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/*
 * Mini fbset implementation for busybox
 *
 * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * This is a from-scratch implementation of fbset; but the de facto fbset
 * implementation was a good reference. fbset (original) is released under
 * the GPL, and is (c) 1995-1999 by: 
 *     Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
 */

#include "internal.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <sys/ioctl.h>
#include <linux/fb.h>
#include <linux/version.h>

#define PERROR(ctx)   do { perror(ctx); exit(1); } while(0)

#ifndef KERNEL_VERSION
#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
#endif

#define DEFAULTFBDEV  "/dev/fb0"
#define DEFAULTFBMODE "/etc/fb.modes"

#define OPT_CHANGE    1
#define OPT_INFO      (1 << 1)
#define OPT_READMODE  (1 << 2)

#define CMD_HELP        0
#define CMD_FB		1	
#define CMD_DB		2
#define CMD_GEOMETRY	3
#define CMD_TIMING	4
#define CMD_ACCEL	5
#define CMD_HSYNC	6
#define CMD_VSYNC	7
#define CMD_LACED	8
#define CMD_DOUBLE	9
/* #define CMD_XCOMPAT     10 */
#define CMD_ALL         11
#define CMD_INFO        12

#ifdef BB_FBSET_FANCY
#define CMD_XRES	13
#define CMD_YRES	14
#define CMD_VXRES	15
#define CMD_VYRES	16
#define CMD_DEPTH	17
#define CMD_MATCH	18
#define CMD_PIXCLOCK	19
#define CMD_LEFT	20
#define CMD_RIGHT	21
#define CMD_UPPER	22
#define CMD_LOWER	23
#define CMD_HSLEN	24
#define CMD_VSLEN	25
#define CMD_CSYNC	26
#define CMD_GSYNC	27
#define CMD_EXTSYNC	28
#define CMD_BCAST	29
#define CMD_RGBA	30
#define CMD_STEP	31
#define CMD_MOVE	32
#endif

static unsigned int g_options = 0;

struct cmdoptions_t {
  char *name;
  unsigned char param_count;
  unsigned char code;
} g_cmdoptions[] = {
  { "-h",       0, CMD_HELP },
  { "-fb",	1, CMD_FB },
  { "-db",	1, CMD_DB },
  { "-a",	0, CMD_ALL },
  { "-i",	0, CMD_INFO },
  { "-g",       5, CMD_GEOMETRY },
  { "-t",       7, CMD_TIMING },
  { "-accel",	1, CMD_ACCEL },
  { "-hsync",	1, CMD_HSYNC },
  { "-vsync",	1, CMD_VSYNC },
  { "-laced",	1, CMD_LACED },
  { "-double",	1, CMD_DOUBLE },
  
#ifdef BB_FBSET_FANCY
  { "--help",	0, CMD_HELP },
  { "-all",	0, CMD_ALL },
  { "-xres",	1, CMD_XRES },
  { "-yres",	1, CMD_YRES },
  { "-vxres",   1, CMD_VXRES },
  { "-vyres",   1, CMD_VYRES },
  { "-depth",   1, CMD_DEPTH },
  { "-match",   0, CMD_MATCH },
  { "--geometry", 5, CMD_GEOMETRY },
  
  { "-pixclock", 1, CMD_PIXCLOCK },
  { "-left",	1, CMD_LEFT },
  { "-right",	1, CMD_RIGHT },
  { "-upper",	1, CMD_UPPER },
  { "-lower",	1, CMD_LOWER },
  { "-hslen",	1, CMD_HSLEN },
  { "-vslen",	1, CMD_VSLEN },
  { "--timings", 7, CMD_TIMING },
  
  { "-csync",	1, CMD_CSYNC },
  { "-gsync",	1, CMD_GSYNC },
  { "-extsync", 1, CMD_EXTSYNC },
  { "-bcast",	1, CMD_BCAST },
  { "-rgba",	1, CMD_RGBA },
  { "-step",	1, CMD_STEP },
  { "-move", 	1, CMD_MOVE },
#endif
  { 0, 0, 0 }
};

static int readmode(struct fb_var_screeninfo *base, const char *fn,
		     const char *mode)
{
#ifdef BB_FBSET_READMODE
    FILE *f;
    char buf[256];
    char *p = buf;
    
    if ((f = fopen(fn, "r")) == NULL) PERROR("readmode(fopen)");
    while (!feof(f)) {
	fgets(buf, sizeof(buf), f);
	if ((p = strstr(buf, "mode ")) || (p = strstr(buf, "mode\t"))) {
	    p += 5;
            if ((p = strstr(buf, mode))) {
	        p += strlen(mode);
		if (!isspace(*p) && (*p != 0) && (*p != '"') && (*p != '\r')
		    && (*p != '\n')) continue; /* almost, but not quite */
		while (!feof(f)) {
		    fgets(buf, sizeof(buf), f);
		    if (!strstr(buf, "endmode")) return 1;
		}
	    }
	}
    }
#else
    fprintf(stderr, "W: mode reading was disabled on this copy of fbset; ignoring request\n");
#endif
    return 0;
}

static void setmode(struct fb_var_screeninfo *base, 
		    struct fb_var_screeninfo *set)
{
  if ((int)set->xres > 0) base->xres = set->xres;
  if ((int)set->yres > 0) base->yres = set->yres;
  if ((int)set->xres_virtual > 0) base->xres_virtual = set->xres_virtual;
  if ((int)set->yres_virtual > 0) base->yres_virtual = set->yres_virtual;
  if ((int)set->bits_per_pixel > 0) base->bits_per_pixel = set->bits_per_pixel;
}

