/*
 * Copyright (c) 2006 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *
 */
#include <drm/drmP.h>
#include <drm/drm.h>
#include "psb_drm.h"
#include "psb_drv.h"
#include "psb_intel_drv.h"
#include "psb_intel_reg.h"
#include "psb_intel_bios.h"


static void *find_section(struct bdb_header *bdb, int section_id)
{
	u8 *base = (u8 *)bdb;
	int index = 0;
	u16 total, current_size;
	u8 current_id;

	/* skip to first section */
	index += bdb->header_size;
	total = bdb->bdb_size;

	/* walk the sections looking for section_id */
	while (index < total) {
		current_id = *(base + index);
		index++;
		current_size = *((u16 *)(base + index));
		index += 2;
		if (current_id == section_id)
			return base + index;
		index += current_size;
	}

	return NULL;
}

static void fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
			struct lvds_dvo_timing *dvo_timing)
{
	panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
		dvo_timing->hactive_lo;
	panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
		((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
	panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
		dvo_timing->hsync_pulse_width;
	panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
		((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);

	panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
		dvo_timing->vactive_lo;
	panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
		dvo_timing->vsync_off;
	panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
		dvo_timing->vsync_pulse_width;
	panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
		((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
	panel_fixed_mode->clock = dvo_timing->clock * 10;
	panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;

	/* Some VBTs have bogus h/vtotal values */
	if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
		panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
	if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
		panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;

	drm_mode_set_name(panel_fixed_mode);
}

static void parse_backlight_data(struct drm_psb_private *dev_priv,
				struct bdb_header *bdb)
{
	struct bdb_lvds_backlight *vbt_lvds_bl = NULL;
	struct bdb_lvds_backlight *lvds_bl;
	u8 p_type = 0;
	void *bl_start = NULL;
	struct bdb_lvds_options *lvds_opts
				= find_section(bdb, BDB_LVDS_OPTIONS);

	dev_priv->lvds_bl = NULL;

	if (lvds_opts) {
		DRM_DEBUG("lvds_options found at %p\n", lvds_opts);
		p_type = lvds_opts->panel_type;
	} else {
		DRM_DEBUG("no lvds_options\n");
		return;
	}

	bl_start = find_section(bdb, BDB_LVDS_BACKLIGHT);
	vbt_lvds_bl = (struct bdb_lvds_backlight *)(bl_start + 1) + p_type;

	lvds_bl = kzalloc(sizeof(*vbt_lvds_bl), GFP_KERNEL);
	if (!lvds_bl) {
		DRM_DEBUG("No memory\n");
		return;
	}

	memcpy(lvds_bl, vbt_lvds_bl, sizeof(*vbt_lvds_bl));

	dev_priv->lvds_bl = lvds_bl;
}

/* Try to find integrated panel data */
static void parse_lfp_panel_data(struct drm_psb_private *dev_priv,
			    struct bdb_header *bdb)
{
	struct bdb_lvds_options *lvds_options;
	struct bdb_lvds_lfp_data *lvds_lfp_data;
	struct bdb_lvds_lfp_data_entry *entry;
	struct lvds_dvo_timing *dvo_timing;
	struct drm_display_mode *panel_fixed_mode;

	/* Defaults if we can't find VBT info */
	dev_priv->lvds_dither = 0;
	dev_priv->lvds_vbt = 0;

	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
	if (!lvds_options)
		return;

	dev_priv->lvds_dither = lvds_options->pixel_dither;
	if (lvds_options->panel_type == 0xff)
		return;

	lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
	if (!lvds_lfp_data)
		return;

	dev_priv->lvds_vbt = 1;

	entry = &lvds_lfp_data->data[lvds_options->panel_type];
	dvo_timing = &entry->dvo_timing;

