diff options
Diffstat (limited to 'tmk_core/protocol')
| -rw-r--r-- | tmk_core/protocol/ibm4704.c | 135 |
1 files changed, 78 insertions, 57 deletions
diff --git a/tmk_core/protocol/ibm4704.c b/tmk_core/protocol/ibm4704.c index 10e229fd15..152d7e61b6 100644 --- a/tmk_core/protocol/ibm4704.c +++ b/tmk_core/protocol/ibm4704.c @@ -4,6 +4,7 @@ Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com> #include <stdbool.h> #include <util/delay.h> #include "debug.h" +#include "ring_buffer.h" #include "ibm4704.h" @@ -20,7 +21,9 @@ uint8_t ibm4704_error = 0; void ibm4704_init(void) { - inhibit(); + IBM4704_INT_INIT(); + IBM4704_INT_ON(); + idle(); } /* @@ -47,6 +50,8 @@ uint8_t ibm4704_send(uint8_t data) bool parity = true; // odd parity ibm4704_error = 0; + IBM4704_INT_OFF(); + /* Request to send */ idle(); clock_lo(); @@ -57,7 +62,6 @@ uint8_t ibm4704_send(uint8_t data) /* Data bit */ for (uint8_t i = 0; i < 8; i++) { WAIT(clock_hi, 100, 0x40+i); - //_delay_us(5); if (data&(1<<i)) { parity = !parity; data_hi(); @@ -79,28 +83,25 @@ uint8_t ibm4704_send(uint8_t data) /* End */ WAIT(data_lo, 100, 0x36); - inhibit(); - _delay_us(200); // wait to recover clock to hi + idle(); + IBM4704_INT_ON(); return 0; ERROR: - inhibit(); - if (ibm4704_error >= 0x30) { - xprintf("x%02X ", ibm4704_error); + idle(); + if (ibm4704_error > 0x30) { + xprintf("S:%02X ", ibm4704_error); } - _delay_us(200); // wait to recover clock to hi + IBM4704_INT_ON(); return -1; } -/* receive data when host want else inhibit communication */ +/* wait forever to receive data */ uint8_t ibm4704_recv_response(void) { - // 250 * 100us(wait start bit in ibm4704_recv) - uint8_t data = 0; - uint8_t try = 250; - do { - data = ibm4704_recv(); - } while (try-- && ibm4704_error); - return data; + while (!rbuf_has_data()) { + _delay_ms(1); + } + return rbuf_dequeue(); } /* @@ -121,49 +122,69 @@ Stop bit: Keyboard pulls down Data line to lo after 9th clock. */ uint8_t ibm4704_recv(void) { - uint8_t data = 0; - bool parity = true; // odd parity - ibm4704_error = IBM4704_ERR_NONE; - - idle(); - _delay_us(5); // wait for line settles - - /* start bit */ - WAIT(clock_lo, 100, 0x11); // wait for keyboard to send - WAIT(data_hi, 100, 0x12); // can be delayed that long - - WAIT(clock_hi, 100, 0x13); // first rising edge which can take longer - /* data */ - for (uint8_t i = 0; i < 8; i++) { - WAIT(clock_hi, 100, 0x20+i); - //_delay_us(5); - if (data_in()) { - parity = !parity; - data |= (1<<i); - } - WAIT(clock_lo, 150, 0x28+i); + if (rbuf_has_data()) { + return rbuf_dequeue(); + } else { + return -1; } +} - /* parity */ - WAIT(clock_hi, 100, 0x17); - if (data_in() != parity) { - ibm4704_error = IBM4704_ERR_PARITY; - goto ERROR; - } - WAIT(clock_lo, 150, 0x18); - - /* stop bit */ - WAIT(clock_hi, 100, 0x19); - WAIT(data_lo, 1, 0x19); +ISR(IBM4704_INT_VECT) +{ + static enum { + INIT, START, BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, PARITY, + } state = INIT; + // LSB first + static uint8_t data = 0; + // Odd parity + static uint8_t parity = false; - inhibit(); - _delay_us(200); // wait to recover clock to hi - return data; -ERROR: - if (ibm4704_error > 0x12) { - xprintf("x%02X ", ibm4704_error); + ibm4704_error = 0; + // return unless falling edge + if (clock_in()) { goto RETURN; } // why this occurs? + + state++; + switch (state) { + case START: + // Data:Low + WAIT(data_hi, 10, state); + 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 = !parity; + } + break; + case PARITY: + if (data_in()) { + parity = !parity; + } + if (!parity) + goto ERROR; + rbuf_enqueue(data); + ibm4704_error = IBM4704_ERR_NONE; + goto DONE; + break; + default: + goto ERROR; } - inhibit(); - _delay_us(200); // wait to recover clock to hi - return -1; + goto RETURN; +ERROR: + ibm4704_error = state; + while (ibm4704_send(0xFE)) _delay_ms(1); // resend + xprintf("R:%02X\n", data); +DONE: + state = INIT; + data = 0; + parity = false; +RETURN: + return; } |