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/****************************************************************************

 Title  :   HD44780U LCD library

 Author:    Peter Fleury <pfleury@gmx.ch>  http://jump.to/fleury

 File:      $Id: lcd.c,v 1.14.2.1 2006/01/29 12:16:41 peter Exp $

 Software:  AVR-GCC 3.3

 Target:    any AVR device, memory mapped mode only for AT90S4414/8515/Mega

 DESCRIPTION

       Basic routines for interfacing a HD44780U-based text lcd display

       Originally based on Volker Oth's lcd library,

       changed lcd_init(), added additional constants for lcd_command(),

       added 4-bit I/O mode, improved and optimized code.

       Library can be operated in memory mapped mode (LCD_IO_MODE=0) or in

       4-bit IO port mode (LCD_IO_MODE=1). 8-bit IO port mode not supported.

       Memory mapped mode compatible with Kanda STK200, but supports also

       generation of R/W signal through A8 address line.

 USAGE

       See the C include lcd.h file for a description of each function

*****************************************************************************/

#include <inttypes.h>

#include <avr/io.h>

#include <avr/pgmspace.h>

#include "lcd.h"

/*

** constants/macros

*/

#define DDR(x) (*(&x - 1))      /* address of data direction register of port x */

#if defined(__AVR_ATmega64__) || defined(__AVR_ATmega128__)

    /* on ATmega64/128 PINF is on port 0x00 and not 0x60 */

    #define PIN(x) ( &PORTF==&(x) ? _SFR_IO8(0x00) : (*(&x - 2)) )

#else

    #define PIN(x) (*(&x - 2))    /* address of input register of port x          */

#endif

#if LCD_IO_MODE

#define lcd_e_delay()   __asm__ __volatile__( "rjmp 1f\n 1:" );

#define lcd_e_high()    LCD_E_PORT  |=  _BV(LCD_E_PIN);

#define lcd_e_low()     LCD_E_PORT  &= ~_BV(LCD_E_PIN);

#define lcd_e_toggle()  toggle_e()

#define lcd_rw_high()   LCD_RW_PORT |=  _BV(LCD_RW_PIN)

#define lcd_rw_low()    LCD_RW_PORT &= ~_BV(LCD_RW_PIN)

#define lcd_rs_high()   LCD_RS_PORT |=  _BV(LCD_RS_PIN)

#define lcd_rs_low()    LCD_RS_PORT &= ~_BV(LCD_RS_PIN)

#endif

#if LCD_IO_MODE

#if LCD_LINES==1

#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_4BIT_1LINE 

#else

#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_4BIT_2LINES 

#endif

#else

#if LCD_LINES==1

#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_8BIT_1LINE

#else

#define LCD_FUNCTION_DEFAULT    LCD_FUNCTION_8BIT_2LINES

#endif

#endif

#if LCD_CONTROLLER_KS0073

#if LCD_LINES==4

#define KS0073_EXTENDED_FUNCTION_REGISTER_ON  0x24   /* |0|010|0100 4-bit mode extension-bit RE = 1 */

#define KS0073_EXTENDED_FUNCTION_REGISTER_OFF 0x20   /* |0|000|1001 4 lines mode */

#define KS0073_4LINES_MODE                    0x09   /* |0|001|0000 4-bit mode, extension-bit RE = 0 */

#endif

#endif

/*

** function prototypes

*/

#if LCD_IO_MODE

static void toggle_e(void);

#endif

/*

** local functions

*/

/*************************************************************************

 delay loop for small accurate delays: 16-bit counter, 4 cycles/loop

*************************************************************************/

static inline void _delayFourCycles(unsigned int __count)

{

    if ( __count == 0 )    

        __asm__ __volatile__( "rjmp 1f\n 1:" );    // 2 cycles

    else

        __asm__ __volatile__ (

            "1: sbiw %0,1" "\n\t"                  

            "brne 1b"                              // 4 cycles/loop

            : "=w" (__count)

            : "0" (__count)

           );

}

/*************************************************************************

delay for a minimum of <us> microseconds

the number of loops is calculated at compile-time from MCU clock frequency

*************************************************************************/

#define delay(us)  _delayFourCycles( ( ( 1*(XTAL/4000) )*us)/1000 )

