controller/Scan/SonyNEWS/scan_loop.c

/* Copyright (C) 2011 by Jacob Alexander
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

// ----- Includes -----

// AVR Includes
#include <avr/interrupt.h>
#include <avr/io.h>
#include <util/delay.h>

// Project Includes
#include <led.h>
#include <print.h>

// Local Includes
#include "scan_loop.h"



// ----- Defines -----

// Pinout Defines
#define RESET_PORT PORTB
#define RESET_DDR   DDRD
#define RESET_PIN      0


// ----- Macros -----

// Make sure we haven't overflowed the buffer
#define bufferAdd(byte) \
		if ( KeyIndex_BufferUsed < KEYBOARD_BUFFER ) \
			KeyIndex_Buffer[KeyIndex_BufferUsed++] = byte

#define UNSET_RESET()   RESET_DDR &= ~(1 << RESET_PIN)
#define   SET_RESET()   RESET_DDR |=  (1 << RESET_PIN)



// ----- Variables -----

// Buffer used to inform the macro processing module which keys have been detected as pressed
volatile uint8_t KeyIndex_Buffer[KEYBOARD_BUFFER];
volatile uint8_t KeyIndex_BufferUsed;



// ----- Functions -----

// Setup
inline void scan_setup()
{
	// Setup the the USART interface for keyboard data input
	
	// Setup baud rate
	// 16 MHz / ( 16 * Baud ) = UBRR
	// Baud <- 0.10450 ms per bit, thus 1000 / 0.10450 = 9569.4
	// Thus UBRR = 104.50
	// To deal with the 0.5, setting to double speed, which means UBRR = 209
	uint16_t baud = 209; // Max setting of 4095
	UBRR1H = (uint8_t)(baud >> 8);
	UBRR1L = (uint8_t)baud;

	// Enable Double Read Speed
	UCSR1A = 0x02;

	// Enable the receiver, transitter, and RX Complete Interrupt
	UCSR1B = 0x98;

	// Set frame format: 8 data, no stop bits or parity
	// Asynchrounous USART mode
	UCSR1C = 0x06;

	// Reset the keyboard before scanning, we might be in a wierd state
	scan_resetKeyboard();
}


// Main Detection Loop
// Not needed for the Sony NEWS, this is just a busy loop
inline uint8_t scan_loop()
{
	return 0;
}

void processKeyValue( uint8_t keyValue )
{
	// Detect release condition
	uint8_t release = keyValue & 0x80;

	// Finalize output buffer
	// Mask 8th bit
	keyValue &= 0x7F;

	// Key Release
	if ( release )
	{
		// Check for the released key, and shift the other keys lower on the buffer
		uint8_t c;
		for ( c = 0; c < KeyIndex_BufferUsed; c++ )
		{
			// Key to release found
			if ( KeyIndex_Buffer[c] == keyValue )
			{
				// Shift keys from c position
				for ( uint8_t k = c; k < KeyIndex_BufferUsed - 1; k++ )
					KeyIndex_Buffer[k] = KeyIndex_Buffer[k + 1];

				// Decrement Buffer
				KeyIndex_BufferUsed--;

				break;
			}
		}

		// Error case (no key to release)
		if ( c == KeyIndex_BufferUsed + 1 )
		{
			errorLED( 1 );
			char tmpStr[6];
			hexToStr( keyValue, tmpStr );
			erro_dPrint( "Could not find key to release: ", tmpStr );
		}
	}
	// Press or Repeat Rate
	else
	{
		// Make sure the key isn't already in the buffer
		for ( uint8_t c = 0; c < KeyIndex_BufferUsed + 1; c++ )
		{
			// Key isn't in the buffer yet
			if ( c == KeyIndex_BufferUsed )
			{
				bufferAdd( keyValue );
				break;
			}

			// Key already in the buffer
			if ( KeyIndex_Buffer[c] == keyValue )
				break;
		}
	}
}

// USART Receive Buffer Full Interrupt
ISR(USART1_RX_vect)
{
	cli(); // Disable Interrupts

	uint8_t keyValue = 0x00;

	// One scancode at a time (fastest interval ~3.95 ms - recorded, should still be ok for interrupt polling)
	// Read the raw packet from the USART
	keyValue = UDR1;

	// Debug
	char tmpStr[6];
	hexToStr( keyValue, tmpStr );
	dPrintStrs( tmpStr, " " );

	// Process the scancode
	processKeyValue( keyValue );

	sei(); // Re-enable Interrupts
}

// Send data TODO
//
// Keyboard Input Guide for Micro Switch 8304
// 0xBX is for LED F1,F2,Over Type,Lock
// 0xAX is for LED F3,F8,F9,F10
// 0x92 resets keyboard (LED off, echo scancode mode off)
// 0x9E sets echo scancode mode from (0x81 to 0xFF; translates to 0x01 to 0x7F)
// Other echos: 0x15~0x19 send 0x15~0x19, 0x40 sends 0x40 (as well as 0x44,0x45, 0x80)
// 0x8C Acks the keyboard and gets 0x70 sent back (delayed)
uint8_t scan_sendData( uint8_t dataPayload )
{
	UDR1 = dataPayload;
	return 0;
}

// Signal KeyIndex_Buffer that it has been properly read
// Not needed as a signal is sent to remove key-presses
void scan_finishedWithBuffer( void )
{
	return;
}

// Reset/Hold keyboard TODO
// Warning! This will cause the keyboard to not send any data, so you can't disable with a keypress
// The Micro Switch 8304 has a dedicated reset line
void scan_lockKeyboard( void )
{
	//UNSET_RESET();
}

void scan_unlockKeyboard( void )
{
	//SET_RESET();
}

// Reset Keyboard TODO
void scan_resetKeyboard( void )
{
	// Reset command for the 8304
	//scan_sendData( 0x92 );

	// Empty buffer, now that keyboard has been reset
	KeyIndex_BufferUsed = 0;
}