spl: spl_mmc: Clearer structure in spl_mmc_load_image and cosmetics

This refactors spl_mmc_load_image to use a switch/case structure and easier
to understand spl_start_uboot checks. This also introduces some more automatic
fallback on the next mmc boot mode as long as it keeps failing.

Lines that go beyond 80 chars are also reduced by reducing the number of tabs.
Debug and error strings are refctored to match a common style.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
[trini: Fix a thinko in the SPL_EXT_SUPPORT + SPL_OS conversion, make part be
 __maybe_unused]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
index e580f22..3cc05bb 100644
--- a/common/spl/spl_mmc.c
+++ b/common/spl/spl_mmc.c
@@ -8,6 +8,7 @@
  */
 #include <common.h>
 #include <spl.h>
+#include <linux/compiler.h>
 #include <asm/u-boot.h>
 #include <mmc.h>
 #include <image.h>
@@ -21,7 +22,7 @@
 	struct image_header *header;
 
 	header = (struct image_header *)(CONFIG_SYS_TEXT_BASE -
-						sizeof(struct image_header));
+					 sizeof(struct image_header));
 
 	/* read image header to find the image size & load address */
 	err = mmc->block_dev.block_read(0, sector, 1, header);
@@ -35,7 +36,7 @@
 
 	/* convert size to sectors - round up */
 	image_size_sectors = (spl_image.size + mmc->read_bl_len - 1) /
-				mmc->read_bl_len;
+			     mmc->read_bl_len;
 
 	/* Read the header too to avoid extra memcpy */
 	err = mmc->block_dev.block_read(0, sector, image_size_sectors,
@@ -44,7 +45,7 @@
 end:
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
 	if (err == 0)
-		printf("spl: mmc blk read err - %lu\n", err);
+		printf("spl: mmc block read error\n");
 #endif
 
 	return (err == 0);
@@ -69,33 +70,38 @@
 #ifdef CONFIG_SPL_OS_BOOT
 static int mmc_load_image_raw_os(struct mmc *mmc)
 {
-	if (!mmc->block_dev.block_read(0,
-				       CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
-				       CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS,
-				       (void *)CONFIG_SYS_SPL_ARGS_ADDR)) {
+	unsigned long err;
+
+	err = mmc->block_dev.block_read(0,
+					CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
+					CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS,
+					(void *)CONFIG_SYS_SPL_ARGS_ADDR);
+	if (err) {
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
-		printf("mmc args blk read error\n");
+		printf("spl: mmc block read error\n");
 #endif
 		return -1;
 	}
 
 	return mmc_load_image_raw_sector(mmc,
-						CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR);
+		CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR);
 }
 #endif
 
 void spl_mmc_load_image(void)
 {
 	struct mmc *mmc;
-	int err;
 	u32 boot_mode;
+	int err;
+	__maybe_unused int part;
 
 	mmc_initialize(gd->bd);
+
 	/* We register only one device. So, the dev id is always 0 */
 	mmc = find_mmc_device(0);
 	if (!mmc) {
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
-		puts("spl: mmc device not found!!\n");
+		puts("spl: mmc device not found\n");
 #endif
 		hang();
 	}
@@ -103,16 +109,22 @@
 	err = mmc_init(mmc);
 	if (err) {
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
-		printf("spl: mmc init failed: err - %d\n", err);
+		printf("spl: mmc init failed with error: %d\n", err);
 #endif
 		hang();
 	}
 
