/**************************************************************************

 *

 * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA

 * All Rights Reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sub license, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice (including the

 * next paragraph) shall be included in all copies or substantial portions

 * of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL

 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,

 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

 * USE OR OTHER DEALINGS IN THE SOFTWARE.

 *

 **************************************************************************/

/*

 * Thanks to krh and jcristau for the tips on

 * going from fd to pci id via fstat and udev.

 */

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <xf86drm.h>

#include <string.h>

#include <unistd.h>

#include <sys/stat.h>

#include <sys/types.h>

#ifdef MAJOR_IN_MKDEV

#include <sys/mkdev.h>

#endif

#ifdef MAJOR_IN_SYSMACROS

#include <sys/sysmacros.h>

#endif

#include "libdrm_macros.h"

#include "internal.h"

#define PATH_SIZE 512

static int

linux_name_from_sysfs(int fd, char **out)

{

	char path[PATH_SIZE+1] = ""; /* initialize to please valgrind */

	char link[PATH_SIZE+1] = "";

	struct stat buffer;

	unsigned maj, min;

	char* slash_name;

	int ret;

	/* 

	 * Inside the sysfs directory for the device there is a symlink

	 * to the directory representing the driver module, that path

	 * happens to hold the name of the driver.

	 *

	 * So lets get the symlink for the drm device. Then read the link

	 * and filter out the last directory which happens to be the name

	 * of the driver, which we can use to load the correct interface.

	 *

	 * Thanks to Ray Strode of Plymouth for the code.

	 */

	ret = fstat(fd, &buffer);

	if (ret)

		return -EINVAL;

	if (!S_ISCHR(buffer.st_mode))

		return -EINVAL;

	maj = major(buffer.st_rdev);

	min = minor(buffer.st_rdev);

	snprintf(path, PATH_SIZE, "/sys/dev/char/%d:%d/device/driver", maj, min);

	if (readlink(path, link, PATH_SIZE) < 0)

		return -EINVAL;

	/* link looks something like this: ../../../bus/pci/drivers/intel */

	slash_name = strrchr(link, '/');

	if (!slash_name)

		return -EINVAL;

	/* copy name and at the same time remove the slash */

	*out = strdup(slash_name + 1);

	return 0;

}

static int

linux_from_sysfs(int fd, struct kms_driver **out)

{

	char *name;

	int ret;

	ret = linux_name_from_sysfs(fd, &name);

	if (ret)

		return ret;

#if HAVE_INTEL

	if (!strcmp(name, "intel"))

		ret = intel_create(fd, out);

	else

#endif

#if HAVE_VMWGFX

	if (!strcmp(name, "vmwgfx"))

		ret = vmwgfx_create(fd, out);

	else

#endif

#if HAVE_NOUVEAU

	if (!strcmp(name, "nouveau"))

		ret = nouveau_create(fd, out);

	else

#endif

#if HAVE_RADEON

	if (!strcmp(name, "radeon"))

		ret = radeon_create(fd, out);

	else

#endif

#if HAVE_EXYNOS

	if (!strcmp(name, "exynos"))

		ret = exynos_create(fd, out);

	else

#endif

		ret = -ENOSYS;

	free(name);

	return ret;

}

drm_private int

linux_create(int fd, struct kms_driver **out)

{

	if (!dumb_create(fd, out))

		return 0;

	return linux_from_sysfs(fd, out);

}