uvesafb.c

Linux环境下视频显示卡设备的驱动程序源代码

				(green << info->var.green.offset) |
				(blue  << info->var.blue.offset);
			break;
		}
	}
	return err;
}

static int uvesafb_setcmap(struct fb_cmap *cmap, struct fb_info *info)
{
	struct uvesafb_pal_entry *entries;
	int shift = 16 - info->var.green.length;
	int i, err = 0;

	if (info->var.bits_per_pixel == 8) {
		if (cmap->start + cmap->len > info->cmap.start +
		    info->cmap.len || cmap->start < info->cmap.start)
			return -EINVAL;

		entries = kmalloc(sizeof(*entries) * cmap->len, GFP_KERNEL);
		if (!entries)
			return -ENOMEM;

		for (i = 0; i < cmap->len; i++) {
			entries[i].red   = cmap->red[i]   >> shift;
			entries[i].green = cmap->green[i] >> shift;
			entries[i].blue  = cmap->blue[i]  >> shift;
			entries[i].pad   = 0;
		}
		err = uvesafb_setpalette(entries, cmap->len, cmap->start, info);
		kfree(entries);
	} else {
		/*
		 * For modes with bpp > 8, we only set the pseudo palette in
		 * the fb_info struct. We rely on uvesafb_setcolreg to do all
		 * sanity checking.
		 */
		for (i = 0; i < cmap->len; i++) {
			err |= uvesafb_setcolreg(cmap->start + i, cmap->red[i],
						cmap->green[i], cmap->blue[i],
						0, info);
		}
	}
	return err;
}

static int uvesafb_pan_display(struct fb_var_screeninfo *var,
		struct fb_info *info)
{
#ifdef CONFIG_X86_32
	int offset;
	struct uvesafb_par *par = info->par;

	offset = (var->yoffset * info->fix.line_length + var->xoffset) / 4;

	/*
	 * It turns out it's not the best idea to do panning via vm86,
	 * so we only allow it if we have a PMI.
	 */
	if (par->pmi_start) {
		__asm__ __volatile__(
			"call *(%%edi)"
			: /* no return value */
			: "a" (0x4f07),         /* EAX */
			  "b" (0),              /* EBX */
			  "c" (offset),         /* ECX */
			  "d" (offset >> 16),   /* EDX */
			  "D" (&par->pmi_start));    /* EDI */
	}
#endif
	return 0;
}

static int uvesafb_blank(int blank, struct fb_info *info)
{
	struct uvesafb_ktask *task;
	int err = 1;
#ifdef CONFIG_X86
	struct uvesafb_par *par = info->par;

	if (par->vbe_ib.capabilities & VBE_CAP_VGACOMPAT) {
		int loop = 10000;
		u8 seq = 0, crtc17 = 0;

		if (blank == FB_BLANK_POWERDOWN) {
			seq = 0x20;
			crtc17 = 0x00;
			err = 0;
		} else {
			seq = 0x00;
			crtc17 = 0x80;
			err = (blank == FB_BLANK_UNBLANK) ? 0 : -EINVAL;
		}

		vga_wseq(NULL, 0x00, 0x01);
		seq |= vga_rseq(NULL, 0x01) & ~0x20;
		vga_wseq(NULL, 0x00, seq);

		crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
		while (loop--);
		vga_wcrt(NULL, 0x17, crtc17);
		vga_wseq(NULL, 0x00, 0x03);
	} else
#endif /* CONFIG_X86 */
	{
		task = uvesafb_prep();
		if (!task)
			return -ENOMEM;

		task->t.regs.eax = 0x4f10;
		switch (blank) {
		case FB_BLANK_UNBLANK:
			task->t.regs.ebx = 0x0001;
			break;
		case FB_BLANK_NORMAL:
			task->t.regs.ebx = 0x0101;	/* standby */
			break;
		case FB_BLANK_POWERDOWN:
			task->t.regs.ebx = 0x0401;	/* powerdown */
			break;
		default:
			goto out;
		}

		err = uvesafb_exec(task);
		if (err || (task->t.regs.eax & 0xffff) != 0x004f)
			err = 1;
out:		uvesafb_free(task);
	}
	return err;
}

static int uvesafb_open(struct fb_info *info, int user)
{
	struct uvesafb_par *par = info->par;
	int cnt = atomic_read(&par->ref_count);

	if (!cnt && par->vbe_state_size)
		par->vbe_state_orig = uvesafb_vbe_state_save(par);

	atomic_inc(&par->ref_count);
	return 0;
}

static int uvesafb_release(struct fb_info *info, int user)
{
	struct uvesafb_ktask *task = NULL;
	struct uvesafb_par *par = info->par;
	int cnt = atomic_read(&par->ref_count);

	if (!cnt)
		return -EINVAL;

	if (cnt != 1)
		goto out;

	task = uvesafb_prep();
	if (!task)
		goto out;

	/* First, try to set the standard 80x25 text mode. */
	task->t.regs.eax = 0x0003;
	uvesafb_exec(task);

