// SPDX-License-Identifier: GPL-2.0-only
/*
 * PMC551 PCI Mezzanine Ram Device
 *
 * Author:
 *      Mark Ferrell <mferrell@mvista.com>
 *      Copyright 1999,2000 Nortel Networks
 *
 * Description:
 *      This driver is intended to support the PMC551 PCI Ram device
 *      from Ramix Inc.  The PMC551 is a PMC Mezzanine module for
 *      cPCI embedded systems.  The device contains a single SROM
 *      that initially programs the V370PDC chipset onboard the
 *      device, and various banks of DRAM/SDRAM onboard.  This driver
 *      implements this PCI Ram device as an MTD (Memory Technology
 *      Device) so that it can be used to hold a file system, or for
 *      added swap space in embedded systems.  Since the memory on
 *      this board isn't as fast as main memory we do not try to hook
 *      it into main memory as that would simply reduce performance
 *      on the system.  Using it as a block device allows us to use
 *      it as high speed swap or for a high speed disk device of some
 *      sort.  Which becomes very useful on diskless systems in the
 *      embedded market I might add.
 *
 * Notes:
 *      Due to what I assume is more buggy SROM, the 64M PMC551 I
 *      have available claims that all 4 of its DRAM banks have 64MiB
 *      of ram configured (making a grand total of 256MiB onboard).
 *      This is slightly annoying since the BAR0 size reflects the
 *      aperture size, not the dram size, and the V370PDC supplies no
 *      other method for memory size discovery.  This problem is
 *      mostly only relevant when compiled as a module, as the
 *      unloading of the module with an aperture size smaller than
 *      the ram will cause the driver to detect the onboard memory
 *      size to be equal to the aperture size when the module is
 *      reloaded.  Soooo, to help, the module supports an msize
 *      option to allow the specification of the onboard memory, and
 *      an asize option, to allow the specification of the aperture
 *      size.  The aperture must be equal to or less then the memory
 *      size, the driver will correct this if you screw it up.  This
 *      problem is not relevant for compiled in drivers as compiled
 *      in drivers only init once.
 *
 * Credits:
 *      Saeed Karamooz <saeed@ramix.com> of Ramix INC. for the
 *      initial example code of how to initialize this device and for
 *      help with questions I had concerning operation of the device.
 *
 *      Most of the MTD code for this driver was originally written
 *      for the slram.o module in the MTD drivers package which
 *      allows the mapping of system memory into an MTD device.
 *      Since the PMC551 memory module is accessed in the same
 *      fashion as system memory, the slram.c code became a very nice
 *      fit to the needs of this driver.  All we added was PCI
 *      detection/initialization to the driver and automatically figure
 *      out the size via the PCI detection.o, later changes by Corey
 *      Minyard set up the card to utilize a 1M sliding apature.
 *
 *      Corey Minyard <minyard@nortelnetworks.com>
 *      * Modified driver to utilize a sliding aperture instead of
 *       mapping all memory into kernel space which turned out to
 *       be very wasteful.
 *      * Located a bug in the SROM's initialization sequence that
 *       made the memory unusable, added a fix to code to touch up
 *       the DRAM some.
 *
 * Bugs/FIXMEs:
 *      * MUST fix the init function to not spin on a register
 *      waiting for it to set .. this does not safely handle busted
 *      devices that never reset the register correctly which will
 *      cause the system to hang w/ a reboot being the only chance at
 *      recover. [sort of fixed, could be better]
 *      * Add I2C handling of the SROM so we can read the SROM's information
 *      about the aperture size.  This should always accurately reflect the
 *      onboard memory size.
 *      * Comb the init routine.  It's still a bit cludgy on a few things.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <asm/io.h>
#include <linux/pci.h>
#include <linux/mtd/mtd.h>

#define PMC551_VERSION \
        "Ramix PMC551 PCI Mezzanine Ram Driver. (C) 1999,2000 Nortel Networks.\n"

#define PCI_VENDOR_ID_V3_SEMI 0x11b0
#define PCI_DEVICE_ID_V3_SEMI_V370PDC 0x0200

