Support for running Redshift without a graphical environment in Linux by using Direct Rendering Manager

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 280 insertions, 0 deletions

diff --git a/src/gamma-drm.c b/src/gamma-drm.c
new file mode 100644
index 0000000..e784b47
--- /dev/null
+++ b/src/gamma-drm.c
@@ -0,0 +1,280 @@
+/* gamma-drm.c -- DRM gamma adjustment source
+   This file is part of Redshift.
+
+   Redshift 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.
+
+   Redshift 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 Redshift.  If not, see <http://www.gnu.org/licenses/>.
+
+   Copyright (c) 2014  Mattias Andrée <maandree@member.fsf.org>
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <alloca.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#ifdef ENABLE_NLS
+# include <libintl.h>
+# define _(s) gettext(s)
+#else
+# define _(s) s
+#endif
+
+#ifndef O_CLOEXEC
+  #define O_CLOEXEC  02000000
+#endif
+
+#include "gamma-drm.h"
+#include "colorramp.h"
+
+
+int
+drm_init(drm_state_t *state)
+{
+	/* Initialize state. */
+	state->card_num = 0;
+	state->crtc_num = -1;
+	state->fd = -1;
+	state->res = NULL;
+	state->crtcs = NULL;
+
+	return 0;
+}
+
+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 = alloca(maxlen * sizeof(char));
+
+	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");
+		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;
+}
+
+void
+drm_restore(drm_state_t *state)
+{
+	drm_crtc_state_t *crtcs = state->crtcs;
+	while (crtcs->crtc_num >= 0) {
+		if (crtcs->r_gamma != NULL) {
+			drmModeCrtcSetGamma(state->fd, crtcs->crtc_id, crtcs->gamma_size,
+					    crtcs->r_gamma, crtcs->g_gamma, crtcs->b_gamma);
+		}
+		crtcs++;
+	}
+}
+
+void
+drm_free(drm_state_t *state)
+{
+	if (state->crtcs != NULL) {
+		drm_crtc_state_t *crtcs = state->crtcs;
+		while (crtcs->crtc_num >= 0) {
+			if (crtcs->r_gamma != NULL)
+				free(crtcs->r_gamma);
+			crtcs->crtc_num = -1;
+			crtcs++;
+		}
+		free(state->crtcs);
+		state->crtcs = NULL;
+	}
+	if (state->res != NULL) {
+		drmModeFreeResources(state->res);
+		state->res = NULL;
+	}
+	if (state->fd >= 0) {
+		close(state->fd);
+		state->fd = -1;
+	}
+}
+
+void
+drm_print_help(FILE *f)
+{
+	fputs(_("Adjust gamma ramps with Direct Rendering Manager.\n"), f);
+	fputs("\n", f);
+
+	/* TRANSLATORS: DRM help output
+	   left column must not be translated */
+	fputs(_("  card=N\tGraphics card to apply adjustments to\n"
+		"  crtc=N\tCRTC to apply adjustments to\n"), f);
+	fputs("\n", f);
+}
+
+int
+drm_set_option(drm_state_t *state, const char *key, const char *value)
+{
+	if (strcasecmp(key, "card") == 0) {
+		state->card_num = atoi(value);
+	} else if (strcasecmp(key, "crtc") == 0) {
+		state->crtc_num = atoi(value);
+		if (state->crtc_num < 0) {
+			fprintf(stderr, _("CRTC must be a non-negative integer\n"));
+			return -1;
+		}
+	} else {
+		fprintf(stderr, _("Unknown method parameter: `%s'.\n"), key);
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+drm_set_temperature(drm_state_t *state, int temp, float brightness, const float gamma[3])
+{
+	drm_crtc_state_t *crtcs = state->crtcs;
+	int last_gamma_size = 0;
+	uint16_t *r_gamma = NULL;
+	uint16_t *g_gamma = NULL;
+	uint16_t *b_gamma = NULL;
+
+	for (; crtcs->crtc_num >= 0; crtcs++) {
+		if (crtcs->gamma_size <= 1)
+			continue;
+		if (crtcs->gamma_size != last_gamma_size) {
+			if (last_gamma_size == 0) {
+				r_gamma = malloc(3 * crtcs->gamma_size * sizeof(uint16_t));
+				g_gamma = r_gamma + crtcs->gamma_size;
+				b_gamma = g_gamma + crtcs->gamma_size;
+			} else if (crtcs->gamma_size > last_gamma_size) {
+				r_gamma = realloc(r_gamma, 3 * crtcs->gamma_size * sizeof(uint16_t));
+				g_gamma = r_gamma + crtcs->gamma_size;
+				b_gamma = g_gamma + crtcs->gamma_size;
+			}
+			if (r_gamma == NULL) {
+				perror(last_gamma_size == 0 ? "malloc" : "realloc");
+				return -1;
+			}
+			last_gamma_size = crtcs->gamma_size;
+		}
+		colorramp_fill(r_gamma, g_gamma, b_gamma, crtcs->gamma_size,
+			       temp, brightness, gamma);
+		drmModeCrtcSetGamma(state->fd, crtcs->crtc_id, crtcs->gamma_size,
+				    r_gamma, g_gamma, b_gamma);
+	}
+
+	free(r_gamma);
+
+	return 0;
+}