path: root/drivers/gpu/drm/drm_crtc_helper.c

/*
 * Copyright (c) 2006-2008 Intel Corporation
 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
 *
 * DRM core CRTC related functions
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 *
 * Authors:
 *      Keith Packard
 *	Eric Anholt <eric@anholt.net>
 *      Dave Airlie <airlied@linux.ie>
 *      Jesse Barnes <jesse.barnes@intel.com>
 */

#include <linux/export.h>
#include <linux/moduleparam.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_edid.h>

MODULE_AUTHOR("David Airlie, Jesse Barnes");
MODULE_DESCRIPTION("DRM KMS helper");
MODULE_LICENSE("GPL and additional rights");

/**
 * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
 * 						connector list
 * @dev: drm device to operate on
 *
 * Some userspace presumes that the first connected connector is the main
 * display, where it's supposed to display e.g. the login screen. For
 * laptops, this should be the main panel. Use this function to sort all
 * (eDP/LVDS) panels to the front of the connector list, instead of
 * painstakingly trying to initialize them in the right order.
 */
void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
{
	struct drm_connector *connector, *tmp;
	struct list_head panel_list;

	INIT_LIST_HEAD(&panel_list);

	list_for_each_entry_safe(connector, tmp,
				 &dev->mode_config.connector_list, head) {
		if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
		    connector->connector_type == DRM_MODE_CONNECTOR_eDP)
			list_move_tail(&connector->head, &panel_list);
	}

	list_splice(&panel_list, &dev->mode_config.connector_list);
}
EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);

static bool drm_kms_helper_poll = true;
module_param_named(poll, drm_kms_helper_poll, bool, 0600);

static void drm_mode_validate_flag(struct drm_connector *connector,
				   int flags)
{
	struct drm_display_mode *mode;

	if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE |
		      DRM_MODE_FLAG_3D_MASK))
		return;

	list_for_each_entry(mode, &connector->modes, head) {
		if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
				!(flags & DRM_MODE_FLAG_INTERLACE))
			mode->status = MODE_NO_INTERLACE;
		if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
				!(flags & DRM_MODE_FLAG_DBLSCAN))
			mode->status = MODE_NO_DBLESCAN;
		if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
				!(flags & DRM_MODE_FLAG_3D_MASK))
			mode->status = MODE_NO_STEREO;
	}

	return;
}

/**
 * drm_helper_probe_single_connector_modes - get complete set of display modes
 * @connector: connector to probe
 * @maxX: max width for modes
 * @maxY: max height for modes
 *
 * LOCKING:
 * Caller must hold mode config lock.
 *
 * Based on the helper callbacks implemented by @connector try to detect all
 * valid modes.  Modes will first be added to the connector's probed_modes list,
 * then culled (based on validity and the @maxX, @maxY parameters) and put into
 * the normal modes list.
 *
 * Intended to be use as a generic implementation of the ->fill_modes()
 * @connector vfunc for drivers that use the crtc helpers for output mode
 * filtering and detection.
 *
 * RETURNS:
 * Number of modes found on @connector.
 */
int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
					    uint32_t maxX, uint32_t maxY)
{
	struct drm_device *dev = connector->dev;
	struct drm_display_mode *mode;
	struct drm_connector_helper_funcs *connector_funcs =
		connector->helper_private;
	int count = 0;
	int mode_flags = 0;
	bool verbose_prune = true;

	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
			drm_get_connector_name(connector));
	/* set all modes to the unverified state */
	list_for_each_entry(mode, &connector->modes, head)
		mode->status = MODE_UNVERIFIED;

	if (connector->force) {
		if (connector->force ==