fat/fs: move ls to generic implementation

Add a generic implementation of 'ls' using opendir/readdir/closedir, and
replace fat's custom implementation.  Other filesystems should move to
the generic implementation after they add opendir/readdir/closedir
support.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

fs/fat/fat.c

@@ -1029,38 +1029,6 @@ int file_fat_detectfs(void)
 	return 0;
 }
 
-int file_fat_ls(const char *dir)
-{
-	fsdata fsdata;
-	fat_itr itrblock, *itr = &itrblock;
-	int files = 0, dirs = 0;
-	int ret;
-
-	ret = fat_itr_root(itr, &fsdata);
-	if (ret)
-		return ret;
-
-	ret = fat_itr_resolve(itr, dir, TYPE_DIR);
-	if (ret)
-		return ret;
-
-	while (fat_itr_next(itr)) {
-		if (fat_itr_isdir(itr)) {
-			printf("            %s/\n", itr->name);
-			dirs++;
-		} else {
-			printf(" %8u   %s\n",
-			       FAT2CPU32(itr->dent->size),
-			       itr->name);
-			files++;
-		}
-	}
-
-	printf("\n%d file(s), %d dir(s)\n\n", files, dirs);
-
-	return 0;
-}
-
 int fat_exists(const char *filename)
 {
 	fsdata fsdata;

fs/fs.c

@@ -37,6 +37,35 @@ static inline int fs_ls_unsupported(const char *dirname)
 	return -1;
 }
 
+/* generic implementation of ls in terms of opendir/readdir/closedir */
+__maybe_unused
+static int fs_ls_generic(const char *dirname)
+{
+	struct fs_dir_stream *dirs;
+	struct fs_dirent *dent;
+	int nfiles = 0, ndirs = 0;
+
+	dirs = fs_opendir(dirname);
+	if (!dirs)
+		return -errno;
+
+	while ((dent = fs_readdir(dirs))) {
+		if (dent->type == FS_DT_DIR) {
+			printf("            %s/\n", dent->name);
+			ndirs++;
+		} else {
+			printf(" %8lld   %s\n", dent->size, dent->name);
+			nfiles++;
+		}
+	}
+
+	fs_closedir(dirs);
+
+	printf("\n%d file(s), %d dir(s)\n\n", nfiles, ndirs);
+
+	return 0;
+}
+
 static inline int fs_exists_unsupported(const char *filename)
 {
 	return 0;
@@ -123,7 +152,7 @@ static struct fstype_info fstypes[] = {
 		.null_dev_desc_ok = false,
 		.probe = fat_set_blk_dev,
 		.close = fat_close,
-		.ls = file_fat_ls,
+		.ls = fs_ls_generic,
 		.exists = fat_exists,
 		.size = fat_size,
 		.read = fat_read_file,
@@ -133,7 +162,9 @@ static struct fstype_info fstypes[] = {
 		.write = fs_write_unsupported,
 #endif
 		.uuid = fs_uuid_unsupported,
-		.opendir = fs_opendir_unsupported,
+		.opendir = fat_opendir,
+		.readdir = fat_readdir,
+		.closedir = fat_closedir,
 	},
 #endif
 #ifdef CONFIG_FS_EXT4

include/fat.h

@@ -11,6 +11,7 @@
 #define _FAT_H_
 
 #include <asm/byteorder.h>
+#include <fs.h>
 
 #define CONFIG_SUPPORT_VFAT
 /* Maximum Long File Name length supported here is 128 UTF-16 code units */
@@ -179,7 +180,6 @@ static inline u32 clust_to_sect(fsdata *fsdata, u32 clust)
 }
 
 int file_fat_detectfs(void);
-int file_fat_ls(const char *dir);
 int fat_exists(const char *filename);
 int fat_size(const char *filename, loff_t *size);
 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
@@ -192,5 +192,8 @@ int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len,
 		   loff_t *actwrite);
 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
 		  loff_t *actread);
+int fat_opendir(const char *filename, struct fs_dir_stream **dirsp);
+int fat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp);
+void fat_closedir(struct fs_dir_stream *dirs);
 void fat_close(void);
 #endif /* _FAT_H_ */