tpm: do not suspend/resume if power stays on
The suspend/resume behavior of the TPM can be controlled by setting
"powered-while-suspended" in the DTS. This is useful for the cases
when hardware does not power-off the TPM.
Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 3123a6e..fe597e6 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1119,6 +1119,9 @@ int tpm_pm_suspend(struct device *dev)
if (chip == NULL)
return -ENODEV;
+ if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
+ return 0;
+
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
tpm2_shutdown(chip, TPM2_SU_STATE);
return 0;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 71d661a..04fbff2 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -174,6 +174,7 @@ enum tpm_chip_flags {
TPM_CHIP_FLAG_IRQ = BIT(2),
TPM_CHIP_FLAG_VIRTUAL = BIT(3),
TPM_CHIP_FLAG_HAVE_TIMEOUTS = BIT(4),
+ TPM_CHIP_FLAG_ALWAYS_POWERED = BIT(5),
};
struct tpm_bios_log {
diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
index de57d4a..aadb7f4 100644
--- a/drivers/char/tpm/tpm_of.c
+++ b/drivers/char/tpm/tpm_of.c
@@ -36,6 +36,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
else
return -ENODEV;
+ if (of_property_read_bool(np, "powered-while-suspended"))
+ chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
+
sizep = of_get_property(np, "linux,sml-size", NULL);
basep = of_get_property(np, "linux,sml-base", NULL);
if (sizep == NULL && basep == NULL)