kbc: initial commit

3 files changed, 287 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..0b31adb
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+*.o
+*.flash
+*.eeprom
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..642202a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,38 @@
+MCU=atmega48
+AVRDUDE=avrdude
+ACC=avr-gcc
+AOBJCOPY=avr-objcopy
+ALD=avr-ld
+CFLAGS=-Wall -Wextra -Wno-unused-parameter -pedantic -std=c99
+ifdef PIN
+DPIN=-DPIN=\"$(PIN)\"
+endif
+ACFLAGS=-g -mmcu=$(MCU) $(CFLAGS) $(DPIN) -Os -mcall-prologues
+# ALDFLAGS=-L/usr/avr/lib/avr4 -L/usr/lib/binutils/avr/2.18
+LD=gcc
+CC=gcc
+CXX=g++ -g
+LDXX=g++ -g
+
+love: kbc.flash
+
+%.flash: %.ld.o
+	$(AOBJCOPY) -O binary $< $@
+
+%.eeprom: %.ld.o
+	$(AOBJCOPY) -j .eeprom -O binary $^ $@
+
+%.ld.o: %.o
+	$(ACC) $(ACFLAGS) $(ALDFLAGS) -o $@ $<
+
+%.o: %.c
+	$(ACC) $(ACFLAGS) -c -o $@ $<
+
+flash: kbc.flash
+	$(AVRDUDE) -y -p m48 -E noreset -U $^
+
+clean:
+	rm -f *.flash *.eeprom *.o
+
+.PHONY: love flash clean
+
diff --git a/kbc.c b/kbc.c
new file mode 100644
index 0000000..6a161c3
--- /dev/null
+++ b/kbc.c
@@ -0,0 +1,246 @@
+#include <stdint.h>
+#include <string.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+
+#ifndef PIN
+#error need to define a PIN
+#endif
+
+#define B_RED (1 << 0)
+#define B_YLW (1 << 1)
+
+static void usart_rx()
+{
+	UCSR0B = (1 << RXCIE0)				/* recv int en */
+		| (1 << RXEN0);				/* do RX */
+}
+
+static void usart_rxpoll()
+{
+	UCSR0B = (1 << RXEN0);				/* do RX*/
+}
+
+static void usart_dis()
+{
+	UCSR0B = 0;
+}
+
+#define CLK (1 << 3)
+#define DATA (1 << 1)
+
+static uint8_t send_byte(uint8_t byte)
+{
+	uint8_t cntr, bit, parity = 1, rv;
+
+	usart_dis();
+	rv = UDR0;
+
+	/* make clock low, request clock from keyboard */
+	PORTD = 0;
+	DDRD = CLK;
+
+#define delay(x) for (cntr = 0; cntr < x; cntr++) __asm__ volatile ("nop\n")
+
+	delay(200);
+
+	DDRD = CLK | DATA;
+
+	delay(10);
+
+	DDRD = DATA;
+	PORTD = CLK;
+
+#define wait_CLKlo while (PIND & CLK) __asm__ volatile ("nop\n")
+#define wait_CLKhi while (!(PIND & CLK)) __asm__ volatile ("nop\n")
+#define wait_CLK wait_CLKhi; wait_CLKlo; delay(3)
+
+	for (bit = 0; bit < 8; bit++) {
+		wait_CLK;
+		if (byte & 1) {
+			PORTD = CLK | DATA;
+			parity++;
+		} else {
+			PORTD = CLK;
+		}
+		byte >>= 1;
+	}
+	wait_CLK;
+	PORTD = (parity & 1) ? (CLK | DATA) : CLK;
+	wait_CLK;
+
+	PORTD = CLK | DATA;
+	wait_CLKhi;
+
+	DDRD = 0;
+
+	wait_CLKlo;
+	wait_CLKhi;
+
+	usart_rxpoll();
+
+	while (!(UCSR0A & (1 << RXC0)))
+		__asm__ volatile("nop\n");
+
+	rv = UDR0;
+	usart_rx();
+
+	return rv;
+}
+
+uint8_t ext, brk, pressed, state;
+const char passwd[4] = PIN;
+char code[sizeof(passwd)];
+
+const char kbc_60[32] = {
+	'_', '_', '_', '_', '_', '_', '_', '_', /* 60 - 67 */
+	'_', '1', '_', '4', '7', '_', '_', '_', /* 68 - 6f */
