qmk-firmware/keyboards/handwired/108key_trackpoint/config.h

#pragma once


#ifdef PS2_DRIVER_USART
#define PS2_CLOCK_PIN   D5
#define PS2_DATA_PIN    D2

  /* synchronous, odd parity, 1-bit stop, 8-bit data, sample at falling edge */
  /* set DDR of CLOCK as input to be slave */
  #define PS2_USART_INIT() do {   \
      PS2_CLOCK_DDR &= ~(1<<PS2_CLOCK_BIT);   \
      PS2_DATA_DDR &= ~(1<<PS2_DATA_BIT);     \
      UCSR1C = ((1 << UMSEL10) |  \
                (3 << UPM10)   |  \
                (0 << USBS1)   |  \
                (3 << UCSZ10)  |  \
                (0 << UCPOL1));   \
      UCSR1A = 0;                 \
      UBRR1H = 0;                 \
      UBRR1L = 0;                 \
  } while (0)
  #define PS2_USART_RX_INT_ON() do {  \
      UCSR1B = ((1 << RXCIE1) |       \
                (1 << RXEN1));        \
  } while (0)
  #define PS2_USART_RX_POLL_ON() do { \
      UCSR1B = (1 << RXEN1);          \
  } while (0)
  #define PS2_USART_OFF() do {    \
      UCSR1C = 0;                 \
      UCSR1B &= ~((1 << RXEN1) |  \
                  (1 << TXEN1));  \
  } while (0)
  #define PS2_USART_RX_READY      (UCSR1A & (1<<RXC1))
  #define PS2_USART_RX_DATA       UDR1
  #define PS2_USART_ERROR         (UCSR1A & ((1<<FE1) | (1<<DOR1) | (1<<UPE1)))
  #define PS2_USART_RX_VECT       USART1_RX_vect
#endif

#define LOCKING_SUPPORT_ENABLE
#define LOCKING_RESYNC_ENABLE