v4.19.13 snapshot.
diff --git a/include/linux/mtd/flashchip.h b/include/linux/mtd/flashchip.h
new file mode 100644
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--- /dev/null
+++ b/include/linux/mtd/flashchip.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright © 2000      Red Hat UK Limited
+ * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef __MTD_FLASHCHIP_H__
+#define __MTD_FLASHCHIP_H__
+
+/* For spinlocks. sched.h includes spinlock.h from whichever directory it
+ * happens to be in - so we don't have to care whether we're on 2.2, which
+ * has asm/spinlock.h, or 2.4, which has linux/spinlock.h
+ */
+#include <linux/sched.h>
+#include <linux/mutex.h>
+
+typedef enum {
+	FL_READY,
+	FL_STATUS,
+	FL_CFI_QUERY,
+	FL_JEDEC_QUERY,
+	FL_ERASING,
+	FL_ERASE_SUSPENDING,
+	FL_ERASE_SUSPENDED,
+	FL_WRITING,
+	FL_WRITING_TO_BUFFER,
+	FL_OTP_WRITE,
+	FL_WRITE_SUSPENDING,
+	FL_WRITE_SUSPENDED,
+	FL_PM_SUSPENDED,
+	FL_SYNCING,
+	FL_UNLOADING,
+	FL_LOCKING,
+	FL_UNLOCKING,
+	FL_POINT,
+	FL_XIP_WHILE_ERASING,
+	FL_XIP_WHILE_WRITING,
+	FL_SHUTDOWN,
+	/* These 2 come from nand_state_t, which has been unified here */
+	FL_READING,
+	FL_CACHEDPRG,
+	/* These 4 come from onenand_state_t, which has been unified here */
+	FL_RESETING,
+	FL_OTPING,
+	FL_PREPARING_ERASE,
+	FL_VERIFYING_ERASE,
+
+	FL_UNKNOWN
+} flstate_t;
+
+
+
+/* NOTE: confusingly, this can be used to refer to more than one chip at a time,
+   if they're interleaved.  This can even refer to individual partitions on
+   the same physical chip when present. */
+
+struct flchip {
+	unsigned long start; /* Offset within the map */
+	//	unsigned long len;
+	/* We omit len for now, because when we group them together
+	   we insist that they're all of the same size, and the chip size
+	   is held in the next level up. If we get more versatile later,
+	   it'll make it a damn sight harder to find which chip we want from
+	   a given offset, and we'll want to add the per-chip length field
+	   back in.
+	*/
+	int ref_point_counter;
+	flstate_t state;
+	flstate_t oldstate;
+
+	unsigned int write_suspended:1;
+	unsigned int erase_suspended:1;
+	unsigned long in_progress_block_addr;
+	unsigned long in_progress_block_mask;
+
+	struct mutex mutex;
+	wait_queue_head_t wq; /* Wait on here when we're waiting for the chip
+			     to be ready */
+	int word_write_time;
+	int buffer_write_time;
+	int erase_time;
+
+	int word_write_time_max;
+	int buffer_write_time_max;
+	int erase_time_max;
+
+	void *priv;
+};
+
+/* This is used to handle contention on write/erase operations
+   between partitions of the same physical chip. */
+struct flchip_shared {
+	struct mutex lock;
+	struct flchip *writing;
+	struct flchip *erasing;
+};
+
+
+#endif /* __MTD_FLASHCHIP_H__ */