/* setup.c
 *
 * Copyright (c) 2012 Ben Dooks <ben@fluff.org>
 */

#define F_CPU 16000000

#include <avr/io.h>
#include <util/delay.h>

/* setup values from: http://www.farnell.com/datasheets/12825.pdf
 */

/* wiring:
 * PBx = D[x+10]
 * PC5 = read   [active low]
 * PC4 = write  [active low]
 * PC7 = regsel [0=command,1=data]
 * PD5 = reset [active low]
 * PC6 = CSB   [active low]
 * PD6 = 13V5 DCDC enable
 */


#define SEL_CMD 0
#define SEL_DATA 1

static void inline display_select(unsigned which)
{
  if (which == SEL_CMD)
    PORTC &= ~(1 << 7);
  else
    PORTC |= (1 << 7);
}

static void display_send(unsigned char byte)
{
  PORTB = byte;
  PORTC &= ~(1 << 6);
  PORTC &= ~(1 << 4);
  PORTC |= (1 << 4);
  PORTC |= (1 << 6);
}


static void display_command(unsigned char command)
{
  display_select(SEL_CMD);
  display_send(command);
  display_select(SEL_DATA);
}

static void display_command_data(unsigned char command, unsigned char data)
{
  display_select(SEL_CMD);
  display_send(command);
  display_select(SEL_DATA);
  display_send(data);
}

static void display_power_up(void)
{
  DDRB = 0xff;
  PORTB = 0x00;

  //  PORTB = 0x00;
  DDRC = 0xff;
  PORTC = (1 << 5) | (1 << 4); // ensure read/write strobes high
  PORTC |= (1 << 6);           // csb high

  DDRD = 0x7f;
  PORTD = 0x00;

  PORTD |= (1 << 6);  // power the DCDC
  _delay_ms(1);
  PORTD |= (1 << 5);  // release reset

  _delay_ms(1);
  display_command_data(0x4, 0x1);
  _delay_ms(1);
  display_command_data(0x4, 0x0);
  _delay_ms(1);
}

#define T0_05sec() _delay_ms(500)

void display_init(void)
{
  display_power_up();

  //Reg:04h Action:Normal current and PS ON ; Internal osc power off
  display_command_data(0x04,0x03);
  T0_05sec();
  //Reg:04h Action:Normal current and PS OFF
  display_command_data(0x4,0x00);
  T0_05sec();
  //Reg:3Bh Action:Screen Saver OFF
  display_command_data(0x3b,0x00);
  //Reg:02h Action:Export 0 /OSC with external resister/Internal OSC ON
  display_command_data(0x02,/*0x41*/ 0x01);
  //Reg:03h Action:FR=90Hz DIV=1
  display_command_data(0x03,/*0x30*/ 0x90);
  //Reg:80h Action:PDAC OFF,DDAC OFF/Reference Volt.control with external resister
  display_command_data(0x80,0x00);
  //Reg:08h Action:set color R precharge time
  display_command_data(0x08,0x03);
  //Reg:09h Action:set color G precharge time
  display_command_data(0x09,0x05);
  //Reg:0Ah Action:set color B precharge tiem
  display_command_data(0x0a,0x05);
  //Reg:0Bh Action:set color R precharge current
  display_command_data(0x0b,0x0a);
  //Reg:0Ch Action:set color G precharge current
  display_command_data(0x0c,0x0a);
  //Reg:0Dh Action:set color B precharge current
  display_command_data(0x0d,0x0a);
  //Reg:10h Action:set color R dot driving current
  display_command_data(0x10,0x56);
  //Reg:11h Action:set color G dot driving current
  display_command_data(0x11,0x4d);
  //Reg:12h Action:set color B dot driving current
  display_command_data(0x12,0x46);
  //Reg:13h Action:Col D0 to D159/col normal display
  display_command_data(0x13,0x00);
  //Reg:14h Action:MPU mode
  display_command_data(0x14,0x31);
  //Reg:16h Action:8btis dual transfer,65K support
  display_command_data(0x16,0x66);
  //Reg:17h Action:Memory addr.X start
  display_command_data(0x17,0x00);
  //Reg:18h Action:Memory addr.X end
  display_command_data(0x18,0x9f);
  //Reg:18h Action:Memory addr.Y start
  display_command_data(0x19,0x00);
  //Reg:1Ah Action:Memory addr.Y end
  display_command_data(0x1a,0x7f);
  //Reg:20h Action:Memory X start addr.
  display_command_data(0x20,0x00);
  //Reg:21h Action:Memory Y start addr.
  display_command_data(0x21,0x00);
  //Reg:28h Action:Display duty ratio
  display_command_data(0x28,0x7f);
  //Reg:29h Action:Display start line
  display_command_data(0x29,0x00);
  //Reg:2Eh Action:Display First screen X start point
  display_command_data(0x2e,0x00);
  //Reg:2Fh Action:Display First screen Y start point
  display_command_data(0x2f,0x00);
  //Reg:31h Action:Display Second screen X start point
  display_command_data(0x31,0x00);
  //Reg:32h Action:Display Second screen Y start point
  display_command_data(0x32,0x00);
  //Reg:33h Action:Display size X start
  display_command_data(0x33,0x00);
  //Reg:34h Action:Display size X end
  display_command_data(0x34,0x9f);
  //Reg:35h Action:Display size Y start
  display_command_data(0x35,0x00);
  //Reg:36h Action:Display size Y end
  display_command_data(0x36,0x7f);
  //Reg:06h Action:Scan signal is high level at precharge period/Dispaly ON
  display_command_data(0x06,0x01);

  _delay_ms(10);

  /* write is dual transfer, 8bit */
  // already done. display_command_data(0x16, (1<<5) | (1<<6) | (3<<1) | 0);

  {
    int x, y;

    display_command(0x22);  // access memory
    display_select(SEL_DATA);

    for (y = 0; y < 64; y++) {
      for (x = 0; x < 160; x++) {
	display_send(0xf8);
	display_send(0x00);
      }
    }

    for (; y < 128; y++) {
      for (x = 0; x < 160; x++) {
	display_send(0x00);
	display_send(0x1f);
      }
    }
  }
}