/*
 * (C) Copyright 2002
 * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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.
 *
 * 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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <pci.h>
#include <asm/io.h>
#include <asm/pci.h>

#undef PCI_ROM_SCAN_VERBOSE

int pci_shadow_rom(pci_dev_t dev, unsigned char *dest)
{
	struct pci_controller *hose;
	int res = -1;
	int i;

	u32 rom_addr;
	u32 addr_reg;
	u32 size;

	u16 vendor;
	u16 device;
	u32 class_code;

	hose = pci_bus_to_hose(PCI_BUS(dev));
#if 0
	printf("pci_shadow_rom() asked to shadow device %x to %x\n",
	       dev, (u32)dest);
#endif
	pci_read_config_word(dev, PCI_VENDOR_ID, &vendor);
	pci_read_config_word(dev, PCI_DEVICE_ID, &device);
	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class_code);

	class_code &= 0xffffff00;
	class_code >>= 8;

	debug("PCI Header Vendor %04x device %04x class %06x\n",
	       vendor, device, class_code);

	/* Enable the rom addess decoder */
	pci_write_config_dword(dev, PCI_ROM_ADDRESS, (u32)PCI_ROM_ADDRESS_MASK);
	pci_read_config_dword(dev, PCI_ROM_ADDRESS, &addr_reg);

	if (!addr_reg) {
		/* register unimplemented */
		printf("pci_chadow_rom: device do not seem to have a rom\n");
		return -1;
	}

	size = (~(addr_reg&PCI_ROM_ADDRESS_MASK))+1;

	debug("ROM is %d bytes\n", size);

	rom_addr = pci_get_rom_window(hose, size);

	debug("ROM mapped at %x\n", rom_addr);

	pci_write_config_dword(dev, PCI_ROM_ADDRESS,
			       pci_phys_to_mem(dev, rom_addr)
			       |PCI_ROM_ADDRESS_ENABLE);


	for (i=rom_addr;i<rom_addr+size; i+=512) {


		if (readw(i) == 0xaa55) {
			u32 pci_data;
#ifdef PCI_ROM_SCAN_VERBOSE
			printf("ROM signature found\n");
#endif
			pci_data = readw(0x18+i);
			pci_data += i;

			if (0==memcmp((void*)pci_data, "PCIR", 4)) {
#ifdef PCI_ROM_SCAN_VERBOSE
				printf("Fount PCI rom image at offset %d\n", i-rom_addr);
				printf("Vendor %04x device %04x class %06x\n",
				       readw(pci_data+4), readw(pci_data+6),
				       readl(pci_data+0x0d)&0xffffff);
				printf("%s\n",
				       (readw(pci_data+0x15) &0x80)?
				       "Last image":"More images follow");
				switch	(readb(pci_data+0x14)) {
				case 0:
					printf("X86 code\n");
					break;
				case 1:
					printf("Openfirmware code\n");
					break;
				case 2:
					printf("PARISC code\n");
					break;
				}
				printf("Image size %d\n", readw(pci_data+0x10) * 512);
#endif
				/* FixMe: I think we should compare the class code
				 * bytes as well but I have no reference on the
				 * exact order of these bytes in the PCI ROM header */
				if (readw(pci_data+4) == vendor &&
				    readw(pci_data+6) == device &&
				    /* (readl(pci_data+0x0d)&0xffffff) == class_code && */
				    readb(pci_data+0x14) == 0 /* x86 code image */ ) {
#ifdef PCI_ROM_SCAN_VERBOSE
					printf("Suitable ROM image found, copying\n");
#endif
					memmove(dest, (void*)rom_addr, readw(pci_data+0x10) * 512);
					res = 0;
					break;

				}
				if (readw(pci_data+0x15) &0x80) {
					break;
				}
			}
		}

	}

#ifdef PCI_ROM_SCAN_VERBOSE
	if (res) {
		printf("No suitable image found\n");
	}
#endif
	/* disable PAR register and PCI device ROM address devocer */
	pci_remove_rom_window(hose, rom_addr);

	pci_write_config_dword(dev, PCI_ROM_ADDRESS, 0);

	return res;
}