#define PMC551_PCI_MEM_MAP0 0x50
#define PMC551_PCI_MEM_MAP1 0x54
#define PMC551_PCI_MEM_MAP_MAP_ADDR_MASK 0x3ff00000
#define PMC551_PCI_MEM_MAP_APERTURE_MASK 0x000000f0
#define PMC551_PCI_MEM_MAP_REG_EN 0x00000002
#define PMC551_PCI_MEM_MAP_ENABLE 0x00000001

#define PMC551_SDRAM_MA  0x60
#define PMC551_SDRAM_CMD 0x62
#define PMC551_DRAM_CFG  0x64
#define PMC551_SYS_CTRL_REG 0x78

#define PMC551_DRAM_BLK0 0x68
#define PMC551_DRAM_BLK1 0x6c
#define PMC551_DRAM_BLK2 0x70
#define PMC551_DRAM_BLK3 0x74
#define PMC551_DRAM_BLK_GET_SIZE(x) (524288 << ((x >> 4) & 0x0f))
#define PMC551_DRAM_BLK_SET_COL_MUX(x, v) (((x) & ~0x00007000) | (((v) & 0x7) << 12))
#define PMC551_DRAM_BLK_SET_ROW_MUX(x, v) (((x) & ~0x00000f00) | (((v) & 0xf) << 8))

struct mypriv {
        struct pci_dev *dev;
        u_char *start;
        u32 base_map0;
        u32 curr_map0;
        u32 asize;
        struct mtd_info *nextpmc551;
};

static struct mtd_info *pmc551list;

static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, void **virt, resource_size_t *phys);

static int pmc551_erase(struct mtd_info *mtd, struct erase_info *instr)
{
        struct mypriv *priv = mtd->priv;
        u32 soff_hi, soff_lo;   /* start address offset hi/lo */
        u32 eoff_hi, eoff_lo;   /* end address offset hi/lo */
        unsigned long end;
        u_char *ptr;
        size_t retlen;

#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_erase(pos:%ld, len:%ld)\n", (long)instr->addr,
                (long)instr->len);
#endif

        end = instr->addr + instr->len - 1;
        eoff_hi = end & ~(priv->asize - 1);
        soff_hi = instr->addr & ~(priv->asize - 1);
        eoff_lo = end & (priv->asize - 1);
        soff_lo = instr->addr & (priv->asize - 1);

        pmc551_point(mtd, instr->addr, instr->len, &retlen,
                     (void **)&ptr, NULL);

        if (soff_hi == eoff_hi || mtd->size == priv->asize) {
                /* The whole thing fits within one access, so just one shot
                   will do it. */
                memset(ptr, 0xff, instr->len);
        } else {
                /* We have to do multiple writes to get all the data
                   written. */
                while (soff_hi != eoff_hi) {
#ifdef CONFIG_MTD_PMC551_DEBUG
                        printk(KERN_DEBUG "pmc551_erase() soff_hi: %ld, "
                                "eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
#endif
                        memset(ptr, 0xff, priv->asize);
                        if (soff_hi + priv->asize >= mtd->size) {
                                goto out;
                        }
                        soff_hi += priv->asize;
                        pmc551_point(mtd, (priv->base_map0 | soff_hi),
                                     priv->asize, &retlen,
                                     (void **)&ptr, NULL);
                }
                memset(ptr, 0xff, eoff_lo);
        }

      out:
#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_erase() done\n");
#endif

        return 0;
}

static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, void **virt, resource_size_t *phys)
{
        struct mypriv *priv = mtd->priv;
        u32 soff_hi;
        u32 soff_lo;

#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_point(%ld, %ld)\n", (long)from, (long)len);
#endif

        soff_hi = from & ~(priv->asize - 1);
        soff_lo = from & (priv->asize - 1);

        /* Cheap hack optimization */
        if (priv->curr_map0 != from) {
                pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
                                        (priv->base_map0 | soff_hi));
                priv->curr_map0 = soff_hi;
        }

        *virt = priv->start + soff_lo;
        *retlen = len;
        return 0;
}

static int pmc551_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_unpoint()\n");
#endif
        return 0;
}

static int pmc551_read(struct mtd_info *mtd, loff_t from, size_t len,
                        size_t * retlen, u_char * buf)
{
        struct mypriv *priv = mtd->priv;
        u32 soff_hi, soff_lo;   /* start address offset hi/lo */
        u32 eoff_hi, eoff_lo;   /* end address offset hi/lo */
        unsigned long end;
        u_char *ptr;
        u_char *copyto = buf;

