vga16fb.c

Linux环境下视频显示卡设备的驱动程序源代码

	par->crtc[VGA_CRTC_LINE_COMPARE] = 0xFF;
	par->crtc[VGA_CRTC_OVERFLOW] = r7;

	par->vss = 0x00;	/* 3DA */

	par->misc = 0xE3;	/* enable CPU, ports 0x3Dx, positive sync */
	if (var->sync & FB_SYNC_HOR_HIGH_ACT)
		par->misc &= ~0x40;
	if (var->sync & FB_SYNC_VERT_HIGH_ACT)
		par->misc &= ~0x80;
	
	par->mode = mode;

	if (mode & MODE_8BPP)
		/* pixel clock == vga clock / 2 */
		vga16fb_clock_chip(par, var->pixclock, info, 1, 2);
	else
		/* pixel clock == vga clock */
		vga16fb_clock_chip(par, var->pixclock, info, 1, 1);
	
	var->red.offset = var->green.offset = var->blue.offset = 
	var->transp.offset = 0;
	var->red.length = var->green.length = var->blue.length =
		(par->isVGA) ? 6 : 2;
	var->transp.length = 0;
	var->activate = FB_ACTIVATE_NOW;
	var->height = -1;
	var->width = -1;
	var->accel_flags = 0;
	return 0;
}
#undef FAIL

static int vga16fb_set_par(struct fb_info *info)
{
	struct vga16fb_par *par = info->par;
	u8 gdc[VGA_GFX_C];
	u8 seq[VGA_SEQ_C];
	u8 atc[VGA_ATT_C];
	int fh, i;

	seq[VGA_SEQ_CLOCK_MODE] = 0x01 | par->clkdiv;
	if (par->mode & MODE_TEXT)
		seq[VGA_SEQ_PLANE_WRITE] = 0x03;
	else
		seq[VGA_SEQ_PLANE_WRITE] = 0x0F;
	seq[VGA_SEQ_CHARACTER_MAP] = 0x00;
	if (par->mode & MODE_TEXT)
		seq[VGA_SEQ_MEMORY_MODE] = 0x03;
	else if (par->mode & MODE_SKIP4)
		seq[VGA_SEQ_MEMORY_MODE] = 0x0E;
	else
		seq[VGA_SEQ_MEMORY_MODE] = 0x06;

	gdc[VGA_GFX_SR_VALUE] = 0x00;
	gdc[VGA_GFX_SR_ENABLE] = 0x00;
	gdc[VGA_GFX_COMPARE_VALUE] = 0x00;
	gdc[VGA_GFX_DATA_ROTATE] = 0x00;
	gdc[VGA_GFX_PLANE_READ] = 0;
	if (par->mode & MODE_TEXT) {
		gdc[VGA_GFX_MODE] = 0x10;
		gdc[VGA_GFX_MISC] = 0x06;
	} else {
		if (par->mode & MODE_CFB)
			gdc[VGA_GFX_MODE] = 0x40;
		else
			gdc[VGA_GFX_MODE] = 0x00;
		gdc[VGA_GFX_MISC] = 0x05;
	}
	gdc[VGA_GFX_COMPARE_MASK] = 0x0F;
	gdc[VGA_GFX_BIT_MASK] = 0xFF;

	for (i = 0x00; i < 0x10; i++)
		atc[i] = i;
	if (par->mode & MODE_TEXT)
		atc[VGA_ATC_MODE] = 0x04;
	else if (par->mode & MODE_8BPP)
		atc[VGA_ATC_MODE] = 0x41;
	else
		atc[VGA_ATC_MODE] = 0x81;
	atc[VGA_ATC_OVERSCAN] = 0x00;	/* 0 for EGA, 0xFF for VGA */
	atc[VGA_ATC_PLANE_ENABLE] = 0x0F;
	if (par->mode & MODE_8BPP)
		atc[VGA_ATC_PEL] = (info->var.xoffset & 3) << 1;
	else
		atc[VGA_ATC_PEL] = info->var.xoffset & 7;
	atc[VGA_ATC_COLOR_PAGE] = 0x00;
	
	if (par->mode & MODE_TEXT) {
		fh = 16; // FIXME !!! Fudge font height. 
		par->crtc[VGA_CRTC_MAX_SCAN] = (par->crtc[VGA_CRTC_MAX_SCAN] 
					       & ~0x1F) | (fh - 1);
	}

	vga_io_w(VGA_MIS_W, vga_io_r(VGA_MIS_R) | 0x01);

