cfi_probe.c

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/*
   Common Flash Interface probe code.
   (C) 2000 Red Hat. GPL'd.
*/

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/byteorder.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/interrupt.h>

#include <linux/mtd/xip.h>
#include <linux/mtd/map.h>
#include <linux/mtd/cfi.h>
#include <linux/mtd/gen_probe.h>

//#define DEBUG_CFI

#ifdef DEBUG_CFI
static void print_cfi_ident(struct cfi_ident *);
#endif

static int cfi_probe_chip(struct map_info *map, __u32 base,
              unsigned long *chip_map, struct cfi_private *cfi);
static int cfi_chip_setup(struct map_info *map, struct cfi_private *cfi);

struct mtd_info *cfi_probe(struct map_info *map);

#ifdef CONFIG_MTD_XIP

/* only needed for short periods, so this is rather simple */
#define xip_disable()   local_irq_disable()

#define xip_allowed(base, map) \
do { \
    (void) map_read(map, base); \
    xip_iprefetch(); \
    local_irq_enable(); \
} while (0)

#define xip_enable(base, map, cfi) \
do { \
    cfi_qry_mode_off(base, map, cfi);       \
    xip_allowed(base, map); \
} while (0)

#define xip_disable_qry(base, map, cfi) \
do { \
    xip_disable(); \
    cfi_qry_mode_on(base, map, cfi); \
} while (0)

#else

#define xip_disable()           do { } while (0)
#define xip_allowed(base, map)      do { } while (0)
#define xip_enable(base, map, cfi)  do { } while (0)
#define xip_disable_qry(base, map, cfi) do { } while (0)

#endif

/* check for QRY.
   in: interleave,type,mode
   ret: table index, <0 for error
 */

static int __xipram cfi_probe_chip(struct map_info *map, __u32 base,
                   unsigned long *chip_map, struct cfi_private *cfi)
{
    int i;

    if ((base + 0) >= map->size) {
        printk(KERN_NOTICE
            "Probe at base[0x00](0x%08lx) past the end of the map(0x%08lx)\n",
            (unsigned long)base, map->size -1);
        return 0;
    }
    if ((base + 0xff) >= map->size) {
        printk(KERN_NOTICE
            "Probe at base[0x55](0x%08lx) past the end of the map(0x%08lx)\n",
            (unsigned long)base + 0x55, map->size -1);
        return 0;
    }

    xip_disable();
    if (!cfi_qry_mode_on(base, map, cfi)) {
        xip_enable(base, map, cfi);
        return 0;
    }

    if (!cfi->numchips) {
        /* This is the first time we're called. Set up the CFI
           stuff accordingly and return */
        return cfi_chip_setup(map, cfi);
    }

    /* Check each previous chip to see if it's an alias */
    for (i=0; i < (base >> cfi->chipshift); i++) {
        unsigned long start;
        if(!test_bit(i, chip_map)) {
            /* Skip location; no valid chip at this address */
            continue;
        }
        start = i << cfi->chipshift;
        /* This chip should be in read mode if it's one
           we've already touched. */
        if (cfi_qry_present(map, start, cfi)) {
            /* Eep. This chip also had the QRY marker.
             * Is it an alias for the new one? */
            cfi_qry_mode_off(start, map, cfi);

            /* If the QRY marker goes away, it's an alias */
            if (!cfi_qry_present(map, start, cfi)) {
                xip_allowed(base, map);
                printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
                       map->name, base, start);
                return 0;
            }
            /* Yes, it's actually got QRY for data. Most
             * unfortunate. Stick the new chip in read mode
             * too and if it's the same, assume it's an alias. */
            /* FIXME: Use other modes to do a proper check */
            cfi_qry_mode_off(base, map, cfi);

            if (cfi_qry_present(map, base, cfi)) {
                xip_allowed(base, map);
                printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
                       map->name, base, start);
                return 0;
            }
        }
    }