#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_read(pos:%ld, len:%ld) asize: %ld\n",
                (long)from, (long)len, (long)priv->asize);
#endif

        end = from + len - 1;
        soff_hi = from & ~(priv->asize - 1);
        eoff_hi = end & ~(priv->asize - 1);
        soff_lo = from & (priv->asize - 1);
        eoff_lo = end & (priv->asize - 1);

        pmc551_point(mtd, from, len, retlen, (void **)&ptr, NULL);

        if (soff_hi == eoff_hi) {
                /* The whole thing fits within one access, so just one shot
                   will do it. */
                memcpy(copyto, ptr, len);
                copyto += len;
        } else {
                /* We have to do multiple writes to get all the data
                   written. */
                while (soff_hi != eoff_hi) {
#ifdef CONFIG_MTD_PMC551_DEBUG
                        printk(KERN_DEBUG "pmc551_read() soff_hi: %ld, "
                                "eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
#endif
                        memcpy(copyto, ptr, priv->asize);
                        copyto += priv->asize;
                        if (soff_hi + priv->asize >= mtd->size) {
                                goto out;
                        }
                        soff_hi += priv->asize;
                        pmc551_point(mtd, soff_hi, priv->asize, retlen,
                                     (void **)&ptr, NULL);
                }
                memcpy(copyto, ptr, eoff_lo);
                copyto += eoff_lo;
        }

      out:
#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_read() done\n");
#endif
        *retlen = copyto - buf;
        return 0;
}

static int pmc551_write(struct mtd_info *mtd, loff_t to, size_t len,
                        size_t * retlen, const u_char * buf)
{
        struct mypriv *priv = mtd->priv;
        u32 soff_hi, soff_lo;   /* start address offset hi/lo */
        u32 eoff_hi, eoff_lo;   /* end address offset hi/lo */
        unsigned long end;
        u_char *ptr;
        const u_char *copyfrom = buf;

#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_write(pos:%ld, len:%ld) asize:%ld\n",
                (long)to, (long)len, (long)priv->asize);
#endif

        end = to + len - 1;
        soff_hi = to & ~(priv->asize - 1);
        eoff_hi = end & ~(priv->asize - 1);
        soff_lo = to & (priv->asize - 1);
        eoff_lo = end & (priv->asize - 1);

        pmc551_point(mtd, to, len, retlen, (void **)&ptr, NULL);

        if (soff_hi == eoff_hi) {
                /* The whole thing fits within one access, so just one shot
                   will do it. */
                memcpy(ptr, copyfrom, len);
                copyfrom += len;
        } else {
                /* We have to do multiple writes to get all the data
                   written. */
                while (soff_hi != eoff_hi) {
#ifdef CONFIG_MTD_PMC551_DEBUG
                        printk(KERN_DEBUG "pmc551_write() soff_hi: %ld, "
                                "eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
#endif
                        memcpy(ptr, copyfrom, priv->asize);
                        copyfrom += priv->asize;
                        if (soff_hi >= mtd->size) {
                                goto out;
                        }
                        soff_hi += priv->asize;
                        pmc551_point(mtd, soff_hi, priv->asize, retlen,
                                     (void **)&ptr, NULL);
                }
                memcpy(ptr, copyfrom, eoff_lo);
                copyfrom += eoff_lo;
        }

      out:
#ifdef CONFIG_MTD_PMC551_DEBUG
        printk(KERN_DEBUG "pmc551_write() done\n");
#endif
        *retlen = copyfrom - buf;
        return 0;
}

/*
 * Fixup routines for the V370PDC
 * PCI device ID 0x020011b0
 *
 * This function basically kick starts the DRAM oboard the card and gets it
 * ready to be used.  Before this is done the device reads VERY erratic, so
 * much that it can crash the Linux 2.2.x series kernels when a user cat's
 * /proc/pci .. though that is mainly a kernel bug in handling the PCI DEVSEL
 * register.  FIXME: stop spinning on registers .. must implement a timeout
 * mechanism
 * returns the size of the memory region found.
 */
static int __init fixup_pmc551(struct pci_dev *dev)
{
#ifdef CONFIG_MTD_PMC551_BUGFIX
        u32 dram_data;
#endif
        u32 size, dcmd, cfg, dtmp;
        u16 cmd, tmp, i;
        u8 bcmd, counter;

