+/*
+Copyright 2010,2011,2012,2013,2019 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 IBMPC_H
+#define IBMPC_H
+
+#include <stdbool.h>
+#include "wait.h"
+#include "print.h"
+
+/*
+ * IBM PC keyboard protocol
+ *
+ * PS/2 Resources
+ * --------------
+ * [1] The PS/2 Mouse/Keyboard Protocol
+ * http://www.computer-engineering.org/ps2protocol/
+ * Concise and thorough primer of PS/2 protocol.
+ *
+ * [2] Keyboard and Auxiliary Device Controller
+ * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
+ * Signal Timing and Format
+ *
+ * [3] Keyboards(101- and 102-key)
+ * http://www.mcamafia.de/pdf/ibm_hitrc11.pdf
+ * Keyboard Layout, Scan Code Set, POR, and Commands.
+ *
+ * [4] PS/2 Reference Manuals
+ * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
+ * Collection of IBM Personal System/2 documents.
+ *
+ * [5] TrackPoint Engineering Specifications for version 3E
+ * https://web.archive.org/web/20100526161812/http://wwwcssrv.almaden.ibm.com/trackpoint/download.html
+ */
+#define IBMPC_ACK 0xFA
+#define IBMPC_RESEND 0xFE
+#define IBMPC_SET_LED 0xED
+
+#define IBMPC_PROTOCOL_AT 0
+#define IBMPC_PROTOCOL_XT 1
+
+// TODO: error numbers
+#define IBMPC_ERR_NONE 0
+#define IBMPC_ERR_RECV 0x00
+#define IBMPC_ERR_SEND 0x10
+#define IBMPC_ERR_TIMEOUT 0x20
+#define IBMPC_ERR_FULL 0x40
+
+#define IBMPC_LED_SCROLL_LOCK 0
+#define IBMPC_LED_NUM_LOCK 1
+#define IBMPC_LED_CAPS_LOCK 2
+
+
+extern volatile uint8_t ibmpc_protocol;
+extern volatile uint8_t ibmpc_error;
+
+void ibmpc_host_init(void);
+int16_t ibmpc_host_send(uint8_t data);
+int16_t ibmpc_host_recv_response(void);
+int16_t ibmpc_host_recv(void);
+void ibmpc_host_set_led(uint8_t usb_led);
+
+
+/*--------------------------------------------------------------------
+ * static functions
+ *------------------------------------------------------------------*/
+#if defined(__AVR__)
+/*
+ * Clock
+ */
+static inline void clock_init(void)
+{
+ IBMPC_CLOCK_PORT &= ~(1<<IBMPC_CLOCK_BIT);
+ IBMPC_CLOCK_DDR |= (1<<IBMPC_CLOCK_BIT);
+}
+
+static inline void clock_lo(void)
+{
+ IBMPC_CLOCK_PORT &= ~(1<<IBMPC_CLOCK_BIT);
+ IBMPC_CLOCK_DDR |= (1<<IBMPC_CLOCK_BIT);
+}
+
+static inline void clock_hi(void)
+{
+ /* input with pull up */
+ IBMPC_CLOCK_DDR &= ~(1<<IBMPC_CLOCK_BIT);
+ IBMPC_CLOCK_PORT |= (1<<IBMPC_CLOCK_BIT);
+}
+
+static inline bool clock_in(void)
+{
+ IBMPC_CLOCK_DDR &= ~(1<<IBMPC_CLOCK_BIT);
+ IBMPC_CLOCK_PORT |= (1<<IBMPC_CLOCK_BIT);
+ wait_us(1);
+ return IBMPC_CLOCK_PIN&(1<<IBMPC_CLOCK_BIT);
+}
+
+/*
+ * Data
+ */
+static inline void data_init(void)
+{
+ IBMPC_DATA_DDR &= ~(1<<IBMPC_DATA_BIT);
+ IBMPC_DATA_PORT |= (1<<IBMPC_DATA_BIT);
+}
+
+static inline void data_lo(void)
+{
+ IBMPC_DATA_PORT &= ~(1<<IBMPC_DATA_BIT);
+ IBMPC_DATA_DDR |= (1<<IBMPC_DATA_BIT);
+}
+
+static inline void data_hi(void)
+{
+ /* input with pull up */
+ IBMPC_DATA_DDR &= ~(1<<IBMPC_DATA_BIT);
+ IBMPC_DATA_PORT |= (1<<IBMPC_DATA_BIT);
+}
+
+static inline bool data_in(void)
+{
+ IBMPC_DATA_DDR &= ~(1<<IBMPC_DATA_BIT);
+ IBMPC_DATA_PORT |= (1<<IBMPC_DATA_BIT);
+ wait_us(1);
+ return IBMPC_DATA_PIN&(1<<IBMPC_DATA_BIT);
+}
+#endif
+
+
+static inline uint16_t wait_clock_lo(uint16_t us)
+{
+ while (clock_in() && us) { asm(""); wait_us(1); us--; }
+ return us;
+}
+static inline uint16_t wait_clock_hi(uint16_t us)
+{
+ while (!clock_in() && us) { asm(""); wait_us(1); us--; }
+ return us;
+}
+static inline uint16_t wait_data_lo(uint16_t us)
+{
+ while (data_in() && us) { asm(""); wait_us(1); us--; }
+ return us;
+}
+static inline uint16_t wait_data_hi(uint16_t us)
+{
+ while (!data_in() && us) { asm(""); wait_us(1); us--; }
+ return us;
+}
+
+/* idle state that device can send */
+static inline void idle(void)
+{
+ clock_hi();
+ data_hi();
+}
+
+/* inhibit device to send */
+static inline void inhibit(void)
+{
+ clock_lo();
+ data_hi();
+}
+
+#endif