chocodile_vpdmcu: Firmware for chocodile mcu

Implement Chocodile Charge-Through Vconn Powered firmware for mcu
using new Type-C/PD State machine stack.

BUG=b:115626873
BRANCH=none
TEST=manual
  Charge-Through was tested on an Atlas running a DRP USB-C/PD state
  machine with CTUnattached.SNK and CTAttached.SNK states.

Signed-off-by: Sam Hurst <shurst@chromium.org>
Change-Id: I847f1bcd2fc3ce41e66edd133a10c943d5e8c819
Reviewed-on: https://chromium-review.googlesource.com/1225250
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Sam Hurst <shurst@google.com>
Reviewed-by: Stefan Reinauer <reinauer@google.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/include/usb_sm.h b/include/usb_sm.h
new file mode 100644
index 0000000000..15de5f9ef4
--- /dev/null
+++ b/include/usb_sm.h
@@ -0,0 +1,67 @@
+/* Copyright 2019 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.
+ */
+
+/* USB State Machine Framework */
+
+#ifndef __CROS_EC_USB_SM_H
+#define __CROS_EC_USB_SM_H
+
+#define SM_OBJ(smo)    ((struct sm_obj *)&smo)
+#define SUPER(r, sig, s)  ((((r) == 0) || ((sig) == ENTRY_SIG) || \
+			((sig) == EXIT_SIG)) ? 0 : ((uintptr_t)(s)))
+#define RUN_SUPER	1
+
+/* Local state machine states */
+enum sm_local_state {
+	SM_INIT,
+	SM_RUN,
+	SM_PAUSED
+};
+
+/* State Machine signals */
+enum signal {
+	ENTRY_SIG = 0,
+	RUN_SIG,
+	EXIT_SIG,
+	SUPER_SIG,
+};
+
+typedef unsigned int (*state_sig)(int port);
+typedef unsigned int (*sm_state)(int port, enum signal sig);
+
+struct sm_obj {
+	sm_state task_state;
+	sm_state last_state;
+};
+
+/**
+ * Initialize a State Machine
+ *
+ * @param port   USB-C port number
+ * @param obj    State machine object
+ * @param target Initial state of state machine
+ */
+void init_state(int port, struct sm_obj *obj, sm_state target);
+
+/**
+ * Changes a state machines state
+ *
+ * @param port   USB-C port number
+ * @param obj    State machine object
+ * @param target State to transition to
+ * @return 0
+ */
+int set_state(int port, struct sm_obj *obj, sm_state target);
+
+/**
+ * Executes a state machine
+ *
+ * @param port USB-C port number
+ * @param obj  State machine object
+ * @param sig  State machine signal
+ */
+void exe_state(int port, struct sm_obj *obj, enum signal sig);
+
+#endif /* __CROS_EC_USB_SM_H */