Add keyboard_raw interface

This is the low-level platform-dependent interface to drive keyboard
columns, read rows, and handle keyboard interrupts.

Both lm4 and stm32 had something like this before, but the interfaces
weren't fully explicit or compatible.

BUG=chrome-os-partner:18360
BRANCH=none
TEST=manual

- Build all platforms.
- Boot system and test typing on keyboard.
- Hold power+refresh+esc to test boot key detection; should go to recovery.

Change-Id: Ie3bcc1d066a4da5204f0e236daeb52c4064a6213
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/46156

1 files changed, 74 insertions, 0 deletions

diff --git a/include/keyboard_raw.h b/include/keyboard_raw.h
new file mode 100644
index 0000000000..6432335a52
--- /dev/null
+++ b/include/keyboard_raw.h
@@ -0,0 +1,74 @@
+/* Copyright (c) 2013 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.
+ *
+ * Raw access to keyboard GPIOs.
+ *
+ * The keyboard matrix is read by driving output signals on the column lines
+ * and reading the row lines.
+ */
+
+#ifndef __CROS_EC_KEYBOARD_RAW_H
+#define __CROS_EC_KEYBOARD_RAW_H
+
+#include "common.h"
+#include "gpio.h"
+
+/* used for select_column() */
+enum keyboard_column_index {
+	KEYBOARD_COLUMN_ALL = -2,  /* Drive all columns */
+	KEYBOARD_COLUMN_NONE = -1, /* Drive no columns (tri-state all) */
+	/* 0 ~ 12 for the corresponding column */
+};
+
+/**
+ * Initialize the raw keyboard interface.
+ *
+ * Must be called before any other functions in this interface.
+ */
+void keyboard_raw_init(void);
+
+/**
+ * Finish intitialization after task scheduling has started.
+ *
+ * Call from the keyboard scan task.
+ */
+void keyboard_raw_task_start(void);
+
+/**
+ * Drive the specified column low.
+ *
+ * Other columns are tristated.  See enum keyboard_column_index for special
+ * values for <col>.
+ */
+void keyboard_raw_drive_column(int col);
+
+/**
+ * Read raw row state.
+ *
+ * Bits are 1 if signal is present, 0 if not present.
+ */
+int keyboard_raw_read_rows(void);
+
+/**
+ * Enable or disable keyboard interrupts.
+ *
+ * Enabling interrupts will clear any pending interrupt bits.  To avoid missing
+ * any interrupts that occur between the end of scanning and then, you should
+ * call keyboard_raw_read_rows() after this.  If it returns non-zero, disable
+ * interrupts and go back to polling mode instead of waiting for an interrupt.
+ */
+void keyboard_raw_enable_interrupt(int enable);
+
+#ifdef CONFIG_TASK_KEYSCAN
+
+/**
+ * GPIO interrupt for raw keyboard input
+ */
+void keyboard_raw_gpio_interrupt(enum gpio_signal signal);
+
+#else
+#define keyboard_raw_gpio_interrupt NULL
+#endif
+
+#endif  /* __CROS_EC_KEYBOARD_RAW_H */