tpm/tpm_ftpm_tee: add shutdown call back

Add shutdown call back to close existing session with fTPM TA
to support kexec scenario.

Add parentheses to function names in comments as specified in kdoc.

Signed-off-by: Thirupathaiah Annapureddy <thiruan@microsoft.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

drivers/char/tpm/tpm_ftpm_tee.c

@@ -32,7 +32,7 @@ static const uuid_t ftpm_ta_uuid =
 		  0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96);
 
 /**
- * ftpm_tee_tpm_op_recv - retrieve fTPM response.
+ * ftpm_tee_tpm_op_recv() - retrieve fTPM response.
  * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h.
  * @buf:	the buffer to store data.
  * @count:	the number of bytes to read.
@@ -61,7 +61,7 @@ static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 }
 
 /**
- * ftpm_tee_tpm_op_send - send TPM commands through the TEE shared memory.
+ * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
  * @chip:	the tpm_chip description as specified in driver/char/tpm/tpm.h
  * @buf:	the buffer to send.
  * @len:	the number of bytes to send.
@@ -208,7 +208,7 @@ static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data)
 }
 
 /**
- * ftpm_tee_probe - initialize the fTPM
+ * ftpm_tee_probe() - initialize the fTPM
  * @pdev: the platform_device description.
  *
  * Return:
@@ -298,7 +298,7 @@ out_tee_session:
 }
 
 /**
- * ftpm_tee_remove - remove the TPM device
+ * ftpm_tee_remove() - remove the TPM device
  * @pdev: the platform_device description.
  *
  * Return:
@@ -328,6 +328,19 @@ static int ftpm_tee_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/**
+ * ftpm_tee_shutdown() - shutdown the TPM device
+ * @pdev: the platform_device description.
+ */
+static void ftpm_tee_shutdown(struct platform_device *pdev)
+{
+	struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev);
+
+	tee_shm_free(pvt_data->shm);
+	tee_client_close_session(pvt_data->ctx, pvt_data->session);
+	tee_client_close_context(pvt_data->ctx);
+}
+
 static const struct of_device_id of_ftpm_tee_ids[] = {
 	{ .compatible = "microsoft,ftpm" },
 	{ }
@@ -341,6 +354,7 @@ static struct platform_driver ftpm_tee_driver = {
 	},
 	.probe = ftpm_tee_probe,
 	.remove = ftpm_tee_remove,
+	.shutdown = ftpm_tee_shutdown,
 };
 
 module_platform_driver(ftpm_tee_driver);