diff options
Diffstat (limited to 'tmk_core/protocol/ibm4704.c')
| -rw-r--r-- | tmk_core/protocol/ibm4704.c | 62 |
1 files changed, 28 insertions, 34 deletions
diff --git a/tmk_core/protocol/ibm4704.c b/tmk_core/protocol/ibm4704.c index 6a03cd441..fd8fc4dbd 100644 --- a/tmk_core/protocol/ibm4704.c +++ b/tmk_core/protocol/ibm4704.c @@ -7,24 +7,21 @@ Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com> #include "ring_buffer.h" #include "ibm4704.h" - -#define WAIT(stat, us, err) do { \ - if (!wait_##stat(us)) { \ - ibm4704_error = err; \ - goto ERROR; \ - } \ -} while (0) - +#define WAIT(stat, us, err) \ + do { \ + if (!wait_##stat(us)) { \ + ibm4704_error = err; \ + goto ERROR; \ + } \ + } while (0) uint8_t ibm4704_error = 0; - -void ibm4704_init(void) -{ +void ibm4704_init(void) { inhibit(); // keep keyboard from sending IBM4704_INT_INIT(); IBM4704_INT_ON(); - idle(); // allow keyboard sending + idle(); // allow keyboard sending } /* @@ -46,9 +43,8 @@ Timing: After Request keyboard pull up Data and down Clock line to low for s Host writes a bit while Clock is hi and Keyboard reads while low. Stop bit: Host releases or pulls up Data line to hi after 9th clock and waits for keyboard pull down the line to lo. */ -uint8_t ibm4704_send(uint8_t data) -{ - bool parity = true; // odd parity +uint8_t ibm4704_send(uint8_t data) { + bool parity = true; // odd parity ibm4704_error = 0; IBM4704_INT_OFF(); @@ -62,19 +58,23 @@ uint8_t ibm4704_send(uint8_t data) /* Data bit */ for (uint8_t i = 0; i < 8; i++) { - WAIT(clock_hi, 100, 0x40+i); - if (data&(1<<i)) { + WAIT(clock_hi, 100, 0x40 + i); + if (data & (1 << i)) { parity = !parity; data_hi(); } else { data_lo(); } - WAIT(clock_lo, 100, 0x48+i); + WAIT(clock_lo, 100, 0x48 + i); } /* Parity bit */ WAIT(clock_hi, 100, 0x34); - if (parity) { data_hi(); } else { data_lo(); } + if (parity) { + data_hi(); + } else { + data_lo(); + } WAIT(clock_lo, 100, 0x35); /* Stop bit */ @@ -97,16 +97,14 @@ ERROR: } /* wait forever to receive data */ -uint8_t ibm4704_recv_response(void) -{ +uint8_t ibm4704_recv_response(void) { while (!rbuf_has_data()) { _delay_ms(1); } return rbuf_dequeue(); } -uint8_t ibm4704_recv(void) -{ +uint8_t ibm4704_recv(void) { if (rbuf_has_data()) { return rbuf_dequeue(); } else { @@ -121,7 +119,7 @@ Data bits are LSB first and Parity is odd. Clock has around 60us high and 30us l ____ __ __ __ __ __ __ __ __ __ _______ Clock \_____/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ - ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ + ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ Data ____/ X____X____X____X____X____X____X____X____X____X________ Start 0 1 2 3 4 5 6 7 P Stop @@ -130,11 +128,8 @@ Inhibit: Pull Data line down to inhibit keyboard to send. Timing: Host reads bit while Clock is hi.(rising edge) Stop bit: Keyboard pulls down Data line to lo after 9th clock. */ -ISR(IBM4704_INT_VECT) -{ - static enum { - BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, PARITY, STOP - } state = BIT0; +ISR(IBM4704_INT_VECT) { + static enum { BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, PARITY, STOP } state = BIT0; // LSB first static uint8_t data = 0; // Odd parity @@ -161,8 +156,7 @@ ISR(IBM4704_INT_VECT) if (data_in()) { parity = !parity; } - if (!parity) - goto ERROR; + if (!parity) goto ERROR; break; case STOP: // Data:Low @@ -178,11 +172,11 @@ ISR(IBM4704_INT_VECT) goto RETURN; ERROR: ibm4704_error = state; - while (ibm4704_send(0xFE)) _delay_ms(1); // resend + while (ibm4704_send(0xFE)) _delay_ms(1); // resend xprintf("R:%02X%02X\n", state, data); DONE: - state = BIT0; - data = 0; + state = BIT0; + data = 0; parity = false; RETURN: return; |