Current tests showed that fusing just the single field-return bit(0) on i.MX8MP SoCs brick the device. All i.MX8M SoCs have a single field-return bit except for the i.MX8MP which requires a pattern. The pattern is not documented but was discussed here [1] and the final u-boot commit [2] added the support accordingly. This commit is based on the outcome of [1, 2]. [1] https://lore.kernel.org/all/20240621130626.729666-1-paul.geurts@xxxxxxxxxxxxxxxxxxxxxxxxx/ [2] https://github.com/u-boot/u-boot/blob/v2025.01/arch/arm/mach-imx/hab.c#L35 Tested-by: Johannes Schneider <johannes.schneider@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> --- drivers/hab/hab.c | 12 +++++++++++- include/mach/imx/ocotp-fusemap.h | 1 + 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/hab/hab.c b/drivers/hab/hab.c index 73d470be131e..74ba4a48557c 100644 --- a/drivers/hab/hab.c +++ b/drivers/hab/hab.c @@ -252,6 +252,12 @@ static int imx8m_hab_revoke_key_ocotp(unsigned key_idx) return ret; } +/* + * The fuse pattern for i.MX8M Plus is 0x28001401, but bit 2 is already set from factory. + * This means when field return is set, the fuse word value reads 0x28001405 + */ +#define MX8MP_FIELD_RETURN_PATTERN 0x28001401 + static int imx8m_hab_field_return_ocotp(void) { int ret; @@ -264,7 +270,11 @@ static int imx8m_hab_field_return_ocotp(void) if (ret == 1) return -EINVAL; - ret = imx_ocotp_write_field(MX8M_OCOTP_FIELD_RETURN, 1); + if (cpu_is_mx8mp()) + ret = imx_ocotp_write_field(MX8MP_OCOTP_FIELD_RETURN, + MX8MP_FIELD_RETURN_PATTERN); + else + ret = imx_ocotp_write_field(MX8M_OCOTP_FIELD_RETURN, 1); return ret; } diff --git a/include/mach/imx/ocotp-fusemap.h b/include/mach/imx/ocotp-fusemap.h index 37f1ee8298c2..587fe8b15eab 100644 --- a/include/mach/imx/ocotp-fusemap.h +++ b/include/mach/imx/ocotp-fusemap.h @@ -68,6 +68,7 @@ #define MX8MP_OCOTP_ROM_NO_LOG (OCOTP_WORD(0x480) | OCOTP_BIT(22) | OCOTP_WIDTH(1)) #define MX8M_OCOTP_RECOVERY_SDMMC_BOOT_DIS (OCOTP_WORD(0x490) | OCOTP_BIT(23) | OCOTP_WIDTH(1)) #define MX8M_OCOTP_FIELD_RETURN (OCOTP_WORD(0x630) | OCOTP_BIT(0) | OCOTP_WIDTH(1)) +#define MX8MP_OCOTP_FIELD_RETURN (OCOTP_WORD(0x630) | OCOTP_BIT(0) | OCOTP_WIDTH(32)) #define MX8M_OCOTP_SRK_REVOKE (OCOTP_WORD(0x670) | OCOTP_BIT(0) | OCOTP_WIDTH(4)) #endif /* __MACH_IMX_OCOTP_FUSEMAP_H */ -- 2.39.5
