add MTD support for Micron N25Qxxx family of QSPI flash

drivers/mtd/Kconfig

@@ -16,7 +16,7 @@ config MTD_PARTITION
 		accesses do not extend outside of the partition.
 
 		A FLASH device may be broken up into several partitions managed,
-		each managed by a separate MTD driver.  The MTD parition interface
+		each managed by a separate MTD driver.  The MTD partition interface
 		is described in:
 
 			include/nuttx/mtd/mtd.h
@@ -43,7 +43,7 @@ config MTD_SECT512
 		If enabled, a MTD driver will be created that will convert the
 		sector size of any other MTD driver to a 512 byte "apparent" sector
 		size.  The managed MTD driver in this case must have an erase block
-		size that is greater than 512B and an event multiple of 512B.
+		size that is greater than 512B and an even multiple of 512B.
 
 if MTD_SECT512
 
@@ -142,7 +142,7 @@ config MTD_CONFIG_RAM_CONSOLIDATE
 		(For configurations that have only a single erase block assigned
 		to the config device, RAM consolidation is the ONLY option.)
 
-		Another apporach is to allow the driver to use the entire MTD
+		Another approach is to allow the driver to use the entire MTD
 		device (or partition) to save config data, and then allocate a
 		RAM buffer (the size of one erase block) to perform the
 		consolidation.  Enabling this feature basically trades off RAM
@@ -305,7 +305,7 @@ config AT24XX_MULTI
 	default n
 	---help---
 		Build in additional support for multiple AT24XX devices, each with
-		dynamically allocated device structures wiath a separate I2C
+		dynamically allocated device structures with a separate I2C
 		addresses (but otherwise identical -- support for multiple, different
 		AT24xx, devices not yet supported).
 
@@ -334,7 +334,7 @@ config AT24XX_EXTENDED
 	bool "Extended memory"
 	default n
 	---help---
-		If the device supports extended memory, then this operion may be set
+		If the device supports extended memory, then this operation may be set
 		to enabled the MTDIOC_EXTENDED ioctl() operation.  When the
 		extended operation is selected, calls to the driver read method will
 		return data from the extended memory region.
@@ -482,7 +482,7 @@ config S25FL1_SCRAMBLE
 	bool "Scramble data"
 	default n
 	---help---
-		Requires drviver support for data scrambling/descrambling.
+		Requires driver support for data scrambling/descrambling.
 
 config S25FL1_SCRAMBLE_KEY
 	hex "Scramble key"
@@ -491,6 +491,36 @@ config S25FL1_SCRAMBLE_KEY
 
 endif
 
+config MTD_N25QXXX
+	bool "QuadSPI-based Micron N25QXXX family FLASH"
+	default n
+	---help---
+		Support the N25Q016A, N25Q032A, N25Q064A, N25Q128A, N25Q256A
+		
+
+if MTD_N25QXXX
+
+config N25QXXX_QSPIMODE
+	int "N25QXXX QuadSPI Mode"
+	default 0
+	---help---
+		This device can operate in SPI mode 0 or 3.
+
+config N25QXXX_QSPI_FREQUENCY
+	int "N25QXXX QuadSPI Frequency"
+	default 108000000
+	---help---
+		- Clock frequency for all SPI commands except for Read Data
+		  command (0x03)
+		- Clock frequency for Read Data command (0x03): 54 MHz
+		In this implementation, only "Quad" reads are performed.
+
+config N25QXXX_SECTOR512
+	bool "Simulate 512 byte Erase Blocks"
+	default n
+
+endif
+
 config MTD_SMART
 	bool "Sector Mapped Allocation for Really Tiny (SMART) Flash support"
 	default n

drivers/mtd/Make.defs

@@ -104,6 +104,10 @@ ifeq ($(CONFIG_MTD_S25FL1),y)
 CSRCS += s25fl1.c
 endif
 
+ifeq ($(CONFIG_MTD_N25QXXX),y)
+CSRCS += n25qxxx.c
+endif
+
 ifeq ($(CONFIG_MTD_SMART),y)
 ifeq ($(CONFIG_FS_SMARTFS),y)
 CSRCS += smart.c

include/nuttx/mtd/mtd.h

@@ -513,6 +513,19 @@ struct qspi_dev_s; /* Forward reference */
 FAR struct mtd_dev_s *s25fl1_initialize(FAR struct qspi_dev_s *qspi,
                                         bool unprotect);
 
+/****************************************************************************
+ * Name: n25qxxx_initialize
+ *
+ * Description:
+ *   Create an initialize MTD device instance for the QuadSPI-based N25Qxxx
+ *   FLASH part from Micron.
+ *
+ ****************************************************************************/
+
+struct qspi_dev_s; /* Forward reference */
+FAR struct mtd_dev_s *n25qxxx_initialize(FAR struct qspi_dev_s *qspi,
+                                        bool unprotect);
+
 /****************************************************************************
  * Name: up_flashinitialize
  *