[PATCH] ftpm: add shutdown call back

[Pavel Tatashin]

From: thiruan <thiruan@xxxxxxxxxxxxx>

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

Signed-off-by: Thirupathaiah Annapureddy <thiruan@xxxxxxxxxxxxx>
Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
---
 drivers/char/tpm/tpm_ftpm_tee.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
index 6640a14dbe48..c245be6f4015 100644
--- a/drivers/char/tpm/tpm_ftpm_tee.c
+++ b/drivers/char/tpm/tpm_ftpm_tee.c
@@ -328,6 +328,27 @@ static int ftpm_tee_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/**
+ * ftpm_tee_shutdown - shutdown the TPM device
+ * @pdev: the platform_device description.
+ *
+ * Return:
+ * 	none.
+ */
+static void ftpm_tee_shutdown(struct platform_device *pdev)
+{
+	struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev);
+
+	/* Free the shared memory pool */
+	tee_shm_free(pvt_data->shm);
+
+	/* close the existing session with fTPM TA*/
+	tee_client_close_session(pvt_data->ctx, pvt_data->session);
+
+	/* close the context with TEE driver */
+	tee_client_close_context(pvt_data->ctx);
+}
+
 static const struct of_device_id of_ftpm_tee_ids[] = {
 	{ .compatible = "microsoft,ftpm" },
 	{ }
@@ -341,6 +362,7 @@ 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);
-- 
2.23.0