        /* Sanity Check */
        if (!dev) {
                return -ENODEV;
        }

        /*
         * Attempt to reset the card
         * FIXME: Stop Spinning registers
         */
        counter = 0;
        /* unlock registers */
        pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, 0xA5);
        /* read in old data */
        pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
        /* bang the reset line up and down for a few */
        for (i = 0; i < 10; i++) {
                counter = 0;
                bcmd &= ~0x80;
                while (counter++ < 100) {
                        pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
                }
                counter = 0;
                bcmd |= 0x80;
                while (counter++ < 100) {
                        pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
                }
        }
        bcmd |= (0x40 | 0x20);
        pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);

        /*
         * Take care and turn off the memory on the device while we
         * tweak the configurations
         */
        pci_read_config_word(dev, PCI_COMMAND, &cmd);
        tmp = cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
        pci_write_config_word(dev, PCI_COMMAND, tmp);

        /*
         * Disable existing aperture before probing memory size
         */
        pci_read_config_dword(dev, PMC551_PCI_MEM_MAP0, &dcmd);
        dtmp = (dcmd | PMC551_PCI_MEM_MAP_ENABLE | PMC551_PCI_MEM_MAP_REG_EN);
        pci_write_config_dword(dev, PMC551_PCI_MEM_MAP0, dtmp);
        /*
         * Grab old BAR0 config so that we can figure out memory size
         * This is another bit of kludge going on.  The reason for the
         * redundancy is I am hoping to retain the original configuration
         * previously assigned to the card by the BIOS or some previous
         * fixup routine in the kernel.  So we read the old config into cfg,
         * then write all 1's to the memory space, read back the result into
         * "size", and then write back all the old config.
         */
        pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &cfg);
#ifndef CONFIG_MTD_PMC551_BUGFIX
        pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, ~0);
        pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &size);
        size = (size & PCI_BASE_ADDRESS_MEM_MASK);
        size &= ~(size - 1);
        pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, cfg);
#else
        /*
         * Get the size of the memory by reading all the DRAM size values
         * and adding them up.
         *
         * KLUDGE ALERT: the boards we are using have invalid column and
         * row mux values.  We fix them here, but this will break other
         * memory configurations.
         */
        pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dram_data);
        size = PMC551_DRAM_BLK_GET_SIZE(dram_data);
        dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
        dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
        pci_write_config_dword(dev, PMC551_DRAM_BLK0, dram_data);

        pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dram_data);
        size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
        dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
        dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
        pci_write_config_dword(dev, PMC551_DRAM_BLK1, dram_data);

        pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dram_data);
        size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
        dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
        dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
        pci_write_config_dword(dev, PMC551_DRAM_BLK2, dram_data);

        pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dram_data);
        size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
        dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
        dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
        pci_write_config_dword(dev, PMC551_DRAM_BLK3, dram_data);

        /*
         * Oops .. something went wrong
         */
        if ((size &= PCI_BASE_ADDRESS_MEM_MASK) == 0) {
                return -ENODEV;
        }
#endif                          /* CONFIG_MTD_PMC551_BUGFIX */

        if ((cfg & PCI_BASE_ADDRESS_SPACE) != PCI_BASE_ADDRESS_SPACE_MEMORY) {
                return -ENODEV;
        }

        /*
         * Precharge Dram
         */
        pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0400);
        pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x00bf);

        /*
         * Wait until command has gone through
         * FIXME: register spinning issue
         */
        do {
                pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
                if (counter++ > 100)
                        break;
        } while ((PCI_COMMAND_IO) & cmd);

        /*
         * Turn on auto refresh
         * The loop is taken directly from Ramix's example code.  I assume that
         * this must be held high for some duration of time, but I can find no
         * documentation refrencing the reasons why.
         */
        for (i = 1; i <= 8; i++) {
                pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0df);

                /*
                 * Make certain command has gone through
                 * FIXME: register spinning issue
                 */
                counter = 0;
                do {
                        pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
                        if (counter++ > 100)
                                break;
                } while ((PCI_COMMAND_IO) & cmd);
        }

        pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0020);
        pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0ff);

