1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 Socionext Inc.
4  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
5  */
6 
7 #include <mmc.h>
8 #include <spl.h>
9 
spl_mmc_boot_mode(const u32 boot_device)10 u32 spl_mmc_boot_mode(const u32 boot_device)
11 {
12 	struct mmc *mmc;
13 
14 	/*
15 	 * work around a bug in the Boot ROM of LD4, Pro4, and sLD8:
16 	 *
17 	 * The boot ROM in these SoCs breaks the PARTITION_CONFIG [179] of
18 	 * Extended CSD register; when switching to the Boot Partition 1, the
19 	 * Boot ROM should issue the SWITCH command (CMD6) with Set Bits for
20 	 * the Access Bits, but in fact it uses Write Byte for the Access Bits.
21 	 * As a result, the BOOT_PARTITION_ENABLE field of the PARTITION_CONFIG
22 	 * is lost.  This bug was fixed for PH1-Pro5 and later SoCs.
23 	 *
24 	 * Fixup mmc->part_config here because it is used to determine the
25 	 * partition which the U-Boot image is read from.
26 	 */
27 	mmc = find_mmc_device(0);
28 	mmc->part_config &= ~EXT_CSD_BOOT_PART_NUM(PART_ACCESS_MASK);
29 	mmc->part_config |= EXT_CSD_BOOT_PARTITION_ENABLE;
30 
31 	return MMCSD_MODE_EMMCBOOT;
32 }
33