/*
 * switch-display: A tool for switching display for Lenovo T61 laptops
 * 	(and friends - with Nvidia Quadro 140 NVS graphics)
 *
 * Copyright (C) 2008 Andreas Jellinghaus
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of Version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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 Version 2
 * of 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, write to the:
 *
 *           Free Software Foundation, Inc.
 *           59 Temple Place - Suite 330
 *           Boston, MA 02111-1307, USA
 *
 * This program is based on 
 * 	nvidia-settings: A tool for configuring the NVIDIA X driver on Unix
 *  	and Linux systems.
 *    
 *	Copyright (C) 2004 NVIDIA Corporation.
 *
 */

#include <stdio.h>
#include <stdlib.h>

#include <X11/Xlib.h>

#include "NVCtrl.h"
#include "NVCtrlLib.h"

int main(int argc, char *argv[])
{
	Display *dpy;
	Bool ret;
	int screen = -1;
	int display_devices, connected_displays, enabled_displays, new_displays;

	/*
	 * Open a display connection, and make sure the NV-CONTROL X
	 * extension is present on the screen we want to use.
	 */

	dpy = XOpenDisplay(NULL);
	if (!dpy) {
		fprintf(stderr, "Cannot open display '%s'.\n", XDisplayName(NULL));
		return 1;
	}

	screen = DefaultScreen(dpy);

	if (!XNVCTRLIsNvScreen(dpy, screen)) {
		fprintf(stderr, "The NV-CONTROL X not available on screen "
				"%d of '%s'.\n", screen, XDisplayName(NULL));
		return 1;
	}

	/* Probe the GPU for new/old display devices */

	ret = XNVCTRLQueryTargetAttribute(dpy,
									  NV_CTRL_TARGET_TYPE_GPU, 0,
									  0,
									  NV_CTRL_PROBE_DISPLAYS, &display_devices);

	if (!ret) {
		fprintf(stderr, "Failed to probe the enabled Display "
				"Devices on GPU-%d.\n\n", 0);
		return 1;
	}

	printf("  display devices on GPU-%d):\n", 0);

	/*
	 * Get the bitmask of connected display 
	 */

	ret = XNVCTRLQueryAttribute(dpy,
								screen,
								0,
								NV_CTRL_CONNECTED_DISPLAYS,
								&connected_displays);
	if (!ret) {
		fprintf(stderr, "Unable to determine connected displays for "
				"screen %d of '%s'\n", screen, XDisplayName(NULL));
		return 1;
	}

	/*
	 * Get the bitmask of enabled display
	 */

	ret = XNVCTRLQueryAttribute(dpy,
								screen,
								0, NV_CTRL_ENABLED_DISPLAYS, &enabled_displays);
	if (!ret) {
		fprintf(stderr, "Unable to determine enabled displays for "
				"screen %d of '%s'\n", screen, XDisplayName(NULL));
		return 1;
	}

	/* now enable what is not enabled (switch) */

	new_displays = connected_displays ^ enabled_displays;

	printf
		("connected displays: 0x%08x, enabled displays: 0x%08x new displays: 0x%08x\n",
		 connected_displays, enabled_displays, new_displays);

	if (!new_displays) {
		fprintf(stderr, "no new display, aborting!\n");
		return 1;
	}

	ret = XNVCTRLSetAttributeAndGetStatus
		(dpy, screen, 0, NV_CTRL_SWITCH_TO_DISPLAYS, new_displays);

	if (!ret) {
		fprintf(stderr, "Unable to switch to new displays for "
				"screen %d of '%s'\n", screen, XDisplayName(NULL));
		return 1;
	}

	return 0;
}