/*
 * tc-init: We assume the TURBOchannel to be up and running so
 * just probe for Modules and fill in the global data structure
 * tc_bus.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) Harald Koerfgen, 1998
 */
#include <linux/string.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <asm/addrspace.h>
#include <asm/errno.h>
#include <asm/dec/machtype.h>
#include <asm/dec/tcinfo.h>
#include <asm/dec/tcmodule.h>
#include <asm/dec/interrupts.h>

#include <asm/ptrace.h>
#include <linux/kernel.h>
#include <linux/module.h>

#define TC_DEBUG

MODULE_LICENSE("GPL");
slot_info tc_bus[MAX_SLOT];
static int max_tcslot;
static tcinfo *info;

unsigned long system_base;

extern void (*dbe_board_handler)(struct pt_regs *regs);
extern unsigned long *(*rex_slot_address)(int);
extern void *(*rex_gettcinfo)(void);

/*
 * Interface to the world. Read comment in include/asm-mips/tc.h.
 */

int search_tc_card(char *name)
{
        int slot;
        slot_info *sip;

        for (slot = 0; slot <= max_tcslot; slot++) {
                sip = &tc_bus[slot];
                if ((sip->flags & FREE) && (strncmp(sip->name, name, strlen(name)) == 0)) {
                        return slot;
                }
        }

        return -ENODEV;
}

void claim_tc_card(int slot)
{
        if (tc_bus[slot].flags & IN_USE) {
                printk("claim_tc_card: attempting to claim a card already in use\n");
                return;
        }
        tc_bus[slot].flags &= ~FREE;
        tc_bus[slot].flags |= IN_USE;
}

void release_tc_card(int slot)
{
        if (tc_bus[slot].flags & FREE) {
                printk("release_tc_card: attempting to release a card already free\n");
                return;
        }
        tc_bus[slot].flags &= ~IN_USE;
        tc_bus[slot].flags |= FREE;
}

unsigned long get_tc_base_addr(int slot)
{
        return tc_bus[slot].base_addr;
}

unsigned long get_tc_irq_nr(int slot)
{
        return tc_bus[slot].interrupt;
}

unsigned long get_tc_speed(void)
{
        return 100000 * (10000 / (unsigned long)info->clk_period);
}

/*
 * Probing for TURBOchannel modules
 */
static void __init my_dbe_handler(struct pt_regs *regs)
{
        regs->cp0_epc += 4;
}

static void __init tc_probe(unsigned long startaddr, unsigned long size, int max_slot)
{
        int i, slot;
        long offset;
        unsigned char *module;
        void (*old_be_handler)(struct pt_regs *regs);

        /* Install our exception handler temporarily */

        old_be_handler = dbe_board_handler;
        dbe_board_handler = my_dbe_handler;
        for (slot = 0; slot <= max_slot; slot++) {
                module = (char *)(startaddr + slot * size);
                offset = -1;
                if (module[OLDCARD + TC_PATTERN0] == 0x55 && module[OLDCARD + TC_PATTERN1] == 0x00
                  && module[OLDCARD + TC_PATTERN2] == 0xaa && module[OLDCARD + TC_PATTERN3] == 0xff)
                        offset = OLDCARD;
                if (module[TC_PATTERN0] == 0x55 && module[TC_PATTERN1] == 0x00
                  && module[TC_PATTERN2] == 0xaa && module[TC_PATTERN3] == 0xff)
                        offset = 0;

                if (offset != -1) {
                        tc_bus[slot].base_addr = (unsigned long)module;
                        for(i = 0; i < 8; i++) {
                                tc_bus[slot].firmware[i] = module[TC_FIRM_VER + offset + 4 * i];
                                tc_bus[slot].vendor[i] = module[TC_VENDOR + offset + 4 * i];
                                tc_bus[slot].name[i] = module[TC_MODULE + offset + 4 * i];
                        }
                        tc_bus[slot].firmware[8] = 0;
                        tc_bus[slot].vendor[8] = 0;
                        tc_bus[slot].name[8] = 0;
                        /*
                         * Looks unneccesary, but we may change
                         * TC? in the future
                         */
                        switch (slot) {
                        case 0:
                                tc_bus[slot].interrupt = TC0;
                                break;
                        case 1:
                                tc_bus[slot].interrupt = TC1;
                                break;
                        case 2:
                                tc_bus[slot].interrupt = TC2;
                                break;
                        /*
                         * Yuck! DS5000/200 onboard devices
                         */
                        case 5:
                                tc_bus[slot].interrupt = SCSI_INT;
                                break;
                        case 6:
                                tc_bus[slot].interrupt = ETHER;
                                break;
                        default:
                                tc_bus[slot].interrupt = -1;
                                break;
                        }       
                }
        }

        dbe_board_handler = old_be_handler;
}

/*
 * the main entry
 */
void __init tc_init(void)
{
        int tc_clock;
        int i;
        unsigned long slot0addr;
        unsigned long slot_size;

        if (!TURBOCHANNEL)
                return;

        for (i = 0; i < MAX_SLOT; i++) {
                tc_bus[i].base_addr = 0;
                tc_bus[i].name[0] = 0;
                tc_bus[i].vendor[0] = 0;
                tc_bus[i].firmware[0] = 0;
                tc_bus[i].interrupt = -1;
                tc_bus[i].flags = FREE;
        }

        info = (tcinfo *) rex_gettcinfo();
        slot0addr = (unsigned long)KSEG1ADDR(rex_slot_address(0));

        switch (mips_machtype) {
        case MACH_DS5000_200:
                max_tcslot = 6;
                break;
        case MACH_DS5000_1XX:
        case MACH_DS5000_2X0:
                max_tcslot = 2;
                break;
        case MACH_DS5000_XX:
        default:
                max_tcslot = 1;
                break;
        }

        tc_clock = 10000 / info->clk_period;

        if (TURBOCHANNEL && info->slot_size && slot0addr) {
                printk("TURBOchannel rev. %1d at %2d.%1d MHz ", info->revision,
                        tc_clock / 10, tc_clock % 10);
                printk("(with%s parity)\n", info->parity ? "" : "out");

                slot_size = info->slot_size << 20;

                tc_probe(slot0addr, slot_size, max_tcslot);

                /*
                 * All TURBOchannel DECstations have the onboard devices
                 * where the (max_tcslot + 1 or 2 on DS5k/xx) Option Module
                 * would be.
                 */
                if(mips_machtype == MACH_DS5000_XX)
                        i = 2;
                else
                        i = 1;
                
                system_base = slot0addr + slot_size * (max_tcslot + i);

#ifdef TC_DEBUG
                for (i = 0; i <= max_tcslot; i++)
                        if (tc_bus[i].base_addr) {
                                printk("    slot %d: ", i);
                                printk("%s %s %s\n", tc_bus[i].vendor,
                                        tc_bus[i].name, tc_bus[i].firmware);
                        }
#endif
                ioport_resource.end = KSEG2 - 1;
        }
}

subsys_initcall(tc_init);

EXPORT_SYMBOL(search_tc_card);
EXPORT_SYMBOL(claim_tc_card);
EXPORT_SYMBOL(release_tc_card);
EXPORT_SYMBOL(get_tc_base_addr);
EXPORT_SYMBOL(get_tc_irq_nr);
EXPORT_SYMBOL(get_tc_speed);