        /*
         * Wait until command completes
         * FIXME: register spinning issue
         */
        counter = 0;
        do {
                pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
                if (counter++ > 100)
                        break;
        } while ((PCI_COMMAND_IO) & cmd);

        pci_read_config_dword(dev, PMC551_DRAM_CFG, &dcmd);
        dcmd |= 0x02000000;
        pci_write_config_dword(dev, PMC551_DRAM_CFG, dcmd);

        /*
         * Check to make certain fast back-to-back, if not
         * then set it so
         */
        pci_read_config_word(dev, PCI_STATUS, &cmd);
        if ((cmd & PCI_COMMAND_FAST_BACK) == 0) {
                cmd |= PCI_COMMAND_FAST_BACK;
                pci_write_config_word(dev, PCI_STATUS, cmd);
        }

        /*
         * Check to make certain the DEVSEL is set correctly, this device
         * has a tendency to assert DEVSEL and TRDY when a write is performed
         * to the memory when memory is read-only
         */
        if ((cmd & PCI_STATUS_DEVSEL_MASK) != 0x0) {
                cmd &= ~PCI_STATUS_DEVSEL_MASK;
                pci_write_config_word(dev, PCI_STATUS, cmd);
        }
        /*
         * Set to be prefetchable and put everything back based on old cfg.
         * it's possible that the reset of the V370PDC nuked the original
         * setup
         */
        /*
           cfg |= PCI_BASE_ADDRESS_MEM_PREFETCH;
           pci_write_config_dword( dev, PCI_BASE_ADDRESS_0, cfg );
         */

        /*
         * Turn PCI memory and I/O bus access back on
         */
        pci_write_config_word(dev, PCI_COMMAND,
                              PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
#ifdef CONFIG_MTD_PMC551_DEBUG
        /*
         * Some screen fun
         */
        printk(KERN_DEBUG "pmc551: %d%sB (0x%x) of %sprefetchable memory at "
                "0x%llx\n", (size < 1024) ? size : (size < 1048576) ?
                size >> 10 : size >> 20,
                (size < 1024) ? "" : (size < 1048576) ? "Ki" : "Mi", size,
                ((dcmd & (0x1 << 3)) == 0) ? "non-" : "",
                (unsigned long long)pci_resource_start(dev, 0));

        /*
         * Check to see the state of the memory
         */
        pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dcmd);
        printk(KERN_DEBUG "pmc551: DRAM_BLK0 Flags: %s,%s\n"
                "pmc551: DRAM_BLK0 Size: %d at %d\n"
                "pmc551: DRAM_BLK0 Row MUX: %d, Col MUX: %d\n",
                (((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
                (((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
                PMC551_DRAM_BLK_GET_SIZE(dcmd),
                ((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
                ((dcmd >> 9) & 0xF));

        pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dcmd);
        printk(KERN_DEBUG "pmc551: DRAM_BLK1 Flags: %s,%s\n"
                "pmc551: DRAM_BLK1 Size: %d at %d\n"
                "pmc551: DRAM_BLK1 Row MUX: %d, Col MUX: %d\n",
                (((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
                (((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
                PMC551_DRAM_BLK_GET_SIZE(dcmd),
                ((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
                ((dcmd >> 9) & 0xF));

        pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dcmd);
        printk(KERN_DEBUG "pmc551: DRAM_BLK2 Flags: %s,%s\n"
                "pmc551: DRAM_BLK2 Size: %d at %d\n"
                "pmc551: DRAM_BLK2 Row MUX: %d, Col MUX: %d\n",
                (((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
                (((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
                PMC551_DRAM_BLK_GET_SIZE(dcmd),
                ((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
                ((dcmd >> 9) & 0xF));

        pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dcmd);
        printk(KERN_DEBUG "pmc551: DRAM_BLK3 Flags: %s,%s\n"
                "pmc551: DRAM_BLK3 Size: %d at %d\n"
                "pmc551: DRAM_BLK3 Row MUX: %d, Col MUX: %d\n",
                (((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
                (((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
                PMC551_DRAM_BLK_GET_SIZE(dcmd),
                ((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
                ((dcmd >> 9) & 0xF));

