greybus: Add Component Authentication Protocol support

This patch adds Component Authentication Protocol support in greybus.
The purpose of the CAP protocol is to authenticate the Module hardware,
and it can only be used when it is present as part of the
firmware-management bundle, on a separate CPort.

Compile tested only.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Jun Li <li_jun@projectara.com>
Tested-by: Jun Li <li_jun@projectara.com>
Signed-off-by: Alex Elder <elder@linaro.org>

1 files changed, 48 insertions, 3 deletions

diff --git a/drivers/staging/greybus/fw-core.c b/drivers/staging/greybus/fw-core.c
index 33941efe13ea..963973242be0 100644
--- a/drivers/staging/greybus/fw-core.c
+++ b/drivers/staging/greybus/fw-core.c
@@ -17,6 +17,7 @@ struct gb_fw_core {
 	struct gb_connection	*download_connection;
 	struct gb_connection	*mgmt_connection;
 	struct gb_connection	*spi_connection;
+	struct gb_connection	*cap_connection;
 };
 
 struct gb_connection *to_fw_mgmt_connection(struct device *dev)
@@ -135,6 +136,24 @@ static int gb_fw_core_probe(struct gb_bundle *bundle,
 			}
 
 			break;
+		case GREYBUS_PROTOCOL_AUTHENTICATION:
+			/* Disallow multiple CAP CPorts */
+			if (fw_core->cap_connection) {
+				dev_err(&bundle->dev, "multiple Authentication CPorts found\n");
+				ret = -EINVAL;
+				goto err_destroy_connections;
+			}
+
+			connection = gb_connection_create(bundle, cport_id,
+							  NULL);
+			if (IS_ERR(connection)) {
+				dev_err(&bundle->dev, "failed to create Authentication connection (%ld)\n",
+					PTR_ERR(connection));
+			} else {
+				fw_core->cap_connection = connection;
+			}
+
+			break;
 		default:
 			dev_err(&bundle->dev, "invalid protocol id (0x%02x)\n",
 				protocol_id);
@@ -168,6 +187,15 @@ static int gb_fw_core_probe(struct gb_bundle *bundle,
 		fw_core->spi_connection = NULL;
 	}
 
+	ret = gb_cap_connection_init(fw_core->cap_connection);
+	if (ret) {
+		/* We may still be able to work with the Interface */
+		dev_err(&bundle->dev, "failed to initialize CAP connection, disable it (%d)\n",
+			ret);
+		gb_connection_destroy(fw_core->cap_connection);
+		fw_core->cap_connection = NULL;
+	}
+
 	ret = gb_fw_mgmt_connection_init(fw_core->mgmt_connection);
 	if (ret) {
 		/* We may still be able to work with the Interface */
@@ -181,10 +209,12 @@ static int gb_fw_core_probe(struct gb_bundle *bundle,
 	return 0;
 
 err_exit_connections:
+	gb_cap_connection_exit(fw_core->cap_connection);
 	gb_fw_spi_connection_exit(fw_core->spi_connection);
 	gb_fw_download_connection_exit(fw_core->download_connection);
 err_destroy_connections:
 	gb_connection_destroy(fw_core->mgmt_connection);
+	gb_connection_destroy(fw_core->cap_connection);
 	gb_connection_destroy(fw_core->spi_connection);
 	gb_connection_destroy(fw_core->download_connection);
 	kfree(fw_core);
@@ -197,10 +227,12 @@ static void gb_fw_core_disconnect(struct gb_bundle *bundle)
 	struct gb_fw_core *fw_core = greybus_get_drvdata(bundle);
 
 	gb_fw_mgmt_connection_exit(fw_core->mgmt_connection);
+	gb_cap_connection_exit(fw_core->cap_connection);
 	gb_fw_spi_connection_exit(fw_core->spi_connection);
 	gb_fw_download_connection_exit(fw_core->download_connection);
 
 	gb_connection_destroy(fw_core->mgmt_connection);
+	gb_connection_destroy(fw_core->cap_connection);
 	gb_connection_destroy(fw_core->spi_connection);
 	gb_connection_destroy(fw_core->download_connection);
 
@@ -229,19 +261,32 @@ static int fw_core_init(void)
 		return ret;
 	}
 
-	ret = greybus_register(&gb_fw_core_driver);
+	ret = cap_init();
 	if (ret) {
-		fw_mgmt_exit();
-		return ret;
+		pr_err("Failed to initialize component authentication core (%d)\n",
+		       ret);
+		goto fw_mgmt_exit;
 	}
 
+	ret = greybus_register(&gb_fw_core_driver);
+	if (ret)
+		goto cap_exit;
+
 	return 0;
+
+cap_exit:
+	cap_exit();
+fw_mgmt_exit:
+	fw_mgmt_exit();
+
+	return ret;
 }
 module_init(fw_core_init);
 
 static void __exit fw_core_exit(void)
 {
 	greybus_deregister(&gb_fw_core_driver);
+	cap_exit();
 	fw_mgmt_exit();
 }
 module_exit(fw_core_exit);