	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode),
				      GFP_KERNEL);

	fill_detail_timing_data(panel_fixed_mode, dvo_timing);

	if (panel_fixed_mode->htotal > 0 && panel_fixed_mode->vtotal > 0) {
		dev_priv->lfp_lvds_vbt_mode = panel_fixed_mode;
		DRM_DEBUG("Found panel mode in BIOS VBT tables:\n");
		drm_mode_debug_printmodeline(panel_fixed_mode);
	} else {
		DRM_DEBUG("Ignoring bogus LVDS VBT mode.\n");
		dev_priv->lvds_vbt = 0;
		kfree(panel_fixed_mode);
	}

	return;
}

/* Try to find sdvo panel data */
static void parse_sdvo_panel_data(struct drm_psb_private *dev_priv,
		      struct bdb_header *bdb)
{
	struct bdb_sdvo_lvds_options *sdvo_lvds_options;
	struct lvds_dvo_timing *dvo_timing;
	struct drm_display_mode *panel_fixed_mode;

	dev_priv->sdvo_lvds_vbt_mode = NULL;

	sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
	if (!sdvo_lvds_options)
		return;

	dvo_timing = find_section(bdb, BDB_SDVO_PANEL_DTDS);
	if (!dvo_timing)
		return;

	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);

	if (!panel_fixed_mode)
		return;

	fill_detail_timing_data(panel_fixed_mode,
			dvo_timing + sdvo_lvds_options->panel_type);

	dev_priv->sdvo_lvds_vbt_mode = panel_fixed_mode;

	return;
}

static void parse_general_features(struct drm_psb_private *dev_priv,
		       struct bdb_header *bdb)
{
	struct bdb_general_features *general;

	/* Set sensible defaults in case we can't find the general block */
	dev_priv->int_tv_support = 1;
	dev_priv->int_crt_support = 1;

	general = find_section(bdb, BDB_GENERAL_FEATURES);
	if (general) {
		dev_priv->int_tv_support = general->int_tv_support;
		dev_priv->int_crt_support = general->int_crt_support;
		dev_priv->lvds_use_ssc = general->enable_ssc;

		if (dev_priv->lvds_use_ssc) {
			dev_priv->lvds_ssc_freq
				= general->ssc_freq ? 100 : 96;
		}
	}
}

/**
 * psb_intel_init_bios - initialize VBIOS settings & find VBT
 * @dev: DRM device
 *
 * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
 * to appropriate values.
 *
 * VBT existence is a sanity check that is relied on by other i830_bios.c code.
 * Note that it would be better to use a BIOS call to get the VBT, as BIOSes may
 * feed an updated VBT back through that, compared to what we'll fetch using
 * this method of groping around in the BIOS data.
 *
 * Returns 0 on success, nonzero on failure.
 */
bool psb_intel_init_bios(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = dev->dev_private;
	struct pci_dev *pdev = dev->pdev;
	struct vbt_header *vbt = NULL;
	struct bdb_header *bdb;
	u8 __iomem *bios;
	size_t size;
	int i;

	bios = pci_map_rom(pdev, &size);
	if (!bios)
		return -1;

	/* Scour memory looking for the VBT signature */
	for (i = 0; i + 4 < size; i++) {
		if (!memcmp(bios + i, "$VBT", 4)) {
			vbt = (struct vbt_header *)(bios + i);
			break;
		}
	}

	if (!vbt) {
		DRM_ERROR("VBT signature missing\n");
		pci_unmap_rom(pdev, bios);
		return -1;
	}

	bdb = (struct bdb_header *)(bios + i + vbt->bdb_offset);

	/* Grab useful general definitions */
	parse_general_features(dev_priv, bdb);
	parse_lfp_panel_data(dev_priv, bdb);
	parse_sdvo_panel_data(dev_priv, bdb);
	parse_backlight_data(dev_priv, bdb);

	pci_unmap_rom(pdev, bios);

	return 0;
}

/**
 * Destroy and free VBT data
 */
void psb_intel_destroy_bios(struct drm_device *dev)
{
	struct drm_psb_private *dev_priv = dev->dev_private;
	struct drm_display_mode *sdvo_lvds_vbt_mode =
				dev_priv->sdvo_lvds_vbt_mode;
	struct drm_display_mode *lfp_lvds_vbt_mode =
				dev_priv->lfp_lvds_vbt_mode;
	struct bdb_lvds_backlight *lvds_bl =
				dev_priv->lvds_bl;

	/*free sdvo panel mode*/
	if (sdvo_lvds_vbt_mode) {
		dev_priv->sdvo_lvds_vbt_mode = NULL;
		kfree(sdvo_lvds_vbt_mode);
	}

	if (lfp_lvds_vbt_mode) {
		dev_priv->lfp_lvds_vbt_mode = NULL;
		kfree(lfp_lvds_vbt_mode);
	}

	if (lvds_bl) {
		dev_priv->lvds_bl = NULL;
		kfree(lvds_bl);
	}
}