1 files changed, 108 insertions, 0 deletions
diff --git a/drivers/mtd/chips/fwh_lock.h b/drivers/mtd/chips/fwh_lock.h
new file mode 100644
index 000000000..53e6b2d59
--- /dev/null
+++ b/drivers/mtd/chips/fwh_lock.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef FWH_LOCK_H
+#define FWH_LOCK_H
+
+
+enum fwh_lock_state {
+        FWH_UNLOCKED   = 0,
+	FWH_DENY_WRITE = 1,
+	FWH_IMMUTABLE  = 2,
+	FWH_DENY_READ  = 4,
+};
+
+struct fwh_xxlock_thunk {
+	enum fwh_lock_state val;
+	flstate_t state;
+};
+
+
+#define FWH_XXLOCK_ONEBLOCK_LOCK   ((struct fwh_xxlock_thunk){ FWH_DENY_WRITE, FL_LOCKING})
+#define FWH_XXLOCK_ONEBLOCK_UNLOCK ((struct fwh_xxlock_thunk){ FWH_UNLOCKED,   FL_UNLOCKING})
+
+/*
+ * This locking/unlock is specific to firmware hub parts.  Only one
+ * is known that supports the Intel command set.    Firmware
+ * hub parts cannot be interleaved as they are on the LPC bus
+ * so this code has not been tested with interleaved chips,
+ * and will likely fail in that context.
+ */
+static int fwh_xxlock_oneblock(struct map_info *map, struct flchip *chip,
+	unsigned long adr, int len, void *thunk)
+{
+	struct cfi_private *cfi = map->fldrv_priv;
+	struct fwh_xxlock_thunk *xxlt = (struct fwh_xxlock_thunk *)thunk;
+	int ret;
+
+	/* Refuse the operation if the we cannot look behind the chip */
+	if (chip->start < 0x400000) {
+		pr_debug( "MTD %s(): chip->start: %lx wanted >= 0x400000\n",
+			__func__, chip->start );
+		return -EIO;
+	}
+	/*
+	 * lock block registers:
+	 * - on 64k boundariesand
+	 * - bit 1 set high
+	 * - block lock registers are 4MiB lower - overflow subtract (danger)
+	 *
+	 * The address manipulation is first done on the logical address
+	 * which is 0 at the start of the chip, and then the offset of
+	 * the individual chip is addted to it.  Any other order a weird
+	 * map offset could cause problems.
+	 */
+	adr = (adr & ~0xffffUL) | 0x2;
+	adr += chip->start - 0x400000;
+
+	/*
+	 * This is easy because these are writes to registers and not writes
+	 * to flash memory - that means that we don't have to check status
+	 * and timeout.
+	 */
+	mutex_lock(&chip->mutex);
+	ret = get_chip(map, chip, adr, FL_LOCKING);
+	if (ret) {
+		mutex_unlock(&chip->mutex);
+		return ret;
+	}
+
+	chip->oldstate = chip->state;
+	chip->state = xxlt->state;
+	map_write(map, CMD(xxlt->val), adr);
+
+	/* Done and happy. */
+	chip->state = chip->oldstate;
+	put_chip(map, chip, adr);
+	mutex_unlock(&chip->mutex);
+	return 0;
+}
+
+
+static int fwh_lock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	int ret;
+
+	ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
+		(void *)&FWH_XXLOCK_ONEBLOCK_LOCK);
+
+	return ret;
+}
+
+
+static int fwh_unlock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	int ret;
+
+	ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
+		(void *)&FWH_XXLOCK_ONEBLOCK_UNLOCK);
+
+	return ret;
+}
+
+static void fixup_use_fwh_lock(struct mtd_info *mtd)
+{
+	printk(KERN_NOTICE "using fwh lock/unlock method\n");
+	/* Setup for the chips with the fwh lock method */
+	mtd->_lock   = fwh_lock_varsize;
+	mtd->_unlock = fwh_unlock_varsize;
+}
+#endif /* FWH_LOCK_H */