// SPDX-License-Identifier: GPL-2.0-only
/* linux/drivers/mtd/maps/scx200_docflash.c

   Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>

   National Semiconductor SCx200 flash mapped with DOCCS
*/

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>

#include <linux/pci.h>
#include <linux/scx200.h>

#define NAME "scx200_docflash"

MODULE_AUTHOR("Christer Weinigel <wingel@hack.org>");
MODULE_DESCRIPTION("NatSemi SCx200 DOCCS Flash Driver");
MODULE_LICENSE("GPL");

static int probe = 0;           /* Don't autoprobe */
static unsigned size = 0x1000000; /* 16 MiB the whole ISA address space */
static unsigned width = 8;      /* Default to 8 bits wide */
static char *flashtype = "cfi_probe";

module_param(probe, int, 0);
MODULE_PARM_DESC(probe, "Probe for a BIOS mapping");
module_param(size, int, 0);
MODULE_PARM_DESC(size, "Size of the flash mapping");
module_param(width, int, 0);
MODULE_PARM_DESC(width, "Data width of the flash mapping (8/16)");
module_param(flashtype, charp, 0);
MODULE_PARM_DESC(flashtype, "Type of MTD probe to do");

static struct resource docmem = {
        .flags = IORESOURCE_MEM,
        .name  = "NatSemi SCx200 DOCCS Flash",
};

static struct mtd_info *mymtd;

static struct mtd_partition partition_info[] = {
        {
                .name   = "DOCCS Boot kernel",
                .offset = 0,
                .size   = 0xc0000
        },
        {
                .name   = "DOCCS Low BIOS",
                .offset = 0xc0000,
                .size   = 0x40000
        },
        {
                .name   = "DOCCS File system",
                .offset = 0x100000,
                .size   = ~0    /* calculate from flash size */
        },
        {
                .name   = "DOCCS High BIOS",
                .offset = ~0,   /* calculate from flash size */
                .size   = 0x80000
        },
};
#define NUM_PARTITIONS ARRAY_SIZE(partition_info)

static struct map_info scx200_docflash_map = {
        .name      = "NatSemi SCx200 DOCCS Flash",
};

static int __init init_scx200_docflash(void)
{
        unsigned u;
        unsigned base;
        unsigned ctrl;
        unsigned pmr;
        struct pci_dev *bridge;

        printk(KERN_DEBUG NAME ": NatSemi SCx200 DOCCS Flash Driver\n");

        if ((bridge = pci_get_device(PCI_VENDOR_ID_NS,
                                      PCI_DEVICE_ID_NS_SCx200_BRIDGE,
                                      NULL)) == NULL)
                return -ENODEV;

        /* check that we have found the configuration block */
        if (!scx200_cb_present()) {
                pci_dev_put(bridge);
                return -ENODEV;
        }

        if (probe) {
                /* Try to use the present flash mapping if any */
                pci_read_config_dword(bridge, SCx200_DOCCS_BASE, &base);
                pci_read_config_dword(bridge, SCx200_DOCCS_CTRL, &ctrl);
                pci_dev_put(bridge);

                pmr = inl(scx200_cb_base + SCx200_PMR);

                if (base == 0
                    || (ctrl & 0x07000000) != 0x07000000
                    || (ctrl & 0x0007ffff) == 0)
                        return -ENODEV;

                size = ((ctrl&0x1fff)<<13) + (1<<13);

                for (u = size; u > 1; u >>= 1)
                        ;
                if (u != 1)
                        return -ENODEV;

                if (pmr & (1<<6))
                        width = 16;
                else
                        width = 8;

                docmem.start = base;
                docmem.end = base + size;

                if (request_resource(&iomem_resource, &docmem)) {
                        printk(KERN_ERR NAME ": unable to allocate memory for flash mapping\n");
                        return -ENOMEM;
                }
        } else {
                pci_dev_put(bridge);
                for (u = size; u > 1; u >>= 1)
                        ;
                if (u != 1) {
                        printk(KERN_ERR NAME ": invalid size for flash mapping\n");
                        return -EINVAL;
                }

                if (width != 8 && width != 16) {
                        printk(KERN_ERR NAME ": invalid bus width for flash mapping\n");
                        return -EINVAL;
                }

                if (allocate_resource(&iomem_resource, &docmem,
                                      size,
                                      0xc0000000, 0xffffffff,
                                      size, NULL, NULL)) {
                        printk(KERN_ERR NAME ": unable to allocate memory for flash mapping\n");
                        return -ENOMEM;
                }

                ctrl = 0x07000000 | ((size-1) >> 13);

                printk(KERN_INFO "DOCCS BASE=0x%08lx, CTRL=0x%08lx\n", (long)docmem.start, (long)ctrl);

                pci_write_config_dword(bridge, SCx200_DOCCS_BASE, docmem.start);
                pci_write_config_dword(bridge, SCx200_DOCCS_CTRL, ctrl);
                pmr = inl(scx200_cb_base + SCx200_PMR);

                if (width == 8) {
                        pmr &= ~(1<<6);
                } else {
                        pmr |= (1<<6);
                }
                outl(pmr, scx200_cb_base + SCx200_PMR);
        }

        printk(KERN_INFO NAME ": DOCCS mapped at %pR, width %d\n",
               &docmem, width);

        scx200_docflash_map.size = size;
        if (width == 8)
                scx200_docflash_map.bankwidth = 1;
        else
                scx200_docflash_map.bankwidth = 2;

        simple_map_init(&scx200_docflash_map);

        scx200_docflash_map.phys = docmem.start;
        scx200_docflash_map.virt = ioremap(docmem.start, scx200_docflash_map.size);
        if (!scx200_docflash_map.virt) {
                printk(KERN_ERR NAME ": failed to ioremap the flash\n");
                release_resource(&docmem);
                return -EIO;
        }

        mymtd = do_map_probe(flashtype, &scx200_docflash_map);
        if (!mymtd) {
                printk(KERN_ERR NAME ": unable to detect flash\n");
                iounmap(scx200_docflash_map.virt);
                release_resource(&docmem);
                return -ENXIO;
        }

        if (size < mymtd->size)
                printk(KERN_WARNING NAME ": warning, flash mapping is smaller than flash size\n");

        mymtd->owner = THIS_MODULE;

        partition_info[3].offset = mymtd->size-partition_info[3].size;
        partition_info[2].size = partition_info[3].offset-partition_info[2].offset;
        mtd_device_register(mymtd, partition_info, NUM_PARTITIONS);

        return 0;
}

static void __exit cleanup_scx200_docflash(void)
{
        if (mymtd) {
                mtd_device_unregister(mymtd);
                map_destroy(mymtd);
        }
        if (scx200_docflash_map.virt) {
                iounmap(scx200_docflash_map.virt);
                release_resource(&docmem);
        }
}

module_init(init_scx200_docflash);
module_exit(cleanup_scx200_docflash);