[U-Boot] [PATCH v2 3/5] sunxi: When we've both mmc0 and mmc2, detect from which one we're booting

[Hans de Goede]

sunxi SOCs can boot from both mmc0 and mmc2, detect from which one we're
booting, and make that one "mmc dev 0" so that a single u-boot binary can
be used for both the onboard eMMC and for external sdcards.

When we're booting from mmc2, we make it dev 0 because that is where the SPL
will load the tertiary payload (the actual u-boot binary in our case) from,
see: common/spl/spl_mmc.c, which has dev 0 hardcoded everywhere.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 arch/arm/include/asm/arch-sunxi/mmc.h |  2 +-
 board/sunxi/board.c                   | 25 +++++++++++++++++++++++--
 drivers/mmc/sunxi_mmc.c               |  7 ++-----
 3 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/arch/arm/include/asm/arch-sunxi/mmc.h b/arch/arm/include/asm/arch-sunxi/mmc.h
index 53196e3..ff2602d 100644
--- a/arch/arm/include/asm/arch-sunxi/mmc.h
+++ b/arch/arm/include/asm/arch-sunxi/mmc.h
@@ -120,5 +120,5 @@ struct sunxi_mmc {
 #define SUNXI_MMC_IDIE_TXIRQ		(0x1 << 0)
 #define SUNXI_MMC_IDIE_RXIRQ		(0x1 << 1)
 
-int sunxi_mmc_init(int sdc_no);
+struct mmc *sunxi_mmc_init(int sdc_no);
 #endif /* _SUNXI_MMC_H */
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 4d602ca..0a7be31 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -12,6 +12,7 @@
  */
 
 #include <common.h>
+#include <mmc.h>
 #ifdef CONFIG_AXP152_POWER
 #include <axp152.h>
 #endif
@@ -108,11 +109,31 @@ static void mmc_pinmux_setup(int sdc)
 
 int board_mmc_init(bd_t *bis)
 {
+	__maybe_unused struct mmc *mmc0, *mmc1;
+	__maybe_unused char buf[512];
+
 	mmc_pinmux_setup(CONFIG_MMC_SUNXI_SLOT);
-	sunxi_mmc_init(CONFIG_MMC_SUNXI_SLOT);
+	mmc0 = sunxi_mmc_init(CONFIG_MMC_SUNXI_SLOT);
 #if CONFIG_MMC_SUNXI_SLOT_EXTRA != -1
 	mmc_pinmux_setup(CONFIG_MMC_SUNXI_SLOT_EXTRA);
-	sunxi_mmc_init(CONFIG_MMC_SUNXI_SLOT_EXTRA);
+	mmc1 = sunxi_mmc_init(CONFIG_MMC_SUNXI_SLOT_EXTRA);
+#endif
+
+#if CONFIG_MMC_SUNXI_SLOT == 0 && CONFIG_MMC_SUNXI_SLOT_EXTRA == 2
+	/*
+	 * Both mmc0 and mmc2 are bootable, figure out where we're booting
+	 * from. Try mmc0 first, just like the brom does.
+	 */
+	if (mmc_getcd(mmc0) && mmc_init(mmc0) == 0 &&
+	    mmc0->block_dev.block_read(0, 16, 1, buf) == 1) {
+		buf[12] = 0;
+		if (strcmp(&buf[4], "eGON.BT0") == 0)
+			return 0;
+	}
+
+	/* no bootable card in mmc0, so we must be booting from mmc2, swap */
+	mmc0->block_dev.dev = 1;
+	mmc1->block_dev.dev = 0;
 #endif
 
 	return 0;
diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
index 0ea9f4d..7526540 100644
--- a/drivers/mmc/sunxi_mmc.c
+++ b/drivers/mmc/sunxi_mmc.c
@@ -370,7 +370,7 @@ static const struct mmc_ops sunxi_mmc_ops = {
 	.getcd		= sunxi_mmc_getcd,
 };
 
-int sunxi_mmc_init(int sdc_no)
+struct mmc *sunxi_mmc_init(int sdc_no)
 {
 	struct mmc_config *cfg = &mmc_host[sdc_no].cfg;
 
@@ -393,8 +393,5 @@ int sunxi_mmc_init(int sdc_no)
 	mmc_resource_init(sdc_no);
 	mmc_clk_io_on(sdc_no);
 
-	if (mmc_create(cfg, &mmc_host[sdc_no]) == NULL)
-		return -1;
-
-	return 0;
+	return mmc_create(cfg, &mmc_host[sdc_no]);
 }
-- 
2.1.0