#if LCD_IO_MODE

/* toggle Enable Pin to initiate write */

static void toggle_e(void)

{

    lcd_e_high();

    lcd_e_delay();

    lcd_e_low();

}

#endif

/*************************************************************************

Low-level function to write byte to LCD controller

Input:    data   byte to write to LCD

          rs     1: write data    

                 0: write instruction

Returns:  none

*************************************************************************/

#if LCD_IO_MODE

static void lcd_write(uint8_t data,uint8_t rs)

{

    unsigned char dataBits ;

    if (rs) {   /* write data        (RS=1, RW=0) */

       lcd_rs_high();

    } else {    /* write instruction (RS=0, RW=0) */

       lcd_rs_low();

    }

    lcd_rw_low();

    if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )

      && (LCD_DATA0_PIN == 0) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )

    {

        /* configure data pins as output */

        DDR(LCD_DATA0_PORT) |= 0x0F;

        /* output high nibble first */

        dataBits = LCD_DATA0_PORT & 0xF0;

        LCD_DATA0_PORT = dataBits |((data>>4)&0x0F);

        lcd_e_toggle();

        /* output low nibble */

        LCD_DATA0_PORT = dataBits | (data&0x0F);

        lcd_e_toggle();

        /* all data pins high (inactive) */

        LCD_DATA0_PORT = dataBits | 0x0F;

    }

    else

    {

        /* configure data pins as output */

        DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN);

        DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN);

        DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN);

        DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN);

        /* output high nibble first */

        LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN);

        LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN);

        LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN);

        LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);

        if(data & 0x80) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);

        if(data & 0x40) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);

        if(data & 0x20) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);

        if(data & 0x10) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);  

        lcd_e_toggle();

        /* output low nibble */

        LCD_DATA3_PORT &= ~_BV(LCD_DATA3_PIN);

        LCD_DATA2_PORT &= ~_BV(LCD_DATA2_PIN);

        LCD_DATA1_PORT &= ~_BV(LCD_DATA1_PIN);

        LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);

        if(data & 0x08) LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);

        if(data & 0x04) LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);

        if(data & 0x02) LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);

        if(data & 0x01) LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);

        lcd_e_toggle();        

        /* all data pins high (inactive) */

        LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);

        LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);

        LCD_DATA2_PORT |= _BV(LCD_DATA2_PIN);

        LCD_DATA3_PORT |= _BV(LCD_DATA3_PIN);

    }

}

#else

#define lcd_write(d,rs) if (rs) *(volatile uint8_t*)(LCD_IO_DATA) = d; else *(volatile uint8_t*)(LCD_IO_FUNCTION) = d;

/* rs==0 -> write instruction to LCD_IO_FUNCTION */

/* rs==1 -> write data to LCD_IO_DATA */

#endif

/*************************************************************************

Low-level function to read byte from LCD controller

Input:    rs     1: read data    

                 0: read busy flag / address counter

Returns:  byte read from LCD controller

*************************************************************************/

#if LCD_IO_MODE

static uint8_t lcd_read(uint8_t rs)

{

    uint8_t data;

    if (rs)

        lcd_rs_high();                       /* RS=1: read data      */

    else

        lcd_rs_low();                        /* RS=0: read busy flag */

    lcd_rw_high();                           /* RW=1  read mode      */

    if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )

      && ( LCD_DATA0_PIN == 0 )&& (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )

    {

        DDR(LCD_DATA0_PORT) &= 0xF0;         /* configure data pins as input */

        lcd_e_high();

        lcd_e_delay();        

        data = PIN(LCD_DATA0_PORT) << 4;     /* read high nibble first */

        lcd_e_low();

        lcd_e_delay();                       /* Enable 500ns low       */

        lcd_e_high();

        lcd_e_delay();

        data |= PIN(LCD_DATA0_PORT)&0x0F;    /* read low nibble        */

        lcd_e_low();

    }

    else

    {

        /* configure data pins as input */

        DDR(LCD_DATA0_PORT) &= ~_BV(LCD_DATA0_PIN);

