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-rw-r--r--include/usb_sm.h67
1 files changed, 67 insertions, 0 deletions
diff --git a/include/usb_sm.h b/include/usb_sm.h
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--- /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 */