Add raw NAND framework

The raw NAND framework supports SLC NAND devices.

It introduces a new high level interface (io_mtd) that
defines operations a driver can register to the NAND framework.
This interface will fill in the io_mtd device specification:
	- device_size
        - erase_size
that could be used by the io_storage interface.

NAND core source file integrates the standard read loop that
performs NAND device read operations using a skip bad block strategy.
A platform buffer must be defined in case of unaligned
data. This buffer must fit to the maximum device page size
defined by PLATFORM_MTD_MAX_PAGE_SIZE.

The raw_nand.c source file embeds the specific NAND operations
to read data.
The read command is a raw page read without any ECC correction.
This can be overridden by a low level driver.
No generic support for write or erase command or software
ECC correction.

NAND ONFI detection is available and can be enabled using
NAND_ONFI_DETECT=1.
For non-ONFI NAND management, platform can define required
information.

Change-Id: Id80e9864456cf47f02b74938cf25d99261da8e82
Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
diff --git a/include/drivers/nand.h b/include/drivers/nand.h
new file mode 100644
index 0000000..1dbb008
--- /dev/null
+++ b/include/drivers/nand.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2019, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef DRIVERS_NAND_H
+#define DRIVERS_NAND_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <lib/utils_def.h>
+
+#define PSEC_TO_MSEC(x)	div_round_up((x), 1000000000ULL)
+
+struct ecc {
+	unsigned int mode; /* ECC mode NAND_ECC_MODE_{NONE|HW|ONDIE} */
+	unsigned int size; /* Data byte per ECC step */
+	unsigned int bytes; /* ECC bytes per step */
+	unsigned int max_bit_corr; /* Max correctible bits per ECC steps */
+};
+
+struct nand_device {
+	unsigned int block_size;
+	unsigned int page_size;
+	unsigned long long size;
+	unsigned int nb_planes;
+	unsigned int buswidth;
+	struct ecc ecc;
+	int (*mtd_block_is_bad)(unsigned int block);
+	int (*mtd_read_page)(struct nand_device *nand, unsigned int page,
+			     uintptr_t buffer);
+};
+
+/*
+ * Read bytes from NAND device
+ *
+ * @offset: Byte offset to read from in device
+ * @buffer: [out] Bytes read from device
+ * @length: Number of bytes to read
+ * @length_read: [out] Number of bytes read from device
+ * Return: 0 on success, a negative errno on failure
+ */
+int nand_read(unsigned int offset, uintptr_t buffer, size_t length,
+	      size_t *length_read);
+
+/*
+ * Get NAND device instance
+ *
+ * Return: NAND device instance reference
+ */
+struct nand_device *get_nand_device(void);
+
+#endif	/* DRIVERS_NAND_H */