Add `output modeline` command

Only works with DRM backend.

include/sway/commands.h

@@ -282,6 +282,7 @@ sway_cmd output_cmd_dpms;
 sway_cmd output_cmd_enable;
 sway_cmd output_cmd_max_render_time;
 sway_cmd output_cmd_mode;
+sway_cmd output_cmd_modeline;
 sway_cmd output_cmd_position;
 sway_cmd output_cmd_scale;
 sway_cmd output_cmd_scale_filter;

include/sway/config.h

@@ -8,6 +8,7 @@
 #include <wlr/types/wlr_tablet_tool.h>
 #include <wlr/util/box.h>
 #include <xkbcommon/xkbcommon.h>
+#include <xf86drmMode.h>
 #include "../include/config.h"
 #include "list.h"
 #include "swaynag.h"
@@ -257,6 +258,7 @@ struct output_config {
 	int width, height;
 	float refresh_rate;
 	int custom_mode;
+	drmModeModeInfo drm_mode;
 	int x, y;
 	float scale;
 	enum scale_filter_mode scale_filter;

sway/commands/output.c

@@ -15,6 +15,7 @@ static const struct cmd_handler output_handlers[] = {
 	{ "enable", output_cmd_enable },
 	{ "max_render_time", output_cmd_max_render_time },
 	{ "mode", output_cmd_mode },
+	{ "modeline", output_cmd_modeline },
 	{ "pos", output_cmd_position },
 	{ "position", output_cmd_position },
 	{ "res", output_cmd_mode },

sway/commands/output/mode.c

@@ -20,6 +20,9 @@ struct cmd_results *output_cmd_mode(int argc, char **argv) {
 		output->custom_mode = 0;
 	}
 
+	// Reset custom modeline, if any
+	output->drm_mode.type = 0;
+
 	char *end;
 	output->width = strtol(*argv, &end, 10);
 	if (*end) {
@@ -58,3 +61,58 @@ struct cmd_results *output_cmd_mode(int argc, char **argv) {
 	return NULL;
 }
 
+static bool parse_modeline(char **argv, drmModeModeInfo *mode) {
+	mode->type = DRM_MODE_TYPE_USERDEF;
+	mode->clock = strtof(argv[0], NULL) * 1000;
+	mode->hdisplay = strtol(argv[1], NULL, 10);
+	mode->hsync_start = strtol(argv[2], NULL, 10);
+	mode->hsync_end = strtol(argv[3], NULL, 10);
+	mode->htotal = strtol(argv[4], NULL, 10);
+	mode->vdisplay = strtol(argv[5], NULL, 10);
+	mode->vsync_start = strtol(argv[6], NULL, 10);
+	mode->vsync_end = strtol(argv[7], NULL, 10);
+	mode->vtotal = strtol(argv[8], NULL, 10);
+
+	mode->vrefresh = mode->clock * 1000.0 * 1000.0
+		/ mode->htotal / mode->vtotal;
+	if (strcasecmp(argv[9], "+hsync") == 0) {
+		mode->flags |= DRM_MODE_FLAG_PHSYNC;
+	} else if (strcasecmp(argv[9], "-hsync") == 0) {
+		mode->flags |= DRM_MODE_FLAG_NHSYNC;
+	} else {
+		return false;
+	}
+
+	if (strcasecmp(argv[10], "+vsync") == 0) {
+		mode->flags |= DRM_MODE_FLAG_PVSYNC;
+	} else if (strcasecmp(argv[10], "-vsync") == 0) {
+		mode->flags |= DRM_MODE_FLAG_NVSYNC;
+	} else {
+		return false;
+	}
+
+	snprintf(mode->name, sizeof(mode->name), "%dx%d@%d",
+		 mode->hdisplay, mode->vdisplay, mode->vrefresh / 1000);
+
+	return true;
+}
+
+struct cmd_results *output_cmd_modeline(int argc, char **argv) {
+	if (!config->handler_context.output_config) {
+		return cmd_results_new(CMD_FAILURE, "Missing output config");
+	}
+	if (!argc) {
+		return cmd_results_new(CMD_INVALID, "Missing modeline argument.");
+	}
+
+	struct output_config *output = config->handler_context.output_config;
+
+	if (argc != 11 || !parse_modeline(argv, &output->drm_mode)) {
+		return cmd_results_new(CMD_INVALID, "Invalid modeline");
+	}
+
+	config->handler_context.leftovers.argc = argc - 12;
+	config->handler_context.leftovers.argv = argv + 12;
+	return NULL;
+}
+

