[PATCH v2 1/5] imx8mn-var-som: read and print SoM infos from eeprom on startup

Hugo Villeneuve
2023-05-25T21:04:19Z

Enable support to read and display configuration/manufacturing infos
from 4Kbit EEPROM located on SOM board.

Note: CONFIG_DISPLAY_BOARDINFO is automatically selected for ARM arch.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
.../dts/imx8mn-var-som-symphony-u-boot.dtsi | 4 +
arch/arm/dts/imx8mn-var-som.dtsi | 10 ++
arch/arm/mach-imx/imx8m/Kconfig | 2 +
.../variscite/imx8mn_var_som/imx8mn_var_som.c | 134 ++++++++++++++++++
configs/imx8mn_var_som_defconfig | 1 +
5 files changed, 151 insertions(+)

diff --git a/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi b/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi
index af80aaea0b..7272fc2b4c 100644
--- a/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi
+++ b/arch/arm/dts/imx8mn-var-som-symphony-u-boot.dtsi
@@ -68,3 +68,7 @@
&usdhc3 {
bootph-pre-ram;
};
+
+&eeprom_som {
+ bootph-pre-ram;
+};
diff --git a/arch/arm/dts/imx8mn-var-som.dtsi b/arch/arm/dts/imx8mn-var-som.dtsi
index 87b5e23c76..dea9eff3f0 100644
--- a/arch/arm/dts/imx8mn-var-som.dtsi
+++ b/arch/arm/dts/imx8mn-var-som.dtsi
@@ -11,6 +11,10 @@
model = "Variscite VAR-SOM-MX8MN module";
compatible = "variscite,var-som-mx8mn", "fsl,imx8mn";

+ aliases {
+ eeprom-som = &eeprom_som;
+ };
+
chosen {
stdout-path = &uart4;
};
@@ -222,6 +226,12 @@
};
};
};
+
+ eeprom_som: eeprom@52 {
+ compatible = "atmel,24c04";
+ reg = <0x52>;
+ pagesize = <16>;
+ };
};

&i2c3 {
diff --git a/arch/arm/mach-imx/imx8m/Kconfig b/arch/arm/mach-imx/imx8m/Kconfig
index 7639439bdc..3450399d6f 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -245,6 +245,8 @@ config TARGET_IMX8MN_VAR_SOM
select IMX8MN
select SUPPORT_SPL
select IMX8M_DDR4
+ select MISC
+ select I2C_EEPROM

config TARGET_KONTRON_PITX_IMX8M
bool "Support Kontron pITX-imx8m"
diff --git a/board/variscite/imx8mn_var_som/imx8mn_var_som.c b/board/variscite/imx8mn_var_som/imx8mn_var_som.c
index d40f4d0176..a89457e8f5 100644
--- a/board/variscite/imx8mn_var_som/imx8mn_var_som.c
+++ b/board/variscite/imx8mn_var_som/imx8mn_var_som.c
@@ -1,11 +1,49 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2021 Collabora Ltd.
+ * Copyright 2018-2020 Variscite Ltd.
+ * Copyright 2023 DimOnOff Inc.
*/

#include <common.h>
+#include <dm.h>
#include <env.h>
+#include <fdtdec.h>
+#include <fdt_support.h>
+#include <i2c_eeprom.h>
+#include <malloc.h>
#include <asm/io.h>
+#include <asm/global_data.h>
+#include <linux/libfdt.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Optional SOM features flags. */
+#define VAR_EEPROM_F_WIFI BIT(0)
+#define VAR_EEPROM_F_ETH BIT(1) /* Ethernet PHY on SOM. */
+#define VAR_EEPROM_F_AUDIO BIT(2)
+#define VAR_EEPROM_F_MX8M_LVDS BIT(3) /* i.MX8MM, i.MX8MN, i.MX8MQ only */
+#define VAR_EEPROM_F_MX8Q_SOC_ID BIT(3) /* 0 = i.MX8QM, 1 = i.MX8QP */
+#define VAR_EEPROM_F_NAND BIT(4)
+
+#define VAR_IMX8_EEPROM_MAGIC 0x384D /* "8M" */
+
+/* Number of DRAM adjustment tables. */
+#define DRAM_TABLES_NUM 7
+
+struct var_imx8_eeprom_info {
+ u16 magic;
+ u8 partnumber[3]; /* Part number */
+ u8 assembly[10]; /* Assembly number */
+ u8 date[9]; /* Build date */
+ u8 mac[6]; /* MAC address */
+ u8 somrev;
+ u8 eeprom_version;
+ u8 features; /* SOM features */
+ u8 dramsize; /* DRAM size */
+ u8 off[DRAM_TABLES_NUM + 1]; /* DRAM table offsets */
+ u8 partnumber2[5]; /* Part number 2 */
+} __packed;

