X-Git-Url: https://git.friedersdorff.com/?a=blobdiff_plain;f=tmk_core%2Fprotocol%2Fibmpc.c;h=5f2ca79b2fba9f1bd8067b46ed1d2ca8ca6044a1;hb=12e5a3a13eb86852ad58c131e28ba29c5f09bb2d;hp=e65ac461c287c135ed1fc68a92872789de1144ca;hpb=c4b8b36950a0b936c4b699afaecd77cdc642d471;p=max%2Ftmk_keyboard.git diff --git a/tmk_core/protocol/ibmpc.c b/tmk_core/protocol/ibmpc.c index e65ac461..5f2ca79b 100644 --- a/tmk_core/protocol/ibmpc.c +++ b/tmk_core/protocol/ibmpc.c @@ -41,7 +41,7 @@ POSSIBILITY OF SUCH DAMAGE. #include #include -#include "ringbuf.h" +#include #include "ibmpc.h" #include "debug.h" #include "timer.h" @@ -56,27 +56,42 @@ POSSIBILITY OF SUCH DAMAGE. } while (0) -#define BUF_SIZE 16 -static uint8_t buf[BUF_SIZE]; -static ringbuf_t rb = { - .buffer = buf, - .head = 0, - .tail = 0, - .size_mask = BUF_SIZE - 1 -}; - -volatile uint8_t ibmpc_protocol = IBMPC_PROTOCOL_AT; +volatile uint16_t ibmpc_isr_debug = 0; +volatile uint8_t ibmpc_protocol = IBMPC_PROTOCOL_NO; volatile uint8_t ibmpc_error = IBMPC_ERR_NONE; +/* 2-byte buffer for data received from keyboard + * buffer states: + * FFFF: empty + * FFss: one data + * sstt: two data + * eeFF: error + * where ss, tt and ee are 0x00-0xFE. 0xFF means empty or no data in buffer. + */ +static volatile uint16_t recv_data = 0xFFFF; +/* internal state of receiving data */ +static volatile uint16_t isr_state = 0x8000; +static uint8_t timer_start = 0; + void ibmpc_host_init(void) { - clock_init(); - data_init(); - idle(); + // initialize reset pin to HiZ + IBMPC_RST_HIZ(); + inhibit(); IBMPC_INT_INIT(); + IBMPC_INT_OFF(); +} + +void ibmpc_host_enable(void) +{ IBMPC_INT_ON(); - // POR(150-2000ms) plus BAT(300-500ms) may take 2.5sec([3]p.20) - //wait_ms(2500); + idle(); +} + +void ibmpc_host_disable(void) +{ + IBMPC_INT_OFF(); + inhibit(); } int16_t ibmpc_host_send(uint8_t data) @@ -84,20 +99,19 @@ int16_t ibmpc_host_send(uint8_t data) bool parity = true; ibmpc_error = IBMPC_ERR_NONE; - if (ibmpc_protocol == IBMPC_PROTOCOL_XT) return -1; - dprintf("w%02X ", data); IBMPC_INT_OFF(); /* terminate a transmission if we have */ inhibit(); - wait_us(100); // 100us [4]p.13, [5]p.50 + wait_us(100); // [5]p.54 /* 'Request to Send' and Start bit */ data_lo(); - clock_hi(); - WAIT(clock_lo, 10000, 1); // 10ms [5]p.50 + wait_us(100); + clock_hi(); // [5]p.54 [clock low]>100us [5]p.50 + WAIT(clock_lo, 10000, 1); // [5]p.53, -10ms [5]p.50 /* Data bit[2-9] */ for (uint8_t i = 0; i < 8; i++) { @@ -121,14 +135,19 @@ int16_t ibmpc_host_send(uint8_t data) /* Stop bit */ wait_us(15); data_hi(); + WAIT(clock_hi, 50, 6); + WAIT(clock_lo, 50, 7); /* Ack */ - WAIT(data_lo, 50, 6); - WAIT(clock_lo, 50, 7); + WAIT(data_lo, 50, 8); /* wait for idle state */ - WAIT(clock_hi, 50, 8); - WAIT(data_hi, 50, 9); + WAIT(clock_hi, 50, 9); + WAIT(data_hi, 50, 10); + + // clear buffer to get response correctly + recv_data = 0xFFFF; + ibmpc_host_isr_clear(); idle(); IBMPC_INT_ON(); @@ -140,125 +159,261 @@ ERROR: return -1; } +/* + * Receive data from keyboard + */ +int16_t ibmpc_host_recv(void) +{ + uint16_t data = 0; + uint8_t ret = 0xFF; + + ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { + data = recv_data; + + // remove data from buffer: + // FFFF(empty) -> FFFF + // FFss(one data) -> FFFF + // sstt(two data) -> FFtt + // eeFF(errror) -> FFFF + recv_data = data | (((data&0xFF00) == 0xFF00) ? 