atafb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

		hdb_off = (base_off + 16 * plen) + prescale;
	}
	else {
		hde_off = ((128 / var->bits_per_pixel + 2) * plen);
		if (hw->ste_mode)
			hdb_off = (64 + base_off + (128 / var->bits_per_pixel + 2) * plen)
					 + prescale;
		else
			hdb_off = (base_off + (128 / var->bits_per_pixel + 18) * plen)
					 + prescale;
	}

	/* Right margin includes hsync */
	var->left_margin = hdb_off + prescale * ((hw->hdb & 0x1ff) -
					   (hw->hdb & 0x200 ? 2+hw->hht : 0));
	if (hw->ste_mode || mon_type!=F_MON_VGA)
		var->right_margin = prescale * (hw->hht + 2 - hw->hde) - hde_off;
	else
		/* can't use this in ste_mode, because hbb is +1 off */
		var->right_margin = prescale * (hw->hht + 2 - hw->hbb);
	var->hsync_len = prescale * (hw->hht + 2 - hw->hss);

	/* Lower margin includes vsync */
	var->upper_margin = hw->vdb / 2 ;  /* round down to full lines */
	var->lower_margin = (hw->vft+1 - hw->vde + 1) / 2; /* round up */
	var->vsync_len    = (hw->vft+1 - hw->vss + 1) / 2; /* round up */
	if (var->vmode & FB_VMODE_INTERLACED) {
		var->upper_margin *= 2;
		var->lower_margin *= 2;
		var->vsync_len *= 2;
	}
	else if (var->vmode & FB_VMODE_DOUBLE) {
		var->upper_margin = (var->upper_margin + 1) / 2;
		var->lower_margin = (var->lower_margin + 1) / 2;
		var->vsync_len = (var->vsync_len + 1) / 2;
	}

	var->pixclock *= plen;
	var->left_margin /= plen;
	var->right_margin /= plen;
	var->hsync_len /= plen;

	var->right_margin -= var->hsync_len;
	var->lower_margin -= var->vsync_len;

	if (screen_base)
		var->yoffset=(par->screen_base - screen_base)/linelen;
	else
		var->yoffset=0;
	var->nonstd=0;	/* what is this for? */
	var->activate=0;
	return 0;
}


static int f_change_mode = 0;
static struct falcon_hw f_new_mode;
static int f_pan_display = 0;

static void falcon_get_par( struct atafb_par *par )
{
	unsigned long addr;
	struct falcon_hw *hw = &par->hw.falcon;

	hw->line_width = shifter_f030.scn_width;
	hw->line_offset = shifter_f030.off_next;
	hw->st_shift = videl.st_shift & 0x300;
	hw->f_shift = videl.f_shift;
	hw->vid_control = videl.control;
	hw->vid_mode = videl.mode;
	hw->sync = shifter.syncmode & 0x1;
	hw->xoffset = videl.xoffset & 0xf;
	hw->hht = videl.hht;
	hw->hbb = videl.hbb;
	hw->hbe = videl.hbe;
	hw->hdb = videl.hdb;
	hw->hde = videl.hde;
	hw->hss = videl.hss;
	hw->vft = videl.vft;
	hw->vbb = videl.vbb;
	hw->vbe = videl.vbe;
	hw->vdb = videl.vdb;
	hw->vde = videl.vde;
	hw->vss = videl.vss;

	addr = (shifter.bas_hi & 0xff) << 16 |
	       (shifter.bas_md & 0xff) << 8  |
	       (shifter.bas_lo & 0xff);
	par->screen_base = phys_to_virt(addr);

	/* derived parameters */
	hw->ste_mode = (hw->f_shift & 0x510)==0 && hw->st_shift==0x100;
	hw->mono = (hw->f_shift & 0x400) ||
	           ((hw->f_shift & 0x510)==0 && hw->st_shift==0x200);
}

static void falcon_set_par( struct atafb_par *par )
{
	f_change_mode = 0;

	/* only set screen_base if really necessary */
	if (current_par.screen_base != par->screen_base)
		fbhw->set_screen_base(par->screen_base);

