Re: [PATCH] board: am62x: Add support for reading eeprom data

[Mattijs Korpershoek <mkorpershoek@kernel.org>]

Hi Guillaume,

Thank you for the patch.

On Fri, Oct 17, 2025 at 08:24, "Guillaume La Roque (TI.com)" <glaroque@baylibre.com> wrote:

> I2C EEPROM data contains the board name and its revision.
> Add support for:
> - Reading EEPROM data and store a copy at end of SRAM
> - Updating env variable with relevant board info
> - Printing board info during boot.
>
> Signed-off-by: Guillaume La Roque (TI.com) <glaroque@baylibre.com>
> ---
>  arch/arm/mach-k3/am62x/Kconfig |  3 ++
>  board/ti/am62x/evm.c           | 95 +++++++++++++++++++++++++++++++++++++++++-
>  configs/am62x_evm_r5_defconfig |  1 +
>  3 files changed, 98 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-k3/am62x/Kconfig b/arch/arm/mach-k3/am62x/Kconfig
> index 81199ada3a1..f7ad52db7d8 100644
> --- a/arch/arm/mach-k3/am62x/Kconfig
> +++ b/arch/arm/mach-k3/am62x/Kconfig
> @@ -14,6 +14,8 @@ config TARGET_AM625_A53_EVM
>  	select ARM64
>  	select BINMAN
>  	select OF_SYSTEM_SETUP
> +	imply TI_COMMON_CMD_OPTIONS
> +	imply TI_I2C_BOARD_DETECT
>  
>  config TARGET_AM625_R5_EVM
>  	bool "TI K3 based AM625 EVM running on R5"
> @@ -25,6 +27,7 @@ config TARGET_AM625_R5_EVM
>  	select K3_DDRSS
>  	select BINMAN
>  	imply SYS_K3_SPL_ATF
> +	imply TI_I2C_BOARD_DETECT
>  
>  config TARGET_PHYCORE_AM62X_A53
>  	bool "PHYTEC phyCORE-AM62x running on A53"
> diff --git a/board/ti/am62x/evm.c b/board/ti/am62x/evm.c
> index d7b07a0d34d..fbd45608efa 100644
> --- a/board/ti/am62x/evm.c
> +++ b/board/ti/am62x/evm.c
> @@ -22,8 +22,18 @@
>  #include <dm/uclass.h>
>  #include <asm/arch/k3-ddr.h>
>  
> +#include "../common/board_detect.h"
>  #include "../common/fdt_ops.h"
>  
> +#include "../common/k3-ddr.h"
> +
> +#define board_is_am62x_skevm()  (board_ti_k3_is("AM62-SKEVM") || \
> +				 board_ti_k3_is("AM62B-SKEVM"))
> +#define board_is_am62b_p1_skevm() board_ti_k3_is("AM62B-SKEVM-P1")
> +#define board_is_am62x_lp_skevm()  board_ti_k3_is("AM62-LP-SKEVM")
> +#define board_is_am62x_sip_skevm()  board_ti_k3_is("AM62SIP-SKEVM")
> +#define board_is_am62x_play()	board_ti_k3_is("BEAGLEPLAY-A0-")
> +
>  DECLARE_GLOBAL_DATA_PTR;
>  
>  #if CONFIG_IS_ENABLED(SPLASH_SCREEN)
> @@ -74,9 +84,92 @@ struct efi_capsule_update_info update_info = {
>  	.images = fw_images,
>  };
>  
> -#ifdef CONFIG_BOARD_LATE_INIT
> +#if CONFIG_IS_ENABLED(TI_I2C_BOARD_DETECT)
> +int do_board_detect(void)

Can't this be static?

