tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()

Commit 5e572cab92f0bb5 ("tpm: Enable CLKRUN protocol for Braswell
systems") disabled CLKRUN protocol during TPM transactions and re-enabled
once the transaction is completed. But there were still some corner cases
observed where, reading of TPM header failed for savestate command
while going to suspend, which resulted in suspend failure.
To fix this issue keep the CLKRUN protocol disabled for the entire
duration of a single TPM command and not disabling and re-enabling
again for every TPM transaction. For the other TPM accesses outside
TPM command flow, add a higher level of disabling and re-enabling
the CLKRUN protocol, instead of doing for every TPM transaction.

Fixes: 5e572cab92f0bb5 ("tpm: Enable CLKRUN protocol for Braswell systems")
Signed-off-by: Azhar Shaikh <azhar.shaikh@intel.com>
Reviewed-by: Jarkko Sakkinen  <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen  <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen  <jarkko.sakkinen@linux.intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index af355bd97bea..76df4fbcf089 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -425,6 +425,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 	if (chip->dev.parent)
 		pm_runtime_get_sync(chip->dev.parent);
 
+	if (chip->ops->clk_enable != NULL)
+		chip->ops->clk_enable(chip, true);
+
 	/* Store the decision as chip->locality will be changed. */
 	need_locality = chip->locality == -1;
 
@@ -501,6 +504,9 @@ out:
 		chip->locality = -1;
 	}
 out_no_locality:
+	if (chip->ops->clk_enable != NULL)
+		chip->ops->clk_enable(chip, false);
+
 	if (chip->dev.parent)
 		pm_runtime_put_sync(chip->dev.parent);