[PATCH v3 08/14] dfu_mtd: Add provision to unlock mtd device

[Sughosh Ganu]

Prior to writing to an mtd device, mtd_erase is called. This call
fails in case the sector being erased is locked. Call mtd_unlock to
unlock the region which is to be erased and later written to. Lock the
region once the write to the region has completed.

Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
---

Changes since V2: None

 drivers/dfu/dfu_mtd.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/dfu/dfu_mtd.c b/drivers/dfu/dfu_mtd.c
index 36cd4e945b..b34975dbb0 100644
--- a/drivers/dfu/dfu_mtd.c
+++ b/drivers/dfu/dfu_mtd.c
@@ -21,7 +21,7 @@ static bool mtd_is_aligned_with_block_size(struct mtd_info *mtd, u64 size)
 static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu,
 			u64 offset, void *buf, long *len)
 {
-	u64 off, lim, remaining;
+	u64 off, lim, remaining, lock_ofs, lock_len;
 	struct mtd_info *mtd = dfu->data.mtd.info;
 	struct mtd_oob_ops io_op = {};
 	int ret = 0;
@@ -34,7 +34,7 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu,
 		return 0;
 	}
 
-	off = dfu->data.mtd.start + offset + dfu->bad_skip;
+	off = lock_ofs = dfu->data.mtd.start + offset + dfu->bad_skip;
 	lim = dfu->data.mtd.start + dfu->data.mtd.size;
 
 	if (off >= lim) {
@@ -56,12 +56,19 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu,
 	if (op == DFU_OP_WRITE) {
 		struct erase_info erase_op = {};
 
-		remaining = round_up(*len, mtd->erasesize);
+		remaining = lock_len = round_up(*len, mtd->erasesize);
 		erase_op.mtd = mtd;
 		erase_op.addr = off;
 		erase_op.len = mtd->erasesize;
 		erase_op.scrub = 0;
 
+		debug("Unlocking the mtd device\n");
+		ret = mtd_unlock(mtd, lock_ofs, lock_len);
+		if (ret && ret != -EOPNOTSUPP) {
+			printf("MTD device unlock failed\n");
+			return 0;
+		}
+
 		while (remaining) {
 			if (erase_op.addr + remaining > lim) {
 				printf("Limit reached 0x%llx while erasing at offset 0x%llx\n",
@@ -139,6 +146,13 @@ static int mtd_block_op(enum dfu_op op, struct dfu_entity *dfu,
 			io_op.len = mtd->writesize;
 	}
 
+	if (op == DFU_OP_WRITE) {
+		/* Write done, lock again */
+		debug("Locking the mtd device\n");
+		ret = mtd_lock(mtd, lock_ofs, lock_len);
+		if (ret && ret != -EOPNOTSUPP)
+			printf("MTD device lock failed\n");
+	}
 	return ret;
 }
 
-- 
2.17.1