mtd: nand: Add core infrastructure to support SPI NANDs

Add a SPI NAND framework based on the generic NAND framework and the
spi-mem infrastructure.

In its current state, this framework supports the following features:

- single/dual/quad IO modes
- on-die ECC
Signed-off-by: Peter Pan <peterpandong@micron.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

drivers/mtd/nand/Kconfig

@@ -4,3 +4,4 @@ config MTD_NAND_CORE
 source "drivers/mtd/nand/onenand/Kconfig"
 
 source "drivers/mtd/nand/raw/Kconfig"
+source "drivers/mtd/nand/spi/Kconfig"

drivers/mtd/nand/Makefile

@@ -5,3 +5,4 @@ obj-$(CONFIG_MTD_NAND_CORE) += nandcore.o
 
 obj-y	+= onenand/
 obj-y	+= raw/
+obj-y	+= spi/

drivers/mtd/nand/spi/Kconfig

+menuconfig MTD_SPI_NAND
+	tristate "SPI NAND device Support"
+	select MTD_NAND_CORE
+	depends on SPI_MASTER
+	select SPI_MEM
+	help
+	  This is the framework for the SPI NAND device drivers.

drivers/mtd/nand/spi/Makefile

+# SPDX-License-Identifier: GPL-2.0
+spinand-objs := core.o
+obj-$(CONFIG_MTD_SPI_NAND) += spinand.o

include/linux/spi/spi-mem.h

@@ -3,7 +3,9 @@
  * Copyright (C) 2018 Exceet Electronics GmbH
  * Copyright (C) 2018 Bootlin
  *
- * Author: Boris Brezillon <boris.brezillon@bootlin.com>
+ * Author:
+ *	Peter Pan <peterpandong@micron.com>
+ *	Boris Brezillon <boris.brezillon@bootlin.com>
  */
 
 #ifndef __LINUX_SPI_MEM_H