tqm8xxl.c

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/*
 * Handle mapping of the flash memory access routines
 * on TQM8xxL based devices.
 *
 * based on rpxlite.c
 *
 * Copyright(C) 2001 Kirk Lee <[email protected]>
 *
 * This code is GPLed
 *
 */

/*
 * According to TQM8xxL hardware manual, TQM8xxL series have
 * following flash memory organisations:
 *  | capacity |    | chip type |   | bank0 |   | bank1 |
 *      2MiB       512Kx16    2MiB         0
 *      4MiB       1Mx16      4MiB         0
 *      8MiB       1Mx16      4MiB         4MiB
 * Thus, we choose CONFIG_MTD_CFI_I2 & CONFIG_MTD_CFI_B4 at
 * kernel configuration.
 */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>

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

#include <asm/io.h>

#define FLASH_ADDR 0x40000000
#define FLASH_SIZE 0x00800000
#define FLASH_BANK_MAX 4

// trivial struct to describe partition information
struct mtd_part_def
{
    int nums;
    unsigned char *type;
    struct mtd_partition* mtd_part;
};

//static struct mtd_info *mymtd;
static struct mtd_info* mtd_banks[FLASH_BANK_MAX];
static struct map_info* map_banks[FLASH_BANK_MAX];
static struct mtd_part_def part_banks[FLASH_BANK_MAX];
static unsigned long num_banks;
static void __iomem *start_scan_addr;

/*
 * Here are partition information for all known TQM8xxL series devices.
 * See include/linux/mtd/partitions.h for definition of the mtd_partition
 * structure.
 *
 * The *_max_flash_size is the maximum possible mapped flash size which
 * is not necessarily the actual flash size.  It must correspond to the
 * value specified in the mapping definition defined by the
 * "struct map_desc *_io_desc" for the corresponding machine.
 */

/* Currently, TQM8xxL has up to 8MiB flash */
static unsigned long tqm8xxl_max_flash_size = 0x00800000;

/* partition definition for first flash bank
 * (cf. "drivers/char/flash_config.c")
 */
static struct mtd_partition tqm8xxl_partitions[] = {
    {
      .name = "ppcboot",
      .offset = 0x00000000,
      .size = 0x00020000,           /* 128KB           */
      .mask_flags = MTD_WRITEABLE,  /* force read-only */
    },
    {
      .name = "kernel",             /* default kernel image */
      .offset = 0x00020000,
      .size = 0x000e0000,
      .mask_flags = MTD_WRITEABLE,  /* force read-only */
    },
    {
      .name = "user",
      .offset = 0x00100000,
      .size = 0x00100000,
    },
    {
      .name = "initrd",
      .offset = 0x00200000,
      .size = 0x00200000,
    }
};
/* partition definition for second flash bank */
static struct mtd_partition tqm8xxl_fs_partitions[] = {
    {
      .name = "cramfs",
      .offset = 0x00000000,
      .size = 0x00200000,
    },
    {
      .name = "jffs",
      .offset = 0x00200000,
      .size = 0x00200000,
      //.size = MTDPART_SIZ_FULL,
    }
};

static int __init init_tqm_mtd(void)
{
    int idx = 0, ret = 0;
    unsigned long flash_addr, flash_size, mtd_size = 0;
    /* pointer to TQM8xxL board info data */
    bd_t *bd = (bd_t *)__res;

    flash_addr = bd->bi_flashstart;
    flash_size = bd->bi_flashsize;

    //request maximum flash size address space
    start_scan_addr = ioremap(flash_addr, flash_size);
    if (!start_scan_addr) {
        printk(KERN_WARNING "%s:Failed to ioremap address:0x%x\n", __func__, flash_addr);
        return -EIO;
    }

    for (idx = 0 ; idx < FLASH_BANK_MAX ; idx++) {
        if(mtd_size >= flash_size)
            break;

        printk(KERN_INFO "%s: chip probing count %d\n", __func__, idx);