    /* OK, if we got to here, then none of the previous chips appear to
       be aliases for the current one. */
    set_bit((base >> cfi->chipshift), chip_map); /* Update chip map */
    cfi->numchips++;

    /* Put it back into Read Mode */
    cfi_qry_mode_off(base, map, cfi);
    xip_allowed(base, map);

    printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank\n",
           map->name, cfi->interleave, cfi->device_type*8, base,
           map->bankwidth*8);

    return 1;
}

static int __xipram cfi_chip_setup(struct map_info *map,
                   struct cfi_private *cfi)
{
    int ofs_factor = cfi->interleave*cfi->device_type;
    __u32 base = 0;
    int num_erase_regions = cfi_read_query(map, base + (0x10 + 28)*ofs_factor);
    int i;
    int addr_unlock1 = 0x555, addr_unlock2 = 0x2AA;

    xip_enable(base, map, cfi);
#ifdef DEBUG_CFI
    printk("Number of erase regions: %d\n", num_erase_regions);
#endif
    if (!num_erase_regions)
        return 0;

    cfi->cfiq = kmalloc(sizeof(struct cfi_ident) + num_erase_regions * 4, GFP_KERNEL);
    if (!cfi->cfiq) {
        printk(KERN_WARNING "%s: kmalloc failed for CFI ident structure\n", map->name);
        return 0;
    }

    memset(cfi->cfiq,0,sizeof(struct cfi_ident));

    cfi->cfi_mode = CFI_MODE_CFI;

    cfi->sector_erase_cmd = CMD(0x30);

    /* Read the CFI info structure */
    xip_disable_qry(base, map, cfi);
    for (i=0; i<(sizeof(struct cfi_ident) + num_erase_regions * 4); i++)
        ((unsigned char *)cfi->cfiq)[i] = cfi_read_query(map,base + (0x10 + i)*ofs_factor);

    /* Do any necessary byteswapping */
    cfi->cfiq->P_ID = le16_to_cpu(cfi->cfiq->P_ID);

    cfi->cfiq->P_ADR = le16_to_cpu(cfi->cfiq->P_ADR);
    cfi->cfiq->A_ID = le16_to_cpu(cfi->cfiq->A_ID);
    cfi->cfiq->A_ADR = le16_to_cpu(cfi->cfiq->A_ADR);
    cfi->cfiq->InterfaceDesc = le16_to_cpu(cfi->cfiq->InterfaceDesc);
    cfi->cfiq->MaxBufWriteSize = le16_to_cpu(cfi->cfiq->MaxBufWriteSize);

#ifdef DEBUG_CFI
    /* Dump the information therein */
    print_cfi_ident(cfi->cfiq);
#endif

    for (i=0; i<cfi->cfiq->NumEraseRegions; i++) {
        cfi->cfiq->EraseRegionInfo[i] = le32_to_cpu(cfi->cfiq->EraseRegionInfo[i]);

#ifdef DEBUG_CFI
        printk("  Erase Region #%d: BlockSize 0x%4.4X bytes, %d blocks\n",
               i, (cfi->cfiq->EraseRegionInfo[i] >> 8) & ~0xff,
               (cfi->cfiq->EraseRegionInfo[i] & 0xffff) + 1);
#endif
    }

    if (cfi->cfiq->P_ID == P_ID_SST_OLD) {
        addr_unlock1 = 0x5555;
        addr_unlock2 = 0x2AAA;
    }

    /*
     * Note we put the device back into Read Mode BEFORE going into Auto
     * Select Mode, as some devices support nesting of modes, others
     * don't. This way should always work.
     * On cmdset 0001 the writes of 0xaa and 0x55 are not needed, and
     * so should be treated as nops or illegal (and so put the device
     * back into Read Mode, which is a nop in this case).
     */
    cfi_send_gen_cmd(0xf0,     0, base, map, cfi, cfi->device_type, NULL);
    cfi_send_gen_cmd(0xaa, addr_unlock1, base, map, cfi, cfi->device_type, NULL);
    cfi_send_gen_cmd(0x55, addr_unlock2, base, map, cfi, cfi->device_type, NULL);
    cfi_send_gen_cmd(0x90, addr_unlock1, base, map, cfi, cfi->device_type, NULL);
    cfi->mfr = cfi_read_query16(map, base);
    cfi->id = cfi_read_query16(map, base + ofs_factor);

