atafb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

	var->transp.offset=0;
	var->transp.length=0;
	var->transp.msb_right=0;
	var->xres_virtual=sttt_xres_virtual;
	linelen=var->xres_virtual * var->bits_per_pixel / 8;
	ovsc_addlen=linelen*(sttt_yres_virtual - st_yres);
	
	if (! use_hwscroll)
		var->yres_virtual=var->yres;
	else if (screen_len) {
		if (par->yres_virtual)
			var->yres_virtual = par->yres_virtual;
		else
			/* yres_virtual==0 means use maximum */
			var->yres_virtual = screen_len / linelen;
	}
	else {
		if (hwscroll < 0)
			var->yres_virtual = 2 * var->yres;
		else
			var->yres_virtual=var->yres+hwscroll * 16;
	}
	var->xoffset=0;
	if (screen_base)
		var->yoffset=(par->screen_base - screen_base)/linelen;
	else
		var->yoffset=0;
	var->nonstd=0;
	var->activate=0;
	var->vmode=FB_VMODE_NONINTERLACED;
	return 0;
}


static void stste_get_par( struct atafb_par *par )
{
	unsigned long addr;
	par->hw.st.mode=shifter_tt.st_shiftmode;
	par->hw.st.sync=shifter.syncmode;
	addr = ((shifter.bas_hi & 0xff) << 16) |
	       ((shifter.bas_md & 0xff) << 8);
	if (ATARIHW_PRESENT(EXTD_SHIFTER))
		addr |= (shifter.bas_lo & 0xff);
	par->screen_base = phys_to_virt(addr);
}

static void stste_set_par( struct atafb_par *par )
{
	shifter_tt.st_shiftmode=par->hw.st.mode;
	shifter.syncmode=par->hw.st.sync;
	/* only set screen_base if really necessary */
	if (current_par.screen_base != par->screen_base)
		fbhw->set_screen_base(par->screen_base);
}


static int stste_getcolreg(unsigned regno, unsigned *red,
			   unsigned *green, unsigned *blue,
			   unsigned *transp, struct fb_info *info)
{
	unsigned col, t;
	
	if (regno > 15)
		return 1;
	col = shifter_tt.color_reg[regno];
	if (ATARIHW_PRESENT(EXTD_SHIFTER)) {
		t = ((col >> 7) & 0xe) | ((col >> 11) & 1);
		t |= t << 4;
		*red = t | (t << 8);
		t = ((col >> 3) & 0xe) | ((col >> 7) & 1);
		t |= t << 4;
		*green = t | (t << 8);
		t = ((col << 1) & 0xe) | ((col >> 3) & 1);
		t |= t << 4;
		*blue = t | (t << 8);
	}
	else {
		t = (col >> 7) & 0xe;
		t |= t << 4;
		*red = t | (t << 8);
		t = (col >> 3) & 0xe;
		t |= t << 4;
		*green = t | (t << 8);
		t = (col << 1) & 0xe;
		t |= t << 4;
		*blue = t | (t << 8);
	}
	*transp = 0;
	return 0;
}


static int stste_setcolreg(unsigned regno, unsigned red,
			   unsigned green, unsigned blue,
			   unsigned transp, struct fb_info *info)
{
	if (regno > 15)
		return 1;
	red >>= 12;
	blue >>= 12;
	green >>= 12;
	if (ATARIHW_PRESENT(EXTD_SHIFTER))
		shifter_tt.color_reg[regno] =
			(((red & 0xe) >> 1) | ((red & 1) << 3) << 8) |
			(((green & 0xe) >> 1) | ((green & 1) << 3) << 4) |
			((blue & 0xe) >> 1) | ((blue & 1) << 3);
	else
		shifter_tt.color_reg[regno] =
			((red & 0xe) << 7) |
			((green & 0xe) << 3) |
			((blue & 0xe) >> 1);
	return 0;
}

						  
static int stste_detect( void )

{	struct atafb_par par;

