hw_lcd.h

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#ifndef HW_LCD_H
#define HW_LCD_H

#include <appconfig.h>
//#include <hw.h>

#include <cpu/attr.h>
#include <cpu/irq.h>
#include <cpu/types.h>

#include <cfg/macros.h> /* BV() */
#include <cfg/debug.h>

#include <avr/io.h>
#include <stdbool.h>
#include <inttypes.h>

#define LCD_RS    BV(PG3)
#define LCD_RW    BV(PG0)
#define LCD_E     BV(PG2)
#define LCD_DB0   BV(PA0)
#define LCD_DB1   BV(PA1)
#define LCD_DB2   BV(PA2)
#define LCD_DB3   BV(PA3)
#define LCD_DB4   BV(PA4)
#define LCD_DB5   BV(PA5)
#define LCD_DB6   BV(PA6)
#define LCD_DB7   BV(PA7)

#define LCD_PORT     PORTG
#define LCD_DB_PORT  PORTA
#define LCD_PIN      PING
#define LCD_DB_PIN   PINA
#define LCD_DDR      DDRG
#define LCD_DB_DDR   DDRA

#if CONFIG_LCD_4BIT
    #define LCD_MASK    (LCD_DB7 | LCD_DB6 | LCD_DB5 | LCD_DB4)
    #define LCD_SHIFT   4
#else
    #define LCD_MASK (uint8_t)0xff
    #define LCD_SHIFT 0
#endif

#define LCD_CLR_RS      (LCD_PORT &= ~LCD_RS)
#define LCD_SET_RS      (LCD_PORT |=  LCD_RS)
#define LCD_CLR_RD      (LCD_PORT &= ~LCD_RW)
#define LCD_SET_RD      (LCD_PORT |=  LCD_RW)
#define LCD_CLR_E       (LCD_PORT &= ~LCD_E)
#define LCD_SET_E       (LCD_PORT |=  LCD_E)

#if CONFIG_LCD_4BIT
    #define LCD_WRITE_H(x)  (LCD_DB_PORT = (LCD_DB_PORT & ~LCD_MASK) | (((x) >> (4 - LCD_SHIFT)) & LCD_MASK))
    #define LCD_WRITE_L(x)  (LCD_DB_PORT = (LCD_DB_PORT & ~LCD_MASK) | (((x) << LCD_SHIFT) & LCD_MASK))
    #define LCD_READ_H      ((LCD_DB_PIN & LCD_MASK) >> (4 - LCD_SHIFT))
    #define LCD_READ_L      ((LCD_DB_PIN & LCD_MASK) >> LCD_SHIFT)
#else
    #define LCD_WRITE(x) (LCD_DB_PORT = (x))
    #define LCD_READ (LCD_DB_PIN)
#endif

#define LCD_DB_OUT  (LCD_DB_DDR |= LCD_MASK)

#define LCD_DB_IN   (LCD_DB_DDR &= ~LCD_MASK)

#define LCD_DELAY_WRITE \
    do { \
        NOP; \
        NOP; \
        NOP; \
        NOP; \
        NOP; \
    } while (0)

#define LCD_DELAY_READ \
    do { \
        NOP; \
        NOP; \
        NOP; \
        NOP; \
    } while (0)


INLINE void lcd_bus_init(void)
{
    cpuflags_t flags;
    IRQ_SAVE_DISABLE(flags);

    LCD_PORT = (LCD_PORT & ~(LCD_E | LCD_RW)) | LCD_RS;
    LCD_DDR  |= LCD_RS | LCD_RW | LCD_E;

    /*
     * Data bus is in output state most of the time:
     * LCD r/w functions assume it is left in output state
     */
    LCD_DB_OUT;


    IRQ_RESTORE(flags);
}

#endif /* HW_LCD_H */