/* podscreen.c: Library providing unified access to Apple iPod displays
   Copyright (C) 2005 Matthew Westcott

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 as
   published by the Free Software Foundation.

   This program 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, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

   Author contact information:

   E-mail: matthew@west.co.tt
   Postal address: 14 Daisy Hill Drive, Adlington, Chorley, Lancs,
       PR6 9NE, United Kingdom

*/

#include "podscreen.h"

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define outl(a,b) (*(volatile unsigned int *)(b) = (a))
#define inl(a) (*(volatile unsigned int *)(a))
#define lcd_wait_write(scr) {while( (inl((scr)->ipod_lcd_base) & 0x8000) ) ;}

#define IPOD_STD_LCD_BUSY_MASK	0x8000
#define IPOD_COLOR_LCD_BUSY_MASK	0x8000

#define IPOD_STD_LCD_WIDTH	160
#define IPOD_STD_LCD_HEIGHT	128
#define IPOD_MINI_LCD_WIDTH	138
#define IPOD_MINI_LCD_HEIGHT	110
#define IPOD_COLOR_LCD_WIDTH	220
#define IPOD_COLOR_LCD_HEIGHT	176

#define IPOD_PP5002_RTC		0xcf001110
#define IPOD_PP5002_LCD_BASE	0xc0001000
#define IPOD_PP5020_RTC		0x60005010
#define IPOD_PP5020_LCD_BASE	0x70003000
#define IPOD_COLOR_LCD_BASE	0x70008a0c

#define LCD_CMD 0x8
#define LCD_DATA 0x10

/* static method prototypes */
static long ipod_get_hw_version(void);
static void lcd_send_data(short data);
static void lcd_prepare_cmd(byte cmd);
static void lcd_cmd_and_data(byte cmd, short data);
static psPixel *mono_find_color(unsigned char r, unsigned char g, unsigned char b);

static long ipod_get_hw_version(void)
{
	int i;
	char cpuinfo[512];
	char * ptr;
	FILE * file;
	if ((file = fopen("/proc/cpuinfo", "r")) != NULL) {
		while (fgets(cpuinfo, sizeof(cpuinfo), file) != NULL)
			if (strncmp(cpuinfo, "Revision", 8) == 0)
				break;
		fclose(file);
	} else {
		return 0;
	}
	for (i = 0; !isspace(cpuinfo[i]); i++);
	for (; isspace(cpuinfo[i]); i++);
	ptr = cpuinfo + i + 2;
	return strtol(ptr, NULL, 16);
}

/* send LCD data */
static void lcd_send_data(psScreen *scr, short data) {
	lcd_wait_write(scr);
	outl(data>>8, scr->ipod_lcd_base + LCD_DATA);
	lcd_wait_write(scr);
	outl(data, scr->ipod_lcd_base + LCD_DATA);
}

/* send LCD command */
static void lcd_prepare_cmd(psScreen *scr, byte cmd) {
	lcd_wait_write(scr);
	outl(0x0, scr->ipod_lcd_base + LCD_CMD);
	lcd_wait_write(scr);
	outl(cmd, scr->ipod_lcd_base + LCD_CMD);
}

/* send LCD command and data */
static void lcd_cmd_and_data(psScreen *scr, byte cmd, short data) {
	lcd_prepare_cmd(scr, cmd);
	lcd_send_data(scr, data);
}

psPixel mono_palette[10] = {
	3, /* PS_COLOR_BLACK */
	2, /* PS_COLOR_DARKGREY */
	1, /* PS_COLOR_LIGHTGREY */
	0, /* PS_COLOR_WHITE */
	2, /* PS_COLOR_RED */
	2, /* PS_COLOR_GREEN */
	2, /* PS_COLOR_BLUE */
	1, /* PS_COLOR_YELLOW */
	1, /* PS_COLOR_MAGENTA */
	1, /* PS_COLOR_CYAN */
}

static psPixel *mono_find_color(unsigned char r, unsigned char g, unsigned char b) {
	int v = r + g + b;
	if (v < 192) {
		return 0;
	} else if (v < 384) {
		return 1;
	} else if (v < 576) {
		return 2;
	} else {
		return 3;
	}
}

psScreen
*psGetScreen(psIpodFamily desired) {
	psScreen *scr;
	int hw_version;
	
	scr = malloc(sizeof(psScreen));
	hw_version = ipod_get_hw_version();
	
	switch (hw_version) {
		case 6:	
			scr->lcd_base = IPOD_COLOR_LCD_BASE;
			scr->lcd_busy_mask = IPOD_COLOR_LCD_BUSY_MASK;
			scr->lcd_width = IPOD_COLOR_LCD_WIDTH;
			scr->lcd_height = IPOD_COLOR_LCD_HEIGHT;
			scr->ipod_rtc = IPOD_PP5020_RTC;
			scr->is_color = 1;
			break;
		case 5:
			scr->lcd_base = IPOD_PP5020_LCD_BASE;
			scr->lcd_busy_mask = IPOD_STD_LCD_BUSY_MASK;
			scr->lcd_width = IPOD_STD_LCD_WIDTH;
			scr->lcd_height = IPOD_STD_LCD_HEIGHT;
			scr->ipod_rtc = IPOD_PP5020_RTC;
			scr->is_color = 0;
			break;	
		case 7:	
		case 4:
			scr->lcd_width = IPOD_MINI_LCD_WIDTH;
			scr->lcd_height = IPOD_MINI_LCD_HEIGHT;
			scr->lcd_base = IPOD_PP5020_LCD_BASE;
			scr->lcd_busy_mask = IPOD_STD_LCD_BUSY_MASK;
			scr->ipod_rtc = IPOD_PP5020_RTC;
			scr->is_color = 0;
			break;
		case 3:
		case 2:
		case 1:
			scr->width = IPOD_STD_LCD_WIDTH;
			scr->height = IPOD_STD_LCD_HEIGHT;
			scr->lcd_base = IPOD_PP5002_LCD_BASE;
			scr->ipod_rtc = IPOD_PP5002_RTC;
			scr->lcd_busy_mask = IPOD_STD_LCD_BUSY_MASK;
			scr->is_color = 0;
			break;
	}
	
	if (scr->is_color) {
	} else {
		scr->find_color = &mono_find_color;
		scr->palette = mono_palette;
	}
}

void
*psReleaseScreen(psScreen *scr) {
	free(scr);
}