	/*
	 * Now try to restore whatever hardware state we might have
	 * saved when the fb device was first opened.
	 */
	uvesafb_vbe_state_restore(par, par->vbe_state_orig);
out:
	atomic_dec(&par->ref_count);
	if (task)
		uvesafb_free(task);
	return 0;
}

static int uvesafb_set_par(struct fb_info *info)
{
	struct uvesafb_par *par = info->par;
	struct uvesafb_ktask *task = NULL;
	struct vbe_crtc_ib *crtc = NULL;
	struct vbe_mode_ib *mode = NULL;
	int i, err = 0, depth = info->var.bits_per_pixel;

	if (depth > 8 && depth != 32)
		depth = info->var.red.length + info->var.green.length +
			info->var.blue.length;

	i = uvesafb_vbe_find_mode(par, info->var.xres, info->var.yres, depth,
				 UVESAFB_EXACT_RES | UVESAFB_EXACT_DEPTH);
	if (i >= 0)
		mode = &par->vbe_modes[i];
	else
		return -EINVAL;

	task = uvesafb_prep();
	if (!task)
		return -ENOMEM;
setmode:
	task->t.regs.eax = 0x4f02;
	task->t.regs.ebx = mode->mode_id | 0x4000;	/* use LFB */

	if (par->vbe_ib.vbe_version >= 0x0300 && !par->nocrtc &&
	    info->var.pixclock != 0) {
		task->t.regs.ebx |= 0x0800;		/* use CRTC data */
		task->t.flags = TF_BUF_ESDI;
		crtc = kzalloc(sizeof(struct vbe_crtc_ib), GFP_KERNEL);
		if (!crtc) {
			err = -ENOMEM;
			goto out;
		}
		crtc->horiz_start = info->var.xres + info->var.right_margin;
		crtc->horiz_end	  = crtc->horiz_start + info->var.hsync_len;
		crtc->horiz_total = crtc->horiz_end + info->var.left_margin;

		crtc->vert_start  = info->var.yres + info->var.lower_margin;
		crtc->vert_end    = crtc->vert_start + info->var.vsync_len;
		crtc->vert_total  = crtc->vert_end + info->var.upper_margin;

		crtc->pixel_clock = PICOS2KHZ(info->var.pixclock) * 1000;
		crtc->refresh_rate = (u16)(100 * (crtc->pixel_clock /
				(crtc->vert_total * crtc->horiz_total)));

		if (info->var.vmode & FB_VMODE_DOUBLE)
			crtc->flags |= 0x1;
		if (info->var.vmode & FB_VMODE_INTERLACED)
			crtc->flags |= 0x2;
		if (!(info->var.sync & FB_SYNC_HOR_HIGH_ACT))
			crtc->flags |= 0x4;
		if (!(info->var.sync & FB_SYNC_VERT_HIGH_ACT))
			crtc->flags |= 0x8;
		memcpy(&par->crtc, crtc, sizeof(*crtc));
	} else {
		memset(&par->crtc, 0, sizeof(*crtc));
	}

	task->t.buf_len = sizeof(struct vbe_crtc_ib);
	task->buf = &par->crtc;

	err = uvesafb_exec(task);
	if (err || (task->t.regs.eax & 0xffff) != 0x004f) {
		/*
		 * The mode switch might have failed because we tried to
		 * use our own timings.  Try again with the default timings.
		 */
		if (crtc != NULL) {
			printk(KERN_WARNING "uvesafb: mode switch failed "
				"(eax=0x%x, err=%d). Trying again with "
				"default timings.\n", task->t.regs.eax, err);
			uvesafb_reset(task);
			kfree(crtc);
			crtc = NULL;
			info->var.pixclock = 0;
			goto setmode;
		} else {
			printk(KERN_ERR "uvesafb: mode switch failed (eax="
				"0x%x, err=%d)\n", task->t.regs.eax, err);
			err = -EINVAL;
			goto out;
		}
	}
	par->mode_idx = i;

	/* For 8bpp modes, always try to set the DAC to 8 bits. */
	if (par->vbe_ib.capabilities & VBE_CAP_CAN_SWITCH_DAC &&
	    mode->bits_per_pixel <= 8) {
		uvesafb_reset(task);
		task->t.regs.eax = 0x4f08;
		task->t.regs.ebx = 0x0800;

		err = uvesafb_exec(task);
		if (err || (task->t.regs.eax & 0xffff) != 0x004f ||
		    ((task->t.regs.ebx & 0xff00) >> 8) != 8) {
			/*
			 * We've failed to set the DAC palette format -
			 * time to correct var.
			 */
			info->var.red.length    = 6;
			info->var.green.length  = 6;
			info->var.blue.length   = 6;
		}
	}

	info->fix.visual = (info->var.bits_per_pixel == 8) ?
				FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;
	info->fix.line_length = mode->bytes_per_scan_line;

out:	if (crtc != NULL)
		kfree(crtc);
	uvesafb_free(task);

	return err;
}

static void uvesafb_check_limits(struct fb_var_screeninfo *var,
		struct fb_info *info)
{
	const struct fb_videomode *mode;
	struct uvesafb_par *par = info->par;

