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 3123a6e4468777fc75aed3d60a52afbcbef82624..fe597e6c55c40ca34f070f83a2af53e9b42a66de 100644 (file)
--- 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 71d661a60df200c8205a232002398ebb64e5c0ca..04fbff2edbf38ce19845e5c1fdd1cd619293419d 100644 (file)
--- 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 de57d4ac8901df9b2c2f5585db825efc0ae3587c..aadb7f464076ba8f83fb7775f2ca88cb1386af5a 100644 (file)
--- 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)