tmk_core/protocol/ibm4704.h

   1 /*
   2 Copyright 2014 Jun WAKO <wakojun@gmail.com>
   3 */
   4 #ifndef IBM4704_H
   5 #define IBM4704_H
   6
   7 #define IBM4704_ERR_NONE        0
   8 #define IBM4704_ERR_PARITY      0x70
   9
  10
  11 void ibm4704_init(void);
  12 uint8_t ibm4704_send(uint8_t data);
  13 uint8_t ibm4704_recv_response(void);
  14 uint8_t ibm4704_recv(void);
  15
  16
  17 /* Check pin configuration */
  18 #if !(defined(IBM4704_CLOCK_PORT) && \
  19       defined(IBM4704_CLOCK_PIN) && \
  20       defined(IBM4704_CLOCK_DDR) && \
  21       defined(IBM4704_CLOCK_BIT))
  22 #   error "ibm4704 clock pin configuration is required in config.h"
  23 #endif
  24
  25 #if !(defined(IBM4704_DATA_PORT) && \
  26       defined(IBM4704_DATA_PIN) && \
  27       defined(IBM4704_DATA_DDR) && \
  28       defined(IBM4704_DATA_BIT))
  29 #   error "ibm4704 data pin configuration is required in config.h"
  30 #endif
  31
  32
  33 /*--------------------------------------------------------------------
  34  * static functions
  35  *------------------------------------------------------------------*/
  36 static inline void clock_lo(void)
  37 {
  38     IBM4704_CLOCK_PORT &= ~(1<<IBM4704_CLOCK_BIT);
  39     IBM4704_CLOCK_DDR  |=  (1<<IBM4704_CLOCK_BIT);
  40 }
  41 static inline void clock_hi(void)
  42 {
  43     /* input with pull up */
  44     IBM4704_CLOCK_DDR  &= ~(1<<IBM4704_CLOCK_BIT);
  45     IBM4704_CLOCK_PORT |=  (1<<IBM4704_CLOCK_BIT);
  46 }
  47 static inline bool clock_in(void)
  48 {
  49     IBM4704_CLOCK_DDR  &= ~(1<<IBM4704_CLOCK_BIT);
  50     IBM4704_CLOCK_PORT |=  (1<<IBM4704_CLOCK_BIT);
  51     _delay_us(1);
  52     return IBM4704_CLOCK_PIN&(1<<IBM4704_CLOCK_BIT);
  53 }
  54 static inline void data_lo(void)
  55 {
  56     IBM4704_DATA_PORT &= ~(1<<IBM4704_DATA_BIT);
  57     IBM4704_DATA_DDR  |=  (1<<IBM4704_DATA_BIT);
  58 }
  59 static inline void data_hi(void)
  60 {
  61     /* input with pull up */
  62     IBM4704_DATA_DDR  &= ~(1<<IBM4704_DATA_BIT);
  63     IBM4704_DATA_PORT |=  (1<<IBM4704_DATA_BIT);
  64 }
  65 static inline bool data_in(void)
  66 {
  67     IBM4704_DATA_DDR  &= ~(1<<IBM4704_DATA_BIT);
  68     IBM4704_DATA_PORT |=  (1<<IBM4704_DATA_BIT);
  69     _delay_us(1);
  70     return IBM4704_DATA_PIN&(1<<IBM4704_DATA_BIT);
  71 }
  72
  73 static inline uint16_t wait_clock_lo(uint16_t us)
  74 {
  75     while (clock_in()  && us) { asm(""); _delay_us(1); us--; }
  76     return us;
  77 }
  78 static inline uint16_t wait_clock_hi(uint16_t us)
  79 {
  80     while (!clock_in() && us) { asm(""); _delay_us(1); us--; }
  81     return us;
  82 }
  83 static inline uint16_t wait_data_lo(uint16_t us)
  84 {
  85     while (data_in() && us)  { asm(""); _delay_us(1); us--; }
  86     return us;
  87 }
  88 static inline uint16_t wait_data_hi(uint16_t us)
  89 {
  90     while (!data_in() && us)  { asm(""); _delay_us(1); us--; }
  91     return us;
  92 }
  93
  94 /* idle state that device can send */
  95 static inline void idle(void)
  96 {
  97     clock_hi();
  98     data_hi();
  99 }
 100
 101 /* inhibit device to send
 102  * keyboard checks Data line on start bit(Data:hi) and it stops sending if Data line is low.
 103  */
 104 static inline void inhibit(void)
 105 {
 106     clock_hi();
 107     data_lo();
 108 }
 109
 110 #endif