/*
 *      TURBOchannel bus services.
 *
 *      Copyright (c) Harald Koerfgen, 1998
 *      Copyright (c) 2001, 2003, 2005, 2006, 2018  Maciej W. Rozycki
 *      Copyright (c) 2005  James Simmons
 *
 *      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.
 */
#include <linux/compiler.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tc.h>
#include <linux/types.h>

#include <asm/io.h>

static struct tc_bus tc_bus = {
        .name = "TURBOchannel",
};

/*
 * Probing for TURBOchannel modules.
 */
static void __init tc_bus_add_devices(struct tc_bus *tbus)
{
        resource_size_t slotsize = tbus->info.slot_size << 20;
        resource_size_t extslotsize = tbus->ext_slot_size;
        resource_size_t slotaddr;
        resource_size_t extslotaddr;
        resource_size_t devsize;
        void __iomem *module;
        struct tc_dev *tdev;
        int i, slot, err;
        u8 pattern[4];
        long offset;

        for (slot = 0; slot < tbus->num_tcslots; slot++) {
                slotaddr = tbus->slot_base + slot * slotsize;
                extslotaddr = tbus->ext_slot_base + slot * extslotsize;
                module = ioremap(slotaddr, slotsize);
                BUG_ON(!module);

                offset = TC_OLDCARD;

                err = 0;
                err |= tc_preadb(pattern + 0, module + offset + TC_PATTERN0);
                err |= tc_preadb(pattern + 1, module + offset + TC_PATTERN1);
                err |= tc_preadb(pattern + 2, module + offset + TC_PATTERN2);
                err |= tc_preadb(pattern + 3, module + offset + TC_PATTERN3);
                if (err)
                        goto out_err;

                if (pattern[0] != 0x55 || pattern[1] != 0x00 ||
                    pattern[2] != 0xaa || pattern[3] != 0xff) {
                        offset = TC_NEWCARD;

                        err = 0;
                        err |= tc_preadb(pattern + 0,
                                         module + offset + TC_PATTERN0);
                        err |= tc_preadb(pattern + 1,
                                         module + offset + TC_PATTERN1);
                        err |= tc_preadb(pattern + 2,
                                         module + offset + TC_PATTERN2);
                        err |= tc_preadb(pattern + 3,
                                         module + offset + TC_PATTERN3);
                        if (err)
                                goto out_err;
                }

                if (pattern[0] != 0x55 || pattern[1] != 0x00 ||
                    pattern[2] != 0xaa || pattern[3] != 0xff)
                        goto out_err;

                /* Found a board, allocate it an entry in the list */
                tdev = kzalloc_obj(*tdev);
                if (!tdev) {
                        pr_err("tc%x: unable to allocate tc_dev\n", slot);
                        goto out_err;
                }
                dev_set_name(&tdev->dev, "tc%x", slot);
                tdev->bus = tbus;
                tdev->dev.parent = &tbus->dev;
                tdev->dev.bus = &tc_bus_type;
                tdev->slot = slot;

                /* TURBOchannel has 34-bit DMA addressing (16GiB space). */
                tdev->dma_mask = DMA_BIT_MASK(34);
                tdev->dev.dma_mask = &tdev->dma_mask;
                tdev->dev.coherent_dma_mask = DMA_BIT_MASK(34);

                for (i = 0; i < 8; i++) {
                        tdev->firmware[i] =
                                readb(module + offset + TC_FIRM_VER + 4 * i);
                        tdev->vendor[i] =
                                readb(module + offset + TC_VENDOR + 4 * i);
                        tdev->name[i] =
                                readb(module + offset + TC_MODULE + 4 * i);
                }
                tdev->firmware[8] = 0;
                tdev->vendor[8] = 0;
                tdev->name[8] = 0;

                pr_info("%s: %s %s %s\n", dev_name(&tdev->dev), tdev->vendor,
                        tdev->name, tdev->firmware);

                devsize = readb(module + offset + TC_SLOT_SIZE);
                devsize <<= 22;
                if (devsize <= slotsize) {
                        tdev->resource.start = slotaddr;
                        tdev->resource.end = slotaddr + devsize - 1;
                } else if (devsize <= extslotsize) {
                        tdev->resource.start = extslotaddr;
                        tdev->resource.end = extslotaddr + devsize - 1;
                } else {
                        pr_err("%s: Cannot provide slot space "
                               "(%ldMiB required, up to %ldMiB supported)\n",
                               dev_name(&tdev->dev), (long)(devsize >> 20),
                               (long)(max(slotsize, extslotsize) >> 20));
                        kfree(tdev);
                        goto out_err;
                }
                tdev->resource.name = tdev->name;
                tdev->resource.flags = IORESOURCE_MEM;

                tc_device_get_irq(tdev);

                if (device_register(&tdev->dev)) {
                        put_device(&tdev->dev);
                        goto out_err;
                }
                list_add_tail(&tdev->node, &tbus->devices);

out_err:
                iounmap(module);
        }
}

/*
 * The main entry.
 */
static int __init tc_init(void)
{
        /* Initialize the TURBOchannel bus */
        if (tc_bus_get_info(&tc_bus))
                goto out_err;

        INIT_LIST_HEAD(&tc_bus.devices);
        dev_set_name(&tc_bus.dev, "tc");
        if (device_register(&tc_bus.dev))
                goto out_err_device;

        if (tc_bus.info.slot_size) {
                unsigned int tc_clock = tc_get_speed(&tc_bus) / 100000;

                pr_info("tc: TURBOchannel rev. %d at %u.%u MHz "
                        "(with%s parity)\n", tc_bus.info.revision,
                        tc_clock / 10, tc_clock % 10,
                        tc_bus.info.parity ? "" : "out");

                tc_bus.resource[0].start = tc_bus.slot_base;
                tc_bus.resource[0].end = tc_bus.slot_base +
                                         (tc_bus.info.slot_size << 20) *
                                         tc_bus.num_tcslots - 1;
                tc_bus.resource[0].name = tc_bus.name;
                tc_bus.resource[0].flags = IORESOURCE_MEM;
                if (request_resource(&iomem_resource,
                                     &tc_bus.resource[0]) < 0) {
                        pr_err("tc: Cannot reserve resource\n");
                        goto out_err_device;
                }
                if (tc_bus.ext_slot_size) {
                        tc_bus.resource[1].start = tc_bus.ext_slot_base;
                        tc_bus.resource[1].end = tc_bus.ext_slot_base +
                                                 tc_bus.ext_slot_size *
                                                 tc_bus.num_tcslots - 1;
                        tc_bus.resource[1].name = tc_bus.name;
                        tc_bus.resource[1].flags = IORESOURCE_MEM;
                        if (request_resource(&iomem_resource,
                                             &tc_bus.resource[1]) < 0) {
                                pr_err("tc: Cannot reserve resource\n");
                                goto out_err_resource;
                        }
                }

                tc_bus_add_devices(&tc_bus);
        }

        return 0;

out_err_resource:
        release_resource(&tc_bus.resource[0]);
out_err_device:
        put_device(&tc_bus.dev);
out_err:
        return 0;
}

subsys_initcall(tc_init);