        DDR(LCD_DATA1_PORT) &= ~_BV(LCD_DATA1_PIN);

        DDR(LCD_DATA2_PORT) &= ~_BV(LCD_DATA2_PIN);

        DDR(LCD_DATA3_PORT) &= ~_BV(LCD_DATA3_PIN);

        /* read high nibble first */

        lcd_e_high();

        lcd_e_delay();        

        data = 0;

        if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x10;

        if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x20;

        if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x40;

        if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x80;

        lcd_e_low();

        lcd_e_delay();                       /* Enable 500ns low       */

        /* read low nibble */    

        lcd_e_high();

        lcd_e_delay();

        if ( PIN(LCD_DATA0_PORT) & _BV(LCD_DATA0_PIN) ) data |= 0x01;

        if ( PIN(LCD_DATA1_PORT) & _BV(LCD_DATA1_PIN) ) data |= 0x02;

        if ( PIN(LCD_DATA2_PORT) & _BV(LCD_DATA2_PIN) ) data |= 0x04;

        if ( PIN(LCD_DATA3_PORT) & _BV(LCD_DATA3_PIN) ) data |= 0x08;        

        lcd_e_low();

    }

    return data;

}

#else

#define lcd_read(rs) (rs) ? *(volatile uint8_t*)(LCD_IO_DATA+LCD_IO_READ) : *(volatile uint8_t*)(LCD_IO_FUNCTION+LCD_IO_READ)

/* rs==0 -> read instruction from LCD_IO_FUNCTION */

/* rs==1 -> read data from LCD_IO_DATA */

#endif

/*************************************************************************

loops while lcd is busy, returns address counter

*************************************************************************/

static uint8_t lcd_waitbusy(void)

{

    register uint8_t c;

    /* wait until busy flag is cleared */

    while ( (c=lcd_read(0)) & (1<<LCD_BUSY)) {}

    /* the address counter is updated 4us after the busy flag is cleared */

    delay(2);

    /* now read the address counter */

    return (lcd_read(0));  // return address counter

}/* lcd_waitbusy */

/*************************************************************************

Move cursor to the start of next line or to the first line if the cursor

is already on the last line.

*************************************************************************/

static inline void lcd_newline(uint8_t pos)

{

    register uint8_t addressCounter;

#if LCD_LINES==1

    addressCounter = 0;

#endif

#if LCD_LINES==2

    if ( pos < (LCD_START_LINE2) )

        addressCounter = LCD_START_LINE2;

    else

        addressCounter = LCD_START_LINE1;

#endif

#if LCD_LINES==4

#if KS0073_4LINES_MODE

    if ( pos < LCD_START_LINE2 )

        addressCounter = LCD_START_LINE2;

    else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE3) )

        addressCounter = LCD_START_LINE3;

    else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE4) )

        addressCounter = LCD_START_LINE4;

    else

        addressCounter = LCD_START_LINE1;

#else

    if ( pos < LCD_START_LINE3 )

        addressCounter = LCD_START_LINE2;

    else if ( (pos >= LCD_START_LINE2) && (pos < LCD_START_LINE4) )

        addressCounter = LCD_START_LINE3;

    else if ( (pos >= LCD_START_LINE3) && (pos < LCD_START_LINE2) )

        addressCounter = LCD_START_LINE4;

    else

        addressCounter = LCD_START_LINE1;

#endif

#endif

    lcd_command((1<<LCD_DDRAM)+addressCounter);

}/* lcd_newline */

/*

** PUBLIC FUNCTIONS

*/

/*************************************************************************

Send LCD controller instruction command

Input:   instruction to send to LCD controller, see HD44780 data sheet

Returns: none

*************************************************************************/

void lcd_command(uint8_t cmd)

{

    lcd_waitbusy();

    lcd_write(cmd,0);

}

/*************************************************************************

Send data byte to LCD controller

Input:   data to send to LCD controller, see HD44780 data sheet

Returns: none

*************************************************************************/

void lcd_data(uint8_t data)

{

    lcd_waitbusy();

    lcd_write(data,1);

}

/*************************************************************************

Set cursor to specified position

Input:    x  horizontal position  (0: left most position)

          y  vertical position    (0: first line)

