Add PS/2 mouse support to connect TrackPoint Unit.

Change build options:  Makefile and config.h. See README.

ps2.h

@@ -0,0 +1,72 @@
+/*
+Copyright (c) 2010 Jun WAKO <wakojun@gmail.com>
+
+This software is licensed with a Modified BSD License.
+All of this is supposed to be Free Software, Open Source, DFSG-free,
+GPL-compatible, and OK to use in both free and proprietary applications.
+Additions and corrections to this file are welcome.
+
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright
+  notice, this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright
+  notice, this list of conditions and the following disclaimer in
+  the documentation and/or other materials provided with the
+  distribution.
+
+* Neither the name of the copyright holders nor the names of
+  contributors may be used to endorse or promote products derived
+  from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+*/
+#ifndef PS2_H
+#define PS2_H
+/*
+ * Primitive PS/2 Library for AVR
+ */
+
+
+/* port settings for clock and data line */
+#if !(defined(PS2_CLOCK_PORT) && \
+      defined(PS2_CLOCK_PIN) && \
+      defined(PS2_CLOCK_DDR) && \
+      defined(PS2_CLOCK_BIT))
+#   error "PS/2 clock port setting is required in config.h"
+#endif
+
+#if !(defined(PS2_DATA_PORT) && \
+      defined(PS2_DATA_PIN) && \
+      defined(PS2_DATA_DDR) && \
+      defined(PS2_DATA_BIT))
+#   error "PS/2 data port setting is required in config.h"
+#endif
+
+#define PS2_ERR_NONE    0
+#define PS2_ERR_PARITY  0x10
+
+
+extern uint8_t ps2_error;
+
+/* host side */
+void ps2_host_init(void);
+uint8_t ps2_host_send(uint8_t);
+uint8_t ps2_host_recv(void);
+
+/* TODO: device side */
+
+#endif