+	'0', '.', '2', '5', '6', '8', '_', '_', /* 70 - 77 */
+	'_', '+', '3', '-', '*', '9', '_', '_'  /* 78 - 7f */
+};
+
+#define KBLED_STATE 0x02
+#define KBLED_ERROR 0x04
+#define KBLED_OK    0x01
+
+#define DDRD_BEEP	0x20
+#define DDRD_OPEN	0x40
+#define DDRD_CLOSE	0x80
+
+#define CNTRTOP		96
+#define CNTRERR		90
+#define CNTRKEYBEEPOFF	4
+#define CNTROK		88 /* regulates length of keymatic button press */
+#define CNTROK_BEEPOFF	90
+#define CNTROK_BEEPON2	94
+#define OK_WAIT		3 /* mult CNTRTOP */
+
+static uint8_t cntr = 0;
+
+ISR(SIG_OVERFLOW0)
+{
+	switch (cntr) {
+	case CNTRTOP:
+		DDRD = 0;
+		if (state > 1) {
+			state--;
+		} else if (state == 1) {
+			memset(&code, 0, sizeof(code));
+			state = 0;
+		} else {
+			send_byte(0xed);
+			send_byte(KBLED_STATE);
+		}
+		cntr = 0;
+		return;
+	case CNTROK_BEEPOFF:
+		if (state > 1)
+			DDRD &= ~DDRD_BEEP;
+		break;
+	case CNTROK_BEEPON2:
+		if (state > 1)
+			DDRD |= DDRD_BEEP;
+		break;
+	case CNTRKEYBEEPOFF:
+		DDRD = 0;
+		break;
+	case 0x00:
+		if (state <= 1) {
+			send_byte(0xed);
+			send_byte(state ? KBLED_STATE : 0);
+		}
+		break;
+	}
+	cntr++;
+}
+
+ISR(SIG_USART_RECV)
+{
+	uint8_t data = UDR0, now;
+
+	if (data == 0xe0) {
+		ext = 0x80;
+		return;
+	}
+	if (data == 0xf0) {
+		brk = 1;
+		return;
+	}
+	if (data < 0x80) {
+		if (brk) {
+			pressed = 0;
+			brk = 0;
+			ext = 0;
+			return;
+		} else {
+			now = (data | ext);
+			ext = 0;
+			if (pressed == now)
+				return;
+			pressed = now;
+
+			if (pressed > 0x60 && pressed < 0x80 && pressed != 0x76 && pressed != 0x77) {
+				uint8_t c;
+				for (c = 1; c < sizeof(code); c++)
+					code[c - 1] = code[c];
+				code[sizeof(code) - 1] = kbc_60[pressed - 0x60];
+
+				TCNT0 = 0;
+				state = 1;
+				send_byte(0xed);
+				send_byte(0x00);
+				DDRD = DDRD_BEEP;
+				cntr = 0;
+				TIFR0 = (1 << TOV0);
+			};
+			if (pressed == 0xda || pressed == 0x76 || pressed == 0x77) {
+				if (memcmp(passwd, code, sizeof(passwd))) {
+					TCNT0 = 0;
+					memset(&code, 0, sizeof(code));
+					state = 0;
+					send_byte(0xed);
+					send_byte(KBLED_ERROR);
+					DDRD = DDRD_BEEP;
+					cntr = CNTRERR;
+					TIFR0 = (1 << TOV0);
+					return;
+				}
+				TCNT0 = 0;
+				send_byte(0xed);
+				send_byte(KBLED_OK);
+				state = OK_WAIT;
+				cntr = CNTROK;
+				TIFR0 = (1 << TOV0);
+
+				DDRD = DDRD_BEEP | ((pressed == 0xda) ? DDRD_OPEN : DDRD_CLOSE);
+			}
+		}
+		return;
+	}
+}
+
+int main()
+{
+	DDRB = (1 << 4) | B_RED | B_YLW;
+	PORTB = (1 << 4) | B_RED | B_YLW;
+
+	DDRD = 0;
+	PORTD = 0x3f;
+
+	TCCR0A = 0;
+	TIMSK0 = (1 << TOIE0);
+	TCCR0B = (1 << CS02);
+
+	UCSR0C = (1 << UMSEL00)				/* synch mode */
+		| (1 << UPM01) | (1 << UPM00)		/* odd parity */
+		| (1 << UCSZ01) | (1 << UCSZ00)		/* 8-bit chars */
+		| (0 << UCPOL0);			/* polarity: sample on falling */
+
+	usart_rx();
+
+	sei();
+	while (1)
+		;
+}
+