/*
 * 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 "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)
                p_type = lvds_opts->panel_type;
        else
                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) {
                dev_err(dev_priv->dev->dev, "out of memory for backlight data\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;


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

        panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode),
                                      GFP_KERNEL);
        if (panel_fixed_mode == NULL) {
                dev_err(dev_priv->dev->dev, "out of memory for fixed panel mode\n");
                return;
        }

        dev_priv->lvds_vbt = 1;
        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_mode_debug_printmodeline(panel_fixed_mode);
        } else {
                dev_dbg(dev_priv->dev->dev, "ignoring invalid LVDS VBT\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) {
                dev_err(dev->dev, "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);
        }
}