	/* Don't touch any other registers if we keep the default resolution */
	if (DontCalcRes)
		return;

	/* Tell vbl-handler to change video mode.
	 * We change modes only on next VBL, to avoid desynchronisation
	 * (a shift to the right and wrap around by a random number of pixels
	 * in all monochrome modes).
	 * This seems to work on my Falcon.
	 */
	f_new_mode = par->hw.falcon;
	f_change_mode = 1;
}


static void falcon_vbl_switcher( int irq, void *dummy, struct pt_regs *fp )
{
	struct falcon_hw *hw = &f_new_mode;

	if (f_change_mode) {
		f_change_mode = 0;

		if (hw->sync & 0x1) {
			/* Enable external pixelclock. This code only for ScreenWonder */
			*(volatile unsigned short*)0xffff9202 = 0xffbf;
		}
		else {
			/* Turn off external clocks. Read sets all output bits to 1. */
			*(volatile unsigned short*)0xffff9202;
		}
		shifter.syncmode = hw->sync;

		videl.hht = hw->hht;
		videl.hbb = hw->hbb;
		videl.hbe = hw->hbe;
		videl.hdb = hw->hdb;
		videl.hde = hw->hde;
		videl.hss = hw->hss;
		videl.vft = hw->vft;
		videl.vbb = hw->vbb;
		videl.vbe = hw->vbe;
		videl.vdb = hw->vdb;
		videl.vde = hw->vde;
		videl.vss = hw->vss;

		videl.f_shift = 0; /* write enables Falcon palette, 0: 4 planes */
		if (hw->ste_mode) {
			videl.st_shift = hw->st_shift; /* write enables STE palette */
		}
		else {
			/* IMPORTANT:
			 * set st_shift 0, so we can tell the screen-depth if f_shift==0.
			 * Writing 0 to f_shift enables 4 plane Falcon mode but
			 * doesn't set st_shift. st_shift!=0 (!=4planes) is impossible
			 * with Falcon palette.
			 */
			videl.st_shift = 0;
			/* now back to Falcon palette mode */
			videl.f_shift = hw->f_shift;
		}
		/* writing to st_shift changed scn_width and vid_mode */
		videl.xoffset = hw->xoffset;
		shifter_f030.scn_width = hw->line_width;
		shifter_f030.off_next = hw->line_offset;
		videl.control = hw->vid_control;
		videl.mode = hw->vid_mode;
	}
	if (f_pan_display) {
		f_pan_display = 0;
		videl.xoffset = current_par.hw.falcon.xoffset;
		shifter_f030.off_next = current_par.hw.falcon.line_offset;
	}
}


static int falcon_pan_display( struct fb_var_screeninfo *var,
							   struct atafb_par *par )
{
	int xoffset;
	int bpp = fb_display[currcon].var.bits_per_pixel;

	if (bpp == 1)
		var->xoffset = up(var->xoffset, 32);
	if (bpp != 16)
		par->hw.falcon.xoffset = var->xoffset & 15;
	else {
		par->hw.falcon.xoffset = 0;
		var->xoffset = up(var->xoffset, 2);
	}
	par->hw.falcon.line_offset = bpp *
	       	(fb_display[currcon].var.xres_virtual - fb_display[currcon].var.xres) / 16;
	if (par->hw.falcon.xoffset)
		par->hw.falcon.line_offset -= bpp;
	xoffset = var->xoffset - par->hw.falcon.xoffset;

	par->screen_base = screen_base +
	        (var->yoffset * fb_display[currcon].var.xres_virtual + xoffset) * bpp / 8;
	if (fbhw->set_screen_base)
		fbhw->set_screen_base (par->screen_base);
	else
		return -EINVAL; /* shouldn't happen */
	f_pan_display = 1;
	return 0;
}


static int falcon_getcolreg( unsigned regno, unsigned *red,
				 unsigned *green, unsigned *blue,
				 unsigned *transp, struct fb_info *info )
{	unsigned long col;
	