	/* Determine the connected monitor: The DMA sound must be
	 * disabled before reading the MFP GPIP, because the Sound
	 * Done Signal and the Monochrome Detect are XORed together!
	 */
	if (ATARIHW_PRESENT(PCM_8BIT)) {
		tt_dmasnd.ctrl = DMASND_CTRL_OFF;
		udelay(20);	/* wait a while for things to settle down */
	}
	mono_moni = (mfp.par_dt_reg & 0x80) == 0;

	stste_get_par(&par);
	stste_encode_var(&atafb_predefined[0], &par);

	if (!ATARIHW_PRESENT(EXTD_SHIFTER))
		use_hwscroll = 0;
	return 1;
}

static void stste_set_screen_base(void *s_base)
{
	unsigned long addr;
	addr= virt_to_phys(s_base);
	/* Setup Screen Memory */
	shifter.bas_hi=(unsigned char) ((addr & 0xff0000) >> 16);
  	shifter.bas_md=(unsigned char) ((addr & 0x00ff00) >> 8);
	if (ATARIHW_PRESENT(EXTD_SHIFTER))
		shifter.bas_lo=(unsigned char)  (addr & 0x0000ff);
}

#endif /* ATAFB_STE */

/* Switching the screen size should be done during vsync, otherwise
 * the margins may get messed up. This is a well known problem of
 * the ST's video system.
 *
 * Unfortunately there is hardly any way to find the vsync, as the
 * vertical blank interrupt is no longer in time on machines with
 * overscan type modifications.
 *
 * We can, however, use Timer B to safely detect the black shoulder,
 * but then we've got to guess an appropriate delay to find the vsync.
 * This might not work on every machine.
 *
 * martin_rogge @ ki.maus.de, 8th Aug 1995
 */

#define LINE_DELAY  (mono_moni ? 30 : 70)
#define SYNC_DELAY  (mono_moni ? 1500 : 2000)

/* SWITCH_ACIA may be used for Falcon (ScreenBlaster III internal!) */
static void st_ovsc_switch(void)
{
    unsigned long flags;
    register unsigned char old, new;

    if (!(atari_switches & ATARI_SWITCH_OVSC_MASK))
	return;
    save_flags(flags);
    cli();

    mfp.tim_ct_b = 0x10;
    mfp.active_edge |= 8;
    mfp.tim_ct_b = 0;
    mfp.tim_dt_b = 0xf0;
    mfp.tim_ct_b = 8;
    while (mfp.tim_dt_b > 1)	/* TOS does it this way, don't ask why */
	;
    new = mfp.tim_dt_b;
    do {
	udelay(LINE_DELAY);
	old = new;
	new = mfp.tim_dt_b;
    } while (old != new);
    mfp.tim_ct_b = 0x10;
    udelay(SYNC_DELAY);

    if (atari_switches & ATARI_SWITCH_OVSC_IKBD)
	acia.key_ctrl = ACIA_DIV64 | ACIA_D8N1S | ACIA_RHTID | ACIA_RIE;
    if (atari_switches & ATARI_SWITCH_OVSC_MIDI)
	acia.mid_ctrl = ACIA_DIV16 | ACIA_D8N1S | ACIA_RHTID;
    if (atari_switches & (ATARI_SWITCH_OVSC_SND6|ATARI_SWITCH_OVSC_SND7)) {
	sound_ym.rd_data_reg_sel = 14;
	sound_ym.wd_data = sound_ym.rd_data_reg_sel |
			   ((atari_switches&ATARI_SWITCH_OVSC_SND6) ? 0x40:0) |
			   ((atari_switches&ATARI_SWITCH_OVSC_SND7) ? 0x80:0);
    }
    restore_flags(flags);
}

/* ------------------- External Video ---------------------- */

#ifdef ATAFB_EXT

static int ext_encode_fix( struct fb_fix_screeninfo *fix,
						   struct atafb_par *par )