	/* Enable graphics register modification */
	if (!par->isVGA) {
		vga_io_w(EGA_GFX_E0, 0x00);
		vga_io_w(EGA_GFX_E1, 0x01);
	}
	
	/* update misc output register */
	vga_io_w(VGA_MIS_W, par->misc);
	
	/* synchronous reset on */
	vga_io_wseq(0x00, 0x01);

	if (par->isVGA)
		vga_io_w(VGA_PEL_MSK, par->pel_msk);

	/* write sequencer registers */
	vga_io_wseq(VGA_SEQ_CLOCK_MODE, seq[VGA_SEQ_CLOCK_MODE] | 0x20);
	for (i = 2; i < VGA_SEQ_C; i++) {
		vga_io_wseq(i, seq[i]);
	}
	
	/* synchronous reset off */
	vga_io_wseq(0x00, 0x03);

	/* deprotect CRT registers 0-7 */
	vga_io_wcrt(VGA_CRTC_V_SYNC_END, par->crtc[VGA_CRTC_V_SYNC_END]);

	/* write CRT registers */
	for (i = 0; i < VGA_CRTC_REGS; i++) {
		vga_io_wcrt(i, par->crtc[i]);
	}
	
	/* write graphics controller registers */
	for (i = 0; i < VGA_GFX_C; i++) {
		vga_io_wgfx(i, gdc[i]);
	}
	
	/* write attribute controller registers */
	for (i = 0; i < VGA_ATT_C; i++) {
		vga_io_r(VGA_IS1_RC);		/* reset flip-flop */
		vga_io_wattr(i, atc[i]);
	}

	/* Wait for screen to stabilize. */
	mdelay(50);

	vga_io_wseq(VGA_SEQ_CLOCK_MODE, seq[VGA_SEQ_CLOCK_MODE]);

	vga_io_r(VGA_IS1_RC);
	vga_io_w(VGA_ATT_IW, 0x20);

	vga16fb_update_fix(info);
	return 0;
}

static void ega16_setpalette(int regno, unsigned red, unsigned green, unsigned blue)
{
	static const unsigned char map[] = { 000, 001, 010, 011 };
	int val;
	
	if (regno >= 16)
		return;
	val = map[red>>14] | ((map[green>>14]) << 1) | ((map[blue>>14]) << 2);
	vga_io_r(VGA_IS1_RC);   /* ! 0x3BA */
	vga_io_wattr(regno, val);
	vga_io_r(VGA_IS1_RC);   /* some clones need it */
	vga_io_w(VGA_ATT_IW, 0x20); /* unblank screen */
}

static void vga16_setpalette(int regno, unsigned red, unsigned green, unsigned blue)
{
	outb(regno,       VGA_PEL_IW);
	outb(red   >> 10, VGA_PEL_D);
	outb(green >> 10, VGA_PEL_D);
	outb(blue  >> 10, VGA_PEL_D);
}

static int vga16fb_setcolreg(unsigned regno, unsigned red, unsigned green,
			     unsigned blue, unsigned transp,
			     struct fb_info *info)
{
	struct vga16fb_par *par = info->par;
	int gray;

	/*
	 *  Set a single color register. The values supplied are
	 *  already rounded down to the hardware's capabilities
	 *  (according to the entries in the `var' structure). Return
	 *  != 0 for invalid regno.
	 */
	
	if (regno >= 256)
		return 1;

	gray = info->var.grayscale;
	
	if (gray) {
		/* gray = 0.30*R + 0.59*G + 0.11*B */
		red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
	}
	if (par->isVGA) 
		vga16_setpalette(regno,red,green,blue);
	else
		ega16_setpalette(regno,red,green,blue);
	return 0;
}

static int vga16fb_pan_display(struct fb_var_screeninfo *var,
			       struct fb_info *info) 
{
	vga16fb_pan_var(info, var);
	return 0;
}

/* The following VESA blanking code is taken from vgacon.c.  The VGA
   blanking code was originally by Huang shi chao, and modified by
   Christoph Rimek ([e-mail]) and todd j. derr
   ([e-mail]) for Linux. */

static void vga_vesa_blank(struct vga16fb_par *par, int mode)
{
	unsigned char SeqCtrlIndex = vga_io_r(VGA_SEQ_I);
	unsigned char CrtCtrlIndex = vga_io_r(VGA_CRT_IC);
	