	if (regno > 255)
		return 1;
	/* This works in STE-mode (with 4bit/color) since f030_col-registers
	 * hold up to 6bit/color.
	 * Even with hicolor r/g/b=5/6/5 bit!
	 */
	col = f030_col[regno];
	*red = (col >> 16) & 0xff00;
	*green = (col >> 8) & 0xff00;
	*blue = (col << 8) & 0xff00;
	*transp = 0;
	return 0;
}


static int falcon_setcolreg( unsigned regno, unsigned red,
							 unsigned green, unsigned blue,
							 unsigned transp, struct fb_info *info )
{
	if (regno > 255)
		return 1;
	f030_col[regno] = (((red & 0xfc00) << 16) |
			   ((green & 0xfc00) << 8) |
			   ((blue & 0xfc00) >> 8));
	if (regno < 16) {
		shifter_tt.color_reg[regno] =
			(((red & 0xe000) >> 13) | ((red & 0x1000) >> 12) << 8) |
			(((green & 0xe000) >> 13) | ((green & 0x1000) >> 12) << 4) |
			((blue & 0xe000) >> 13) | ((blue & 0x1000) >> 12);
#ifdef FBCON_HAS_CFB16
		fbcon_cfb16_cmap[regno] = ((red & 0xf800) |
					   ((green & 0xfc00) >> 5) |
					   ((blue & 0xf800) >> 11));
#endif
	}
	return 0;
}


static int falcon_blank( int blank_mode )
{
/* ++guenther: we can switch off graphics by changing VDB and VDE,
 * so VIDEL doesn't hog the bus while saving.
 * (this may affect usleep()).
 */
	int vdb, vss, hbe, hss;

	if (mon_type == F_MON_SM)	/* this doesn't work on SM124 */
		return 1;

	vdb = current_par.VDB;
	vss = current_par.VSS;
	hbe = current_par.HBE;
	hss = current_par.HSS;

	if (blank_mode >= 1) {
		/* disable graphics output (this speeds up the CPU) ... */
		vdb = current_par.VFT + 1;
		/* ... and blank all lines */
		hbe = current_par.HHT + 2;
	}
	/* use VESA suspend modes on VGA monitors */
	if (mon_type == F_MON_VGA) {
		if (blank_mode == 2 || blank_mode == 4)
			vss = current_par.VFT + 1;
		if (blank_mode == 3 || blank_mode == 4)
			hss = current_par.HHT + 2;
	}

	videl.vdb = vdb;
	videl.vss = vss;
	videl.hbe = hbe;
	videl.hss = hss;

	return 0;
}

 
static int falcon_detect( void )
{
	struct atafb_par par;
	unsigned char fhw;

	/* Determine connected monitor and set monitor parameters */
	fhw = *(unsigned char*)0xffff8006;
	mon_type = fhw >> 6 & 0x3;
	/* bit 1 of fhw: 1=32 bit ram bus, 0=16 bit */
	f030_bus_width = fhw << 6 & 0x80;
	switch (mon_type) {
	case F_MON_SM:
		fb_info.monspecs.vfmin = 70;
		fb_info.monspecs.vfmax = 72;
		fb_info.monspecs.hfmin = 35713;
		fb_info.monspecs.hfmax = 35715;
		break;
	case F_MON_SC:
	case F_MON_TV:
		/* PAL...NTSC */
		fb_info.monspecs.vfmin = 49; /* not 50, since TOS defaults to 49.9x Hz */
		fb_info.monspecs.vfmax = 60;
		fb_info.monspecs.hfmin = 15620;
		fb_info.monspecs.hfmax = 15755;
		break;
	}
	/* initialize hsync-len */
	f25.hsync = h_syncs[mon_type] / f25.t;
	f32.hsync = h_syncs[mon_type] / f32.t;
	if (fext.t)
		fext.hsync = h_syncs[mon_type] / fext.t;

	falcon_get_par(&par);
	falcon_encode_var(&atafb_predefined[0], &par);