Returns:  none

*************************************************************************/

void lcd_gotoxy(uint8_t x, uint8_t y)

{

#if LCD_LINES==1

    lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);

#endif

#if LCD_LINES==2

    if ( y==0 )

        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);

    else

        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x);

#endif

#if LCD_LINES==4

    if ( y==0 )

        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE1+x);

    else if ( y==1)

        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE2+x);

    else if ( y==2)

        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE3+x);

    else /* y==3 */

        lcd_command((1<<LCD_DDRAM)+LCD_START_LINE4+x);

#endif

}/* lcd_gotoxy */

/*************************************************************************

*************************************************************************/

int lcd_getxy(void)

{

    return lcd_waitbusy();

}

/*************************************************************************

Clear display and set cursor to home position

*************************************************************************/

void lcd_clrscr(void)

{

    lcd_command(1<<LCD_CLR);

}

/*************************************************************************

Set cursor to home position

*************************************************************************/

void lcd_home(void)

{

    lcd_command(1<<LCD_HOME);

}

/*************************************************************************

Display character at current cursor position

Input:    character to be displayed                                      

Returns:  none

*************************************************************************/

void lcd_putc(char c)

{

    uint8_t pos;

    pos = lcd_waitbusy();   // read busy-flag and address counter

    if (c=='\n')

    {

        lcd_newline(pos);

    }

    else

    {

#if LCD_WRAP_LINES==1

#if LCD_LINES==1

        if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) {

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);

        }

#elif LCD_LINES==2

        if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) {

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0);    

        }else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH ){

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);

        }

#elif LCD_LINES==4

        if ( pos == LCD_START_LINE1+LCD_DISP_LENGTH ) {

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE2,0);    

        }else if ( pos == LCD_START_LINE2+LCD_DISP_LENGTH ) {

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE3,0);

        }else if ( pos == LCD_START_LINE3+LCD_DISP_LENGTH ) {

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE4,0);

        }else if ( pos == LCD_START_LINE4+LCD_DISP_LENGTH ) {

            lcd_write((1<<LCD_DDRAM)+LCD_START_LINE1,0);

        }

#endif

        lcd_waitbusy();

#endif

        lcd_write(c, 1);

    }

}/* lcd_putc */

/*************************************************************************

Display string without auto linefeed

Input:    string to be displayed

Returns:  none

*************************************************************************/

void lcd_puts(const char *s)

/* print string on lcd (no auto linefeed) */

{

    register char c;

    while ( (c = *s++) ) {

        lcd_putc(c);

    }

}/* lcd_puts */

/*************************************************************************

Display string from program memory without auto linefeed

Input:     string from program memory be be displayed                                        

Returns:   none

*************************************************************************/

void lcd_puts_p(const char *progmem_s)

/* print string from program memory on lcd (no auto linefeed) */

{

    register char c;

    while ( (c = pgm_read_byte(progmem_s++)) ) {

        lcd_putc(c);

    }

}/* lcd_puts_p */

/*************************************************************************

Initialize display and select type of cursor

Input:    dispAttr LCD_DISP_OFF            display off

                   LCD_DISP_ON             display on, cursor off

                   LCD_DISP_ON_CURSOR      display on, cursor on

                   LCD_DISP_CURSOR_BLINK   display on, cursor on flashing

Returns:  none

*************************************************************************/

void lcd_init(uint8_t dispAttr)

{

#if LCD_IO_MODE

    /*

     *  Initialize LCD to 4 bit I/O mode

     */

//    LED_ON

    if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )

      && ( &LCD_RS_PORT == &LCD_DATA0_PORT) && ( &LCD_RW_PORT == &LCD_DATA0_PORT) && (&LCD_E_PORT == &LCD_DATA0_PORT)

      && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3)

      && (LCD_RS_PIN == 4 ) && (LCD_RW_PIN == 5) && (LCD_E_PIN == 6 ) )

    {

        /* configure all port bits as output (all LCD lines on same port) */

        DDR(LCD_DATA0_PORT) |= 0x7F;

