mtd: support mtd block model

Attach the mtd driver to block device, then we can call common interface
(blk_dread & blk_dwrite) to operate storage in application layer.

Usage:
Open CONFIG_MTD_BLK & CONFIG_MTD.

Change-Id: I47a969322e2d20c12d46898bdc88f4104e1a15bf
Signed-off-by: Jason Zhu <jason.zhu@rock-chips.com>

drivers/block/blk-uclass.c

@@ -28,7 +28,7 @@ static const char *if_typename_str[IF_TYPE_COUNT] = {
 	[IF_TYPE_SPINAND]	= "spinand",
 	[IF_TYPE_SPINOR]	= "spinor",
 	[IF_TYPE_RAMDISK]	= "ramdisk",
-
+	[IF_TYPE_MTD]		= "mtd",
 };
 
 static enum uclass_id if_type_uclass_id[IF_TYPE_COUNT] = {
@@ -46,6 +46,7 @@ static enum uclass_id if_type_uclass_id[IF_TYPE_COUNT] = {
 	[IF_TYPE_SPINAND]	= UCLASS_SPI_FLASH,
 	[IF_TYPE_SPINOR]	= UCLASS_SPI_FLASH,
 	[IF_TYPE_RAMDISK]	= UCLASS_RAMDISK,
+	[IF_TYPE_MTD]		= UCLASS_MTD,
 	[IF_TYPE_SYSTEMACE]	= UCLASS_INVALID,
 };
 

drivers/mtd/Kconfig

@@ -8,6 +8,12 @@ config MTD
 	  flash, RAM and similar chips, often used for solid state file
 	  systems on embedded devices.
 
+config MTD_BLK
+	bool "Enable mtd block model for MTD drivers"
+	depends on MTD
+	help
+	  Enable mtd block model for Memory Technology Devices (MTD).
+
 config MTD_NOR_FLASH
 	bool "Enable parallel NOR flash support"
 	help

drivers/mtd/Makefile

@@ -9,6 +9,7 @@ ifneq (,$(findstring y,$(CONFIG_MTD_DEVICE)$(CONFIG_CMD_NAND)$(CONFIG_CMD_ONENAN
 obj-y += mtdcore.o mtd_uboot.o
 endif
 obj-$(CONFIG_MTD) += mtd-uclass.o
+obj-$(CONFIG_MTD_BLK) += mtd_blk.o
 obj-$(CONFIG_MTD_PARTITIONS) += mtdpart.o
 obj-$(CONFIG_MTD_CONCAT) += mtdconcat.o
 obj-$(CONFIG_ALTERA_QSPI) += altera_qspi.o

drivers/mtd/mtd_blk.c

@@ -0,0 +1,97 @@
+/*
+ * (C) Copyright 2019 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <nand.h>
+#include <dm/device-internal.h>
+
+ulong mtd_dread(struct udevice *udev, lbaint_t start,
+		lbaint_t blkcnt, void *dst)
+{
+	struct blk_desc *desc = dev_get_uclass_platdata(udev);
+
+	if (!desc)
+		return 0;
+
+	if (blkcnt == 0)
+		return 0;
+
+	if (desc->devnum == BLK_MTD_NAND) {
+		int ret = 0;
+		size_t rwsize = blkcnt * 512;
+		struct mtd_info *mtd = dev_get_priv(udev->parent);
+		struct nand_chip *chip = mtd_to_nand(mtd);
+		loff_t off = (loff_t)(start * 512);
+
+		if (!mtd) {
+			puts("\nno mtd available\n");
+			return 0;
+		}
+
+		if (!chip) {
+			puts("\nno chip available\n");
+			return 0;
+		}
+
+		ret = nand_read_skip_bad(&chip->mtd, off, &rwsize,
+					 NULL, chip->mtd.size,
+					 (u_char *)(dst));
+		if (ret)
+			return 0;
+		else
+			return blkcnt;
+	} else if (desc->devnum == BLK_MTD_SPI_NAND) {
+		/* Not implemented */
+		return 0;
+	} else if (desc->devnum == BLK_MTD_SPI_NOR) {
+		/* Not implemented */
+		return 0;
+	} else {
+		return 0;
+	}
+}
+
+ulong mtd_dwrite(struct udevice *udev, lbaint_t start,
+		 lbaint_t blkcnt, const void *src)
+{
+	/* Not implemented */
+	return 0;
+}
+
+ulong mtd_derase(struct udevice *udev, lbaint_t start,
+		 lbaint_t blkcnt)
+{
+	/* Not implemented */
+	return 0;
+}
+
+static int mtd_blk_probe(struct udevice *udev)
+{
+	struct blk_desc *desc = dev_get_uclass_platdata(udev);
+
+	sprintf(desc->vendor, "0x%.4x", 0x2207);
+	memcpy(desc->product, "MTD", sizeof("MTD"));
+	memcpy(desc->revision, "V1.00", sizeof("V1.00"));
+
+	return 0;
+}
+
+static const struct blk_ops mtd_blk_ops = {
+	.read	= mtd_dread,
+#ifndef CONFIG_SPL_BUILD
+	.write	= mtd_dwrite,
+	.erase	= mtd_derase,
+#endif
+};
+
+U_BOOT_DRIVER(mtd_blk) = {
+	.name		= "mtd_blk",
+	.id		= UCLASS_BLK,
+	.ops		= &mtd_blk_ops,
+	.probe		= mtd_blk_probe,
+};

include/blk.h

@@ -38,10 +38,15 @@ enum if_type {
 	IF_TYPE_SPINAND,
 	IF_TYPE_SPINOR,
 	IF_TYPE_RAMDISK,
-
+	IF_TYPE_MTD,
 	IF_TYPE_COUNT,			/* Number of interface types */
 };
 
+/* define mtd device devnum */
+#define BLK_MTD_NAND		0
+#define BLK_MTD_SPI_NAND	1
+#define BLK_MTD_SPI_NOR		2
+
 #define BLK_VEN_SIZE		40
 #define BLK_PRD_SIZE		20
 #define BLK_REV_SIZE		8