	/* save original values of VGA controller registers */
	if(!par->vesa_blanked) {
		par->vga_state.CrtMiscIO = vga_io_r(VGA_MIS_R);
		//sti();

		par->vga_state.HorizontalTotal = vga_io_rcrt(0x00);	/* HorizontalTotal */
		par->vga_state.HorizDisplayEnd = vga_io_rcrt(0x01);	/* HorizDisplayEnd */
		par->vga_state.StartHorizRetrace = vga_io_rcrt(0x04);	/* StartHorizRetrace */
		par->vga_state.EndHorizRetrace = vga_io_rcrt(0x05);	/* EndHorizRetrace */
		par->vga_state.Overflow = vga_io_rcrt(0x07);		/* Overflow */
		par->vga_state.StartVertRetrace = vga_io_rcrt(0x10);	/* StartVertRetrace */
		par->vga_state.EndVertRetrace = vga_io_rcrt(0x11);	/* EndVertRetrace */
		par->vga_state.ModeControl = vga_io_rcrt(0x17);	/* ModeControl */
		par->vga_state.ClockingMode = vga_io_rseq(0x01);	/* ClockingMode */
	}

	/* assure that video is enabled */
	/* "0x20" is VIDEO_ENABLE_bit in register 01 of sequencer */
	vga_io_wseq(0x01, par->vga_state.ClockingMode | 0x20);

	/* test for vertical retrace in process.... */
	if ((par->vga_state.CrtMiscIO & 0x80) == 0x80)
		vga_io_w(VGA_MIS_W, par->vga_state.CrtMiscIO & 0xef);

	/*
	 * Set <End of vertical retrace> to minimum (0) and
	 * <Start of vertical Retrace> to maximum (incl. overflow)
	 * Result: turn off vertical sync (VSync) pulse.
	 */
	if (mode & FB_BLANK_VSYNC_SUSPEND) {
		vga_io_wcrt(VGA_CRTC_V_SYNC_START, 0xff);
		vga_io_wcrt(VGA_CRTC_V_SYNC_END, 0x40);
		/* bits 9,10 of vert. retrace */
		vga_io_wcrt(VGA_CRTC_OVERFLOW, par->vga_state.Overflow | 0x84);
	}

	if (mode & FB_BLANK_HSYNC_SUSPEND) {
		/*
		 * Set <End of horizontal retrace> to minimum (0) and
		 *  <Start of horizontal Retrace> to maximum
		 * Result: turn off horizontal sync (HSync) pulse.
		 */
		vga_io_wcrt(VGA_CRTC_H_SYNC_START, 0xff);
		vga_io_wcrt(VGA_CRTC_H_SYNC_END, 0x00);
	}

	/* restore both index registers */
	outb_p(SeqCtrlIndex, VGA_SEQ_I);
	outb_p(CrtCtrlIndex, VGA_CRT_IC);
}

static void vga_vesa_unblank(struct vga16fb_par *par)
{
	unsigned char SeqCtrlIndex = vga_io_r(VGA_SEQ_I);
	unsigned char CrtCtrlIndex = vga_io_r(VGA_CRT_IC);
	
	/* restore original values of VGA controller registers */
	vga_io_w(VGA_MIS_W, par->vga_state.CrtMiscIO);

	/* HorizontalTotal */
	vga_io_wcrt(0x00, par->vga_state.HorizontalTotal);
	/* HorizDisplayEnd */
	vga_io_wcrt(0x01, par->vga_state.HorizDisplayEnd);
	/* StartHorizRetrace */
	vga_io_wcrt(0x04, par->vga_state.StartHorizRetrace);
	/* EndHorizRetrace */
	vga_io_wcrt(0x05, par->vga_state.EndHorizRetrace);
	/* Overflow */
	vga_io_wcrt(0x07, par->vga_state.Overflow);
	/* StartVertRetrace */
	vga_io_wcrt(0x10, par->vga_state.StartVertRetrace);
	/* EndVertRetrace */
	vga_io_wcrt(0x11, par->vga_state.EndVertRetrace);
	/* ModeControl */
	vga_io_wcrt(0x17, par->vga_state.ModeControl);
	/* ClockingMode */
	vga_io_wseq(0x01, par->vga_state.ClockingMode);

	/* restore index/control registers */
	vga_io_w(VGA_SEQ_I, SeqCtrlIndex);
	vga_io_w(VGA_CRT_IC, CrtCtrlIndex);
}

static void vga_pal_blank(void)
{
	int i;

	for (i=0; i<16; i++) {
		outb_p(i, VGA_PEL_IW);
		outb_p(0, VGA_PEL_D);
		outb_p(0, VGA_PEL_D);
		outb_p(0, VGA_PEL_D);
	}
}

