protocol/ps2.h

   1 /*
   2 Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com>
   3
   4 This software is licensed with a Modified BSD License.
   5 All of this is supposed to be Free Software, Open Source, DFSG-free,
   6 GPL-compatible, and OK to use in both free and proprietary applications.
   7 Additions and corrections to this file are welcome.
   8
   9
  10 Redistribution and use in source and binary forms, with or without
  11 modification, are permitted provided that the following conditions are met:
  12
  13 * Redistributions of source code must retain the above copyright
  14   notice, this list of conditions and the following disclaimer.
  15
  16 * Redistributions in binary form must reproduce the above copyright
  17   notice, this list of conditions and the following disclaimer in
  18   the documentation and/or other materials provided with the
  19   distribution.
  20
  21 * Neither the name of the copyright holders nor the names of
  22   contributors may be used to endorse or promote products derived
  23   from this software without specific prior written permission.
  24
  25 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  26 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  29 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35 POSSIBILITY OF SUCH DAMAGE.
  36 */
  37
  38 #ifndef PS2_H
  39 #define PS2_H
  40
  41 #include <stdbool.h>
  42 #include <util/delay.h>
  43 #include <avr/io.h>
  44
  45 /*
  46  * Primitive PS/2 Library for AVR
  47  *
  48  * PS/2 Resources
  49  * --------------
  50  * [1] The PS/2 Mouse/Keyboard Protocol
  51  * http://www.computer-engineering.org/ps2protocol/
  52  * Concise and thorough primer of PS/2 protocol.
  53  *
  54  * [2] Keyboard and Auxiliary Device Controller
  55  * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
  56  * Signal Timing and Format
  57  *
  58  * [3] Keyboards(101- and 102-key)
  59  * http://www.mcamafia.de/pdf/ibm_hitrc11.pdf
  60  * Keyboard Layout, Scan Code Set, POR, and Commands.
  61  *
  62  * [4] PS/2 Reference Manuals
  63  * http://www.mcamafia.de/pdf/ibm_hitrc07.pdf
  64  * Collection of IBM Personal System/2 documents.
  65  *
  66  * [5] TrackPoint Engineering Specifications for version 3E
  67  * https://web.archive.org/web/20100526161812/http://wwwcssrv.almaden.ibm.com/trackpoint/download.html
  68  */
  69 #define PS2_ACK         0xFA
  70 #define PS2_RESEND      0xFE
  71 #define PS2_SET_LED     0xED
  72
  73 // TODO: error numbers
  74 #define PS2_ERR_NONE        0
  75 #define PS2_ERR_STARTBIT1   1
  76 #define PS2_ERR_STARTBIT2   2
  77 #define PS2_ERR_STARTBIT3   3
  78 #define PS2_ERR_PARITY      0x10
  79 #define PS2_ERR_NODATA      0x20
  80
  81 #define PS2_LED_SCROLL_LOCK 0
  82 #define PS2_LED_NUM_LOCK    1
  83 #define PS2_LED_CAPS_LOCK   2
  84
  85
  86 extern uint8_t ps2_error;
  87
  88 void ps2_host_init(void);
  89 uint8_t ps2_host_send(uint8_t data);
  90 uint8_t ps2_host_recv_response(void);
  91 uint8_t ps2_host_recv(void);
  92 void ps2_host_set_led(uint8_t usb_led);
  93
  94
  95 /* Check port settings for clock and data line */
  96 #if !(defined(PS2_CLOCK_PORT) && \
  97       defined(PS2_CLOCK_PIN) && \
  98       defined(PS2_CLOCK_DDR) && \
  99       defined(PS2_CLOCK_BIT))
 100 #   error "PS/2 clock port setting is required in config.h"
 101 #endif
 102
 103 #if !(defined(PS2_DATA_PORT) && \
 104       defined(PS2_DATA_PIN) && \
 105       defined(PS2_DATA_DDR) && \
 106       defined(PS2_DATA_BIT))
 107 #   error "PS/2 data port setting is required in config.h"
 108 #endif
 109
 110 /*--------------------------------------------------------------------
 111  * static functions
 112  *------------------------------------------------------------------*/
 113 static inline void clock_lo(void)
 114 {
 115     PS2_CLOCK_PORT &= ~(1<<PS2_CLOCK_BIT);
 116     PS2_CLOCK_DDR  |=  (1<<PS2_CLOCK_BIT);
 117 }
 118 static inline void clock_hi(void)
 119 {
 120     /* input with pull up */
 121     PS2_CLOCK_DDR  &= ~(1<<PS2_CLOCK_BIT);
 122     PS2_CLOCK_PORT |=  (1<<PS2_CLOCK_BIT);
 123 }
 124 static inline bool clock_in(void)
 125 {
 126     PS2_CLOCK_DDR  &= ~(1<<PS2_CLOCK_BIT);
 127     PS2_CLOCK_PORT |=  (1<<PS2_CLOCK_BIT);
 128     _delay_us(1);
 129     return PS2_CLOCK_PIN&(1<<PS2_CLOCK_BIT);
 130 }
 131 static inline void data_lo(void)
 132 {
 133     PS2_DATA_PORT &= ~(1<<PS2_DATA_BIT);
 134     PS2_DATA_DDR  |=  (1<<PS2_DATA_BIT);
 135 }
 136 static inline void data_hi(void)
 137 {
 138     /* input with pull up */
 139     PS2_DATA_DDR  &= ~(1<<PS2_DATA_BIT);
 140     PS2_DATA_PORT |=  (1<<PS2_DATA_BIT);
 141 }
 142 static inline bool data_in(void)
 143 {
 144     PS2_DATA_DDR  &= ~(1<<PS2_DATA_BIT);
 145     PS2_DATA_PORT |=  (1<<PS2_DATA_BIT);
 146     _delay_us(1);
 147     return PS2_DATA_PIN&(1<<PS2_DATA_BIT);
 148 }
 149
 150 static inline uint16_t wait_clock_lo(uint16_t us)
 151 {
 152     while (clock_in()  && us) { asm(""); _delay_us(1); us--; }
 153     return us;
 154 }
 155 static inline uint16_t wait_clock_hi(uint16_t us)
 156 {
 157     while (!clock_in() && us) { asm(""); _delay_us(1); us--; }
 158     return us;
 159 }
 160 static inline uint16_t wait_data_lo(uint16_t us)
 161 {
 162     while (data_in() && us)  { asm(""); _delay_us(1); us--; }
 163     return us;
 164 }
 165 static inline uint16_t wait_data_hi(uint16_t us)
 166 {
 167     while (!data_in() && us)  { asm(""); _delay_us(1); us--; }
 168     return us;
 169 }
 170
 171 /* idle state that device can send */
 172 static inline void idle(void)
 173 {
 174     clock_hi();
 175     data_hi();
 176 }
 177
 178 /* inhibit device to send */
 179 static inline void inhibit(void)
 180 {
 181     clock_lo();
 182     data_hi();
 183 }
 184
 185 #endif