diff options
Diffstat (limited to 'ps2.c')
| -rw-r--r-- | ps2.c | 123 |
1 files changed, 90 insertions, 33 deletions
@@ -96,13 +96,15 @@ void ps2_host_init(void) #endif } +// TODO: send using interrupt if available uint8_t ps2_host_send(uint8_t data) { - bool parity; -RETRY: - parity = true; - ps2_error = 0; - + uint8_t res = 0; + bool parity = true; + ps2_error = PS2_ERR_NONE; +#ifdef PS2_INT_DISABLE + PS2_INT_DISABLE(); +#endif /* terminate a transmission if we have */ inhibit(); _delay_us(100); @@ -139,15 +141,15 @@ RETRY: WAIT(clock_hi, 50, 8); WAIT(data_hi, 50, 9); - uint8_t res = ps2_host_recv_response(); - if (res == 0xFE && data != 0xFE) - goto RETRY; - - inhibit(); - return res; + res = ps2_host_recv_response(); ERROR: +#ifdef PS2_INT_ENABLE + PS2_INT_ENABLE(); + idle(); +#else inhibit(); - return 0; +#endif + return res; } /* receive data when host want else inhibit communication */ @@ -209,46 +211,99 @@ static inline uint8_t pbuf_dequeue(void) /* get data received by interrupt */ uint8_t ps2_host_recv(void) { + // TODO: release clock line after 100us when inhibited by error + if (ps2_error) { + ps2_host_send(0xFE); // request to resend + ps2_error = PS2_ERR_NONE; + } return pbuf_dequeue(); } +#define DEBUGP_INIT() do { DDRC = 0xFF; } while (0) +#define DEBUGP(x) do { PORTC = x; } while (0) ISR(PS2_INT_VECT) { - /* interrupt means start bit comes */ - pbuf_enqueue(recv_data()); + static enum { + INIT, + START, + BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, + PARITY, + STOP, + } state = INIT; + static uint8_t data = 0; + static uint8_t parity = 1; + + // TODO: abort if elapse 100us from previous interrupt + + // return unless falling edge + if (clock_in()) { + goto RETURN; + } - /* release lines(idle state) */ - idle(); - _delay_us(5); + state++; + DEBUGP(state); + switch (state) { + case START: + if (data_in()) + goto ERROR; + break; + case BIT0: + case BIT1: + case BIT2: + case BIT3: + case BIT4: + case BIT5: + case BIT6: + case BIT7: + data >>= 1; + if (data_in()) { + data |= 0x80; + parity++; + } + break; + case PARITY: + if (data_in()) { + if (!(parity & 0x01)) + goto ERROR; + } else { + if (parity & 0x01) + goto ERROR; + } + break; + case STOP: + if (!data_in()) + goto ERROR; + pbuf_enqueue(data); + goto DONE; + break; + default: + goto ERROR; + } + goto RETURN; +ERROR: + DEBUGP(0xFF); + inhibit(); + ps2_error = state; +DONE: + state = INIT; + data = 0; + parity = 1; +RETURN: + return; } #endif -/* static void ps2_reset(void) { ps2_host_send(0xFF); - if (ps2_host_recv_response() == 0xFA) { - _delay_ms(1000); - ps2_host_recv_response(); - } } -*/ /* send LED state to keyboard */ void ps2_host_set_led(uint8_t led) { -#ifdef PS2_INT_DISABLE - PS2_INT_DISABLE(); -#endif ps2_host_send(0xED); - ps2_host_recv_response(); ps2_host_send(led); - ps2_host_recv_response(); -#ifdef PS2_INT_ENABLE - PS2_INT_ENABLE(); - idle(); -#endif } @@ -257,7 +312,7 @@ static uint8_t recv_data(void) { uint8_t data = 0; bool parity = true; - ps2_error = 0; + ps2_error = PS2_ERR_NONE; /* start bit [1] */ WAIT(clock_lo, 1, 1); @@ -307,6 +362,7 @@ static inline bool clock_in() { PS2_CLOCK_DDR &= ~(1<<PS2_CLOCK_BIT); PS2_CLOCK_PORT |= (1<<PS2_CLOCK_BIT); + _delay_us(1); return PS2_CLOCK_PIN&(1<<PS2_CLOCK_BIT); } static inline void data_lo() @@ -324,6 +380,7 @@ static inline bool data_in() { PS2_DATA_DDR &= ~(1<<PS2_DATA_BIT); PS2_DATA_PORT |= (1<<PS2_DATA_BIT); + _delay_us(1); return PS2_DATA_PIN&(1<<PS2_DATA_BIT); } |