sun_uflash.c

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/* sun_uflash.c - Driver for user-programmable flash on
 *                Sun Microsystems SME boardsets.
 *
 * This driver does NOT provide access to the OBP-flash for
 * safety reasons-- use <linux>/drivers/sbus/char/flash.c instead.
 *
 * Copyright (c) 2001 Eric Brower ([email protected])
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <asm/prom.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>

#define UFLASH_OBPNAME  "flashprom"
#define DRIVER_NAME "sun_uflash"
#define PFX     DRIVER_NAME ": "

#define UFLASH_WINDOW_SIZE  0x200000
#define UFLASH_BUSWIDTH     1           /* EBus is 8-bit */

MODULE_AUTHOR("Eric Brower <[email protected]>");
MODULE_DESCRIPTION("User-programmable flash device on Sun Microsystems boardsets");
MODULE_SUPPORTED_DEVICE(DRIVER_NAME);
MODULE_LICENSE("GPL");
MODULE_VERSION("2.1");

struct uflash_dev {
    const char      *name;  /* device name */
    struct map_info     map;    /* mtd map info */
    struct mtd_info     *mtd;   /* mtd info */
};

struct map_info uflash_map_templ = {
    .name =     "SUNW,???-????",
    .size =     UFLASH_WINDOW_SIZE,
    .bankwidth =    UFLASH_BUSWIDTH,
};

int uflash_devinit(struct platform_device *op, struct device_node *dp)
{
    struct uflash_dev *up;

    if (op->resource[1].flags) {
        /* Non-CFI userflash device-- once I find one we
         * can work on supporting it.
         */
        printk(KERN_ERR PFX "Unsupported device at %s, 0x%llx\n",
               dp->full_name, (unsigned long long)op->resource[0].start);

        return -ENODEV;
    }

    up = kzalloc(sizeof(struct uflash_dev), GFP_KERNEL);
    if (!up) {
        printk(KERN_ERR PFX "Cannot allocate struct uflash_dev\n");
        return -ENOMEM;
    }

    /* copy defaults and tweak parameters */
    memcpy(&up->map, &uflash_map_templ, sizeof(uflash_map_templ));

    up->map.size = resource_size(&op->resource[0]);

    up->name = of_get_property(dp, "model", NULL);
    if (up->name && 0 < strlen(up->name))
        up->map.name = (char *)up->name;

    up->map.phys = op->resource[0].start;

    up->map.virt = of_ioremap(&op->resource[0], 0, up->map.size,
                  DRIVER_NAME);
    if (!up->map.virt) {
        printk(KERN_ERR PFX "Failed to map device.\n");
        kfree(up);

        return -EINVAL;
    }

    simple_map_init(&up->map);

    /* MTD registration */
    up->mtd = do_map_probe("cfi_probe", &up->map);
    if (!up->mtd) {
        of_iounmap(&op->resource[0], up->map.virt, up->map.size);
        kfree(up);

        return -ENXIO;
    }

    up->mtd->owner = THIS_MODULE;

    mtd_device_register(up->mtd, NULL, 0);

    dev_set_drvdata(&op->dev, up);

    return 0;
}

static int __devinit uflash_probe(struct platform_device *op)
{
    struct device_node *dp = op->dev.of_node;

    /* Flashprom must have the "user" property in order to
     * be used by this driver.
     */
    if (!of_find_property(dp, "user", NULL))
        return -ENODEV;

    return uflash_devinit(op, dp);
}

static int __devexit uflash_remove(struct platform_device *op)
{
    struct uflash_dev *up = dev_get_drvdata(&op->dev);

    if (up->mtd) {
        mtd_device_unregister(up->mtd);
        map_destroy(up->mtd);
    }
    if (up->map.virt) {
        of_iounmap(&op->resource[0], up->map.virt, up->map.size);
        up->map.virt = NULL;
    }

    kfree(up);

    return 0;
}

static const struct of_device_id uflash_match[] = {
    {
        .name = UFLASH_OBPNAME,
    },
    {},
};

MODULE_DEVICE_TABLE(of, uflash_match);

static struct platform_driver uflash_driver = {
    .driver = {
        .name = DRIVER_NAME,
        .owner = THIS_MODULE,
        .of_match_table = uflash_match,
    },
    .probe      = uflash_probe,
    .remove     = __devexit_p(uflash_remove),
};

module_platform_driver(uflash_driver);