card->connectors = calloc(n, sizeof(drmModeConnector*));
if (card->connectors == NULL)
goto fail;
card->encoders = calloc(n, sizeof(drmModeEncoder*));
if (card->encoders == NULL)
goto fail;
for (i = 0; i < n; i++)
{
card->connectors[i] = drmModeGetConnector(card->fd, card->res->connectors[i]);
if (card->connectors[i] == NULL)
goto fail;
if (card->connectors[i]->encoder_id != 0)
{
card->encoders[i] = drmModeGetEncoder(card->fd, card->connectors[i]->encoder_id);
if (card->encoders[i] == NULL)
goto fail;
}
}
return 0;
fail:
old_errno = errno;
drm_card_close(card);
errno = old_errno;
return -1;
}
/**
* Release access to a graphics card
*
* @param card The graphics card information
*/
void drm_card_close(drm_card_t* restrict card)
{
size_t i, n = card->connector_count;
if (card->encoders != NULL)
for (i = 0; i < n; i++)
if (card->encoders[i] != NULL)
drmModeFreeEncoder(card->encoders[i]);
free(card->encoders), card->encoders = NULL;
if (card->connectors != NULL)
for (i = 0; i < n; i++)
if (card->connectors[i] != NULL)
drmModeFreeConnector(card->connectors[i]);
free(card->connectors), card->connectors = NULL;
if (card->res != NULL)
drmModeFreeResources(card->res), card->res = NULL;
if (card->fd != -1)
close(card->fd), card->fd = -1;
}
/**
* Acquire access to a CRT controller
*
* @param index The index of the CRT controller
* @param card The graphics card information
* @param crtc CRT controller information to fill in
* @return Zero on success, -1 on error
*/
int drm_crtc_open(size_t index, drm_card_t* restrict card, drm_crtc_t* restrict crtc)
{
drmModePropertyRes* restrict prop;
drmModePropertyBlobRes* restrict blob;
drmModeCrtc* restrict info;
size_t i;
int old_errno;
crtc->edid = NULL;
crtc->red = NULL;
crtc->green = NULL;
crtc->blue = NULL;
crtc->id = card->res->crtcs[index];
crtc->card = card;
for (i = 0; i < card->connector_count; i++)
if (card->encoders[i] != NULL)
if (card->encoders[i]->crtc_id == crtc->id)
{
crtc->connector = card->connectors[i];
crtc->encoder = card->encoders[i];
}
crtc->connected = crtc->connector->connection == DRM_MODE_CONNECTED;
info = drmModeGetCrtc(card->fd, crtc->id);
if (info == NULL)
return -1;
crtc->gamma_stops = (size_t)(info->gamma_size);
drmModeFreeCrtc(info);
/* `calloc` is for some reason required when reading the gamma ramps. */
crtc->red = calloc(3 * crtc->gamma_stops, sizeof(uint16_t));
if (crtc->red == NULL)
return -1;
crtc->green = crtc->red + crtc->gamma_stops;
crtc->blue = crtc->green + crtc->gamma_stops;
for (i = 0; i < crtc->connector->count_props; i++)
{
size_t j;
prop = drmModeGetProperty(card->fd, crtc->connector->props[i]);
if (prop == NULL)
continue;
if (strcmp(prop->name, "EDID"))
goto free_prop;
blob = drmModeGetPropertyBlob(card->fd, (uint32_t)(crtc->connector->prop_values[i]));
i = crtc->connector->count_props;
if ((blob == NULL) || (blob->data == NULL))
goto free_blob;
crtc->edid = malloc((blob->length * 2 + 1) * sizeof(char));
if (crtc->edid == NULL)
{
old_errno = errno;
drmModeFreePropertyBlob(blob);
drmModeFreeProperty(prop);
free(crtc->red), crtc->red = NULL;
errno = old_errno;
return -1;
}
for (j = 0; j < blob->length; j++)
{
unsigned char c = ((unsigned char*)(blob->data))[j];
crtc->edid[j * 2 + 0] = "0123456789ABCDEF"[(c >> 4) & 15];
crtc->edid[j * 2 + 1] = "0123456789ABCDEF"[(c >> 0) & 15];
}
crtc->edid[blob->length * 2] = '\0';
free_blob:
if (blob != NULL)
drmModeFreePropertyBlob(blob);
free_prop:
drmModeFreeProperty(prop);
}
return 0;
}
/**
* Release access to a CRT controller
*
* @param crtc The CRT controller information to fill in
*/
void drm_crtc_close(drm_crtc_t* restrict crtc)
{
free(crtc->edid), crtc->edid = NULL;
free(crtc->red), crtc->red = NULL;
}
/**
* Read the gamma ramps for a CRT controller
*
* @param crtc CRT controller information
* @return Zero on success, -1 on error
*/
int drm_get_gamma(drm_crtc_t* restrict crtc)
{
int r;
r = drmModeCrtcGetGamma(crtc->card->fd, crtc->id, crtc->gamma_stops,
crtc->red, crtc->green, crtc->blue);
return -!!r;
}
/**
* Apply gamma ramps for a CRT controller
*
* @param crtc CRT controller information
* @return Zero on success, -1 on error
*/
int drm_set_gamma(drm_crtc_t* restrict crtc)
{
int r;
r = drmModeCrtcSetGamma(crtc->card->fd, crtc->id, crtc->gamma_stops,
crtc->red, crtc->green, crtc->blue);
return -!!r;
}
