/* Copyright 2014 Jun WAKO <wakojun@gmail.com> */ #pragma once #define IBM4704_ERR_NONE 0 #define IBM4704_ERR_PARITY 0x70 void ibm4704_init(void); uint8_t ibm4704_send(uint8_t data); uint8_t ibm4704_recv_response(void); uint8_t ibm4704_recv(void); /* Check pin configuration */ #if !(defined(IBM4704_CLOCK_PORT) && defined(IBM4704_CLOCK_PIN) && defined(IBM4704_CLOCK_DDR) && defined(IBM4704_CLOCK_BIT)) # error "ibm4704 clock pin configuration is required in config.h" #endif #if !(defined(IBM4704_DATA_PORT) && defined(IBM4704_DATA_PIN) && defined(IBM4704_DATA_DDR) && defined(IBM4704_DATA_BIT)) # error "ibm4704 data pin configuration is required in config.h" #endif /*-------------------------------------------------------------------- * static functions *------------------------------------------------------------------*/ static inline void clock_lo(void) { IBM4704_CLOCK_PORT &= ~(1 << IBM4704_CLOCK_BIT); IBM4704_CLOCK_DDR |= (1 << IBM4704_CLOCK_BIT); } static inline void clock_hi(void) { /* input with pull up */ IBM4704_CLOCK_DDR &= ~(1 << IBM4704_CLOCK_BIT); IBM4704_CLOCK_PORT |= (1 << IBM4704_CLOCK_BIT); } static inline bool clock_in(void) { IBM4704_CLOCK_DDR &= ~(1 << IBM4704_CLOCK_BIT); IBM4704_CLOCK_PORT |= (1 << IBM4704_CLOCK_BIT); _delay_us(1); return IBM4704_CLOCK_PIN & (1 << IBM4704_CLOCK_BIT); } static inline void data_lo(void) { IBM4704_DATA_PORT &= ~(1 << IBM4704_DATA_BIT); IBM4704_DATA_DDR |= (1 << IBM4704_DATA_BIT); } static inline void data_hi(void) { /* input with pull up */ IBM4704_DATA_DDR &= ~(1 << IBM4704_DATA_BIT); IBM4704_DATA_PORT |= (1 << IBM4704_DATA_BIT); } static inline bool data_in(void) { IBM4704_DATA_DDR &= ~(1 << IBM4704_DATA_BIT); IBM4704_DATA_PORT |= (1 << IBM4704_DATA_BIT); _delay_us(1); return IBM4704_DATA_PIN & (1 << IBM4704_DATA_BIT); } static inline uint16_t wait_clock_lo(uint16_t us) { while (clock_in() && us) { asm(""); _delay_us(1); us--; } return us; } static inline uint16_t wait_clock_hi(uint16_t us) { while (!clock_in() && us) { asm(""); _delay_us(1); us--; } return us; } static inline uint16_t wait_data_lo(uint16_t us) { while (data_in() && us) { asm(""); _delay_us(1); us--; } return us; } static inline uint16_t wait_data_hi(uint16_t us) { while (!data_in() && us) { asm(""); _delay_us(1); us--; } return us; } /* idle state that device can send */ static inline void idle(void) { clock_hi(); data_hi(); } /* inhibit device to send * keyboard checks Data line on start bit(Data:hi) and it stops sending if Data line is low. */ static inline void inhibit(void) { clock_hi(); data_lo(); }