        pci_read_config_word(dev, PCI_COMMAND, &cmd);
        printk(KERN_DEBUG "pmc551: Memory Access %s\n",
                (((0x1 << 1) & cmd) == 0) ? "off" : "on");
        printk(KERN_DEBUG "pmc551: I/O Access %s\n",
                (((0x1 << 0) & cmd) == 0) ? "off" : "on");

        pci_read_config_word(dev, PCI_STATUS, &cmd);
        printk(KERN_DEBUG "pmc551: Devsel %s\n",
                ((PCI_STATUS_DEVSEL_MASK & cmd) == 0x000) ? "Fast" :
                ((PCI_STATUS_DEVSEL_MASK & cmd) == 0x200) ? "Medium" :
                ((PCI_STATUS_DEVSEL_MASK & cmd) == 0x400) ? "Slow" : "Invalid");

        printk(KERN_DEBUG "pmc551: %sFast Back-to-Back\n",
                ((PCI_COMMAND_FAST_BACK & cmd) == 0) ? "Not " : "");

        pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
        printk(KERN_DEBUG "pmc551: EEPROM is under %s control\n"
                "pmc551: System Control Register is %slocked to PCI access\n"
                "pmc551: System Control Register is %slocked to EEPROM access\n",
                (bcmd & 0x1) ? "software" : "hardware",
                (bcmd & 0x20) ? "" : "un", (bcmd & 0x40) ? "" : "un");
#endif
        return size;
}

/*
 * Kernel version specific module stuffages
 */

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mark Ferrell <mferrell@mvista.com>");
MODULE_DESCRIPTION(PMC551_VERSION);

/*
 * Stuff these outside the ifdef so as to not bust compiled in driver support
 */
static int msize = 0;
static int asize = 0;

module_param(msize, int, 0);
MODULE_PARM_DESC(msize, "memory size in MiB [1 - 1024]");
module_param(asize, int, 0);
MODULE_PARM_DESC(asize, "aperture size, must be <= memsize [1-1024]");

/*
 * PMC551 Card Initialization
 */
static int __init init_pmc551(void)
{
        struct pci_dev *PCI_Device = NULL;
        struct mypriv *priv;
        int found = 0;
        struct mtd_info *mtd;
        int length = 0;

        if (msize) {
                msize = (1 << (ffs(msize) - 1)) << 20;
                if (msize > (1 << 30)) {
                        printk(KERN_NOTICE "pmc551: Invalid memory size [%d]\n",
                                msize);
                        return -EINVAL;
                }
        }

        if (asize) {
                asize = (1 << (ffs(asize) - 1)) << 20;
                if (asize > (1 << 30)) {
                        printk(KERN_NOTICE "pmc551: Invalid aperture size "
                                "[%d]\n", asize);
                        return -EINVAL;
                }
        }

        printk(KERN_INFO PMC551_VERSION);

        /*
         * PCU-bus chipset probe.
         */
        for (;;) {

                if ((PCI_Device = pci_get_device(PCI_VENDOR_ID_V3_SEMI,
                                                  PCI_DEVICE_ID_V3_SEMI_V370PDC,
                                                  PCI_Device)) == NULL) {
                        break;
                }

                printk(KERN_NOTICE "pmc551: Found PCI V370PDC at 0x%llx\n",
                        (unsigned long long)pci_resource_start(PCI_Device, 0));

                /*
                 * The PMC551 device acts VERY weird if you don't init it
                 * first.  i.e. it will not correctly report devsel.  If for
                 * some reason the sdram is in a wrote-protected state the
                 * device will DEVSEL when it is written to causing problems
                 * with the oldproc.c driver in
                 * some kernels (2.2.*)
                 */
                if ((length = fixup_pmc551(PCI_Device)) <= 0) {
                        printk(KERN_NOTICE "pmc551: Cannot init SDRAM\n");
                        break;
                }

