[PATCH 1/3] cmd: mmc: Simplify dev subcommand handling

[Yao Zi]

Replace the big if-else block in do_mmc_dev() with switch-case and use
fallthrough to remove the duplicated code for parsing dev and part.

Signed-off-by: Yao Zi <me at ziyao.cc>
---
 cmd/mmc.c | 34 ++++++++++++++--------------------
 1 file changed, 14 insertions(+), 20 deletions(-)

diff --git a/cmd/mmc.c b/cmd/mmc.c
index 5340a58be8ee..f2a59af087cb 100644
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -16,6 +16,7 @@
 #include <sparse_format.h>
 #include <image-sparse.h>
 #include <vsprintf.h>
+#include <linux/compiler_attributes.h>
 #include <linux/ctype.h>
 
 static int curr_device = -1;
@@ -556,37 +557,30 @@ static int do_mmc_part(struct cmd_tbl *cmdtp, int flag,
 static int do_mmc_dev(struct cmd_tbl *cmdtp, int flag,
 		      int argc, char *const argv[])
 {
-	int dev, part = 0, ret;
+	enum bus_mode speed_mode = MMC_MODES_END;
+	int dev = curr_device, part = 0, ret;
 	struct mmc *mmc;
 
-	if (argc == 1) {
-		dev = curr_device;
-		mmc = init_mmc_device(dev, true);
-	} else if (argc == 2) {
-		dev = (int)dectoul(argv[1], NULL);
-		mmc = init_mmc_device(dev, true);
-	} else if (argc == 3) {
-		dev = (int)dectoul(argv[1], NULL);
+	switch (argc) {
+	case 4:
+		speed_mode = (int)dectoul(argv[3], NULL);
+		fallthrough;
+	case 3:
 		part = (int)dectoul(argv[2], NULL);
 		if (part > PART_ACCESS_MASK) {
 			printf("#part_num shouldn't be larger than %d\n",
 			       PART_ACCESS_MASK);
 			return CMD_RET_FAILURE;
 		}
-		mmc = init_mmc_device(dev, true);
-	} else if (argc == 4) {
-		enum bus_mode speed_mode;
 
+		fallthrough;
+	case 2:
 		dev = (int)dectoul(argv[1], NULL);
-		part = (int)dectoul(argv[2], NULL);
-		if (part > PART_ACCESS_MASK) {
-			printf("#part_num shouldn't be larger than %d\n",
-			       PART_ACCESS_MASK);
-			return CMD_RET_FAILURE;
-		}
-		speed_mode = (int)dectoul(argv[3], NULL);
+		fallthrough;
+	case 1:
 		mmc = __init_mmc_device(dev, true, speed_mode);
-	} else {
+		break;
+	default:
 		return CMD_RET_USAGE;
 	}
 
-- 
2.52.0