path: root/drivers/gpu/drm/i915/intel_panel.c

/*
 * Copyright © 2006-2010 Intel Corporation
 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
 *
 * 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, sublicense,
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Authors:
 *	Eric Anholt <eric@anholt.net>
 *      Dave Airlie <airlied@linux.ie>
 *      Jesse Barnes <jesse.barnes@intel.com>
 *      Chris Wilson <chris@chris-wilson.co.uk>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/moduleparam.h>
#include "intel_drv.h"

#define PCI_LBPC 0xf4 /* legacy/combination backlight modes */

void
intel_fixed_panel_mode(const struct drm_display_mode *fixed_mode,
		       struct drm_display_mode *adjusted_mode)
{
	drm_mode_copy(adjusted_mode, fixed_mode);

	drm_mode_set_crtcinfo(adjusted_mode, 0);
}

/* adjusted_mode has been preset to be the panel's fixed mode */
void
intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
			struct intel_crtc_config *pipe_config,
			int fitting_mode)
{
	struct drm_display_mode *adjusted_mode;
	int x, y, width, height;

	adjusted_mode = &pipe_config->adjusted_mode;

	x = y = width = height = 0;

	/* Native modes don't need fitting */
	if (adjusted_mode->hdisplay == pipe_config->pipe_src_w &&
	    adjusted_mode->vdisplay == pipe_config->pipe_src_h)
		goto done;

	switch (fitting_mode) {
	case DRM_MODE_SCALE_CENTER:
		width = pipe_config->pipe_src_w;
		height = pipe_config->pipe_src_h;
		x = (adjusted_mode->hdisplay - width + 1)/2;
		y = (adjusted_mode->vdisplay - height + 1)/2;
		break;

	case DRM_MODE_SCALE_ASPECT:
		/* Scale but preserve the aspect ratio */
		{
			u32 scaled_width = adjusted_mode->hdisplay
				* pipe_config->pipe_src_h;
			u32 scaled_height = pipe_config->pipe_src_w
				* adjusted_mode->vdisplay;
			if (scaled_width > scaled_height) { /* pillar */
				width = scaled_height / pipe_config->pipe_src_h;
				if (width & 1)
					width++;
				x = (adjusted_mode->hdisplay - width + 1) / 2;
				y = 0;
				height = adjusted_mode->vdisplay;
			} else if (scaled_width < scaled_height) { /* letter */
				height = scaled_width / pipe_config->pipe_src_w;
				if (height & 1)
				    height++;
				y = (adjusted_mode->vdisplay - height + 1) / 2;
				x = 0;
				width = adjusted_mode->hdisplay;
			} else {
				x = y = 0;
				width = adjusted_mode->hdisplay;
				height