TCPMv2: Add Entry flow for Thunderbolt mode

Create a separate module for representing Thunderbolt mode which decides
whether and how we can enter into Thunderbolt alternate mode.

Modify the Device Policy Manger (usb_pd_dpm.c) to first check if the
port partner and cable is a Thunderbolt Compatible. If not, continue the
rest of the PD flow undisturbed.

BUG=b:148528713
BRANCH=none
TEST=1. Attach Thunderbolt dock, DUT should enter Thunderbolt mode
     2. Attach Type-C dock, DUT should enter DP mode
     3. Attach DP dongle, DUT should enter DP mode

Change-Id: I369eb6337144676996c9d94a412eec060eacd273
Signed-off-by: Ayushee <ayushee.shah@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2250488
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>

1 files changed, 65 insertions, 0 deletions

diff --git a/include/usb_tbt_alt_mode.h b/include/usb_tbt_alt_mode.h
new file mode 100644
index 0000000000..186c2f8139
--- /dev/null
+++ b/include/usb_tbt_alt_mode.h
@@ -0,0 +1,65 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/*
+ * Thunderbolt alternate mode support
+ * Refer to USB Type-C Cable and Connector Specification Release 2.0 Section F
+ */
+
+#ifndef __CROS_EC_USB_TBT_ALT_MODE_H
+#define __CROS_EC_USB_TBT_ALT_MODE_H
+
+#include <stdint.h>
+
+#include "tcpm.h"
+
+/*
+ * Initialize Thunderbolt state for the specified port.
+ *
+ * @param port USB-C port number
+ */
+void tbt_init(int port);
+
+/*
+ * Handles received Thunderbolt VDM ACKs.
+ *
+ * @param port      USB-C port number
+ * @param type      Transmit type (SOP, SOP') for received ACK
+ * @param vdo_count The number of VDOs in the ACK VDM
+ * @param vdm       VDM from ACK
+ */
+void intel_vdm_acked(int port, enum tcpm_transmit_type type, int vdo_count,
+		uint32_t *vdm);
+
+/*
+ * Handles NAKed (or Not Supported or timed out) Thunderbolt VDM requests.
+ *
+ * @param port    USB-C port number
+ * @param type    Transmit type (SOP, SOP') for request
+ * @param svid    The SVID of the request
+ * @param vdm_cmd The VDM command of the request
+ */
+void intel_vdm_naked(int port, enum tcpm_transmit_type type, uint8_t vdm_cmd);
+
+/*
+ * Reset the Thunderbolt mode VDM state for the specified port, as when exiting
+ * Thunderbolt mode.
+ *
+ * @param port USB-C port number
+ */
+void tbt_teardown(int port);
+
+/*
+ * Construct the next Thunderbolt VDM that should be sent.
+ *
+ * @param port      USB-C port number
+ * @param vdo_count The number of VDOs in vdm; must be at least VDO_MAX_SIZE
+ * @param vdm       The VDM payload to be sent; output; must point to at least
+ *                  VDO_MAX_SIZE elements
+ * @return          The number of VDOs written to VDM or -1 to indicate error
+ */
+int tbt_setup_next_vdm(int port, int vdo_count, uint32_t *vdm);
+
+#endif