pmc551.c

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/*
 * PMC551 PCI Mezzanine Ram Device
 *
 * Author:
 *  Mark Ferrell <[email protected]>
 *  Copyright 1999,2000 Nortel Networks
 *
 * License:
 *  As part of this driver was derived from the slram.c driver it
 *  falls under the same license, which is GNU General Public
 *  License v2
 *
 * 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 <[email protected]> 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 <[email protected]>
 *  * 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 <asm/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:
    instr->state = MTD_ERASE_DONE;
#ifdef CONFIG_MTD_PMC551_DEBUG
    printk(KERN_DEBUG "pmc551_erase() done\n");
#endif

    mtd_erase_callback(instr);
    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 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 <[email protected]>");
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) {
            printk(KERN_NOTICE "pmc551: Cannot allocate new MTD "
                "device.\n");
            break;
        }

        priv = kzalloc(sizeof(struct mypriv), GFP_KERNEL);
        if (!priv) {
            printk(KERN_NOTICE "pmc551: Cannot allocate new MTD "
                "device.\n");
            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 */
    if (PCI_Device)
        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);