[PATCH 1/6] fat: Create an internal header file

[Heinrich Schuchardt]

From: Simon Glass <simon.glass at canonical.com>

As a first step towards separating fat.c from fat_write.c, create a
header file for the definitions.

Co-developed-by: Claude <noreply at anthropic.com>
Signed-off-by: Simon Glass <simon.glass at canonical.com>
Tested-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
 fs/fat/fat.c          |  91 +---------------------------------
 fs/fat/fat_internal.h | 112 ++++++++++++++++++++++++++++++++++++++++++
 fs/fat/fat_write.c    |   1 +
 3 files changed, 114 insertions(+), 90 deletions(-)
 create mode 100644 fs/fat/fat_internal.h

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 89f2acbba1e..5114e97e924 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -26,9 +26,7 @@
 #include <linux/compiler.h>
 #include <linux/ctype.h>
 #include <linux/log2.h>
-
-/* maximum number of clusters for FAT12 */
-#define MAX_FAT12	0xFF4
+#include "fat_internal.h"
 
 /*
  * Convert a string to lowercase.  Converts at most 'len' characters,
@@ -46,10 +44,6 @@ static void downcase(char *str, size_t len)
 static struct blk_desc *cur_dev;
 static struct disk_partition cur_part_info;
 
-#define DOS_BOOT_MAGIC_OFFSET	0x1fe
-#define DOS_FS_TYPE_OFFSET	0x36
-#define DOS_FS32_TYPE_OFFSET	0x52
-
 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
 {
 	ulong ret;
@@ -705,89 +699,6 @@ static int get_fs_info(fsdata *mydata)
 	return 0;
 }
 
-/**
- * struct fat_itr - directory iterator, to simplify filesystem traversal
- *
- * Implements an iterator pattern to traverse directory tables,
- * transparently handling directory tables split across multiple
- * clusters, and the difference between FAT12/FAT16 root directory
- * (contiguous) and subdirectories + FAT32 root (chained).
- *
- * Rough usage
- *
- * .. code-block:: c
- *
- *     for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) {
- *         // to traverse down to a subdirectory pointed to by
- *         // current iterator position:
- *         fat_itr_child(&itr, &itr);
- *     }
- *
- * For a more complete example, see fat_itr_resolve().
- */
-struct fat_itr {
-	/**
-	 * @fsdata:		filesystem parameters
-	 */
-	fsdata *fsdata;
-	/**
-	 * @start_clust:	first cluster
-	 */
-	unsigned int start_clust;
-	/**
-	 * @clust:		current cluster
-	 */
-	unsigned int clust;
-	/**
-	 * @next_clust:		next cluster if remaining == 0
-	 */
-	unsigned int next_clust;
-	/**
-	 * @last_cluster:	set if last cluster of directory reached
-	 */
-	int last_cluster;
-	/**
-	 * @is_root:		is iterator at root directory
-	 */
-	int is_root;
-	/**
-	 * @remaining:		remaining directory entries in current cluster
-	 */
-	int remaining;
-	/**
-	 * @dent:		current directory entry
-	 */
-	dir_entry *dent;
-	/**
-	 * @dent_rem:		remaining entries after long name start
-	 */
-	int dent_rem;
-	/**
-	 * @dent_clust:		cluster of long name start
-	 */
-	unsigned int dent_clust;
-	/**
-	 * @dent_start:		first directory entry for long name
-	 */
-	dir_entry *dent_start;
-	/**
-	 * @l_name:		long name of current directory entry
-	 */
-	char l_name[VFAT_MAXLEN_BYTES];
-	/**
-	 * @s_name:		short 8.3 name of current directory entry
-	 */
-	char s_name[14];
-	/**
-	 * @name:		l_name if there is one, else s_name
-	 */
-	char *name;
-	/**
-	 * @block:		buffer for current cluster
-	 */
-	u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
-};
-
 static int fat_itr_isdir(fat_itr *itr);
 
 /**
diff --git a/fs/fat/fat_internal.h b/fs/fat/fat_internal.h
new file mode 100644
index 00000000000..0174cd611e7
--- /dev/null
+++ b/fs/fat/fat_internal.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * fat_internal.h
+ *
+ * Internal definitions and structures for FAT filesystem implementation
+ */
+
+#ifndef _FAT_INTERNAL_H_
+#define _FAT_INTERNAL_H_
+
+#include <fat.h>
+#include <linux/compiler.h>
+
+struct blk_desc;
+struct disk_partition;
+
+/* Maximum number of clusters for FAT12 */
+#define MAX_FAT12	0xFF4
+
+/* Boot sector offsets */
+#define DOS_BOOT_MAGIC_OFFSET	0x1fe
+#define DOS_FS_TYPE_OFFSET	0x36
+#define DOS_FS32_TYPE_OFFSET	0x52
+
+/**
+ * struct fat_itr - directory iterator, to simplify filesystem traversal
+ *
+ * Implements an iterator pattern to traverse directory tables,
+ * transparently handling directory tables split across multiple
+ * clusters, and the difference between FAT12/FAT16 root directory
+ * (contiguous) and subdirectories + FAT32 root (chained).
+ *
+ * Rough usage
+ *
+ * .. code-block:: c
+ *
+ *     for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) {
+ *         // to traverse down to a subdirectory pointed to by
+ *         // current iterator position:
+ *         fat_itr_child(&itr, &itr);
+ *     }
+ *
+ * For a more complete example, see fat_itr_resolve().
+ */
+struct fat_itr {
+	/**
+	 * @fsdata:		filesystem parameters
+	 */
+	fsdata *fsdata;
+	/**
+	 * @start_clust:	first cluster
+	 */
+	unsigned int start_clust;
+	/**
+	 * @clust:		current cluster
+	 */
+	unsigned int clust;
+	/**
+	 * @next_clust:		next cluster if remaining == 0
+	 */
+	unsigned int next_clust;
+	/**
+	 * @last_cluster:	set if last cluster of directory reached
+	 */
+	int last_cluster;
+	/**
+	 * @is_root:		is iterator at root directory
+	 */
+	int is_root;
+	/**
+	 * @remaining:		remaining directory entries in current cluster
+	 */
+	int remaining;
+	/**
+	 * @dent:		current directory entry
+	 */
+	dir_entry *dent;
+	/**
+	 * @dent_rem:		remaining entries after long name start
+	 */
+	int dent_rem;
+	/**
+	 * @dent_clust:		cluster of long name start
+	 */
+	unsigned int dent_clust;
+	/**
+	 * @dent_start:		first directory entry for long name
+	 */
+	dir_entry *dent_start;
+	/**
+	 * @l_name:		long name of current directory entry
+	 */
+	char l_name[VFAT_MAXLEN_BYTES];
+	/**
+	 * @s_name:		short 8.3 name of current directory entry
+	 */
+	char s_name[14];
+	/**
+	 * @name:		l_name if there is one, else s_name
+	 */
+	char *name;
+	/**
+	 * @block:		buffer for current cluster
+	 */
+	u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
+};
+
+#define TYPE_FILE 0x1
+#define TYPE_DIR  0x2
+#define TYPE_ANY  (TYPE_FILE | TYPE_DIR)
+
+#endif /* _FAT_INTERNAL_H_ */
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 0b924541187..45a2eef712b 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -20,6 +20,7 @@
 #include <dm/uclass.h>
 #include <linux/ctype.h>
 #include <linux/math64.h>
+#include "fat_internal.h"
 #include "fat.c"
 
 static dir_entry *find_directory_entry(fat_itr *itr, char *filename);
-- 
2.51.0