printer:avr: Fix startup behavior if in correction mode

Also introduce startup wait until 0xFF is received.

ioc/kernel-driver/lw35ioc.c

@@ -294,6 +294,7 @@ static int lw35ioc_chardev_open(struct inode *inodep, struct file *filep) {
 			lw35ioc_reset_ioc_hw(serdev);
 			usleep_range(2100000, 2210000);
 			dev_info(&serdev->dev, "Put ioc into active mode.\n");
+			serdev_device_write(serdev, "\xFF", 1, 0);
 			priv->state = ACTIVE;
 			break;
 		case ACTIVE:

printer/avr/main.c

@@ -112,7 +112,7 @@ void hardfault() {
 #define PRINTER_CONTROL_CHAR 56
 #define PRINTER_NO_CHAR 128
 
-#define ASCII_TRANSLATION_TABLE_SIZE 128 + 12
+#define ASCII_TRANSLATION_TABLE_SIZE (128 + 12)
 const uint8_t ascii_translation_table[ASCII_TRANSLATION_TABLE_SIZE] PROGMEM = {
 	PRINTER_CONTROL_CHAR,
 	PRINTER_CONTROL_CHAR,
@@ -277,6 +277,9 @@ const uint8_t ascii_translation_table[ASCII_TRANSLATION_TABLE_SIZE] PROGMEM = {
 #define PIN_CORRECTION (1 << 1)
 #define PIN_ARMHAMMER (1 << 0)
 
+/* Misc I/O */
+#define MISCIO(t) t##D
+#define PIN_BACKLIGHT (1 << 2)
 
 /* Stepper drive */
 
@@ -671,11 +674,22 @@ void move_carriage_to_far_left(uint8_t reset)
 
 	if (LIMITSWITCH) {
 		debug_write("[car] Clearing switch area...\r\n");
-		while (LIMITSWITCH) {
+		cnt = 32;
+		while (LIMITSWITCH && (cnt> 0)) {
 			if (block_for(TIM_CARRIAGE, STEPPER_CFG_CARRIAGE.delay)) {
 				STEPPER_NEXT(CARRIAGE, 1);
+				cnt--;
 			}
 		}
+		if (LIMITSWITCH && !cnt) { // We're probably in correction mode
+			DCMOTOR_EN;
+			arm_correction();
+			_delay_ms(1000);
+			DCMOTOR_STOP;
+		}
+		if (LIMITSWITCH) { // If the switch is still not released, there's some problem we can't fix from SW
+			hardfault();
+		}
 		for (cnt = 0; cnt < 16; cnt++) {
 			STEPPER_NEXT(CARRIAGE, 1);
 		}
@@ -911,7 +925,7 @@ void printer_process()
 
 	switch (state) {
 	case IDLE:
-		if (print_buffer_rd != print_buffer_wr) { // maybe add "|| current_is_linebreak"
+		if (print_buffer_rd != print_buffer_wr) { // TODO: maybe add "|| current_is_linebreak"
 			if (!DCMOTOR_ISACTIVE) {
 				DCMOTOR_EN;
 				_delay_ms(100); /* Let the motor get up to speed */
@@ -1019,7 +1033,8 @@ void printer_process()
 	//	stepper_status_WHEEL.target_pos += 10;
 	//	// -----------
 
-	if (stepper_status_CARRIAGE.target_pos > PRINTER_STOP_RIGHT) { // Right margin safety
+	if (stepper_status_CARRIAGE.target_pos > PRINTER_STOP_RIGHT ||
+			stepper_status_CARRIAGE.target_pos < 0) { // Margin safety
 		hardfault();
 	}
 	stepper_perform_movement(&stepper_status_LINEFEED, &STEPPER_CFG_LINEFEED);
@@ -1211,10 +1226,10 @@ static void system_test_auto()
 		if (POSITION_REACHED(WHEEL) && POSITION_REACHED(CARRIAGE) && POSITION_REACHED(LINEFEED) && print_stat) {
 			print_stat = 0;
 			debug_printf("[pos] %uL %uC%c %uW\r\n",
-				     stepper_status_LINEFEED.pos,
+			             stepper_status_LINEFEED.pos,
-				     stepper_status_CARRIAGE.pos,
+			             stepper_status_CARRIAGE.pos,
-				     (LIMITSWITCH ? '*' : '+'),
+			             (LIMITSWITCH ? '*' : '+'),
-				     stepper_status_WHEEL.pos);
+			             stepper_status_WHEEL.pos);
 		}
 
 		if (do_it) {
@@ -1274,6 +1289,10 @@ int main()
 	STEPPER_SET_IO(WHEEL);
 	STEPPER_SET_IO(LINEFEED);
 
+	/* Set up miscellaneous I/O */
+	MISCIO(DDR) |= PIN_BACKLIGHT;
+	MISCIO(PORT) |= PIN_BACKLIGHT; /* Permanently enable backlight */
+
 	/* Set up SysTick Timer */
 	TCCR1B = (1 << WGM12) | (1 << CS11); // f_tim = 8 MHz / 8
 	OCR1A = 2000 / TIMESCALE;
@@ -1283,6 +1302,11 @@ int main()
 	sync_uart();
 	update_status(0);
 	debug_write("\n\n\r[sys] STARTING IO CONTROLLER...\r\n");
+#ifndef DEBUG_BUILD
+	while (!((UCSRA & (1 << RXC)) && (UDR == 0xFF))); /* Wait for init command from driver */
+	update_status(0);
+	_delay_ms(250);
+#endif
 	debug_write("[sys] Enabling interrupts.\r\n");
 	sei();