static void setup_fec(void)
{
@@ -28,3 +66,99 @@ int board_mmc_get_env_dev(int devno)
{
return devno;
}
+
+#if !defined(CONFIG_SPL_BUILD)
+
+#if defined(CONFIG_DISPLAY_BOARDINFO)
+
+static void display_som_infos(struct var_imx8_eeprom_info *info)
+{
+ char partnumber[sizeof(info->partnumber) +
+ sizeof(info->partnumber2) + 1];
+ char assembly[sizeof(info->assembly) + 1];
+ char date[sizeof(info->date) + 1];
+
+ /* Read first part of P/N. */
+ memcpy(partnumber, info->partnumber, sizeof(info->partnumber));
+
+ /* Read second part of P/N. */
+ if (info->eeprom_version >= 3)
+ memcpy(partnumber + sizeof(info->partnumber), info->partnumber2,
+ sizeof(info->partnumber2));
+
+ memcpy(assembly, info->assembly, sizeof(info->assembly));
+ memcpy(date, info->date, sizeof(info->date));
+
+ /* Make sure strings are null terminated. */
+ partnumber[sizeof(partnumber) - 1] = '\0';
+ assembly[sizeof(assembly) - 1] = '\0';
+ date[sizeof(date) - 1] = '\0';
+
+ printf("SOM board: P/N: %s, Assy: %s, Date: %s\n"
+ " Wifi: %s, EthPhy: %s, Rev: %d\n",
+ partnumber, assembly, date,
+ info->features & VAR_EEPROM_F_WIFI ? "yes" : "no",
+ info->features & VAR_EEPROM_F_ETH ? "yes" : "no",
+ info->somrev);
+}
+
+static int var_read_som_eeprom(struct var_imx8_eeprom_info *info)
+{
+ const char *path = "eeprom-som";
+ struct udevice *dev;
+ int ret, off;
+
+ off = fdt_path_offset(gd->fdt_blob, path);
+ if (off < 0) {
+ pr_err("%s: fdt_path_offset() failed: %d\n", __func__, off);
+ return off;
+ }
+
+ ret = uclass_get_device_by_of_offset(UCLASS_I2C_EEPROM, off, &dev);
+ if (ret) {
+ pr_err("%s: uclass_get_device_by_of_offset() failed: %d\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = i2c_eeprom_read(dev, 0, (uint8_t *)info,
+ sizeof(struct var_imx8_eeprom_info));
+ if (ret) {
+ pr_err("%s: i2c_eeprom_read() failed: %d\n", __func__, ret);
+ return ret;
+ }
+
+ if (htons(info->magic) != VAR_IMX8_EEPROM_MAGIC) {
+ /* Do not fail if the content is invalid */
+ pr_err("Board: Invalid board info magic: 0x%08x, expected 0x%08x\n",
+ htons(info->magic), VAR_IMX8_EEPROM_MAGIC);
+ }
+
+ return 0;
+}
+
+int checkboard(void)
+{
+ int rc;
+ struct var_imx8_eeprom_info *info;
+
+ info = malloc(sizeof(struct var_imx8_eeprom_info));
+ if (!info)
+ return -ENOMEM;
+
+ rc = var_read_som_eeprom(info);
+ if (rc)
+ return rc;
+
+ display_som_infos(info);
+
+#if defined(CONFIG_BOARD_TYPES)
+ gd->board_type = info->features;
+#endif /* CONFIG_BOARD_TYPES */
+
+ return 0;
+}
+
+#endif /* CONFIG_DISPLAY_BOARDINFO */
+
+#endif /* CONFIG_SPL_BUILD */
diff --git a/configs/imx8mn_var_som_defconfig b/configs/imx8mn_var_som_defconfig
index 1b4f94c124..f8bbdb6935 100644
--- a/configs/imx8mn_var_som_defconfig
+++ b/configs/imx8mn_var_som_defconfig
@@ -29,6 +29,7 @@ CONFIG_SPL_LOAD_FIT=y
CONFIG_OF_SYSTEM_SETUP=y
CONFIG_DISTRO_DEFAULTS=y
CONFIG_DEFAULT_FDT_FILE="freescale/imx8mn-var-som-symphony.dtb"
+CONFIG_BOARD_TYPES=y
CONFIG_ARCH_MISC_INIT=y
CONFIG_SPL_MAX_SIZE=0x25000
CONFIG_SPL_HAS_BSS_LINKER_SECTION=y
--
2.30.2