libmtd: Add support to access OOB available size

This patch exposes OOB available size to user. Then user can use
OOB free area according to OOB available size.

Steps to get OOB available size:
First, access /sys/class/mtd/mtdX/oobavail. If not exist, then
try to get ecc layout by ioctl "ECCGETLAYOUT". If none of them
work, set OOB available size to 0.

Signed-off-by: Xiaolei Li <xiaolei.li@mediatek.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/libmtd_legacy.c b/lib/libmtd_legacy.c
index 46f51fd..e1ab48e 100644
--- a/lib/libmtd_legacy.c
+++ b/lib/libmtd_legacy.c
@@ -215,6 +215,46 @@ int legacy_mtd_get_info(struct mtd_info *info)
 	return 0;
 }
 
+int legacy_get_mtd_oobavail(const char *node)
+{
+	struct stat st;
+	struct nand_ecclayout_user usrlay;
+	int fd, ret;
+
+	if (stat(node, &st))
+		return sys_errmsg("cannot open \"%s\"", node);
+
+	if (!S_ISCHR(st.st_mode)) {
+		errno = EINVAL;
+		return errmsg("\"%s\" is not a character device", node);
+	}
+
+	fd = open(node, O_RDONLY);
+	if (fd == -1)
+		return sys_errmsg("cannot open \"%s\"", node);
+
+	ret = ioctl(fd, ECCGETLAYOUT, &usrlay);
+	if (ret < 0) {
+		sys_errmsg("ECCGETLAYOUT ioctl request failed");
+		goto out_close;
+	}
+
+	ret = usrlay.oobavail;
+
+out_close:
+	close(fd);
+
+	return ret;
+}
+
+int legacy_get_mtd_oobavail1(int mtd_num)
+{
+	char node[sizeof(MTD_DEV_PATT) + 20];
+
+	sprintf(node, MTD_DEV_PATT, mtd_num);
+	return legacy_get_mtd_oobavail(node);
+}
+
 /**
  * legacy_get_dev_info - legacy version of 'mtd_get_dev_info()'.
  * @node: name of the MTD device node
@@ -335,6 +375,9 @@ int legacy_get_dev_info(const char *node, struct mtd_dev_info *mtd)
 
 	close(fd);
 
+	ret = legacy_get_mtd_oobavail(node);
+	mtd->oobavail = ret > 0 ? ret : 0;
+
 	/*
 	 * Unfortunately, the device name is not available via ioctl, and
 	 * we have to parse /proc/mtd to get it.