atafb.c

Linux环境下视频显示卡设备的驱动程序源代码

		     (hfreq * 2) / (par->VFT + 1 + 4 * lines) >
		     fb_info.monspecs.vfmax;
		     lines += 2)
			;
		upper_margin += lines;
		lower_margin += lines;
		goto again;
	} else if (vfreq > fb_info.monspecs.vfmax && interlace) {
		/* Interlace, too high -> enlarge margins */
		int lines;
		for (lines = 0;
		     (hfreq * 2) / (par->VFT + 1 + 4 * lines) >
		     fb_info.monspecs.vfmax;
		     lines++)
			;
		upper_margin += lines;
		lower_margin += lines;
		goto again;
	} else if (vfreq < fb_info.monspecs.vfmin ||
		   vfreq > fb_info.monspecs.vfmax)
		return -EINVAL;

set_screen_base:
	linelen = xres_virtual * 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;
	par->hw.falcon.xoffset = 0;

	par->next_line = linelen;

	return 0;
}

static int falcon_encode_var(struct fb_var_screeninfo *var,
			     struct atafb_par *par)
{
/* !!! only for VGA !!! */
	int linelen;
	int prescale, plen;
	int hdb_off, hde_off, base_off;
	struct falcon_hw *hw = &par->hw.falcon;

	memset(var, 0, sizeof(struct fb_var_screeninfo));
	/* possible frequencies: 25.175 or 32MHz */
	var->pixclock = hw->sync & 0x1 ? fext.t :
	                hw->vid_control & VCO_CLOCK25 ? f25.t : f32.t;

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

	var->sync = 0;
	if (hw->vid_control & VCO_HSYPOS)
		var->sync |= FB_SYNC_HOR_HIGH_ACT;
	if (hw->vid_control & VCO_VSYPOS)
		var->sync |= FB_SYNC_VERT_HIGH_ACT;

	var->vmode = FB_VMODE_NONINTERLACED;
	if (hw->vid_mode & VMO_INTER)
		var->vmode |= FB_VMODE_INTERLACED;
	if (hw->vid_mode & VMO_DOUBLE)
		var->vmode |= FB_VMODE_DOUBLE;

	/* visible y resolution:
	 * Graphics display starts at line VDB and ends at line
	 * VDE. If interlace mode off unit of VC-registers is
	 * half lines, else lines.
	 */
	var->yres = hw->vde - hw->vdb;
	if (!(var->vmode & FB_VMODE_INTERLACED))
		var->yres >>= 1;
	if (var->vmode & FB_VMODE_DOUBLE)
		var->yres >>= 1;

	/*
	 * to get bpp, we must examine f_shift and st_shift.
	 * f_shift is valid if any of bits no. 10, 8 or 4
	 * is set. Priority in f_shift is: 10 ">" 8 ">" 4, i.e.
	 * if bit 10 set then bit 8 and bit 4 don't care...
	 * If all these bits are 0 get display depth from st_shift
	 * (as for ST and STE)
	 */
	if (hw->f_shift & 0x400)	/* 2 colors */
		var->bits_per_pixel = 1;
	else if (hw->f_shift & 0x100)	/* hicolor */
		var->bits_per_pixel = 16;
	else if (hw->f_shift & 0x010)	/* 8 bitplanes */
		var->bits_per_pixel = 8;
	else if (hw->st_shift == 0)
		var->bits_per_pixel = 4;
	else if (hw->st_shift == 0x100)
		var->bits_per_pixel = 2;
	else				/* if (hw->st_shift == 0x200) */
		var->bits_per_pixel = 1;

	var->xres = hw->line_width * 16 / var->bits_per_pixel;
	var->xres_virtual = var->xres + hw->line_offset * 16 / var->bits_per_pixel;
	if (hw->xoffset)
		var->xres_virtual += 16;

	if (var->bits_per_pixel == 16) {
		var->red.offset = 11;
		var->red.length = 5;
		var->red.msb_right = 0;
		var->green.offset = 5;
		var->green.length = 6;
		var->green.msb_right = 0;
		var->blue.offset = 0;
		var->blue.length = 5;
		var->blue.msb_right = 0;
	} else {
		var->red.offset = 0;
		var->red.length = hw->ste_mode ? 4 : 6;
		if (var->red.length > var->bits_per_pixel)
			var->red.length = var->bits_per_pixel;
		var->red.msb_right = 0;
		var->grayscale = 0;
		var->blue = var->green = var->red;
	}
	var->transp.offset = 0;
	var->transp.length = 0;
	var->transp.msb_right = 0;

	linelen = var->xres_virtual * var->bits_per_pixel / 8;
	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;		/* TODO change this */

	/* hdX-offsets */
	prescale = hxx_prescale(hw);
	plen = 4 >> (hw->vid_mode >> 2 & 0x3);
	base_off = hw->vid_control & VCO_SHORTOFFS ? 64 : 128;
	if (hw->f_shift & 0x100) {
		hde_off = 0;
		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;
static struct falcon_hw f_new_mode;
static int f_pan_display;

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 irqreturn_t falcon_vbl_switcher(int irq, void *dummy)
{
	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;
	}
	return IRQ_HANDLED;
}

static int falcon_pan_display(struct fb_var_screeninfo *var,
			      struct fb_info *info)
{
	struct atafb_par *par = (struct atafb_par *)info->par;

	int xoffset;
	int bpp = info->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 *
		(info->var.xres_virtual - info->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 * info->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_setcolreg(unsigned int regno, unsigned int red,
			    unsigned int green, unsigned int blue,
			    unsigned int 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 ATAFB_FALCON
		((u32 *)info->pseudo_palette)[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;
}