sway/config/output.c

@@ -8,6 +8,7 @@
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/types/wlr_output_layout.h>
 #include <wlr/types/wlr_output.h>
+#include <wlr/backend/drm.h>
 #include "sway/config.h"
 #include "sway/input/cursor.h"
 #include "sway/output.h"
@@ -58,6 +59,7 @@ struct output_config *new_output_config(const char *name) {
 	oc->width = oc->height = -1;
 	oc->refresh_rate = -1;
 	oc->custom_mode = -1;
+	oc->drm_mode.type = -1;
 	oc->x = oc->y = -1;
 	oc->scale = -1;
 	oc->scale_filter = SCALE_FILTER_DEFAULT;
@@ -99,6 +101,9 @@ void merge_output_config(struct output_config *dst, struct output_config *src) {
 	if (src->custom_mode != -1) {
 		dst->custom_mode = src->custom_mode;
 	}
+	if (src->drm_mode.type != (uint32_t) -1) {
+		memcpy(&dst->drm_mode, &src->drm_mode, sizeof(src->drm_mode));
+	}
 	if (src->transform != -1) {
 		dst->transform = src->transform;
 	}
@@ -271,6 +276,18 @@ static void set_mode(struct wlr_output *output, int width, int height,
 	wlr_output_set_mode(output, best);
 }
 
+static void set_modeline(struct wlr_output *output, drmModeModeInfo *drm_mode) {
+	if (!wlr_output_is_drm(output)) {
+		sway_log(SWAY_ERROR, "Modeline can only be set to DRM output");
+		return;
+	}
+	sway_log(SWAY_DEBUG, "Assigning custom modeline to %s", output->name);
+	struct wlr_output_mode *mode = wlr_drm_connector_add_mode(output, drm_mode);
+	if (mode) {
+		wlr_output_set_mode(output, mode);
+	}
+}
+
 /* Some manufacturers hardcode the aspect-ratio of the output in the physical
  * size field. */
 static bool phys_size_is_aspect_ratio(struct wlr_output *output) {
@@ -351,7 +368,11 @@ static void queue_output_config(struct output_config *oc,
 	sway_log(SWAY_DEBUG, "Turning on output %s", wlr_output->name);
 	wlr_output_enable(wlr_output, true);
 
-	if (oc && oc->width > 0 && oc->height > 0) {
+	if (oc && oc->drm_mode.type != 0 && oc->drm_mode.type != (uint32_t) -1) {
+		sway_log(SWAY_DEBUG, "Set %s modeline",
+			wlr_output->name);
+		set_modeline(wlr_output, &oc->drm_mode);
+	} else if (oc && oc->width > 0 && oc->height > 0) {
 		sway_log(SWAY_DEBUG, "Set %s mode to %dx%d (%f Hz)",
 			wlr_output->name, oc->width, oc->height, oc->refresh_rate);
 		set_mode(wlr_output, oc->width, oc->height,

sway/sway-output.5.scd

@@ -40,6 +40,16 @@ must be separated by one space. For example:
 
 		output HDMI-A-1 mode 1920x1080@60Hz
 
+*output* <name> modeline <clock> <hdisplay> <hsync_start> <hsync_end> <htotal> <vdisplay> <vsync_start> <vsync_end> <vtotal> <hsync> <vsync>
+	Configures the specified output to use the given modeline. It can be
+	generated using *cvt*(1) and *gtf*(1) commands. See *xorg.conf*(5).
+	Only supported on DRM backend.
+
+	Example:
+
+		output HDMI-A-1 modeline 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
+
+
 *output* <name> position|pos <X> <Y>
 	Places the specified output at the specific position in the global
 	coordinate space. The cursor may only be moved between immediately