{
	strcpy(fix->id,"Unknown Extern");
	fix->smem_start = (unsigned long)external_addr;
	fix->smem_len = PAGE_ALIGN(external_len);
	if (external_depth == 1) {
		fix->type = FB_TYPE_PACKED_PIXELS;
		/* The letters 'n' and 'i' in the "atavideo=external:" stand
		 * for "normal" and "inverted", rsp., in the monochrome case */
		fix->visual =
			(external_pmode == FB_TYPE_INTERLEAVED_PLANES ||
			 external_pmode == FB_TYPE_PACKED_PIXELS) ?
				FB_VISUAL_MONO10 :
					FB_VISUAL_MONO01;
	}
	else {
		/* Use STATIC if we don't know how to access color registers */
		int visual = external_vgaiobase ?
					 FB_VISUAL_PSEUDOCOLOR :
					 FB_VISUAL_STATIC_PSEUDOCOLOR;
		switch (external_pmode) {
		    case -1:              /* truecolor */
			fix->type=FB_TYPE_PACKED_PIXELS;
			fix->visual=FB_VISUAL_TRUECOLOR;
			break;
		    case FB_TYPE_PACKED_PIXELS:
			fix->type=FB_TYPE_PACKED_PIXELS;
			fix->visual=visual;
			break;
		    case FB_TYPE_PLANES:
			fix->type=FB_TYPE_PLANES;
			fix->visual=visual;
			break;
		    case FB_TYPE_INTERLEAVED_PLANES:
			fix->type=FB_TYPE_INTERLEAVED_PLANES;
			fix->type_aux=2;
			fix->visual=visual;
			break;
		}
	}
	fix->xpanstep = 0;
	fix->ypanstep = 0;
	fix->ywrapstep = 0;
	fix->line_length = 0;
	return 0;
}


static int ext_decode_var( struct fb_var_screeninfo *var,
						   struct atafb_par *par )
{
	struct fb_var_screeninfo *myvar = &atafb_predefined[0];
	
	if (var->bits_per_pixel > myvar->bits_per_pixel ||
		var->xres > myvar->xres ||
		var->xres_virtual > myvar->xres_virtual ||
		var->yres > myvar->yres ||
		var->xoffset > 0 ||
		var->yoffset > 0)
		return -EINVAL;
	return 0;
}


static int ext_encode_var( struct fb_var_screeninfo *var,
						   struct atafb_par *par )
{
	memset(var, 0, sizeof(struct fb_var_screeninfo));
	var->red.offset=0;
	var->red.length=(external_pmode == -1) ? external_depth/3 : 
			(external_vgaiobase ? external_bitspercol : 0);
	var->red.msb_right=0;
	var->grayscale=0;

	var->pixclock=31041;
	var->left_margin=120;		/* these are surely incorrect 	*/
	var->right_margin=100;
	var->upper_margin=8;
	var->lower_margin=16;
	var->hsync_len=140;
	var->vsync_len=30;

	var->height=-1;
	var->width=-1;

	var->sync=0;

	var->xres = external_xres;
	var->yres = external_yres;
	var->xres_virtual = external_xres_virtual;
	var->bits_per_pixel = external_depth;
	
	var->blue=var->green=var->red;
	var->transp.offset=0;
	var->transp.length=0;
	var->transp.msb_right=0;
	var->yres_virtual=var->yres;
	var->xoffset=0;
	var->yoffset=0;
	var->nonstd=0;
	var->activate=0;
	var->vmode=FB_VMODE_NONINTERLACED;
	return 0;
}


static void ext_get_par( struct atafb_par *par )
{
	par->screen_base = external_addr;
}

static void ext_set_par( struct atafb_par *par )
{
}

#define OUTB(port,val) \
	*((unsigned volatile char *) ((port)+external_vgaiobase))=(val)
#define INB(port) \
	(*((unsigned volatile char *) ((port)+external_vgaiobase)))
#define DACDelay 				\
	do {					\
		unsigned char tmp=INB(0x3da);	\
		tmp=INB(0x3da);			\
	} while (0)

static int ext_getcolreg( unsigned regno, unsigned *red,
						  unsigned *green, unsigned *blue,
						  unsigned *transp, struct fb_info *info )
{
	if (! external_vgaiobase)
		return 1;