	/* Detected mode is always the "autodetect" slot */
	return 1;
}

#endif /* ATAFB_FALCON */

/* ------------------- ST(E) specific functions ---------------------- */

#ifdef ATAFB_STE

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

{
	int mode;

	strcpy(fix->id,"Atari Builtin");
	fix->smem_start = (unsigned long)real_screen_base;
	fix->smem_len = screen_len;
	fix->type = FB_TYPE_INTERLEAVED_PLANES;
	fix->type_aux = 2;
	fix->visual = FB_VISUAL_PSEUDOCOLOR;
	mode = par->hw.st.mode & 3;
	if (mode == ST_HIGH) {
		fix->type = FB_TYPE_PACKED_PIXELS;
		fix->type_aux = 0;
		fix->visual = FB_VISUAL_MONO10;
	}
	if (ATARIHW_PRESENT(EXTD_SHIFTER)) {
		fix->xpanstep = 16;
		fix->ypanstep = 1;
	} else {
		fix->xpanstep = 0;
		fix->ypanstep = 0;
	}
	fix->ywrapstep = 0;
	fix->line_length = 0;
	fix->accel = FB_ACCEL_ATARIBLITT;
	return 0;
}


static int stste_decode_var( struct fb_var_screeninfo *var,
						  struct atafb_par *par )
{
	int xres=var->xres;
	int yres=var->yres;
	int bpp=var->bits_per_pixel;
	int linelen;
	int yres_virtual = var->yres_virtual;

	if (mono_moni) {
		if (bpp > 1 || xres > sttt_xres || yres > st_yres)
			return -EINVAL;
		par->hw.st.mode=ST_HIGH;
		xres=sttt_xres;
		yres=st_yres;
		bpp=1;
	} else {
		if (bpp > 4 || xres > sttt_xres || yres > st_yres)
			return -EINVAL;
		if (bpp > 2) {
			if (xres > sttt_xres/2 || yres > st_yres/2)
				return -EINVAL;
			par->hw.st.mode=ST_LOW;
			xres=sttt_xres/2;
			yres=st_yres/2;
			bpp=4;
		}
		else if (bpp > 1) {
			if (xres > sttt_xres || yres > st_yres/2)
				return -EINVAL;
			par->hw.st.mode=ST_MID;
			xres=sttt_xres;
			yres=st_yres/2;
			bpp=2;
		}
		else
			return -EINVAL;
	}
	if (yres_virtual <= 0)
		yres_virtual = 0;
	else if (yres_virtual < yres)
		yres_virtual = yres;
	if (var->sync & FB_SYNC_EXT)
		par->hw.st.sync=(par->hw.st.sync & ~1) | 1;
	else
		par->hw.st.sync=(par->hw.st.sync & ~1);
	linelen=xres*bpp/8;
	if (yres_virtual * linelen > screen_len && screen_len)
		return -EINVAL;
	if (yres * linelen > screen_len && screen_len)
		return -EINVAL;
	if (var->yoffset + yres > yres_virtual && yres_virtual)
		return -EINVAL;
	par->yres_virtual = yres_virtual;
	par->screen_base=screen_base+ var->yoffset*linelen;
	return 0;
}

static int stste_encode_var( struct fb_var_screeninfo *var,
						  struct atafb_par *par )
{
	int linelen;
	memset(var, 0, sizeof(struct fb_var_screeninfo));
	var->red.offset=0;
	var->red.length = ATARIHW_PRESENT(EXTD_SHIFTER) ? 4 : 3;
	var->red.msb_right=0;
	var->grayscale=0;

	var->pixclock=31041;
	var->left_margin=120;		/* these are 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;

	if (!(par->hw.st.sync & 1))
		var->sync=0;
	else
		var->sync=FB_SYNC_EXT;

	switch (par->hw.st.mode & 3) {
	case ST_LOW:
		var->xres=sttt_xres/2;
		var->yres=st_yres/2;
		var->bits_per_pixel=4;
		break;
	case ST_MID:
		var->xres=sttt_xres;
		var->yres=st_yres/2;
		var->bits_per_pixel=2;
		break;
	case ST_HIGH:
		var->xres=sttt_xres;
		var->yres=st_yres;
		var->bits_per_pixel=1;
		break;
	}		
	var->blue=var->green=var->red;