virtualization: Add virtio-can driver as external module.

This driver should conform RFC spec draft v2 [1].

This driver is based on RFC version [2].

Imported from internal OpenSynergy's revision:

  3918336a7caab95a72442c33945a193ca893d5e8

Supply build file `Kbuild` and do not supply makefile [3] since external
kernel module could be built without it. On the other hand, module
BitBake class relies on wrapper makefile presence, therefore
`MAKE_TARGETS` and `MODULES_INSTALL_TARGET` had to be set to specify
arguments per [3].

Add driver as an external module to avoid unnecessary kernel rebuild and
simplify future updates.

[1]: https://lists.oasis-open.org/archives/virtio-dev/202208/msg00159.html
[2]: https://lists.oasis-open.org/archives/virtio-dev/202208/msg00160.html
[3]: https://www.kernel.org/doc/html/v6.0/kbuild/modules.html

Change-Id: I9b654f58cc0c34983cd4103a5f7836263db79ec7
Bug-AGL: SPEC-4597
Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/meta-egvirt/recipes-kernel/kernel-module-virtio-can/files/virtio_can.h b/meta-egvirt/recipes-kernel/kernel-module-virtio-can/files/virtio_can.h
new file mode 100644
index 00000000..0ca75c7a
--- /dev/null
+++ b/meta-egvirt/recipes-kernel/kernel-module-virtio-can/files/virtio_can.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#ifndef _LINUX_VIRTIO_VIRTIO_CAN_H
+#define _LINUX_VIRTIO_VIRTIO_CAN_H
+
+#include <linux/types.h>
+#include <linux/virtio_types.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+
+/* Feature bit numbers */
+#define VIRTIO_CAN_F_CAN_CLASSIC        0u
+#define VIRTIO_CAN_F_CAN_FD             1u
+#define VIRTIO_CAN_F_LATE_TX_ACK        2u
+#define VIRTIO_CAN_F_RTR_FRAMES         3u
+
+/* CAN Result Types */
+#define VIRTIO_CAN_RESULT_OK            0u
+#define VIRTIO_CAN_RESULT_NOT_OK        1u
+
+/* CAN flags to determine type of CAN Id */
+#define VIRTIO_CAN_FLAGS_EXTENDED       0x8000u
+#define VIRTIO_CAN_FLAGS_FD             0x4000u
+#define VIRTIO_CAN_FLAGS_RTR            0x2000u
+
+/* TX queue message types */
+struct virtio_can_tx_out {
+#define VIRTIO_CAN_TX                   0x0001u
+	__le16 msg_type;
+	__le16 reserved;
+	__le32 flags;
+	__le32 can_id;
+	__u8 sdu[64u];
+};
+
+struct virtio_can_tx_in {
+	__u8 result;
+};
+
+/* RX queue message types */
+struct virtio_can_rx {
+#define VIRTIO_CAN_RX                   0x0101u
+	__le16 msg_type;
+	__le16 reserved;
+	__le32 flags;
+	__le32 can_id;
+	__u8 sdu[64u];
+};
+
+/* Control queue message types */
+struct virtio_can_control_out {
+#define VIRTIO_CAN_SET_CTRL_MODE_START  0x0201u
+#define VIRTIO_CAN_SET_CTRL_MODE_STOP   0x0202u
+	__le16 msg_type;
+};
+
+struct virtio_can_control_in {
+	__u8 result;
+};
+
+/* Indication queue message types */
+struct virtio_can_event_ind {
+#define VIRTIO_CAN_BUSOFF_IND           0x0301u
+	__le16 msg_type;
+};
+
+#endif /* #ifndef _LINUX_VIRTIO_VIRTIO_CAN_H */