                /*
                 * This is needed until the driver is capable of reading the
                 * onboard I2C SROM to discover the "real" memory size.
                 */
                if (msize) {
                        length = msize;
                        printk(KERN_NOTICE "pmc551: Using specified memory "
                                "size 0x%x\n", length);
                } else {
                        msize = length;
                }

                mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
                if (!mtd)
                        break;

                priv = kzalloc(sizeof(struct mypriv), GFP_KERNEL);
                if (!priv) {
                        kfree(mtd);
                        break;
                }
                mtd->priv = priv;
                priv->dev = PCI_Device;

                if (asize > length) {
                        printk(KERN_NOTICE "pmc551: reducing aperture size to "
                                "fit %dM\n", length >> 20);
                        priv->asize = asize = length;
                } else if (asize == 0 || asize == length) {
                        printk(KERN_NOTICE "pmc551: Using existing aperture "
                                "size %dM\n", length >> 20);
                        priv->asize = asize = length;
                } else {
                        printk(KERN_NOTICE "pmc551: Using specified aperture "
                                "size %dM\n", asize >> 20);
                        priv->asize = asize;
                }
                priv->start = pci_iomap(PCI_Device, 0, priv->asize);

                if (!priv->start) {
                        printk(KERN_NOTICE "pmc551: Unable to map IO space\n");
                        kfree(mtd->priv);
                        kfree(mtd);
                        break;
                }
#ifdef CONFIG_MTD_PMC551_DEBUG
                printk(KERN_DEBUG "pmc551: setting aperture to %d\n",
                        ffs(priv->asize >> 20) - 1);
#endif

                priv->base_map0 = (PMC551_PCI_MEM_MAP_REG_EN
                                   | PMC551_PCI_MEM_MAP_ENABLE
                                   | (ffs(priv->asize >> 20) - 1) << 4);
                priv->curr_map0 = priv->base_map0;
                pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
                                        priv->curr_map0);

#ifdef CONFIG_MTD_PMC551_DEBUG
                printk(KERN_DEBUG "pmc551: aperture set to %d\n",
                        (priv->base_map0 & 0xF0) >> 4);
#endif

                mtd->size = msize;
                mtd->flags = MTD_CAP_RAM;
                mtd->_erase = pmc551_erase;
                mtd->_read = pmc551_read;
                mtd->_write = pmc551_write;
                mtd->_point = pmc551_point;
                mtd->_unpoint = pmc551_unpoint;
                mtd->type = MTD_RAM;
                mtd->name = "PMC551 RAM board";
                mtd->erasesize = 0x10000;
                mtd->writesize = 1;
                mtd->owner = THIS_MODULE;

                if (mtd_device_register(mtd, NULL, 0)) {
                        printk(KERN_NOTICE "pmc551: Failed to register new device\n");
                        pci_iounmap(PCI_Device, priv->start);
                        kfree(mtd->priv);
                        kfree(mtd);
                        break;
                }

                /* Keep a reference as the mtd_device_register worked */
                pci_dev_get(PCI_Device);

                printk(KERN_NOTICE "Registered pmc551 memory device.\n");
                printk(KERN_NOTICE "Mapped %dMiB of memory from 0x%p to 0x%p\n",
                        priv->asize >> 20,
                        priv->start, priv->start + priv->asize);
                printk(KERN_NOTICE "Total memory is %d%sB\n",
                        (length < 1024) ? length :
                        (length < 1048576) ? length >> 10 : length >> 20,
                        (length < 1024) ? "" : (length < 1048576) ? "Ki" : "Mi");
                priv->nextpmc551 = pmc551list;
                pmc551list = mtd;
                found++;
        }

        /* Exited early, reference left over */
        pci_dev_put(PCI_Device);

        if (!pmc551list) {
                printk(KERN_NOTICE "pmc551: not detected\n");
                return -ENODEV;
        } else {
                printk(KERN_NOTICE "pmc551: %d pmc551 devices loaded\n", found);
                return 0;
        }
}

/*
 * PMC551 Card Cleanup
 */
static void __exit cleanup_pmc551(void)
{
        int found = 0;
        struct mtd_info *mtd;
        struct mypriv *priv;

        while ((mtd = pmc551list)) {
                priv = mtd->priv;
                pmc551list = priv->nextpmc551;

                if (priv->start) {
                        printk(KERN_DEBUG "pmc551: unmapping %dMiB starting at "
                                "0x%p\n", priv->asize >> 20, priv->start);
                        pci_iounmap(priv->dev, priv->start);
                }
                pci_dev_put(priv->dev);

                kfree(mtd->priv);
                mtd_device_unregister(mtd);
                kfree(mtd);
                found++;
        }

        printk(KERN_NOTICE "pmc551: %d pmc551 devices unloaded\n", found);
}

module_init(init_pmc551);
module_exit(cleanup_pmc551);