    }

    else if ( ( &LCD_DATA0_PORT == &LCD_DATA1_PORT) && ( &LCD_DATA1_PORT == &LCD_DATA2_PORT ) && ( &LCD_DATA2_PORT == &LCD_DATA3_PORT )

           && (LCD_DATA0_PIN == 0 ) && (LCD_DATA1_PIN == 1) && (LCD_DATA2_PIN == 2) && (LCD_DATA3_PIN == 3) )

    {

        /* configure all port bits as output (all LCD data lines on same port, but control lines on different ports) */

        DDR(LCD_DATA0_PORT) |= 0x0F;

        DDR(LCD_RS_PORT)    |= _BV(LCD_RS_PIN);

        DDR(LCD_RW_PORT)    |= _BV(LCD_RW_PIN);

        DDR(LCD_E_PORT)     |= _BV(LCD_E_PIN);

    }

    else

    {

        /* configure all port bits as output (LCD data and control lines on different ports */

        DDR(LCD_RS_PORT)    |= _BV(LCD_RS_PIN);

        DDR(LCD_RW_PORT)    |= _BV(LCD_RW_PIN);

        DDR(LCD_E_PORT)     |= _BV(LCD_E_PIN);

        DDR(LCD_DATA0_PORT) |= _BV(LCD_DATA0_PIN);

        DDR(LCD_DATA1_PORT) |= _BV(LCD_DATA1_PIN);

        DDR(LCD_DATA2_PORT) |= _BV(LCD_DATA2_PIN);

        DDR(LCD_DATA3_PORT) |= _BV(LCD_DATA3_PIN);

        LED_ON

    }

    delay(16000);        /* wait 16ms or more after power-on       */

    /* initial write to lcd is 8bit */

    LCD_DATA1_PORT |= _BV(LCD_DATA1_PIN);  // _BV(LCD_FUNCTION)>>4;

    LCD_DATA0_PORT |= _BV(LCD_DATA0_PIN);  // _BV(LCD_FUNCTION_8BIT)>>4;

    lcd_e_toggle();

    delay(4992);         /* delay, busy flag can't be checked here */

    /* repeat last command */

    lcd_e_toggle();      

    delay(64);           /* delay, busy flag can't be checked here */

    /* repeat last command a third time */

    lcd_e_toggle();      

    delay(64);           /* delay, busy flag can't be checked here */

    /* now configure for 4bit mode */

    LCD_DATA0_PORT &= ~_BV(LCD_DATA0_PIN);   // LCD_FUNCTION_4BIT_1LINE>>4

    lcd_e_toggle();

    delay(64);           /* some displays need this additional delay */

    /* from now the LCD only accepts 4 bit I/O, we can use lcd_command() */    

#else

    /*

     * Initialize LCD to 8 bit memory mapped mode

     */

    /* enable external SRAM (memory mapped lcd) and one wait state */        

    MCUCR = _BV(SRE) | _BV(SRW);

    /* reset LCD */

    delay(16000);                           /* wait 16ms after power-on     */

    lcd_write(LCD_FUNCTION_8BIT_1LINE,0);   /* function set: 8bit interface */                  

    delay(4992);                            /* wait 5ms                     */

    lcd_write(LCD_FUNCTION_8BIT_1LINE,0);   /* function set: 8bit interface */                

    delay(64);                              /* wait 64us                    */

    lcd_write(LCD_FUNCTION_8BIT_1LINE,0);   /* function set: 8bit interface */                

    delay(64);                              /* wait 64us                    */

#endif

#if KS0073_4LINES_MODE

    /* Display with KS0073 controller requires special commands for enabling 4 line mode */

    lcd_command(KS0073_EXTENDED_FUNCTION_REGISTER_ON);

    lcd_command(KS0073_4LINES_MODE);

    lcd_command(KS0073_EXTENDED_FUNCTION_REGISTER_OFF);

#else

    lcd_command(LCD_FUNCTION_DEFAULT);      /* function set: display lines  */

#endif

    lcd_command(LCD_DISP_OFF);              /* display off                  */

    lcd_clrscr();                           /* display clear                */

    lcd_command(LCD_MODE_DEFAULT);          /* set entry mode               */

    lcd_command(dispAttr);                  /* display/cursor control       */

}/* lcd_init */