LXR linux/drivers/mtd/chips/fwh

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef FWH_LOCK_H
   3#define FWH_LOCK_H
   4
   5
   6enum fwh_lock_state {
   7        FWH_UNLOCKED   = 0,
   8        FWH_DENY_WRITE = 1,
   9        FWH_IMMUTABLE  = 2,
  10        FWH_DENY_READ  = 4,
  11};
  12
  13struct fwh_xxlock_thunk {
  14        enum fwh_lock_state val;
  15        flstate_t state;
  16};
  17
  18
  19#define FWH_XXLOCK_ONEBLOCK_LOCK   ((struct fwh_xxlock_thunk){ FWH_DENY_WRITE, FL_LOCKING})
  20#define FWH_XXLOCK_ONEBLOCK_UNLOCK ((struct fwh_xxlock_thunk){ FWH_UNLOCKED,   FL_UNLOCKING})
  21
  22/*
  23 * This locking/unlock is specific to firmware hub parts.  Only one
  24 * is known that supports the Intel command set.    Firmware
  25 * hub parts cannot be interleaved as they are on the LPC bus
  26 * so this code has not been tested with interleaved chips,
  27 * and will likely fail in that context.
  28 */
  29static int fwh_xxlock_oneblock(struct map_info *map, struct flchip *chip,
  30        unsigned long adr, int len, void *thunk)
  31{
  32        struct cfi_private *cfi = map->fldrv_priv;
  33        struct fwh_xxlock_thunk *xxlt = (struct fwh_xxlock_thunk *)thunk;
  34        int ret;
  35
  36        /* Refuse the operation if the we cannot look behind the chip */
  37        if (chip->start < 0x400000) {
  38                pr_debug( "MTD %s(): chip->start: %lx wanted >= 0x400000\n",
  39                        __func__, chip->start );
  40                return -EIO;
  41        }
  42        /*
  43         * lock block registers:
  44         * - on 64k boundariesand
  45         * - bit 1 set high
  46         * - block lock registers are 4MiB lower - overflow subtract (danger)
  47         *
  48         * The address manipulation is first done on the logical address
  49         * which is 0 at the start of the chip, and then the offset of
  50         * the individual chip is addted to it.  Any other order a weird
  51         * map offset could cause problems.
  52         */
  53        adr = (adr & ~0xffffUL) | 0x2;
  54        adr += chip->start - 0x400000;
  55
  56        /*
  57         * This is easy because these are writes to registers and not writes
  58         * to flash memory - that means that we don't have to check status
  59         * and timeout.
  60         */
  61        mutex_lock(&chip->mutex);
  62        ret = get_chip(map, chip, adr, FL_LOCKING);
  63        if (ret) {
  64                mutex_unlock(&chip->mutex);
  65                return ret;
  66        }
  67
  68        chip->oldstate = chip->state;
  69        chip->state = xxlt->state;
  70        map_write(map, CMD(xxlt->val), adr);
  71
  72        /* Done and happy. */
  73        chip->state = chip->oldstate;
  74        put_chip(map, chip, adr);
  75        mutex_unlock(&chip->mutex);
  76        return 0;
  77}
  78
  79
  80static int fwh_lock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
  81{
  82        int ret;
  83
  84        ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
  85                (void *)&FWH_XXLOCK_ONEBLOCK_LOCK);
  86
  87        return ret;
  88}
  89
  90
  91static int fwh_unlock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
  92{
  93        int ret;
  94
  95        ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
  96                (void *)&FWH_XXLOCK_ONEBLOCK_UNLOCK);
  97
  98        return ret;
  99}
 100
 101static void fixup_use_fwh_lock(struct mtd_info *mtd)
 102{
 103        printk(KERN_NOTICE "using fwh lock/unlock method\n");
 104        /* Setup for the chips with the fwh lock method */
 105        mtd->_lock   = fwh_lock_varsize;
 106        mtd->_unlock = fwh_unlock_varsize;
 107}
 108#endif /* FWH_LOCK_H */
 109