I8080 System GPIO interface driver

i80_gpio_stm32.c

/*
    ChibiOS/GFX - Copyright (C) 2012
                 Joel Bodenmann aka Tectu <joel@unormal.org>

    This file is part of ChibiOS/GFX.

    ChibiOS/GFX is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS/GFX is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "halconf.h"

#if defined(GDISP_USE_GPIO)
  #define Set_CS      palSetPad(GDISP_CMD_PORT, GDISP_CS_PAD);
  #define Clr_CS      palClearPad(GDISP_CMD_PORT, GDISP_CS_PAD);

  #define Set_RS      palSetPad(GDISP_CMD_PORT, GDISP_RS_PAD);
  #define Clr_RS      palClearPad(GDISP_CMD_PORT, GDISP_RS_PAD);

  #define Set_WR      palSetPad(GDISP_CMD_PORT, GDISP_WR_PAD);
  #define Clr_WR      palClearPad(GDISP_CMD_PORT, GDISP_WR_PAD);

  #define Set_RD      palSetPad(GDISP_CMD_PORT, GDISP_RD_PAD);
  #define Clr_RD      palClearPad(GDISP_CMD_PORT, GDISP_RD_PAD);

  extern void i80_write_gpio(uint16_t data);
  extern uint16_t i80_read_gpio(void);
  extern void i80_gpio_set_direction(bool_t dir);

  /* Place all the GPIO pins in a known state.
   * Note that this does not affect any GPIO configuration,
   * which needs to be set beforehand, preferably in board.h
   */
__inline void i80_interface_init(void) {
      Set_CS;
      Set_RS;
      Set_WR;
      Set_RD;
  }

__inline void i80_interface_delay(void) {
      #if defined(STM32F1XX)
          /* No delay required */
      #elif defined(STM32F4XX)
          /* 2xHCLK delay required to work */
          asm volatile ("nop");
          asm volatile ("nop");
      #endif
  }

__inline void i80_lcd_write_index(uint16_t index)  {
      Clr_RS;
      i80_write_gpio(index);

      Clr_WR;
      i80_interface_delay();
      Set_WR;

      Set_RS;
  }

  __inline void i80_lcd_write_data(uint16_t data)    {
      i80_write_gpio_lld(data);

      Clr_WR;
      i80_interface_delay();
      Set_WR;
  }

  __inline uint16_t i80_lcd_read(void) {
      uint16_t value;

      Clr_RD;
      i80_interface_delay();
      value = i80_read_gpio();
      Set_RD;

      return value;
  }

  __inline void i80_lcd_write_reg(uint16_t lcdReg,uint16_t lcdRegValue) {
      Clr_CS;

      i80_lcd_write_index(lcdReg);
      i80_lcd_write_data(lcdRegValue);

      Set_CS;
  }


   __inline uint16_t i80_lcd_read_reg(uint16_t lcdReg) {
      uint16_t value;

      Clr_CS;
      i80_lcd_write_index(lcdReg);

      i80_gpio_set_direction(1);
      value = i80_lcd_read();
      i80_gpio_set_direction(0);

      Set_CS;
      return value;
  }

   __inline void i80_lcd_burst_write_start(uint16_t writeIndex) {
      Clr_CS;

      i80_lcd_write_index(writeIndex);
  }

   __inline void i80_lcd_burst_write_stop(void) {
      Set_CS;
  }

   __inline void i80_lcd_burst_write(uint16_t *buffer, uint16_t size) {
      while (size-- != 0) {
        i80_write_gpio(data);

        Clr_WR;
        i80_interface_delay();
        Set_WR;
      }
  }

   __inline void i80_lcd_burst_read_start(uint16_t readIndex) {
        Clr_CS;

        i80_lcd_write_index(readIndex);
        i80_gpio_set_direction(1);         /* Configure data pads for input */
    }

   __inline void i80_lcd_burst_read_stop(void) {
        Set_CS;

        i80_gpio_set_direction(0);         /* Configure data pads for output */
    }

   __inline void i80_lcd_burst_read(uint16_t *buffer, size_t size) {
      volatile uint16_t dummy;

      dummy = i80_lcd_read();              /* Dummy read */
      while (size-- != 0)
        *buffer++ = i80_lcd_read();

      (void)dummy;                         /* Keep the compiler happy */
  }
#endif