0x00FF : 0xFF00); + } + + if ((data&0x00FF) == 0x00FF) { + // error: eeFF + switch (data>>8) { + case IBMPC_ERR_FF: + // 0xFF(Overrun/Error) from keyboard + dprintf("!FF! "); + ret = 0xFF; + break; + case IBMPC_ERR_FULL: + // buffer full + dprintf("!FULL! "); + ret = 0xFF; + break; + case 0xFF: + // empty: FFFF + return -1; + default: + // other errors + dprintf("e%02X ", data>>8); + return -1; + } + } else { + if ((data | 0x00FF) != 0xFFFF) { + // two data: sstt + dprintf("b:%04X ", data); + ret = (data>>8); + } else { + // one data: FFss + ret = (data&0x00FF); + } + } + + //dprintf("i%04X ", ibmpc_isr_debug); ibmpc_isr_debug = 0; + dprintf("r%02X ", ret); + return ret; +} + int16_t ibmpc_host_recv_response(void) { // Command may take 25ms/20ms at most([5]p.46, [3]p.21) uint8_t retry = 25; - while (retry-- && ringbuf_is_empty(&rb)) { + int16_t data = -1; + while (retry-- && (data = ibmpc_host_recv()) == -1) { wait_ms(1); } - int16_t data = ringbuf_get(&rb); - if (data != -1) dprintf("r%02X ", data); return data; } -/* get data received by interrupt */ -int16_t ibmpc_host_recv(void) +void ibmpc_host_isr_clear(void) { - int16_t data = ringbuf_get(&rb); - if (data != -1) dprintf("r%02X ", data); - return data; + ibmpc_isr_debug = 0; + ibmpc_protocol = 0; + ibmpc_error = 0; + isr_state = 0x8000; + recv_data = 0xFFFF; } +#define LO8(w) (*((uint8_t *)&(w))) +#define HI8(w) (*(((uint8_t *)&(w))+1)) +// NOTE: With this ISR data line can be read within 2us after clock falling edge. +// To read data line early as possible: +// write naked ISR with asembly code to read the line and call C func to do other job? ISR(IBMPC_INT_VECT) { - static uint16_t last_time = 0; - static enum { - START, - BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, - PARITY, - STOP, - } state = START; - static uint8_t data = 0; - static uint8_t parity = 1; - - // return unless falling edge - if (clock_in()) { - return; - } + uint8_t dbit; + dbit = IBMPC_DATA_PIN&(1<= 3) { + ibmpc_isr_debug = isr_state; + ibmpc_error = IBMPC_ERR_TIMEOUT; + goto ERROR; - // Reset state when taking more than 1ms - if (last_time && timer_elapsed(last_time) > 10) { - ibmpc_error = IBMPC_ERR_TIMEOUT | IBMPC_ERR_RECV | state; - state = START; - data = 0; - parity = 1; + // timeout error recovery - start receiving new data + // it seems to work somehow but may not under unstable situation + //timer_start = t; + //isr_state = 0x8000; + } } - last_time = timer_read(); - switch (state) { - case START: - if (ibmpc_protocol == IBMPC_PROTOCOL_XT) { - // ignore start(0) bit - if (!data_in()) return; - } else { - if (data_in()) - goto ERROR; - } - case BIT0: - case BIT1: - case BIT2: - case BIT3: - case BIT4: - case BIT5: - case BIT6: - case BIT7: - data >>= 1; - if (data_in()) { - data |= 0x80; - parity++; - } - if (state == BIT7 && ibmpc_protocol == IBMPC_PROTOCOL_XT) { - if (!ringbuf_put(&rb, data)) { - ibmpc_error = IBMPC_ERR_FULL; - goto ERROR; + isr_state = isr_state>>1; + if (dbit) isr_state |= 0x8000; + + // isr_state: state of receiving data from keyboard + // + // This should be initialized with 0x8000 before receiving data and + // the MSB '*1' works as marker to discrimitate between protocols. + // It stores sampled bit at MSB after right shift on each clock falling edge. + // + // XT protocol has two variants of signaling; XT_IBM and XT_Clone. + // XT_IBM uses two start bits 0 and 1 while XT_Clone uses just start bit 1. + // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-XT-Keyboard-Protocol + // + // 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + // ----------------------------------------------------- + // *1 0 0 0 0 0 0 0 | 0 0 0 0 0 0 0 0 Initial state(0x8000) + // + // x x x x x x x x | 0 0 0 0 0 0 0 0 midway(0-7 bits received) + // x x x x x x x x | *1 0 0 0 0 0 0 0 midway(8 