/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2017 Patrick Rudolph <siro@das-labor.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that 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.
 */

#include <types.h>
#include <string.h>
#include <console/console.h>
#include <arch/acpi.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <drivers/intel/gma/intel_bios.h>
#include "gma_opregion.h"

static void *get_intel_vbios(void)
{
	/* This should probably be looking at CBFS or we should always
	 * deploy the VBIOS on Intel systems, even if we don't run it
	 * in coreboot (e.g. SeaBIOS only scenarios).
	 */
	u8 *vbios = (u8 *)0xc0000;

	optionrom_header_t *oprom = (optionrom_header_t *)vbios;
	optionrom_pcir_t *pcir = (optionrom_pcir_t *)(vbios +
						oprom->pcir_offset);

	printk(BIOS_DEBUG, "GET_VBIOS: %x %x %x %x %x\n",
		oprom->signature, pcir->vendor, pcir->classcode[0],
		pcir->classcode[1], pcir->classcode[2]);


	if ((oprom->signature == OPROM_SIGNATURE) &&
		(pcir->vendor == PCI_VENDOR_ID_INTEL) &&
		(pcir->classcode[0] == 0x00) &&
		(pcir->classcode[1] == 0x00) &&
		(pcir->classcode[2] == 0x03))
		return (void *)vbios;

	return NULL;
}

static enum cb_err init_opregion_vbt(igd_opregion_t *opregion)
{
	void *vbios;
	vbios = get_intel_vbios();
	if (!vbios) {
		printk(BIOS_DEBUG, "VBIOS not found.\n");
		return CB_ERR;
	}

	printk(BIOS_DEBUG, " ... VBIOS found at %p\n", vbios);
	optionrom_header_t *oprom = (optionrom_header_t *)vbios;
	optionrom_vbt_t *vbt = (optionrom_vbt_t *)(vbios +
						oprom->vbt_offset);

	if (read32(vbt->hdr_signature) != VBT_SIGNATURE) {
		printk(BIOS_DEBUG, "VBT not found!\n");
		return CB_ERR;
	}

	memcpy(opregion->header.vbios_version, vbt->coreblock_biosbuild, 4);
	memcpy(opregion->vbt.gvd1, vbt, vbt->hdr_vbt_size < 7168 ?
						vbt->hdr_vbt_size : 7168);

	return CB_SUCCESS;
}

/* Initialize IGD OpRegion, called from ACPI code and OS drivers */
enum cb_err init_igd_opregion(igd_opregion_t *opregion)
{
	enum cb_err ret;
	device_t igd;
	u16 reg16;

	memset((void *)opregion, 0, sizeof(igd_opregion_t));

	// FIXME if IGD is disabled, we should exit here.

	memcpy(&opregion->header.signature, IGD_OPREGION_SIGNATURE,
		sizeof(opregion->header.signature));

	/* 8kb */
	opregion->header.size = sizeof(igd_opregion_t) / 1024;
	opregion->header.version = IGD_OPREGION_VERSION;

	// FIXME We just assume we're mobile for now
	opregion->header.mailboxes = MAILBOXES_MOBILE;

	// TODO Initialize Mailbox 1

	// TODO Initialize Mailbox 3
	opregion->mailbox3.bclp = IGD_BACKLIGHT_BRIGHTNESS;
	opregion->mailbox3.pfit = IGD_FIELD_VALID | IGD_PFIT_STRETCH;
	opregion->mailbox3.pcft = 0; // should be (IMON << 1) & 0x3e
	opregion->mailbox3.cblv = IGD_FIELD_VALID | IGD_INITIAL_BRIGHTNESS;
	opregion->mailbox3.bclm[0] = IGD_WORD_FIELD_VALID + 0x0000;
	opregion->mailbox3.bclm[1] = IGD_WORD_FIELD_VALID + 0x0a19;
	opregion->mailbox3.bclm[2] = IGD_WORD_FIELD_VALID + 0x1433;
	opregion->mailbox3.bclm[3] = IGD_WORD_FIELD_VALID + 0x1e4c;
	opregion->mailbox3.bclm[4] = IGD_WORD_FIELD_VALID + 0x2866;
	opregion->mailbox3.bclm[5] = IGD_WORD_FIELD_VALID + 0x327f;
	opregion->mailbox3.bclm[6] = IGD_WORD_FIELD_VALID + 0x3c99;
	opregion->mailbox3.bclm[7] = IGD_WORD_FIELD_VALID + 0x46b2;
	opregion->mailbox3.bclm[8] = IGD_WORD_FIELD_VALID + 0x50cc;
	opregion->mailbox3.bclm[9] = IGD_WORD_FIELD_VALID + 0x5ae5;
	opregion->mailbox3.bclm[10] = IGD_WORD_FIELD_VALID + 0x64ff;

	ret = init_opregion_vbt(opregion);
	if (ret != CB_SUCCESS)
		return ret;

	/* TODO This needs to happen in S3 resume, too.
	 * Maybe it should move to the finalize handler
	 */
	igd = dev_find_slot(0, PCI_DEVFN(0x2, 0));
	pci_write_config32(igd, ASLS, (u32)opregion);

	/* Intel's Windows driver relies on this: */
	reg16 = pci_read_config16(igd, SWSCI);
	reg16 &= ~GSSCIE;
	reg16 |= SMISCISEL;
	pci_write_config16(igd, SWSCI, reg16);

	return CB_SUCCESS;
}
