Add missing header for SPI FS and update documentation

Change-Id: I970ebac8288210e57662f2c80e9d04410d16a4e2
Signed-off-by: Ajay Bhargav <[email protected]>

Author: ajaybhargav

docs/book/api/storage/filesystem.rst

@@ -15,3 +15,7 @@ Application can read write files using standard system calls.
 
 See application example for more information.
 
+SPI Flash
+=========
+
+.. include:: /inc/spifs.inc

include/spifs.h

@@ -0,0 +1,39 @@
+/*
+ * spifs.h
+ *
+ */
+
+#ifndef INC_SPIFS_H_
+#define INC_SPIFS_H_
+
+/**
+ * SPI Flash status
+ */
+enum sfstat_e {
+	SF_STAT_NOTENABLED,/**< SPI Flash not enabled (Either not found or Initialization error) */
+	SF_STAT_ENABLED,   /**< SPI Flash enabled but not mounted (Filesystem mount issue, Try spifs_enable() again */
+	SF_STAT_MOUNTED,   /**< SPI Flash enabled and filesystem is mounted successfully */
+};
+
+/**
+ * Enable SPI Flash and mount LFS filesystem
+ * @param gpio_cs	[in] GPIO number connected to SPI chip select
+ * @param speed		[in] SPI Speed in KHz (max 10000 KHz)
+ * @param mode		[in] SPI mode
+ * @return			0 on success, negative value on failure
+ */
+int spifs_enable(int gpio_cs, unsigned int speed, int mode);
+
+/**
+ * Disable SPI Flash and unmount LFS filesystem
+ * @return			0 on success, negative value on failure
+ */
+int spifs_disable(void);
+
+/**
+ * Get status of SPI Flash
+ * @return			SPI Flash status see @ref sfstat_e
+ */
+int spifs_getstatus(void);
+
+#endif /* INC_SPIFS_H_ */