bits received) + // b6 b5 b4 b3 b2 b1 b0 1 | 0 *1 0 0 0 0 0 0 XT_IBM-midway ^1 + // b7 b6 b5 b4 b3 b2 b1 b0 | 0 *1 0 0 0 0 0 0 AT-midway ^1 + // b7 b6 b5 b4 b3 b2 b1 b0 | 1 *1 0 0 0 0 0 0 XT_Clone-done ^3 + // b6 b5 b4 b3 b2 b1 b0 1 | 1 *1 0 0 0 0 0 0 XT_IBM-error ^3 + // pr b7 b6 b5 b4 b3 b2 b1 | 0 0 *1 0 0 0 0 0 AT-midway[b0=0] + // b7 b6 b5 b4 b3 b2 b1 b0 | 1 0 *1 0 0 0 0 0 XT_IBM-done ^2 + // pr b7 b6 b5 b4 b3 b2 b1 | 1 0 *1 0 0 0 0 0 AT-midway[b0=1] ^2 + // b7 b6 b5 b4 b3 b2 b1 b0 | 1 1 *1 0 0 0 0 0 XT_IBM-error-done + // x x x x x x x x | x 1 1 0 0 0 0 0 illegal + // st pr b7 b6 b5 b4 b3 b2 | b1 b0 0 *1 0 0 0 0 AT-done + // x x x x x x x x | x x 1 *1 0 0 0 0 illegal + // all other states than above illegal + // + // ^1: AT and XT_IBM takes same state. + // ^2: AT and XT_IBM takes same state in case that AT b0 is 1, + // we have to check AT stop bit to discriminate between the two protocol. + switch (isr_state & 0xFF) { + case 0b00000000: + case 0b10000000: + case 0b01000000: // ^1 + case 0b00100000: + // midway + goto NEXT; + break; + case 0b11000000: // ^3 + { + uint8_t us = 100; + // wait for rising and falling edge of b7 of XT_IBM + while (!(IBMPC_CLOCK_PIN&(1<>8; + ibmpc_protocol = IBMPC_PROTOCOL_XT_CLONE; + goto DONE; } - ibmpc_error = IBMPC_ERR_NONE; - goto DONE; } break; - case PARITY: - if (data_in()) { - if (!(parity & 0x01)) - goto ERROR; - } else { - if (parity & 0x01) - goto ERROR; - } + case 0b11100000: + // XT_IBM-error-done + ibmpc_isr_debug = isr_state; + isr_state = isr_state>>8; + ibmpc_protocol = IBMPC_PROTOCOL_XT_ERROR; + goto DONE; + break; + case 0b10100000: // ^2 + { + uint8_t us = 100; + // wait for rising and falling edge of AT stop bit to discriminate between XT and AT + while (!(IBMPC_CLOCK_PIN&(1<>8; + ibmpc_protocol = IBMPC_PROTOCOL_XT_IBM; + goto DONE; + } + } break; - case STOP: - if (!data_in()) - goto ERROR; - if (!ringbuf_put(&rb, data)) { - ibmpc_error = IBMPC_ERR_FULL; - goto ERROR; + case 0b00010000: + case 0b10010000: + case 0b01010000: + case 0b11010000: + // AT-done + // TODO: parity check? + ibmpc_isr_debug = isr_state; + // stop bit check + if (isr_state & 0x8000) { + ibmpc_protocol = IBMPC_PROTOCOL_AT; + } else { + // Zenith Z-150 AT(beige/white lable) asserts stop bit as low + // https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-AT-Keyboard-Protocol#zenith-z-150-beige + ibmpc_protocol = IBMPC_PROTOCOL_AT_Z150; } - ibmpc_error = IBMPC_ERR_NONE; + isr_state = isr_state>>6; goto DONE; break; - default: + case 0b01100000: + case 0b00110000: + case 0b10110000: + case 0b01110000: + case 0b11110000: + default: // xxxx_oooo(any 1 in low nibble) + // Illegal + ibmpc_isr_debug = isr_state; + ibmpc_error = IBMPC_ERR_ILLEGAL; goto ERROR; + break; } - goto NEXT; ERROR: - ibmpc_error |= state; - ibmpc_error |= IBMPC_ERR_RECV; - ringbuf_reset(&rb); + // error: eeFF + recv_data = (ibmpc_error<<8) | 0x00FF; + goto CLEAR; DONE: - last_time = 0; - state = START; - data = 0; - parity = 1; - return; + if ((isr_state & 0x00FF) == 0x00FF) { + // receive error code 0xFF + ibmpc_error = IBMPC_ERR_FF; + goto ERROR; + } + if (HI8(recv_data) != 0xFF && LO8(recv_data) != 0xFF) { + // buffer full + ibmpc_error = IBMPC_ERR_FULL; + goto ERROR; + } + // store data + recv_data = recv_data<<8; + recv_data |= isr_state & 0xFF; +CLEAR: + // clear for next data + isr_state = 0x8000; NEXT: - state++; return; } /* send LED state to keyboard */ void ibmpc_host_set_led(uint8_t led) { - ibmpc_host_send(0xED); - ibmpc_host_send(led); + if (0xFA == ibmpc_host_send(0xED)) { + ibmpc_host_send(led); + } }