/**
* Get the current gamma ramps of a monitor
*
* @param connection The identifier for the connection to the card
* @param crtc_index The index of the CRTC to read from
* @param gamma_size The size a gamma ramp
* @param red Storage location for the red gamma ramp
* @param green Storage location for the green gamma ramp
* @param blue Storage location for the blue gamma ramp
* @return Zero on success
*/
int blueshift_drm_get_gamma_ramps(int connection, int crtc_index, int gamma_size, uint16_t* red, uint16_t* green, uint16_t* blue)
{
card_connection* card = card_connections + connection;
/* We need to initialise it to avoid valgrind warnings */
memset(red, 0, (size_t)gamma_size * sizeof(uint16_t));
memset(green, 0, (size_t)gamma_size * sizeof(uint16_t));
memset(blue, 0, (size_t)gamma_size * sizeof(uint16_t));
return drmModeCrtcGetGamma(card->fd, *(card->res->crtcs + crtc_index), (uint32_t)gamma_size, red, green, blue);
}
static int
drm_start(drm_state_t *state)
{
/* Acquire access to a graphics card. */
long maxlen = strlen(DRM_DIR_NAME) + strlen(DRM_DEV_NAME) + 10;
char pathname[maxlen];
sprintf(pathname, DRM_DEV_NAME, DRM_DIR_NAME, state->card_num);
state->fd = open(pathname, O_RDWR | O_CLOEXEC);
if (state->fd < 0) {
/* TODO check if access permissions, normally root or
membership of the video group is required. */
perror("open");
fprintf(stderr, _("Failed to open DRM device: %s\n"),
pathname);
return -1;
}
/* Acquire mode resources. */
state->res = drmModeGetResources(state->fd);
if (state->res == NULL) {
fprintf(stderr, _("Failed to get DRM mode resources\n"));
close(state->fd);
state->fd = -1;
return -1;
}
/* Create entries for selected CRTCs. */
int crtc_count = state->res->count_crtcs;
if (state->crtc_num >= 0) {
if (state->crtc_num >= crtc_count) {
fprintf(stderr, _("CRTC %d does not exist. "),
state->crtc_num);
if (crtc_count > 1) {
fprintf(stderr, _("Valid CRTCs are [0-%d].\n"),
crtc_count-1);
} else {
fprintf(stderr, _("Only CRTC 0 exists.\n"));
}
close(state->fd);
state->fd = -1;
drmModeFreeResources(state->res);
state->res = NULL;
return -1;
}
state->crtcs = malloc(2 * sizeof(drm_crtc_state_t));
state->crtcs[1].crtc_num = -1;
state->crtcs->crtc_num = state->crtc_num;
state->crtcs->crtc_id = -1;
state->crtcs->gamma_size = -1;
state->crtcs->r_gamma = NULL;
state->crtcs->g_gamma = NULL;
state->crtcs->b_gamma = NULL;
} else {
int crtc_num;
state->crtcs = malloc((crtc_count + 1) * sizeof(drm_crtc_state_t));
state->crtcs[crtc_count].crtc_num = -1;
for (crtc_num = 0; crtc_num < crtc_count; crtc_num++) {
state->crtcs[crtc_num].crtc_num = crtc_num;
state->crtcs[crtc_num].crtc_id = -1;
state->crtcs[crtc_num].gamma_size = -1;
state->crtcs[crtc_num].r_gamma = NULL;
state->crtcs[crtc_num].g_gamma = NULL;
state->crtcs[crtc_num].b_gamma = NULL;
}
}
/* Load CRTC information and gamma ramps. */
drm_crtc_state_t *crtcs = state->crtcs;
for (; crtcs->crtc_num >= 0; crtcs++) {
crtcs->crtc_id = state->res->crtcs[crtcs->crtc_num];
drmModeCrtc* crtc_info = drmModeGetCrtc(state->fd, crtcs->crtc_id);
if (crtc_info == NULL) {
fprintf(stderr, _("CRTC %i lost, skipping\n"), crtcs->crtc_num);
continue;
}
crtcs->gamma_size = crtc_info->gamma_size;
drmModeFreeCrtc(crtc_info);
if (crtcs->gamma_size <= 1) {
fprintf(stderr, _("Could not get gamma ramp size for CRTC %i\n"
"on graphics card %i, ignoring device.\n"),
crtcs->crtc_num, state->card_num);
continue;
}
/* Valgrind complains about us reading uninitialize memory if we just use malloc. */
crtcs->r_gamma = calloc(3 * crtcs->gamma_size, sizeof(uint16_t));
crtcs->g_gamma = crtcs->r_gamma + crtcs->gamma_size;
crtcs->b_gamma = crtcs->g_gamma + crtcs->gamma_size;
if (crtcs->r_gamma != NULL) {
int r = drmModeCrtcGetGamma(state->fd, crtcs->crtc_id, crtcs->gamma_size,
crtcs->r_gamma, crtcs->g_gamma, crtcs->b_gamma);
if (r < 0) {
fprintf(stderr, _("DRM could not read gamma ramps on CRTC %i on\n"
"graphics card %i, ignoring device.\n"),
crtcs->crtc_num, state->card_num);
free(crtcs->r_gamma);
crtcs->r_gamma = NULL;
}
} else {
perror("malloc");
drmModeFreeResources(state->res);
state->res = NULL;
close(state->fd);
state->fd = -1;
while (crtcs-- != state->crtcs)
free(crtcs->r_gamma);
free(state->crtcs);
state->crtcs = NULL;
return -1;
}
}
return 0;
}