[PATCH] cmd: mmc: modify partconf to be used in script

[grygorii tertychnyi <grembeter@gmail.com>]

To implement dual-boot strategy we need to know what is the current
boot partition for U-Boot. It can be easily identified by looking at
the PARTITION_CONFIG value shown by "mmc partconf dev", but I didn't
find any way to use it in the boot script.

Hence, modify it, so that "mmc partboot dev part_num" command returns
true if "part_num" is the current boot partition, otherwise it returns
false.

Signed-off-by: Grygorii Tertychnyi <grygorii.tertychnyi@leica-geosystems.com>
---
 cmd/mmc.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/cmd/mmc.c b/cmd/mmc.c
index 1529a3e05ddd..c8db008bc90d 100644
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -792,6 +792,23 @@ static int mmc_partconf_print(struct mmc *mmc)
 	return CMD_RET_SUCCESS;
 }
 
+static int mmc_partnum_cmp(struct mmc *mmc, u8 part_num)
+{
+	u8 part;
+
+	if (mmc->part_config == MMCPART_NOAVAILABLE) {
+		printf("No part_config info for ver. 0x%x\n", mmc->version);
+		return CMD_RET_FAILURE;
+	}
+
+	part = EXT_CSD_EXTRACT_BOOT_PART(mmc->part_config);
+
+	if (part == part_num)
+		return CMD_RET_SUCCESS;
+	else
+		return CMD_RET_FAILURE;
+}
+
 static int do_mmc_partconf(struct cmd_tbl *cmdtp, int flag,
 			   int argc, char *const argv[])
 {
@@ -799,7 +816,7 @@ static int do_mmc_partconf(struct cmd_tbl *cmdtp, int flag,
 	struct mmc *mmc;
 	u8 ack, part_num, access;
 
-	if (argc != 2 && argc != 5)
+	if (argc != 2 && argc != 3 && argc != 5)
 		return CMD_RET_USAGE;
 
 	dev = simple_strtoul(argv[1], NULL, 10);
@@ -815,6 +832,10 @@ static int do_mmc_partconf(struct cmd_tbl *cmdtp, int flag,
 
 	if (argc == 2)
 		return mmc_partconf_print(mmc);
+	if (argc == 3) {
+		part_num = simple_strtoul(argv[2], NULL, 10);
+		return mmc_partnum_cmp(mmc, part_num);
+	}
 
 	ack = simple_strtoul(argv[2], NULL, 10);
 	part_num = simple_strtoul(argv[3], NULL, 10);
-- 
2.25.1