 	boot_mode = spl_boot_mode();
-	if (boot_mode == MMCSD_MODE_RAW) {
-		debug("boot mode - RAW\n");
+	switch (boot_mode) {
+	case MMCSD_MODE_RAW:
+		debug("spl: mmc boot mode: raw\n");
+
 #ifdef CONFIG_SPL_OS_BOOT
-		if (spl_start_uboot() || mmc_load_image_raw_os(mmc))
+		if (!spl_start_uboot()) {
+			err = mmc_load_image_raw_os(mmc);
+			if (!err)
+				return;
+		}
 #endif
 #ifdef CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
 		err = mmc_load_image_raw_partition(mmc,
@@ -121,76 +133,82 @@
 		err = mmc_load_image_raw_sector(mmc,
 			CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR);
 #endif
+		if (!err)
+			return;
 #if defined(CONFIG_SPL_FAT_SUPPORT) || defined(CONFIG_SPL_EXT_SUPPORT)
-	}
-	if (err || boot_mode == MMCSD_MODE_FS) {
-		debug("boot mode - FS\n");
+	case MMCSD_MODE_FS:
+		debug("spl: mmc boot mode: fs\n");
+
 #ifdef CONFIG_SPL_FAT_SUPPORT
 #ifdef CONFIG_SPL_OS_BOOT
-		if (spl_start_uboot() || spl_load_image_fat_os(&mmc->block_dev,
-								CONFIG_SYS_MMCSD_FS_BOOT_PARTITION))
+		if (!spl_start_uboot()) {
+			err = spl_load_image_fat_os(&mmc->block_dev,
+				CONFIG_SYS_MMCSD_FS_BOOT_PARTITION);
+			if (!err)
+				return;
+		}
 #endif
 		err = spl_load_image_fat(&mmc->block_dev,
-					CONFIG_SYS_MMCSD_FS_BOOT_PARTITION,
-					CONFIG_SPL_FS_LOAD_PAYLOAD_NAME);
-		if(err)
-#endif /* CONFIG_SPL_FAT_SUPPORT */
-		{
+					 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION,
+					 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME);
+		if (!err)
+			return;
+#endif
 #ifdef CONFIG_SPL_EXT_SUPPORT
 #ifdef CONFIG_SPL_OS_BOOT
-		if (spl_start_uboot() || spl_load_image_ext_os(&mmc->block_dev,
-								CONFIG_SYS_MMCSD_FS_BOOT_PARTITION))
+		if (!spl_start_uboot()) {
+			err = spl_load_image_ext_os(&mmc->block_dev,
+				CONFIG_SYS_MMCSD_FS_BOOT_PARTITION);
+			if (!err)
+				return;
+		}
 #endif
 		err = spl_load_image_ext(&mmc->block_dev,
-					CONFIG_SYS_MMCSD_FS_BOOT_PARTITION,
-					CONFIG_SPL_FS_LOAD_PAYLOAD_NAME);
-#endif /* CONFIG_SPL_EXT_SUPPORT */
-		}
-#endif /* defined(CONFIG_SPL_FAT_SUPPORT) || defined(CONFIG_SPL_EXT_SUPPORT) */
+					 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION,
+					 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME);
+		if (!err)
+			return;
+#endif
+#endif
 #ifdef CONFIG_SUPPORT_EMMC_BOOT
-	} else if (boot_mode == MMCSD_MODE_EMMCBOOT) {
+	case MMCSD_MODE_EMMCBOOT:
 		/*
 		 * We need to check what the partition is configured to.
 		 * 1 and 2 match up to boot0 / boot1 and 7 is user data
 		 * which is the first physical partition (0).
 		 */
-		int part = (mmc->part_config >> 3) & PART_ACCESS_MASK;
+		part = (mmc->part_config >> 3) & PART_ACCESS_MASK;
 
 		if (part == 7)
 			part = 0;
 
 		if (mmc_switch_part(0, part)) {
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
-			puts("MMC partition switch failed\n");
+			puts("spl: mmc partition switch failed\n");
 #endif
 			hang();
 		}
+
 #ifdef CONFIG_SPL_OS_BOOT
-		if (spl_start_uboot() || mmc_load_image_raw_os(mmc))
+		if (!spl_start_uboot()) {
+			err = mmc_load_image_raw_os(mmc);
+			if (!err)
+				return;
+		}
 #endif
 		err = mmc_load_image_raw_sector(mmc,
 			CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR);
+		if (!err)
+			return;
 #endif
-	}
-
-	switch(boot_mode){
-		case MMCSD_MODE_RAW:
-#if defined(CONFIG_SPL_FAT_SUPPORT) || defined(CONFIG_SPL_EXT_SUPPORT)
-		case MMCSD_MODE_FS:
-#endif
-#ifdef CONFIG_SUPPORT_EMMC_BOOT
-		case MMCSD_MODE_EMMCBOOT:
-#endif
-			/* Boot mode is ok. Nothing to do. */
-			break;
-		case MMCSD_MODE_UNDEFINED:
-		default:
+	case MMCSD_MODE_UNDEFINED:
+	default:
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
-			puts("spl: wrong MMC boot mode\n");
+		if (err)
+			puts("spl: mmc: no boot mode left to try\n");
+		else
+			puts("spl: mmc: wrong boot mode\n");
 #endif
-			hang();
-	}
-
-	if (err)
 		hang();
+	}
 }