/* 0 unblank, 1 blank, 2 no vsync, 3 no hsync, 4 off */
static int vga16fb_blank(int blank, struct fb_info *info)
{
	struct vga16fb_par *par = info->par;

	switch (blank) {
	case FB_BLANK_UNBLANK:				/* Unblank */
		if (par->vesa_blanked) {
			vga_vesa_unblank(par);
			par->vesa_blanked = 0;
		}
		if (par->palette_blanked) {
			par->palette_blanked = 0;
		}
		break;
	case FB_BLANK_NORMAL:				/* blank */
		vga_pal_blank();
		par->palette_blanked = 1;
		break;
	default:			/* VESA blanking */
		vga_vesa_blank(par, blank);
		par->vesa_blanked = 1;
		break;
	}
	return 0;
}

static void vga_8planes_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
	u32 dx = rect->dx, width = rect->width;
        char oldindex = getindex();
        char oldmode = setmode(0x40);
        char oldmask = selectmask();
        int line_ofs, height;
        char oldop, oldsr;
        char __iomem *where;

        dx /= 4;
        where = info->screen_base + dx + rect->dy * info->fix.line_length;

        if (rect->rop == ROP_COPY) {
                oldop = setop(0);
                oldsr = setsr(0);

                width /= 4;
                line_ofs = info->fix.line_length - width;
                setmask(0xff);

                height = rect->height;

                while (height--) {
                        int x;

                        /* we can do memset... */
                        for (x = width; x > 0; --x) {
                                writeb(rect->color, where);
                                where++;
                        }
                        where += line_ofs;
                }
        } else {
                char oldcolor = setcolor(0xf);
                int y;

                oldop = setop(0x18);
                oldsr = setsr(0xf);
                setmask(0x0F);
                for (y = 0; y < rect->height; y++) {
                        rmw(where);
                        rmw(where+1);
                        where += info->fix.line_length;
                }
                setcolor(oldcolor);
        }
        setmask(oldmask);
        setsr(oldsr);
        setop(oldop);
        setmode(oldmode);
        setindex(oldindex);
}

static void vga16fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
	int x, x2, y2, vxres, vyres, width, height, line_ofs;
	char __iomem *dst;

	vxres = info->var.xres_virtual;
	vyres = info->var.yres_virtual;

	if (!rect->width || !rect->height || rect->dx > vxres || rect->dy > vyres)
		return;

	/* We could use hardware clipping but on many cards you get around
	 * hardware clipping by writing to framebuffer directly. */

	x2 = rect->dx + rect->width;
	y2 = rect->dy + rect->height;
	x2 = x2 < vxres ? x2 : vxres;
	y2 = y2 < vyres ? y2 : vyres;
	width = x2 - rect->dx;

	switch (info->fix.type) {
	case FB_TYPE_VGA_PLANES:
		if (info->fix.type_aux == FB_AUX_VGA_PLANES_VGA4) {

			height = y2 - rect->dy;
			width = rect->width/8;

			line_ofs = info->fix.line_length - width;
			dst = info->screen_base + (rect->dx/8) + rect->dy * info->fix.line_length;

			switch (rect->rop) {
			case ROP_COPY:
				setmode(0);
				setop(0);
				setsr(0xf);
				setcolor(rect->color);
				selectmask();

				setmask(0xff);

				while (height--) {
					for (x = 0; x < width; x++) {
						writeb(0, dst);
						dst++;
					}
					dst += line_ofs;
				}
				break;
			case ROP_XOR:
				setmode(0);
				setop(0x18);
				setsr(0xf);
				setcolor(0xf);
				selectmask();

				setmask(0xff);
				while (height--) {
					for (x = 0; x < width; x++) {
						rmw(dst);
						dst++;
					}
					dst += line_ofs;
				}
				break;
			}
		} else 
			vga_8planes_fillrect(info, rect);
		break;
	case FB_TYPE_PACKED_PIXELS:
	default:
		cfb_fillrect(info, rect);
		break;
	}
}

static void vga_8planes_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
        char oldindex = getindex();
        char oldmode = setmode(0x41);
        char oldop = setop(0);
        char oldsr = setsr(0xf);
        int height, line_ofs, x;
	u32 sx, dx, width;
	char __iomem *dest;
	char __iomem *src;

        height = area->height;

        sx = area->sx / 4;