[PATCH] arm: mvebu: Espressobin: Set environment variable fdtfile

[Andre Heider <a.heider@gmail.com>]

Required for the generic distro mechanism.

Linux ships with 4 variants:
marvell/armada-3720-espressobin-v7-emmc.dtb
marvell/armada-3720-espressobin-v7.dtb
marvell/armada-3720-espressobin-emmc.dtb
marvell/armada-3720-espressobin.dtb

Use available information to determine the appropriate filename.

Tested on a v5 board without eMMC.

Signed-off-by: Andre Heider <a.heider@gmail.com>
---
 arch/arm/mach-mvebu/Kconfig             |  1 +
 board/Marvell/mvebu_armada-37xx/board.c | 42 +++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index 0d8e0922a2..31f5d26dc2 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig
@@ -100,6 +100,7 @@ config TARGET_HELIOS4
 config TARGET_MVEBU_ARMADA_37XX
 	bool "Support Armada 37xx platforms"
 	select ARMADA_3700
+	select BOARD_LATE_INIT
 	imply SCSI
 
 config TARGET_DB_88F6720
diff --git a/board/Marvell/mvebu_armada-37xx/board.c b/board/Marvell/mvebu_armada-37xx/board.c
index 90bfc139aa..3bf0a08897 100644
--- a/board/Marvell/mvebu_armada-37xx/board.c
+++ b/board/Marvell/mvebu_armada-37xx/board.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <dm.h>
+#include <env.h>
 #include <i2c.h>
 #include <init.h>
 #include <phy.h>
@@ -50,6 +51,22 @@ DECLARE_GLOBAL_DATA_PTR;
 #define MVEBU_G2_SMI_PHY_CMD_REG	(24)
 #define MVEBU_G2_SMI_PHY_DATA_REG	(25)
 
+/*
+ * Memory Controller Registers
+ *
+ * Assembled based on public information:
+ * https://gitlab.nic.cz/turris/mox-boot-builder/-/blob/master/wtmi/main.c#L332-336
+ * https://github.com/MarvellEmbeddedProcessors/mv-ddr-marvell/blob/mv_ddr-armada-18.12/drivers/mv_ddr_mc6.h#L309-L332
+ *
+ * And checked against the written register values for the various topologies:
+ * https://github.com/MarvellEmbeddedProcessors/mv-ddr-marvell/blob/mv_ddr-armada-atf-mainline/a3700/mv_ddr_tim.h
+ */
+#define A3700_CH0_MC_CTRL2_REG		MVEBU_REGISTER(0x002c4)
+#define A3700_MC_CTRL2_SDRAM_TYPE_MASK	0xf
+#define A3700_MC_CTRL2_SDRAM_TYPE_OFFS	4
+#define A3700_MC_CTRL2_SDRAM_TYPE_DDR3	2
+#define A3700_MC_CTRL2_SDRAM_TYPE_DDR4	3
+
 int board_early_init_f(void)
 {
 	return 0;
@@ -63,6 +80,31 @@ int board_init(void)
 	return 0;
 }
 
+int board_late_init(void)
+{
+	bool ddr4, emmc;
+
+	if (!of_machine_is_compatible("globalscale,espressobin"))
+		return 0;
+
+	/* If the memory controller has been configured for DDR4, we're running on v7 */
+	ddr4 = ((readl(A3700_CH0_MC_CTRL2_REG) >> A3700_MC_CTRL2_SDRAM_TYPE_OFFS)
+		& A3700_MC_CTRL2_SDRAM_TYPE_MASK) == A3700_MC_CTRL2_SDRAM_TYPE_DDR4;
+
+	emmc = of_machine_is_compatible("globalscale,espressobin-emmc");
+
+	if (ddr4 && emmc)
+		env_set("fdtfile", "marvell/armada-3720-espressobin-v7-emmc.dtb");
+	else if (ddr4)
+		env_set("fdtfile", "marvell/armada-3720-espressobin-v7.dtb");
+	else if (emmc)
+		env_set("fdtfile", "marvell/armada-3720-espressobin-emmc.dtb");
+	else
+		env_set("fdtfile", "marvell/armada-3720-espressobin.dtb");
+
+	return 0;
+}
+
 /* Board specific AHCI / SATA enable code */
 int board_ahci_enable(void)
 {
-- 
2.28.0