path: root/drivers/gpu/drm/drm_probe_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>

/**
 * DOC: output probing helper overview
 *
 * This library provides some helper code for output probing. It provides an
 * implementation of the core connector->fill_modes interface with
 * drm_helper_probe_single_connector_modes.
 *
 * It also provides support for polling connectors with a work item and for
 * generic hotplug interrupt handling where the driver doesn't or cannot keep
 * track of a per-connector hpd interrupt.
 *
 * This helper library can be used independently of the modeset helper library.
 * Drivers can also overwrite different parts e.g. use their own hotplug
 * handling code to avoid probing unrelated outputs.
 */

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

static enum drm_mode_status
drm_mode_validate_flag(const struct drm_display_mode *mode,
		       int flags)
{
	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
	    !(flags & DRM_MODE_FLAG_INTERLACE))
		return MODE_NO_INTERLACE;

	if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
	    !(flags & DRM_MODE_FLAG_DBLSCAN))
		return MODE_NO_DBLESCAN;

	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
	    !(flags & DRM_MODE_FLAG_3D_MASK))
		return MODE_NO_STEREO;

	return MODE_OK;
}

static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
{
	struct drm_display_mode *mode;

	if (!connector->cmdline_mode.specified)
		return 0;

	mode = drm_mode_create_from_cmdline_mode(connector->dev,
						 &connector->cmdline_mode);
	if (mode == NULL)
		return 0;

	drm_mode_probed_add(connector, mode);
	return 1;
}

static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
							      uint32_t maxX, uint32_t maxY, bool merge_type_bits)
{
	struct drm_device *dev = connector->dev;
	struct drm_display_mode *mode;
	const struct drm_connector_helper_funcs *connector_funcs =
		connector->helper_private;
	int count = 0;
	int mode_flags = 0;
	bool verbose_prune = true;
	enum drm_connector_status old_status;

	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));

	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
			connector->name);
	/* 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 == DRM_FORCE_ON ||
		    connector->force == DRM_FORCE_ON_DIGITAL)
			connector->status = connector_status_connected;
		else
			connector->status = connector_status_disconnected;
		if (connector->funcs->force)
			connector->funcs->force(connector);
	} else {
		old_status = connector->status;

		connector->status = connector->funcs->detect(connector, true);

		/*
		 * Normally either the driver's hpd code or the poll loop should
		 * pick up any changes and fire the hotplug event. But if
		 * userspace sneaks in a probe, we might miss a change. Hence
		 * check here, and if anything changed start the hotplug code.
		 */
		if (old_status != connector->status) {
			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
				      connector->base.id,
				      connector->name,
				      old_status, connector->status);

			/*
			 * The hotplug event code might call into the fb
			 * helpers, and so expects that we do not hold any
			 * locks. Fire up the poll struct instead, it will
			 * disable itself again.
			 */
			dev->mode_config.delayed_event = true;
			if (dev->mode_config.poll_enabled)
				schedule_delayed_work(&dev->mode_config.output_poll_work,
						      0);
		}
	}

	/* Re-enable polling in case the global poll config changed. */
	if (drm_kms_helper_poll != dev->mode_config.poll_running)
		drm_kms_helper_poll_enable(dev);

	dev->mode_config.poll_running = drm_kms_helper_poll;

	if (connector->status == connector_status_disconnected) {
		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
			connector->base.id, connector->name);
		drm_mode_connector_update_edid_property(connector, NULL);
		verbose_prune = false;
		goto prune;
	}

#ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
	count = drm_load_edid_firmware(connector);
	if (count == 0)
#endif
	{
		if (connector->override_edid) {
			struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;

			count = drm_add_edid_modes(connector, edid);
			drm_edid_to_eld(connector, edid);
		} else
			count = (*connector_funcs->get_modes)(connector);
	}

	if (count == 0 && connector->status == connector_status_connected)
		count = drm_add_modes_noedid(connector, 1024, 768);
	count += drm_helper_probe_add_cmdline_mode(connector);
	if (count == 0)
		goto prune;

	drm_mode_connector_list_update(connector, merge_type_bits);

	if (connector->interlace_allowed)
		mode_flags |= DRM_MODE_FLAG_INTERLACE;
	if (connector->doublescan_allowed)
		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
	if (connector->stereo_allowed)
		mode_flags |= DRM_MODE_FLAG_3D_MASK;

	list_for_each_entry(mode, &connector->modes, head) {
		mode->status = drm_mode_validate_basic(mode);

		if (mode->status == MODE_OK)
			mode->status = drm_mode_validate_size(mode, maxX, maxY);

		if (mode->status == MODE_OK)
			mode->status = drm_mode_validate_flag(mode, mode_flags);

		if (mode->status == MODE_OK && connector_funcs->mode_valid)
			mode->status = connector_funcs->mode_valid(connector,
								   mode);
	}

prune:
	drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);

	if (list_empty(&connector->modes))
		return 0;

	list_for_each_entry(mode, &connector->modes, head)
		mode->vrefresh = drm_mode_vrefresh(mode);

	drm_mode_sort(&connector->modes);

	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
			connector->name);
	list_for_each_entry(mode, &connector->modes, head) {
		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
		drm_mode_debug_printmodeline(mode);
	}

	return count;
}

/**
 * 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
 *
 * 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:
 * The number of modes found on @connector.
 */
int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
					    uint32_t maxX, uint32_t maxY)
{
	return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
}
EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);

/**
 * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
 * @connector: connector to probe
 * @maxX: max width for modes
 * @maxY: max height for modes
 *
 * This operates like drm_hehlper_probe_single_connector_modes except it
 * replaces the mode bits instead of merging them for preferred modes.
 */
int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
					    uint32_t maxX, uint32_t maxY)
{
	return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, <