sprom.c

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/*
 * Sonics Silicon Backplane
 * Common SPROM support routines
 *
 * Copyright (C) 2005-2008 Michael Buesch <[email protected]>
 * Copyright (C) 2005 Martin Langer <[email protected]>
 * Copyright (C) 2005 Stefano Brivio <[email protected]>
 * Copyright (C) 2005 Danny van Dyk <[email protected]>
 * Copyright (C) 2005 Andreas Jaggi <[email protected]>
 *
 * Licensed under the GNU/GPL. See COPYING for details.
 */

#include "ssb_private.h"

#include <linux/ctype.h>
#include <linux/slab.h>


static int(*get_fallback_sprom)(struct ssb_bus *dev, struct ssb_sprom *out);


static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
             size_t sprom_size_words)
{
    int i, pos = 0;

    for (i = 0; i < sprom_size_words; i++)
        pos += snprintf(buf + pos, buf_len - pos - 1,
                "%04X", swab16(sprom[i]) & 0xFFFF);
    pos += snprintf(buf + pos, buf_len - pos - 1, "\n");

    return pos + 1;
}

static int hex2sprom(u16 *sprom, const char *dump, size_t len,
             size_t sprom_size_words)
{
    char c, tmp[5] = { 0 };
    int err, cnt = 0;
    unsigned long parsed;

    /* Strip whitespace at the end. */
    while (len) {
        c = dump[len - 1];
        if (!isspace(c) && c != '\0')
            break;
        len--;
    }
    /* Length must match exactly. */
    if (len != sprom_size_words * 4)
        return -EINVAL;

    while (cnt < sprom_size_words) {
        memcpy(tmp, dump, 4);
        dump += 4;
        err = strict_strtoul(tmp, 16, &parsed);
        if (err)
            return err;
        sprom[cnt++] = swab16((u16)parsed);
    }

    return 0;
}

/* Common sprom device-attribute show-handler */
ssize_t ssb_attr_sprom_show(struct ssb_bus *bus, char *buf,
                int (*sprom_read)(struct ssb_bus *bus, u16 *sprom))
{
    u16 *sprom;
    int err = -ENOMEM;
    ssize_t count = 0;
    size_t sprom_size_words = bus->sprom_size;

    sprom = kcalloc(sprom_size_words, sizeof(u16), GFP_KERNEL);
    if (!sprom)
        goto out;

    /* Use interruptible locking, as the SPROM write might
     * be holding the lock for several seconds. So allow userspace
     * to cancel operation. */
    err = -ERESTARTSYS;
    if (mutex_lock_interruptible(&bus->sprom_mutex))
        goto out_kfree;
    err = sprom_read(bus, sprom);
    mutex_unlock(&bus->sprom_mutex);

    if (!err)
        count = sprom2hex(sprom, buf, PAGE_SIZE, sprom_size_words);

out_kfree:
    kfree(sprom);
out:
    return err ? err : count;
}

/* Common sprom device-attribute store-handler */
ssize_t ssb_attr_sprom_store(struct ssb_bus *bus,
                 const char *buf, size_t count,
                 int (*sprom_check_crc)(const u16 *sprom, size_t size),
                 int (*sprom_write)(struct ssb_bus *bus, const u16 *sprom))
{
    u16 *sprom;
    int res = 0, err = -ENOMEM;
    size_t sprom_size_words = bus->sprom_size;
    struct ssb_freeze_context freeze;

    sprom = kcalloc(bus->sprom_size, sizeof(u16), GFP_KERNEL);
    if (!sprom)
        goto out;
    err = hex2sprom(sprom, buf, count, sprom_size_words);
    if (err) {
        err = -EINVAL;
        goto out_kfree;
    }
    err = sprom_check_crc(sprom, sprom_size_words);
    if (err) {
        err = -EINVAL;
        goto out_kfree;
    }

    /* Use interruptible locking, as the SPROM write might
     * be holding the lock for several seconds. So allow userspace
     * to cancel operation. */
    err = -ERESTARTSYS;
    if (mutex_lock_interruptible(&bus->sprom_mutex))
        goto out_kfree;
    err = ssb_devices_freeze(bus, &freeze);
    if (err) {
        ssb_printk(KERN_ERR PFX "SPROM write: Could not freeze all devices\n");
        goto out_unlock;
    }
    res = sprom_write(bus, sprom);
    err = ssb_devices_thaw(&freeze);
    if (err)
        ssb_printk(KERN_ERR PFX "SPROM write: Could not thaw all devices\n");
out_unlock:
    mutex_unlock(&bus->sprom_mutex);
out_kfree:
    kfree(sprom);
out:
    if (res)
        return res;
    return err ? err : count;
}

int ssb_arch_register_fallback_sprom(int (*sprom_callback)(struct ssb_bus *bus,
                     struct ssb_sprom *out))
{
    if (get_fallback_sprom)
        return -EEXIST;
    get_fallback_sprom = sprom_callback;

    return 0;
}

int ssb_fill_sprom_with_fallback(struct ssb_bus *bus, struct ssb_sprom *out)
{
    if (!get_fallback_sprom)
        return -ENOENT;

    return get_fallback_sprom(bus, out);
}

/* http://bcm-v4.sipsolutions.net/802.11/IsSpromAvailable */
bool ssb_is_sprom_available(struct ssb_bus *bus)
{
    /* status register only exists on chipcomon rev >= 11 and we need check
       for >= 31 only */
    /* this routine differs from specs as we do not access SPROM directly
       on PCMCIA */
    if (bus->bustype == SSB_BUSTYPE_PCI &&
        bus->chipco.dev &&  /* can be unavailable! */
        bus->chipco.dev->id.revision >= 31)
        return bus->chipco.capabilities & SSB_CHIPCO_CAP_SPROM;

    return true;
}