static void showmode(struct fb_var_screeninfo *v)
{
    double drate = 0, hrate = 0, vrate = 0;
    if (v->pixclock) {
        drate = 1e12 / v->pixclock;
	hrate = drate / (v->left_margin+v->xres+v->right_margin+v->hsync_len);
	vrate = hrate / (v->upper_margin+v->yres+v->lower_margin+v->vsync_len);
    }
    printf("\nmode \"%ux%u-%u\"\n", v->xres, v->yres, (int)(vrate+0.5));
#ifdef BB_FBSET_FANCY
    printf("\t# D: %.3f MHz, H: %.3f kHz, V: %.3f Hz\n", drate/1e6, hrate/1e3, 
	   vrate);
#endif
    printf("\tgeometry %u %u %u %u %u\n", v->xres, v->yres, 
           v->xres_virtual, v->yres_virtual, v->bits_per_pixel);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
    printf("\ttimings %u %u %u %u %u %u %u\n", v->pixclock, v->left_margin, 
           v->right_margin, v->upper_margin, v->lower_margin, v->hsync_len,
  	   v->vsync_len);
    printf("\taccel %s\n", (v->accel_flags > 0 ? "true" : "false"));
#else
    printf("\ttimings %lu %lu %lu %lu %lu %lu %lu\n", v->pixclock, v->left_margin, 
           v->right_margin, v->upper_margin, v->lower_margin, v->hsync_len,
  	   v->vsync_len);
#endif
    printf("\trgba %u/%u,%u/%u,%u/%u,%u/%u\n", v->red.length, v->red.offset,
           v->green.length, v->green.offset, v->blue.length, v->blue.offset,
	   v->transp.length, v->transp.offset);
    printf("endmode\n");
}

static void fbset_usage(void)
{
    int i;
#ifndef STANDALONE
    fprintf(stderr, "BusyBox v%s (%s) multi-call binary -- GPL2\n\n", BB_VER, BB_BT);
#endif
    fprintf(stderr, "Usage: fbset [options] [mode]\n");
    fprintf(stderr, "\tThe following options are recognized:\n");
    for (i = 0; g_cmdoptions[i].name; i++)
        fprintf(stderr, "\t\t%s\n", g_cmdoptions[i].name);
    exit(-1);
}

#ifdef STANDALONE
int main(int argc, char **argv)
#else 
extern int fbset_main(int argc, char **argv)
#endif
{
    struct fb_var_screeninfo var, varset;
    int fh, i;    
    char *fbdev = DEFAULTFBDEV;
    char *modefile = DEFAULTFBMODE;
    char *thisarg, *mode = NULL;

    memset(&varset, 0xFF, sizeof(varset));
    
    /* parse cmd args.... why do they have to make things so difficult? */
    argv++; argc--;
    for (; argc > 0 && (thisarg = *argv); argc--, argv++) {
        for (i = 0; g_cmdoptions[i].name; i++) {
	    if (!strcmp(thisarg, g_cmdoptions[i].name)) {
	        if (argc - 1 < g_cmdoptions[i].param_count) fbset_usage();
		switch (g_cmdoptions[i].code) {
		    case CMD_HELP: fbset_usage();
		    case CMD_FB: fbdev = argv[1]; break;
		    case CMD_DB: modefile = argv[1]; break;
		    case CMD_GEOMETRY:
		        varset.xres = strtoul(argv[1],0,0);
			varset.yres = strtoul(argv[2],0,0);
			varset.xres_virtual = strtoul(argv[3],0,0);
			varset.yres_virtual = strtoul(argv[4],0,0);
			varset.bits_per_pixel = strtoul(argv[5],0,0);
			break;
		    case CMD_TIMING:
			varset.pixclock = strtoul(argv[1],0,0);
			varset.left_margin = strtoul(argv[2],0,0);
			varset.right_margin = strtoul(argv[3],0,0);
			varset.upper_margin = strtoul(argv[4],0,0);
			varset.lower_margin = strtoul(argv[5],0,0);
                        varset.hsync_len = strtoul(argv[6],0,0);
			varset.vsync_len = strtoul(argv[7],0,0);
			break;
#ifdef BB_FBSET_FANCY
		    case CMD_XRES: varset.xres = strtoul(argv[1],0,0); break;
		    case CMD_YRES: varset.yres = strtoul(argv[1],0,0); break;
#endif
		}
		argc -= g_cmdoptions[i].param_count;
		argv += g_cmdoptions[i].param_count;
		break;
	    }
	}
	if (!g_cmdoptions[i].name) {
            if (argc == 1) {
                mode = *argv; 
		g_options |= OPT_READMODE;
            } else {
	        fbset_usage();
	    }
	}
    }

    if ((fh = open(fbdev, O_RDONLY)) < 0) PERROR("fbset(open)");
    if (ioctl(fh, FBIOGET_VSCREENINFO, &var)) PERROR("fbset(ioctl)");
    if (g_options & OPT_READMODE) {
        if (!readmode(&var, modefile, mode)) {
            fprintf(stderr, "Unknown video mode `%s'\n", mode);
	    exit(1);
	}
    }

    setmode(&var, &varset);
    if (g_options & OPT_CHANGE)
        if (ioctl(fh, FBIOPUT_VSCREENINFO, &var)) PERROR("fbset(ioctl)");
    showmode(&var);
    close(fh);
    
    return(TRUE);
}