driver_chipcommon_sflash.c

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/*
 * Broadcom specific AMBA
 * ChipCommon serial flash interface
 *
 * Licensed under the GNU/GPL. See COPYING for details.
 */

#include <linux/platform_device.h>
#include <linux/bcma/bcma.h>

#include "bcma_private.h"

static struct resource bcma_sflash_resource = {
    .name   = "bcma_sflash",
    .start  = BCMA_SFLASH,
    .end    = 0,
    .flags  = IORESOURCE_MEM | IORESOURCE_READONLY,
};

struct platform_device bcma_sflash_dev = {
    .name       = "bcma_sflash",
    .resource   = &bcma_sflash_resource,
    .num_resources  = 1,
};

struct bcma_sflash_tbl_e {
    char *name;
    u32 id;
    u32 blocksize;
    u16 numblocks;
};

static struct bcma_sflash_tbl_e bcma_sflash_st_tbl[] = {
    { "", 0x14, 0x10000, 32, },
    { 0 },
};

static struct bcma_sflash_tbl_e bcma_sflash_sst_tbl[] = {
    { 0 },
};

static struct bcma_sflash_tbl_e bcma_sflash_at_tbl[] = {
    { 0 },
};

static void bcma_sflash_cmd(struct bcma_drv_cc *cc, u32 opcode)
{
    int i;
    bcma_cc_write32(cc, BCMA_CC_FLASHCTL,
            BCMA_CC_FLASHCTL_START | opcode);
    for (i = 0; i < 1000; i++) {
        if (!(bcma_cc_read32(cc, BCMA_CC_FLASHCTL) &
              BCMA_CC_FLASHCTL_BUSY))
            return;
        cpu_relax();
    }
    bcma_err(cc->core->bus, "SFLASH control command failed (timeout)!\n");
}

/* Initialize serial flash access */
int bcma_sflash_init(struct bcma_drv_cc *cc)
{
    struct bcma_bus *bus = cc->core->bus;
    struct bcma_sflash *sflash = &cc->sflash;
    struct bcma_sflash_tbl_e *e;
    u32 id, id2;

    switch (cc->capabilities & BCMA_CC_CAP_FLASHT) {
    case BCMA_CC_FLASHT_STSER:
        bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_DP);

        bcma_cc_write32(cc, BCMA_CC_FLASHADDR, 0);
        bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_RES);
        id = bcma_cc_read32(cc, BCMA_CC_FLASHDATA);

        bcma_cc_write32(cc, BCMA_CC_FLASHADDR, 1);
        bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_ST_RES);
        id2 = bcma_cc_read32(cc, BCMA_CC_FLASHDATA);

        switch (id) {
        case 0xbf:
            for (e = bcma_sflash_sst_tbl; e->name; e++) {
                if (e->id == id2)
                    break;
            }
            break;
        default:
            for (e = bcma_sflash_st_tbl; e->name; e++) {
                if (e->id == id)
                    break;
            }
            break;
        }
        if (!e->name) {
            bcma_err(bus, "Unsupported ST serial flash (id: 0x%X, id2: 0x%X)\n", id, id2);
            return -ENOTSUPP;
        }

        break;
    case BCMA_CC_FLASHT_ATSER:
        bcma_sflash_cmd(cc, BCMA_CC_FLASHCTL_AT_STATUS);
        id = bcma_cc_read32(cc, BCMA_CC_FLASHDATA) & 0x3c;

        for (e = bcma_sflash_at_tbl; e->name; e++) {
            if (e->id == id)
                break;
        }
        if (!e->name) {
            bcma_err(bus, "Unsupported Atmel serial flash (id: 0x%X)\n", id);
            return -ENOTSUPP;
        }

        break;
    default:
        bcma_err(bus, "Unsupported flash type\n");
        return -ENOTSUPP;
    }

    sflash->window = BCMA_SFLASH;
    sflash->blocksize = e->blocksize;
    sflash->numblocks = e->numblocks;
    sflash->size = sflash->blocksize * sflash->numblocks;
    sflash->present = true;

    bcma_info(bus, "Found %s serial flash (size: %dKiB, blocksize: 0x%X, blocks: %d)\n",
          e->name, sflash->size / 1024, sflash->blocksize,
          sflash->numblocks);

    /* Prepare platform device, but don't register it yet. It's too early,
     * malloc (required by device_private_init) is not available yet. */
    bcma_sflash_dev.resource[0].end = bcma_sflash_dev.resource[0].start +
                      sflash->size;
    bcma_sflash_dev.dev.platform_data = sflash;

    return 0;
}