stm32mp: use device sequence number in boot_instance variable

Use the device sequence number in boot_instance variable
and no more the SDMMC instance provided by ROM code/TF-A.

After this patch we don't need to define the mmc alias in
device tree, for example:
  mmc0 = &sdmmc1;
  mmc1 = &sdmmc2;
  mmc2 = &sdmmc3;
to have a correct mapping between the ROM code boot device =
"${boot_device}${boot_instance}" and the MMC device in U-Boot.

With this patch the 'mmc0' device (used in mmc commands) is
always used when only one instance sdmmc is activated in device
tree, even if it is only the sdmmc2 or sdmmc3.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>

arch/arm/mach-stm32mp/cpu.c

@@ -483,6 +483,11 @@ static void setup_boot_mode(void)
 		STM32_UART7_BASE,
 		STM32_UART8_BASE
 	};
+	const u32 sdmmc_addr[] = {
+		STM32_SDMMC1_BASE,
+		STM32_SDMMC2_BASE,
+		STM32_SDMMC3_BASE
+	};
 	char cmd[60];
 	u32 boot_ctx = readl(TAMP_BOOT_CONTEXT);
 	u32 boot_mode =
@@ -525,7 +530,16 @@ static void setup_boot_mode(void)
 		break;
 	case BOOT_FLASH_SD:
 	case BOOT_FLASH_EMMC:
-		sprintf(cmd, "%d", instance);
+		if (instance > ARRAY_SIZE(sdmmc_addr))
+			break;
+		/* search associated sdmmc node in devicetree */
+		sprintf(cmd, "mmc@%x", sdmmc_addr[instance]);
+		if (uclass_get_device_by_name(UCLASS_MMC, cmd, &dev)) {
+			printf("mmc%d = %s not found in device tree!\n",
+			       instance, cmd);
+			break;
+		}
+		sprintf(cmd, "%d", dev_seq(dev));
 		env_set("boot_device", "mmc");
 		env_set("boot_instance", cmd);
 		break;

arch/arm/mach-stm32mp/include/mach/stm32.h

@@ -32,6 +32,10 @@
 #define STM32_UART7_BASE		0x40018000
 #define STM32_UART8_BASE		0x40019000
 
+#define STM32_SDMMC1_BASE		0x58005000
+#define STM32_SDMMC2_BASE		0x58007000
+#define STM32_SDMMC3_BASE		0x48004000
+
 #define STM32_SYSRAM_BASE		0x2FFC0000
 #define STM32_SYSRAM_SIZE		SZ_256K
 

board/st/stm32mp1/stm32mp1.c

@@ -841,6 +841,31 @@ const char *env_ext4_get_intf(void)
 	}
 }
 
+int mmc_get_boot(void)
+{
+	struct udevice *dev;
+	u32 boot_mode = get_bootmode();
+	unsigned int instance = (boot_mode & TAMP_BOOT_INSTANCE_MASK) - 1;
+	char cmd[20];
+	const u32 sdmmc_addr[] = {
+		STM32_SDMMC1_BASE,
+		STM32_SDMMC2_BASE,
+		STM32_SDMMC3_BASE
+	};
+
+	if (instance > ARRAY_SIZE(sdmmc_addr))
+		return 0;
+
+	/* search associated sdmmc node in devicetree */
+	snprintf(cmd, sizeof(cmd), "mmc@%x", sdmmc_addr[instance]);
+	if (uclass_get_device_by_name(UCLASS_MMC, cmd, &dev)) {
+		log_err("mmc%d = %s not found in device tree!\n", instance, cmd);
+		return 0;
+	}
+
+	return dev_seq(dev);
+};
+
 const char *env_ext4_get_dev_part(void)
 {
 	static char *const env_dev_part =
@@ -854,22 +879,16 @@ const char *env_ext4_get_dev_part(void)
 	if (strlen(env_dev_part) > 0)
 		return env_dev_part;
 
-	u32 bootmode = get_bootmode();
+	return dev_part[mmc_get_boot()];
-
-	return dev_part[(bootmode & TAMP_BOOT_INSTANCE_MASK) - 1];
 }
 
 int mmc_get_env_dev(void)
 {
-	u32 bootmode;
-
 	if (CONFIG_SYS_MMC_ENV_DEV >= 0)
 		return CONFIG_SYS_MMC_ENV_DEV;
 
-	bootmode = get_bootmode();
-
 	/* use boot instance to select the correct mmc device identifier */
-	return (bootmode & TAMP_BOOT_INSTANCE_MASK) - 1;
+	return mmc_get_boot();
 }
 
 #if defined(CONFIG_OF_BOARD_SETUP)