/*
 * (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 <malloc.h>
#include <asm/ptrace.h>
#include <asm/realmode.h>
#include <asm/io.h>
#include <asm/pci.h>

#undef PCI_BIOS_DEBUG
#undef VGA_BIOS_DEBUG

#ifdef  VGA_BIOS_DEBUG
#define PRINTF(fmt,args...)     printf (fmt ,##args)
#else
#define PRINTF(fmt,args...)
#endif

#ifdef CONFIG_PCI

#ifdef PCI_BIOS_DEBUG
#define RELOC_16(seg, off) *(u32*)(seg << 4 | (u32)&off)
extern u32 num_pci_bios_present;
extern u32 num_pci_bios_find_device;
extern u32 num_pci_bios_find_class;
extern u32 num_pci_bios_generate_special_cycle;
extern u32 num_pci_bios_read_cfg_byte;
extern u32 num_pci_bios_read_cfg_word;
extern u32 num_pci_bios_read_cfg_dword;
extern u32 num_pci_bios_write_cfg_byte;
extern u32 num_pci_bios_write_cfg_word;
extern u32 num_pci_bios_write_cfg_dword;
extern u32 num_pci_bios_get_irq_routing;
extern u32 num_pci_bios_set_irq;
extern u32 num_pci_bios_unknown_function;

void print_bios_bios_stat(void)
{
        printf("16 bit functions:\n");
        printf("pci_bios_present:                %d\n", RELOC_16(0xf000, num_pci_bios_present));
        printf("pci_bios_find_device:            %d\n", RELOC_16(0xf000, num_pci_bios_find_device));
        printf("pci_bios_find_class:             %d\n", RELOC_16(0xf000, num_pci_bios_find_class));
        printf("pci_bios_generate_special_cycle: %d\n", RELOC_16(0xf000, num_pci_bios_generate_special_cycle));
        printf("pci_bios_read_cfg_byte:          %d\n", RELOC_16(0xf000, num_pci_bios_read_cfg_byte));
        printf("pci_bios_read_cfg_word:          %d\n", RELOC_16(0xf000, num_pci_bios_read_cfg_word));
        printf("pci_bios_read_cfg_dword:         %d\n", RELOC_16(0xf000, num_pci_bios_read_cfg_dword));
        printf("pci_bios_write_cfg_byte:         %d\n", RELOC_16(0xf000, num_pci_bios_write_cfg_byte));
        printf("pci_bios_write_cfg_word:         %d\n", RELOC_16(0xf000, num_pci_bios_write_cfg_word));
        printf("pci_bios_write_cfg_dword:        %d\n", RELOC_16(0xf000, num_pci_bios_write_cfg_dword));
        printf("pci_bios_get_irq_routing:        %d\n", RELOC_16(0xf000, num_pci_bios_get_irq_routing));
        printf("pci_bios_set_irq:                %d\n", RELOC_16(0xf000, num_pci_bios_set_irq));
        printf("pci_bios_unknown_function:       %d\n", RELOC_16(0xf000, num_pci_bios_unknown_function));

}
#endif

#define PCI_CLASS_VIDEO             3
#define PCI_CLASS_VIDEO_STD         0
#define PCI_CLASS_VIDEO_PROG_IF_VGA 0


static u32 probe_pci_video(void)
{
        pci_dev_t devbusfn;

        if ((devbusfn = pci_find_class(PCI_CLASS_VIDEO,
                                       PCI_CLASS_VIDEO_STD,
                                       PCI_CLASS_VIDEO_PROG_IF_VGA, 0)) != -1) {
                u32 old;
                u32 addr;

                /* PCI video device detected */
                printf("Found PCI VGA device at %02x.%02x.%x\n",
                       PCI_BUS(devbusfn), PCI_DEV(devbusfn), PCI_FUNC(devbusfn));

                /* Enable I/O decoding as well, PCI viudeo boards
                 * support I/O accesses, but they provide no
                 * bar register for this since the ports are fixed.
                 */
                pci_write_config_word(devbusfn, PCI_COMMAND, PCI_COMMAND_MEMORY | PCI_COMMAND_IO | PCI_COMMAND_MASTER);

                /* Test the ROM decoder, do the device support a rom? */
                pci_read_config_dword(devbusfn, PCI_ROM_ADDRESS, &old);
                pci_write_config_dword(devbusfn, PCI_ROM_ADDRESS, PCI_ROM_ADDRESS_MASK);
                pci_read_config_dword(devbusfn, PCI_ROM_ADDRESS, &addr);
                pci_write_config_dword(devbusfn, PCI_ROM_ADDRESS, old);

                if (!addr) {
                        printf("PCI VGA have no ROM?\n");
                        return 0;
                }

                /* device have a rom */
                if (pci_shadow_rom(devbusfn, (void*)0xc0000)) {
                        printf("Shadowing of PCI VGA BIOS failed\n");
                        return 0;
                }

                /* Now enable lagacy VGA port access */
                if (pci_enable_legacy_video_ports(pci_bus_to_hose(PCI_BUS(devbusfn)))) {
                        printf("PCI VGA enable failed\n");
                        return 0;
                }


                /* return the pci device info, that we'll need later */
                return PCI_BUS(devbusfn) << 8 |
                        PCI_DEV(devbusfn) << 3 | (PCI_FUNC(devbusfn)&7);
        }

        return 0;
}


#endif

#ifdef CONFIG_VIDEO

static int probe_isa_video(void)
{
        u32 ptr;
        char *buf;

        if (0 == (ptr = isa_map_rom(0xc0000, 0x8000))) {
                return -1;
        }
        if (NULL == (buf=malloc(0x8000))) {
                isa_unmap_rom(ptr);
                return -1;
        }
        if (readw(ptr) != 0xaa55) {
                free(buf);
                isa_unmap_rom(ptr);
                return -1;
        }

        /* shadow the rom */
        memcpy(buf, (void*)ptr, 0x8000);
        isa_unmap_rom(ptr);
        memcpy((void*)0xc0000, buf, 0x8000);

        free(buf);

        return 0;
}

int video_bios_init(void)
{
        struct pt_regs regs;

        /* clear the video bios area in case we warmbooted */
        memset((void*)0xc0000, 0, 0x8000);
        memset(&regs, 0, sizeof(struct pt_regs));

        if (probe_isa_video()) {
                /* No ISA board found, try the PCI bus */
                regs.eax = probe_pci_video();
        }

        /* Did we succeed in mapping any video bios */
        if (readw(0xc0000) == 0xaa55) {
                int size;
                int i;
                u8 sum;

                PRINTF("Found video bios signature\n");
                size = 512*readb(0xc0002);
                PRINTF("size %d\n", size);
                sum=0;
                for (i=0;i<size;i++) {
                        sum += readb(0xc0000 + i);
                }
                PRINTF("Checksum is %sOK\n",sum?"NOT ":"");
                if (sum) {
                        return 1;
                }

                /* some video bioses (ATI Mach64) seem to think that
                 * the original int 10 handler is always at
                 * 0xf000:0xf065 , place an iret instruction there
                 */
                writeb(0xcf, 0xff065);

                regs.esp = 0x8000;
                regs.xss = 0x2000;
                enter_realmode(0xc000, 3, &regs, &regs);
                PRINTF("INT 0x10 vector after:  %04x:%04x\n",
                       readw(0x42), readw(0x40));
                PRINTF("BIOS returned %scarry\n", regs.eflags & 1?"":"NOT ");
#ifdef PCI_BIOS_DEBUG
                print_bios_bios_stat();
#endif
                return (regs.eflags & 1);

        }

        return 1;

}
#endif