        map_banks[idx] = kzalloc(sizeof(struct map_info), GFP_KERNEL);
        if(map_banks[idx] == NULL) {
            ret = -ENOMEM;
            /* FIXME: What if some MTD devices were probed already? */
            goto error_mem;
        }

        map_banks[idx]->name = kmalloc(16, GFP_KERNEL);

        if (!map_banks[idx]->name) {
            ret = -ENOMEM;
            /* FIXME: What if some MTD devices were probed already? */
            goto error_mem;
        }
        sprintf(map_banks[idx]->name, "TQM8xxL%d", idx);

        map_banks[idx]->size = flash_size;
        map_banks[idx]->bankwidth = 4;

        simple_map_init(map_banks[idx]);

        map_banks[idx]->virt = start_scan_addr;
        map_banks[idx]->phys = flash_addr;
        /* FIXME: This looks utterly bogus, but I'm trying to
           preserve the behaviour of the original (shown here)...

        map_banks[idx]->map_priv_1 =
        start_scan_addr + ((idx > 0) ?
        (mtd_banks[idx-1] ? mtd_banks[idx-1]->size : 0) : 0);
        */

        if (idx && mtd_banks[idx-1]) {
            map_banks[idx]->virt += mtd_banks[idx-1]->size;
            map_banks[idx]->phys += mtd_banks[idx-1]->size;
        }

        //start to probe flash chips
        mtd_banks[idx] = do_map_probe("cfi_probe", map_banks[idx]);

        if (mtd_banks[idx]) {
            mtd_banks[idx]->owner = THIS_MODULE;
            mtd_size += mtd_banks[idx]->size;
            num_banks++;

            printk(KERN_INFO "%s: bank%d, name:%s, size:%dbytes \n", __func__, num_banks,
            mtd_banks[idx]->name, mtd_banks[idx]->size);
        }
    }

    /* no supported flash chips found */
    if (!num_banks) {
        printk(KERN_NOTICE "TQM8xxL: No support flash chips found!\n");
        ret = -ENXIO;
        goto error_mem;
    }

    /*
     * Select Static partition definitions
     */
    part_banks[0].mtd_part = tqm8xxl_partitions;
    part_banks[0].type = "Static image";
    part_banks[0].nums = ARRAY_SIZE(tqm8xxl_partitions);

    part_banks[1].mtd_part = tqm8xxl_fs_partitions;
    part_banks[1].type = "Static file system";
    part_banks[1].nums = ARRAY_SIZE(tqm8xxl_fs_partitions);

    for(idx = 0; idx < num_banks ; idx++) {
        if (part_banks[idx].nums == 0)
            printk(KERN_NOTICE "TQM flash%d: no partition info available, registering whole flash at once\n", idx);
        else
            printk(KERN_NOTICE "TQM flash%d: Using %s partition definition\n",
                    idx, part_banks[idx].type);
        mtd_device_register(mtd_banks[idx], part_banks[idx].mtd_part,
        part_banks[idx].nums);
    }
    return 0;
error_mem:
    for(idx = 0 ; idx < FLASH_BANK_MAX ; idx++) {
        if(map_banks[idx] != NULL) {
            kfree(map_banks[idx]->name);
            map_banks[idx]->name = NULL;
            kfree(map_banks[idx]);
            map_banks[idx] = NULL;
        }
    }
error:
    iounmap(start_scan_addr);
    return ret;
}

static void __exit cleanup_tqm_mtd(void)
{
    unsigned int idx = 0;
    for(idx = 0 ; idx < num_banks ; idx++) {
        /* destroy mtd_info previously allocated */
        if (mtd_banks[idx]) {
            mtd_device_unregister(mtd_banks[idx]);
            map_destroy(mtd_banks[idx]);
        }
        /* release map_info not used anymore */
        kfree(map_banks[idx]->name);
        kfree(map_banks[idx]);
    }

    if (start_scan_addr) {
        iounmap(start_scan_addr);
        start_scan_addr = 0;
    }
}

module_init(init_tqm_mtd);
module_exit(cleanup_tqm_mtd);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Kirk Lee <[email protected]>");
MODULE_DESCRIPTION("MTD map driver for TQM8xxL boards");