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

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * 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.
 */

#include <drm/drmP.h>
#include <drm/drm_connector.h>
#include <drm/drm_edid.h>
#include <drm/drm_encoder.h>

#include "drm_crtc_internal.h"
#include "drm_internal.h"

/**
 * DOC: overview
 *
 * In DRM connectors are the general abstraction for display sinks, and include
 * als fixed panels or anything else that can display pixels in some form. As
 * opposed to all other KMS objects representing hardware (like CRTC, encoder or
 * plane abstractions) connectors can be hotplugged and unplugged at runtime.
 * Hence they are reference-counted using drm_connector_get() and
 * drm_connector_put().
 *
 * KMS driver must create, initialize, register and attach at a &struct
 * drm_connector for each such sink. The instance is created as other KMS
 * objects and initialized by setting the following fields. The connector is
 * initialized with a call to drm_connector_init() with a pointer to the
 * &struct drm_connector_funcs and a connector type, and then exposed to
 * userspace with a call to drm_connector_register().
 *
 * Connectors must be attached to an encoder to be used. For devices that map
 * connectors to encoders 1:1, the connector should be attached at
 * initialization time with a call to drm_mode_connector_attach_encoder(). The
 * driver must also set the &drm_connector.encoder field to point to the
 * attached encoder.
 *
 * For connectors which are not fixed (like built-in panels) the driver needs to
 * support hotplug notifications. The simplest way to do that is by using the
 * probe helpers, see drm_kms_helper_poll_init() for connectors which don't have
 * hardware support for hotplug interrupts. Connectors with hardware hotplug
 * support can instead use e.g. drm_helper_hpd_irq_event().
 */

struct drm_conn_prop_enum_list {
	int type;
	const char *name;
	struct ida ida;
};

/*
 * Connector and encoder types.
 */
static struct drm_conn_prop_enum_list drm_connector_enum_list[] = {
	{ DRM_MODE_CONNECTOR_Unknown, "Unknown" },
	{ DRM_MODE_CONNECTOR_VGA, "VGA" },
	{ DRM_MODE_CONNECTOR_DVII, "DVI-I" },
	{ DRM_MODE_CONNECTOR_DVID, "DVI-D" },
	{ DRM_MODE_CONNECTOR_DVIA, "DVI-A" },
	{ DRM_MODE_CONNECTOR_Composite, "Composite" },
	{ DRM_MODE_CONNECTOR_SVIDEO, "SVIDEO" },
	{ DRM_MODE_CONNECTOR_LVDS, "LVDS" },
	{ DRM_MODE_CONNECTOR_Component, "Component" },
	{ DRM_MODE_CONNECTOR_9PinDIN, "DIN" },
	{ DRM_MODE_CONNECTOR_DisplayPort, "DP" },
	{ DRM_MODE_CONNECTOR_HDMIA, "HDMI-A" },
	{ DRM_MODE_CONNECTOR_HDMIB, "HDMI-B" },
	{ DRM_MODE_CONNECTOR_TV, "TV" },
	{ DRM_MODE_CONNECTOR_eDP, "eDP" },
	{ DRM_MODE_CONNECTOR_VIRTUAL, "Virtual" },
	{ DRM_MODE_CONNECTOR_DSI, "DSI" },
	{ DRM_MODE_CONNECTOR_DPI, "DPI" },
};

void drm_connector_ida_init(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
		ida_init(&drm_connector_enum_list[i].ida);
}

void drm_connector_ida_destroy(void)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
		ida_destroy(&drm_connector_enum_list[i].ida);
}

/**
 * drm_connector_get_cmdline_mode - reads the user's cmdline mode
 * @connector: connector to quwery
 *
 * The kernel supports per-connector configuration of its consoles through
 * use of the video= parameter. This function parses that option and
 * extracts the user's specified mode (or enable/disable status) for a
 * particular connector. This is typically only used during the early fbdev
 * setup.
 */
static void drm_connector_get_cmdline_mode(struct drm_connector *connector)
{
	struct drm_cmdline_mode *mode = &connector->cmdline_mode;
	char *option = NULL;

	if (fb_get_options(connector->name, &option))
		return;

	if (!drm_mode_parse_command_line_for_connector(option,
						       connector,
						       mode))
		return;

	if (mode->force) {
		DRM_INFO("forcing %s connector %s\n", connector->name,
			 drm_get_connector_force_name(mode->force));
		connector->force = mode->force;
	}

	DRM_DEBUG_KMS("cmdline mode for connector %s %dx%d@%dHz%s%s%s\n",
		      connector->name,
		      mode->xres, mode->yres,
		      mode->refresh_specified ? mode->refresh : 60,
		      mode->rb ? " reduced blanking" : "",
		      mode->margins ? " with margins" : "",
		      mode->interlace ?  " interlaced" : "");
}

static void drm_connector_free(struct kref *kref)
{
	struct drm_connector *connector =
		container_of(kref, struct drm_connector, base.refcount);
	struct drm_device *dev = connector->dev;

	drm_mode_object_unregister(dev, &connector->base);
	connector->funcs->destroy(connector);
}

/**
 * drm_connector_init - Init a preallocated connector
 * @dev: DRM device
 * @connector: the connector to init
 * @funcs: callbacks for this connector
 * @connector_type: user visible type of the connector
 *
 * Initialises a preallocated connector. Connectors should be
 * subclassed as part of driver connector objects.
 *
 * Returns:
 * Zero on success, error code on failure.
 */
int drm_connector_init(struct drm_device *dev,
		       struct drm_connector *connector,
		       const struct drm_connector_funcs *funcs,
		       int connector_type)
{
	struct drm_mode_config *config = &dev->mode_config;
	int ret;
	struct ida *connector_ida =
		&drm_connector_enum_list[connector_type].ida;

	ret = __drm_mode_object_add(dev, &connector->base,
				    DRM_MODE_OBJECT_CONNECTOR,
				    false, drm_connector_free);
	if (ret)
		return ret;

	connector->base.properties = &connector->properties;
	connector->dev = dev;
	connector->funcs = funcs;

	ret = ida_simple_get(&config->connector_ida, 0, 0, GFP_KERNEL);
	if (ret < 0)
		goto out_put;
	connector->index = ret;
	ret = 0;

	connector->connector_type = connector_type;
	connector->connector_type_id =
		ida_simple_get(connector_ida, 1, 0, GFP_KERNEL);
	if (connector->connector_type_id < 0) {
		ret = connector->connector_type_id;
		goto out_put_id;
	}
	connector->name =
		kasprintf(GFP_KERNEL, "%s-%d",
			  drm_connector_enum_list[connector_type].name,
			  connector->connector_type_id);
	if (!connector->name) {
		ret = -ENOMEM;
		goto out_put_type_id;
	}

	INIT_LIST_HEAD(&connector->probed_modes);
	INIT_LIST_HEAD(&connector->modes);
	mutex_init(&connector->mutex);
	connector->edid_blob_ptr = NULL;
	connector->status = connector_status_unknown;

	drm_connector_get_cmdline_mode(connector);

	/* We should add connectors a