/*
* Copyright (c) 2006-2009 Red Hat Inc.
* Copyright (c) 2006-2008 Intel Corporation
* Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
*
* DRM framebuffer helper 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:
* Dave Airlie <airlied@linux.ie>
* Jesse Barnes <jesse.barnes@intel.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/sysrq.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/module.h>
#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>
MODULE_AUTHOR("David Airlie, Jesse Barnes");
MODULE_DESCRIPTION("DRM KMS helper");
MODULE_LICENSE("GPL and additional rights");
static LIST_HEAD(kernel_fb_helper_list);
/**
* DOC: fbdev helpers
*
* The fb helper functions are useful to provide an fbdev on top of a drm kernel
* mode setting driver. They can be used mostly independantely from the crtc
* helper functions used by many drivers to implement the kernel mode setting
* interfaces.
*
* Initialization is done as a three-step process with drm_fb_helper_init(),
* drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config().
* Drivers with fancier requirements than the default beheviour can override the
* second step with their own code. Teardown is done with drm_fb_helper_fini().
*
* At runtime drivers should restore the fbdev console by calling
* drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They
* should also notify the fb helper code from updates to the output
* configuration by calling drm_fb_helper_hotplug_event(). For easier
* integration with the output polling code in drm_crtc_helper.c the modeset
* code proves a ->output_poll_changed callback.
*
* All other functions exported by the fb helper library can be used to
* implement the fbdev driver interface by the driver.
*/
/**
* drm_fb_helper_single_add_all_connectors() - add all connectors to fbdev
* emulation helper
* @fb_helper: fbdev initialized with drm_fb_helper_init
*
* This functions adds all the available connectors for use with the given
* fb_helper. This is a separate step to allow drivers to freely assign
* connectors to the fbdev, e.g. if some are reserved for special purposes or
* not adequate to be used for the fbcon.
*
* Since this is part of the initial setup before
|