[PATCH V2] dfu: add DFU_SKIP layout concept

[Jaehoon Chung]

Add DFU_SKIP layout ccocept.
If layout is "skip", it will be skipped after nothing to do.
It's useful to support multiple board with one tar file.

Signed-off-by: Jaehoon Chung <jh80.chung at samsung.com>
Reviewed-by: Minkyu Kang <mk7.kang at samsung.com>
---
V2: Fix typo and Minkyu's reviewed-tag
---
 doc/README.dfu        | 10 +++++++++-
 drivers/dfu/dfu.c     |  2 +-
 drivers/dfu/dfu_mmc.c |  9 +++++++++
 include/dfu.h         |  1 +
 4 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/doc/README.dfu b/doc/README.dfu
index 4b9f88354072..827d300e251f 100644
--- a/doc/README.dfu
+++ b/doc/README.dfu
@@ -17,7 +17,7 @@ Overview:
   - The access to mediums is done in DFU backends (driver/dfu)
 
   Today the supported DFU backends are:
-  - MMC (RAW or FAT / EXT2 / EXT3 / EXT4 file system)
+  - MMC (RAW or FAT / EXT2 / EXT3 / EXT4 file system / SKIP)
   - NAND
   - RAM
   - SF (serial flash)
@@ -91,6 +91,7 @@ Commands:
       <name> part <dev> <part_id> [mmcpart <num>]  raw access to partition
       <name> fat <dev> <part_id> [mmcpart <num>]   file in FAT partition
       <name> ext4 <dev> <part_id> [mmcpart <num>]  file in EXT4 partition
+      <name> skip 0 0				   Skip after Nothing to do
 
       with <partid> being the GPT or DOS partition index,
       with <num> being the eMMC hardware partition number.
@@ -103,6 +104,13 @@ Commands:
 
       "u-boot raw 0x80 0x800;uImage ext4 0 2"
 
+    If don't want to flash image file to storage, use "skip" layout.
+    - It can be protected to flash wrong image with specific board name.
+    - Especailly, this layout will be useful when thor protocol is used.
+     For example, if make a tar file to support two board with u-boot-<board1>.bin
+	and u-boot-<board2>.bin, it can make to flash a proper u-boot without fail.
+      "u-boot-<board1>.bin raw 0x80 0x800; u-boot-<board2>.bin skip 0 0"
+
   "nand" (raw slc nand device)
     cmd: dfu 0 nand <dev>
     each element in "dfu_alt_info" =
diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index a298c2c43999..f679f1fa5fe5 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -614,7 +614,7 @@ const char *dfu_get_dev_type(enum dfu_device_type t)
 const char *dfu_get_layout(enum dfu_layout l)
 {
 	const char *const dfu_layout[] = {NULL, "RAW_ADDR", "FAT", "EXT2",
-					  "EXT3", "EXT4", "RAM_ADDR" };
+					  "EXT3", "EXT4", "RAM_ADDR", "SKIP" };
 	return dfu_layout[l];
 }
 
diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
index 691d01c7ebdf..c7c324b0a986 100644
--- a/drivers/dfu/dfu_mmc.c
+++ b/drivers/dfu/dfu_mmc.c
@@ -108,6 +108,8 @@ static int mmc_file_op(enum dfu_op op, struct dfu_entity *dfu,
 	case DFU_FS_EXT4:
 		fstype = FS_TYPE_EXT;
 		break;
+	case DFU_SKIP:
+		return 0;
 	default:
 		printf("%s: Layout (%s) not (yet) supported!\n", __func__,
 		       dfu_get_layout(dfu->layout));
@@ -204,6 +206,9 @@ int dfu_write_medium_mmc(struct dfu_entity *dfu,
 	case DFU_FS_EXT4:
 		ret = mmc_file_buf_write(dfu, offset, buf, len);
 		break;
+	case DFU_SKIP:
+		ret = 0;
+		break;
 	default:
 		printf("%s: Layout (%s) not (yet) supported!\n", __func__,
 		       dfu_get_layout(dfu->layout));
@@ -238,6 +243,8 @@ int dfu_get_medium_size_mmc(struct dfu_entity *dfu, u64 *size)
 		if (ret < 0)
 			return ret;
 		return 0;
+	case DFU_SKIP:
+		return 0;
 	default:
 		printf("%s: Layout (%s) not (yet) supported!\n", __func__,
 		       dfu_get_layout(dfu->layout));
@@ -399,6 +406,8 @@ int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char *s)
 		dfu->layout = DFU_FS_FAT;
 	} else if (!strcmp(entity_type, "ext4")) {
 		dfu->layout = DFU_FS_EXT4;
+	} else if (!strcmp(entity_type, "skip")) {
+		dfu->layout = DFU_SKIP;
 	} else {
 		pr_err("Memory layout (%s) not supported!\n", entity_type);
 		return -ENODEV;
diff --git a/include/dfu.h b/include/dfu.h
index 84abdc79acd1..2e8276c69c9f 100644
--- a/include/dfu.h
+++ b/include/dfu.h
@@ -33,6 +33,7 @@ enum dfu_layout {
 	DFU_FS_EXT3,
 	DFU_FS_EXT4,
 	DFU_RAM_ADDR,
+	DFU_SKIP,
 };
 
 enum dfu_op {
-- 
2.29.0