cr50: Add physical presence state machine

This will be used as part of case closed debugging configuration.
Currently, this only adds the state machine, and a test command which
is available when CR50_DEV=1.  It also adds a new sleep mask flag for
physical presence detect, instead of oveloading FORCE_NO_DSLEEP.

The physical presence state machine supports both short (tap 5 times
in 15 seconds) and long (short, followed by 4 more taps 1-5 minutes
apart) sequences.  It will call a callback function at the end of the
sequence, so that multiple things can each request physical presence
in turn.  This will be used by ccdopen / ccdunlock / testlab commands
for CCD V1.

Eventually, CCD config will replace the unlock sequence handling in
wp.c.  But for now, we don't touch that.

See go/cr50-ccd-wp for more information.

BUG=b:62537474
BRANCH=none
TEST=manual
	Short sequence:
		pp short
		pp
		pp
		pp # See "Physical presence good"
	Timeout
		pp short
		pp # 15 sec later, get timeout error
	Long sequence:
		pp long
		pp
		pp
		pp
		(wait 2 sec)
		pp
		(wait 2 sec)
		pp # See "PP good"
	Long sequence, presses too fast:
		pp long
		pp
		pp
		pp
		pp # See "PP L too soon"
		(wait 2 sec)
		pp
		(wait 2 sec)
		pp # See "Physical presence good"
	Abort:
		pp short
		pp abort # See "Physical presence aborted"

Change-Id: I09da81ad11d328e7d7740c3fe838a5f67d7b8708
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/568796
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/include/physical_presence.h b/include/physical_presence.h
new file mode 100644
index 0000000000..f2678993fc
--- /dev/null
+++ b/include/physical_presence.h
@@ -0,0 +1,64 @@
+/* Copyright 2017 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.
+ *
+ * Physical presence detection
+ */
+#ifndef __CROS_EC_PHYSICAL_PRESENCE_H
+#define __CROS_EC_PHYSICAL_PRESENCE_H
+
+/**
+ * Start physical presence detect.
+ *
+ * If the physical presence sequence is successful, callback() will be called
+ * from the hook task context as a deferred function.
+ *
+ * On failure or abort, callback() will not be called.
+ *
+ * @param is_long	Use long (!=0) or short (0) sequence)
+ * @param callback	Function to call when successful
+ * @return EC_SUCCESS, EC_BUSY if detect already in progress, or other
+ *	   non-zero error code if error.
+ */
+int physical_detect_start(int is_long, void (*callback)(void));
+
+/**
+ * Check if a physical detect attempt is in progress
+ *
+ * @return non-zero if in progress
+ */
+int physical_detect_busy(void);
+
+/**
+ * Abort a currently-running physical presence detect.
+ *
+ * Note there is a race condition between stopping detect and a running
+ * detect finishing and calling its callback.  The intent of this function
+ * is not to prevent that, but instead to avoid an aborted physical detect
+ * tying up the button for long periods when we no longer care.
+ */
+void physical_detect_abort(void);
+
+/**
+ * Handle a physical detect button press.
+ *
+ * This may be called from interrupt level.
+ *
+ * Returns EC_SUCCESS if the press was consumed, or EC_ERROR_NOT_HANDLED if
+ * physical detect was idle (so the press is for someone else).
+ */
+int physical_detect_press(void);
+
+/**
+ * Start/stop capturing the button for physical presence.
+ *
+ * When enabled, a debounced button press+release should call
+ * physical_detect_press().
+ *
+ * This should be implemented by the board.
+ *
+ * @param enable	Enable (!=0) or disable (==0) capturing button.
+ */
+void board_physical_presence_enable(int enable);
+
+#endif /* __CROS_EC_PHYSICAL_PRESENCE_H */