    /* Get AMD/Spansion extended JEDEC ID */
    if (cfi->mfr == CFI_MFR_AMD && (cfi->id & 0xff) == 0x7e)
        cfi->id = cfi_read_query(map, base + 0xe * ofs_factor) << 8 |
              cfi_read_query(map, base + 0xf * ofs_factor);

    /* Put it back into Read Mode */
    cfi_qry_mode_off(base, map, cfi);
    xip_allowed(base, map);

    printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank. Manufacturer ID %#08x Chip ID %#08x\n",
           map->name, cfi->interleave, cfi->device_type*8, base,
           map->bankwidth*8, cfi->mfr, cfi->id);

    return 1;
}

#ifdef DEBUG_CFI
static char *vendorname(__u16 vendor)
{
    switch (vendor) {
    case P_ID_NONE:
        return "None";

    case P_ID_INTEL_EXT:
        return "Intel/Sharp Extended";

    case P_ID_AMD_STD:
        return "AMD/Fujitsu Standard";

    case P_ID_INTEL_STD:
        return "Intel/Sharp Standard";

    case P_ID_AMD_EXT:
        return "AMD/Fujitsu Extended";

    case P_ID_WINBOND:
        return "Winbond Standard";

    case P_ID_ST_ADV:
        return "ST Advanced";

    case P_ID_MITSUBISHI_STD:
        return "Mitsubishi Standard";

    case P_ID_MITSUBISHI_EXT:
        return "Mitsubishi Extended";

    case P_ID_SST_PAGE:
        return "SST Page Write";

    case P_ID_SST_OLD:
        return "SST 39VF160x/39VF320x";

    case P_ID_INTEL_PERFORMANCE:
        return "Intel Performance Code";

    case P_ID_INTEL_DATA:
        return "Intel Data";

    case P_ID_RESERVED:
        return "Not Allowed / Reserved for Future Use";

    default:
        return "Unknown";
    }
}


static void print_cfi_ident(struct cfi_ident *cfip)
{
#if 0
    if (cfip->qry[0] != 'Q' || cfip->qry[1] != 'R' || cfip->qry[2] != 'Y') {
        printk("Invalid CFI ident structure.\n");
        return;
    }
#endif
    printk("Primary Vendor Command Set: %4.4X (%s)\n", cfip->P_ID, vendorname(cfip->P_ID));
    if (cfip->P_ADR)
        printk("Primary Algorithm Table at %4.4X\n", cfip->P_ADR);
    else
        printk("No Primary Algorithm Table\n");

    printk("Alternative Vendor Command Set: %4.4X (%s)\n", cfip->A_ID, vendorname(cfip->A_ID));
    if (cfip->A_ADR)
        printk("Alternate Algorithm Table at %4.4X\n", cfip->A_ADR);
    else
        printk("No Alternate Algorithm Table\n");


    printk("Vcc Minimum: %2d.%d V\n", cfip->VccMin >> 4, cfip->VccMin & 0xf);
    printk("Vcc Maximum: %2d.%d V\n", cfip->VccMax >> 4, cfip->VccMax & 0xf);
    if (cfip->VppMin) {
        printk("Vpp Minimum: %2d.%d V\n", cfip->VppMin >> 4, cfip->VppMin & 0xf);
        printk("Vpp Maximum: %2d.%d V\n", cfip->VppMax >> 4, cfip->VppMax & 0xf);
    }
    else
        printk("No Vpp line\n");