> +{
> +	int ret;
> +
> +	ret = ti_i2c_eeprom_am6_get_base(CONFIG_EEPROM_BUS_ADDRESS,
> +					 CONFIG_EEPROM_CHIP_ADDRESS);
> +	if (ret) {
> +		printf("EEPROM not available at 0x%02x, trying to read at 0x%02x\n",
> +		       CONFIG_EEPROM_CHIP_ADDRESS, CONFIG_EEPROM_CHIP_ADDRESS + 1);
> +		ret = ti_i2c_eeprom_am6_get_base(CONFIG_EEPROM_BUS_ADDRESS,
> +						 CONFIG_EEPROM_CHIP_ADDRESS + 1);
> +		if (ret)
> +			pr_err("Reading on-board EEPROM at 0x%02x failed %d\n",
> +			       CONFIG_EEPROM_CHIP_ADDRESS + 1, ret);
> +	}
> +
> +	return ret;
> +}

This code seems very close to what's already in board/ti/am64x/evm.c
Maybe it's not needed before merging this patch, but should we consider
reducing code duplication and move this to a common place?

> +
> +int checkboard(void)
> +{
> +	struct ti_am6_eeprom *ep = TI_AM6_EEPROM_DATA;
> +
> +	if (!do_board_detect())
> +		printf("Board: %s rev %s\n", ep->name, ep->version);
> +
> +	return 0;
> +}
> +
> +#if CONFIG_IS_ENABLED(BOARD_LATE_INIT)
> +static void setup_board_eeprom_env(void)
> +{
> +	char *name = "am62x_skevm";
> +
> +	if (do_board_detect())
> +		goto invalid_eeprom;
> +
> +	if (board_is_am62x_skevm())
> +		name = "am62x_skevm";
> +	else if (board_is_am62b_p1_skevm())
> +		name = "am62b_p1_skevm";
> +	else if (board_is_am62x_lp_skevm())
> +		name = "am62x_lp_skevm";
> +	else if (board_is_am62x_sip_skevm())
> +		name = "am62x_sip_skevm";
> +	else if (board_is_am62x_play())
> +		name = "am62x_beagleplay";
> +	else
> +		printf("Unidentified board claims %s in eeprom header\n",
> +		       board_ti_get_name());
> +
> +invalid_eeprom:
> +	set_board_info_env_am6(name);
> +}
> +
> +static void setup_serial(void)
> +{
> +	struct ti_am6_eeprom *ep = TI_AM6_EEPROM_DATA;
> +	unsigned long board_serial;
> +	char *endp;
> +	char serial_string[17] = { 0 };
> +
> +	if (env_get("serial#"))
> +		return;
> +
> +	board_serial = simple_strtoul(ep->serial, &endp, 16);
> +	if (*endp != '\0') {
> +		pr_err("Error: Can't set serial# to %s\n", ep->serial);
> +		return;
> +	}
> +
> +	snprintf(serial_string, sizeof(serial_string), "%016lx", board_serial);
> +	env_set("serial#", serial_string);
> +}
> +#endif
> +#endif
> +
> +#if CONFIG_IS_ENABLED(BOARD_LATE_INIT)
>  int board_late_init(void)
>  {
> +	if (IS_ENABLED(CONFIG_TI_I2C_BOARD_DETECT)) {
> +		setup_board_eeprom_env();
> +		setup_serial();
> +	}
> +
>  	ti_set_fdt_env(NULL, NULL);
>  	return 0;
>  }
> diff --git a/configs/am62x_evm_r5_defconfig b/configs/am62x_evm_r5_defconfig
> index 18ffc991b25..d42bdf1f074 100644
> --- a/configs/am62x_evm_r5_defconfig
> +++ b/configs/am62x_evm_r5_defconfig
> @@ -85,6 +85,7 @@ CONFIG_SPL_CLK_K3_PLL=y
>  CONFIG_SPL_CLK_K3=y
>  CONFIG_TI_SCI_PROTOCOL=y
>  CONFIG_DA8XX_GPIO=y
> +CONFIG_DM_I2C=y
>  CONFIG_DM_MAILBOX=y
>  CONFIG_K3_SEC_PROXY=y
>  CONFIG_SPL_MISC=y
>
> ---
> base-commit: 2ba64e303b2706e5c42a6bf982326d632342ca66
> change-id: 20251016-am62xeeprom-41a1920b8bd2
>
> Best regards,
> -- 
> Guillaume La Roque (TI.com) <glaroque@baylibre.com>