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 <sonny...@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com>
Reviewed-by: Jason Gunthorpe <jguntho...@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
---
Changes since v3.
- Rebased on top of linux-next
Rob Herring
- Split DT binding from code patch as is preferred.
Changes since v2:
Jarkko Sakkinen
- Add a new TPM_CHIP_FLAG_ALWAYS_POWERED flag instead of using a boolean
variable.
- Remove a trailing newline.
Changes since v1:
Jason Gunthorpe :
- Move the code to handle suspend/resume in the common chip code.
drivers/char/tpm/tpm-interface.c | 3 +++
drivers/char/tpm/tpm.h | 1 +
drivers/char/tpm/tpm_of.c | 3 +++
3 files changed, 7 insertions(+)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index be54159..34ec7ce 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1099,6 +1099,9 @@ 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 af05c14..b44d39c 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -170,6 +170,7 @@ 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)
--
2.9.3