    printk("Typical byte/word write timeout: %d µs\n", 1<<cfip->WordWriteTimeoutTyp);
    printk("Maximum byte/word write timeout: %d µs\n", (1<<cfip->WordWriteTimeoutMax) * (1<<cfip->WordWriteTimeoutTyp));

    if (cfip->BufWriteTimeoutTyp || cfip->BufWriteTimeoutMax) {
        printk("Typical full buffer write timeout: %d µs\n", 1<<cfip->BufWriteTimeoutTyp);
        printk("Maximum full buffer write timeout: %d µs\n", (1<<cfip->BufWriteTimeoutMax) * (1<<cfip->BufWriteTimeoutTyp));
    }
    else
        printk("Full buffer write not supported\n");

    printk("Typical block erase timeout: %d ms\n", 1<<cfip->BlockEraseTimeoutTyp);
    printk("Maximum block erase timeout: %d ms\n", (1<<cfip->BlockEraseTimeoutMax) * (1<<cfip->BlockEraseTimeoutTyp));
    if (cfip->ChipEraseTimeoutTyp || cfip->ChipEraseTimeoutMax) {
        printk("Typical chip erase timeout: %d ms\n", 1<<cfip->ChipEraseTimeoutTyp);
        printk("Maximum chip erase timeout: %d ms\n", (1<<cfip->ChipEraseTimeoutMax) * (1<<cfip->ChipEraseTimeoutTyp));
    }
    else
        printk("Chip erase not supported\n");

    printk("Device size: 0x%X bytes (%d MiB)\n", 1 << cfip->DevSize, 1<< (cfip->DevSize - 20));
    printk("Flash Device Interface description: 0x%4.4X\n", cfip->InterfaceDesc);
    switch(cfip->InterfaceDesc) {
    case CFI_INTERFACE_X8_ASYNC:
        printk("  - x8-only asynchronous interface\n");
        break;

    case CFI_INTERFACE_X16_ASYNC:
        printk("  - x16-only asynchronous interface\n");
        break;

    case CFI_INTERFACE_X8_BY_X16_ASYNC:
        printk("  - supports x8 and x16 via BYTE# with asynchronous interface\n");
        break;

    case CFI_INTERFACE_X32_ASYNC:
        printk("  - x32-only asynchronous interface\n");
        break;

    case CFI_INTERFACE_X16_BY_X32_ASYNC:
        printk("  - supports x16 and x32 via Word# with asynchronous interface\n");
        break;

    case CFI_INTERFACE_NOT_ALLOWED:
        printk("  - Not Allowed / Reserved\n");
        break;

    default:
        printk("  - Unknown\n");
        break;
    }

    printk("Max. bytes in buffer write: 0x%x\n", 1<< cfip->MaxBufWriteSize);
    printk("Number of Erase Block Regions: %d\n", cfip->NumEraseRegions);

}
#endif /* DEBUG_CFI */

static struct chip_probe cfi_chip_probe = {
    .name       = "CFI",
    .probe_chip = cfi_probe_chip
};

struct mtd_info *cfi_probe(struct map_info *map)
{
    /*
     * Just use the generic probe stuff to call our CFI-specific
     * chip_probe routine in all the possible permutations, etc.
     */
    return mtd_do_chip_probe(map, &cfi_chip_probe);
}

static struct mtd_chip_driver cfi_chipdrv = {
    .probe      = cfi_probe,
    .name       = "cfi_probe",
    .module     = THIS_MODULE
};

static int __init cfi_probe_init(void)
{
    register_mtd_chip_driver(&cfi_chipdrv);
    return 0;
}

static void __exit cfi_probe_exit(void)
{
    unregister_mtd_chip_driver(&cfi_chipdrv);
}

module_init(cfi_probe_init);
module_exit(cfi_probe_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <[email protected]> et al.");
MODULE_DESCRIPTION("Probe code for CFI-compliant flash chips");