From: Enric Balletbo i Serra <enric.balle...@collabora.com>

commit b5d0ebc99bf5d0801a5ecbe958caa3d68b8eaee8 upstream

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>
Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
Signed-off-by: James Morris <james.l.mor...@oracle.com>
---
 drivers/char/tpm/tpm-chip.c      | 12 ++++++++++++
 drivers/char/tpm/tpm-interface.c |  3 +++
 drivers/char/tpm/tpm.h           |  1 +
 3 files changed, 16 insertions(+)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index a0d9ac6b6cc9..a8d7220f613c 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -324,8 +324,20 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
  */
 int tpm_chip_register(struct tpm_chip *chip)
 {
+#ifdef CONFIG_TCG_IBMVTPM
+       struct device_node *np;
+#endif
        int rc;
 
+#ifdef CONFIG_TCG_IBMVTPM
+       np = of_find_node_by_name(NULL, "vtpm");
+       if (!np)
+               return -ENODEV;
+       if (of_property_read_bool(np, "powered-while-suspended"))
+               chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
+       of_node_put(np);
+#endif
+
        rc = tpm1_chip_register(chip);
        if (rc)
                return rc;
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index aaa5fa95dede..247dd2b6504a 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -931,6 +931,9 @@ 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 772d99b3a8e4..36e1abda00f9 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -168,6 +168,7 @@ struct tpm_vendor_specific {
 enum tpm_chip_flags {
        TPM_CHIP_FLAG_REGISTERED        = BIT(0),
        TPM_CHIP_FLAG_TPM2              = BIT(1),
+       TPM_CHIP_FLAG_ALWAYS_POWERED    = BIT(5),
 };
 
 struct tpm_chip {
-- 
2.17.0


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