stm32: Implement keyscan test infrastructure

Support the keyscan test functionality on stm32.

Note: This is enabled by default so that it continues to build. But it
is unlikely that we will want this in a shipping image. I suggest we add
the facility for a dev build.

Secondly, the stack has to be larger due to a printf (which admittedly I
could just remove). Should we make the stack size conditional on the
CONFIG? Seems a bit ugly, on the other hand we don't want to waste IRAM.

BUG=chrome-os-partner:12179
BRANCH=none
TEST=manual for now:
On snow:
./ectool keyscan 20000 key_sequence.txt

See that the test passes.

Change-Id: Ic441ca0bde1be9589a924374605e2f146d16f423
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/35118

1 files changed, 42 insertions, 0 deletions

diff --git a/include/keyboard_test.h b/include/keyboard_test.h
new file mode 100644
index 0000000000..df95d9c081
--- /dev/null
+++ b/include/keyboard_test.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2012 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.
+ */
+
+/* Keyboard scanner test module for Chrome EC */
+
+#ifndef __CROS_EC_KEYBOARD_TEST_H
+#define __CROS_EC_KEYBOARD_TEST_H
+
+#include <timer.h>
+
+/*
+ * Keyboard scan test item - contains a single scan to 'present' to key scan
+ * logic.
+ */
+struct keyscan_item {
+	timestamp_t abs_time;	/* absolute timestamp to present this item */
+	uint32_t time_us;	/* time for this item relative to test start */
+	uint8_t done;		/* 1 if we managed to present this */
+	uint8_t scan[KB_OUTPUTS];
+};
+
+/**
+ * Get the next key scan from the test sequence, if any
+ *
+ * @param column	Column to read (-1 to OR all columns together
+ * @param scan		Raw scan data read from GPIOs
+ * @return test scan, or just 'scan' if no test is active
+ */
+uint8_t keyscan_seq_get_scan(int column, uint8_t scan);
+
+/**
+ * Calculate the delay until the next key scan event needs to be presented
+ *
+ * @return number of microseconds from now until the next key scan event, or
+ *	-1 if there is no future key scan event (e.g. testing is complete)
+ */
+int keyscan_seq_next_event_delay(void);
+
+#endif