	    *red   = ext_color[regno].red;
	    *green = ext_color[regno].green;
	    *blue  = ext_color[regno].blue;
	    *transp=0;
	    return 0;
}
	
static int ext_setcolreg( unsigned regno, unsigned red,
						  unsigned green, unsigned blue,
						  unsigned transp, struct fb_info *info )

{	unsigned char colmask = (1 << external_bitspercol) - 1;

	if (! external_vgaiobase)
		return 1;

	ext_color[regno].red = red;
	ext_color[regno].green = green;
	ext_color[regno].blue = blue;

	switch (external_card_type) {
	  case IS_VGA:
	    OUTB(0x3c8, regno);
	    DACDelay;
	    OUTB(0x3c9, red & colmask);
	    DACDelay;
	    OUTB(0x3c9, green & colmask);
	    DACDelay;
	    OUTB(0x3c9, blue & colmask);
	    DACDelay;
	    return 0;

	  case IS_MV300:
	    OUTB((MV300_reg[regno] << 2)+1, red);
	    OUTB((MV300_reg[regno] << 2)+1, green);
	    OUTB((MV300_reg[regno] << 2)+1, blue);
	    return 0;

	  default:
	    return 1;
	  }
}
	

static int ext_detect( void )

{
	struct fb_var_screeninfo *myvar = &atafb_predefined[0];
	struct atafb_par dummy_par;

	myvar->xres = external_xres;
	myvar->xres_virtual = external_xres_virtual;
	myvar->yres = external_yres;
	myvar->bits_per_pixel = external_depth;
	ext_encode_var(myvar, &dummy_par);
	return 1;
}

#endif /* ATAFB_EXT */

/* ------ This is the same for most hardware types -------- */

static void set_screen_base(void *s_base)
{
	unsigned long addr;
	addr= virt_to_phys(s_base);
	/* Setup Screen Memory */
	shifter.bas_hi=(unsigned char) ((addr & 0xff0000) >> 16);
  	shifter.bas_md=(unsigned char) ((addr & 0x00ff00) >> 8);
  	shifter.bas_lo=(unsigned char)  (addr & 0x0000ff);
}


static int pan_display( struct fb_var_screeninfo *var,
                        struct atafb_par *par )
{
	if (!fbhw->set_screen_base ||
		(!ATARIHW_PRESENT(EXTD_SHIFTER) && var->xoffset))
		return -EINVAL;
	var->xoffset = up(var->xoffset, 16);
	par->screen_base = screen_base +
	        (var->yoffset * fb_display[currcon].var.xres_virtual + var->xoffset)
	        * fb_display[currcon].var.bits_per_pixel / 8;
	fbhw->set_screen_base (par->screen_base);
	return 0;
}


/* ------------ Interfaces to hardware functions ------------ */


#ifdef ATAFB_TT
static struct fb_hwswitch tt_switch = {
	tt_detect, tt_encode_fix, tt_decode_var, tt_encode_var,
	tt_get_par, tt_set_par, tt_getcolreg, tt_setcolreg,
	set_screen_base, NULL, pan_display
};
#endif

#ifdef ATAFB_FALCON
static struct fb_hwswitch falcon_switch = {
	falcon_detect, falcon_encode_fix, falcon_decode_var, falcon_encode_var,
	falcon_get_par, falcon_set_par, falcon_getcolreg,
	falcon_setcolreg, set_screen_base, falcon_blank, falcon_pan_display
};
#endif

#ifdef ATAFB_STE
static struct fb_hwswitch st_switch = {
	stste_detect, stste_encode_fix, stste_decode_var, stste_encode_var,
	stste_get_par, stste_set_par, stste_getcolreg, stste_setcolreg,
	stste_set_screen_base, NULL, pan_display
};
#endif

#ifdef ATAFB_EXT
static struct fb_hwswitch ext_switch = {
	ext_detect, ext_encode_fix, ext_decode_var, ext_encode_var,
	ext_get_par, ext_set_par, ext_getcolreg, ext_setcolreg, NULL, NULL, NULL
};
#endif



static void atafb_g