From: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
Add a convenient helper to burn the field-return fuse which wraps the
platform specific hook. At the moment only i.MX8M devices are supported.
Adding support for other platforms can be done by providing the platform
specific hook.
Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
Signed-off-by: Stefan Kerkmann <s.kerkmann@xxxxxxxxxxxxxx>
---
drivers/hab/hab.c | 41 ++++++++++++++++++++++++++++++++++++++++
include/hab.h | 1 +
include/mach/imx/ocotp-fusemap.h | 1 +
3 files changed, 43 insertions(+)
diff --git a/drivers/hab/hab.c b/drivers/hab/hab.c
index b966410eacfea4763ac9959c17a552cb7580a6f4..0f0c8766f069697944570290cb5796430ddae125 100644
--- a/drivers/hab/hab.c
+++ b/drivers/hab/hab.c
@@ -252,6 +252,23 @@ static int imx8m_hab_revoke_key_ocotp(unsigned key_idx)
return ret;
}
+static int imx8m_hab_field_return_ocotp(void)
+{
+ int ret;
+
+ ret = imx_ocotp_field_return_locked();
+ if (ret < 0)
+ return ret;
+
+ /* Return -EINVAL in case the FIELD_RETURN write is locked */
+ if (ret == 1)
+ return -EINVAL;
+
+ ret = imx_ocotp_write_field(MX8M_OCOTP_FIELD_RETURN, 1);
+
+ return ret;
+}
+
struct imx_hab_ops {
int (*write_srk_hash)(const u8 *srk, unsigned flags);
int (*read_srk_hash)(u8 *srk);
@@ -260,6 +277,7 @@ struct imx_hab_ops {
int (*device_locked_down)(void);
int (*print_status)(void);
int (*revoke_key)(unsigned key_idx);
+ int (*field_return)(void);
};
static struct imx_hab_ops imx_hab_ops_iim = {
@@ -288,6 +306,7 @@ static struct imx_hab_ops imx8m_hab_ops_ocotp = {
.permanent_write_enable = imx_hab_permanent_write_enable_ocotp,
.print_status = imx8m_hab_print_status,
.revoke_key = imx8m_hab_revoke_key_ocotp,
+ .field_return = imx8m_hab_field_return_ocotp,
};
static int imx_ahab_write_srk_hash(const u8 *__newsrk, unsigned flags)
@@ -583,3 +602,25 @@ int imx_hab_revoke_key(unsigned key_idx, bool permanent)
return ret;
}
+
+int imx_hab_field_return(bool permanent)
+{
+ struct imx_hab_ops *ops = imx_get_hab_ops();
+ int ret;
+
+ if (!ops || !ops->field_return)
+ return -ENOSYS;
+
+ if (permanent) {
+ ret = ops->permanent_write_enable(1);
+ if (ret)
+ return ret;
+ }
+
+ ret = ops->field_return();
+
+ if (permanent)
+ ops->permanent_write_enable(0);
+
+ return ret;
+}
diff --git a/include/hab.h b/include/hab.h
index 7a70c67f048819dec0581f7e7e130fe8477b6fc4..393cf0513e0cbbf4040dc624b26e4a297a1f50e4 100644
--- a/include/hab.h
+++ b/include/hab.h
@@ -52,5 +52,6 @@ int imx_hab_lockdown_device(unsigned flags);
int imx_hab_device_locked_down(void);
int imx_hab_print_status(void);
int imx_hab_revoke_key(unsigned key_idx, bool permanent);
+int imx_hab_field_return(bool permanent);
#endif /* __HABV4_H */
diff --git a/include/mach/imx/ocotp-fusemap.h b/include/mach/imx/ocotp-fusemap.h
index 1aece9195ff9a60739d84dfef02c86657f77da0b..37f1ee8298c2ae47406c6ae58b73f1eba9effed8 100644
--- a/include/mach/imx/ocotp-fusemap.h
+++ b/include/mach/imx/ocotp-fusemap.h
@@ -67,6 +67,7 @@
#define MX8M_OCOTP_TZASC_EN (OCOTP_WORD(0x480) | OCOTP_BIT(11) | OCOTP_WIDTH(1))
#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 MX8M_OCOTP_SRK_REVOKE (OCOTP_WORD(0x670) | OCOTP_BIT(0) | OCOTP_WIDTH(4))
#endif /* __MACH_IMX_OCOTP_FUSEMAP_H */
--
2.39.5