	/*
	 * If pixclock is set to 0, then we're using default BIOS timings
	 * and thus don't have to perform any checks here.
	 */
	if (!var->pixclock)
		return;

	if (par->vbe_ib.vbe_version < 0x0300) {
		fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON, 60, var, info);
		return;
	}

	if (!fb_validate_mode(var, info))
		return;

	mode = fb_find_best_mode(var, &info->modelist);
	if (mode) {
		if (mode->xres == var->xres && mode->yres == var->yres &&
		    !(mode->vmode & (FB_VMODE_INTERLACED | FB_VMODE_DOUBLE))) {
			fb_videomode_to_var(var, mode);
			return;
		}
	}

	if (info->monspecs.gtf && !fb_get_mode(FB_MAXTIMINGS, 0, var, info))
		return;
	/* Use default refresh rate */
	var->pixclock = 0;
}

static int uvesafb_check_var(struct fb_var_screeninfo *var,
		struct fb_info *info)
{
	struct uvesafb_par *par = info->par;
	struct vbe_mode_ib *mode = NULL;
	int match = -1;
	int depth = var->red.length + var->green.length + var->blue.length;

	/*
	 * Various apps will use bits_per_pixel to set the color depth,
	 * which is theoretically incorrect, but which we'll try to handle
	 * here.
	 */
	if (depth == 0 || abs(depth - var->bits_per_pixel) >= 8)
		depth = var->bits_per_pixel;

	match = uvesafb_vbe_find_mode(par, var->xres, var->yres, depth,
						UVESAFB_EXACT_RES);
	if (match == -1)
		return -EINVAL;

	mode = &par->vbe_modes[match];
	uvesafb_setup_var(var, info, mode);

	/*
	 * Check whether we have remapped enough memory for this mode.
	 * We might be called at an early stage, when we haven't remapped
	 * any memory yet, in which case we simply skip the check.
	 */
	if (var->yres * mode->bytes_per_scan_line > info->fix.smem_len
						&& info->fix.smem_len)
		return -EINVAL;

	if ((var->vmode & FB_VMODE_DOUBLE) &&
				!(par->vbe_modes[match].mode_attr & 0x100))
		var->vmode &= ~FB_VMODE_DOUBLE;

	if ((var->vmode & FB_VMODE_INTERLACED) &&
				!(par->vbe_modes[match].mode_attr & 0x200))
		var->vmode &= ~FB_VMODE_INTERLACED;

	uvesafb_check_limits(var, info);

	var->xres_virtual = var->xres;
	var->yres_virtual = (par->ypan) ?
				info->fix.smem_len / mode->bytes_per_scan_line :
				var->yres;
	return 0;
}

static void uvesafb_save_state(struct fb_info *info)
{
	struct uvesafb_par *par = info->par;

	if (par->vbe_state_saved)
		kfree(par->vbe_state_saved);

	par->vbe_state_saved = uvesafb_vbe_state_save(par);
}

static void uvesafb_restore_state(struct fb_info *info)
{
	struct uvesafb_par *par = info->par;

	uvesafb_vbe_state_restore(par, par->vbe_state_saved);
}

static struct fb_ops uvesafb_ops = {
	.owner		= THIS_MODULE,
	.fb_open	= uvesafb_open,
	.fb_release	= uvesafb_release,
	.fb_setcolreg	= uvesafb_setcolreg,
	.fb_setcmap	= uvesafb_setcmap,
	.fb_pan_display	= uvesafb_pan_display,
	.fb_blank	= uvesafb_blank,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
	.fb_check_var	= uvesafb_check_var,
	.fb_set_par	= uvesafb_set_par,
	.fb_save_state	= uvesafb_save_state,
	.fb_restore_state = uvesafb_restore_state,
};

static void __devinit uvesafb_init_info(struct fb_info *info,
		struct vbe_mode_ib *mode)
{
	unsigned int size_vmode;
	unsigned int size_remap;
	unsigned int size_total;
	struct uvesafb_par *par = info->par;
	int i, h;

	info->pseudo_palette = ((u8 *)info->par + sizeof(struct uvesafb_par));
	info->fix = uvesafb_fix;
	info->fix.ypanstep = par->ypan ? 1 : 0;
	info->fix.ywrapstep = (par->ypan > 1) ? 1 : 0;

	/*
	 * If we were unable to get the state buffer size, disable
	 * functions for saving and restoring the hardware state.
	 */
	if (par->vbe_state_size == 0) {
		info->fbops->fb_save_state = NULL;
		info->fbops->fb_restore_state = NULL;
	}

	/* Disable blanking if the user requested so. */
	if (!blank)
		info->fbops->fb_blank = NULL;

	/*
	 * Find out how much IO memory is required for the mode with
	 * the highest resolution.
	 */
	size_remap = 0;
	for (i = 0; i < par->vbe_modes_cnt; i++) {
		h = par->vbe_modes[i].bytes_per_scan_line *
					par->vbe_modes[i].y_res;
		if (h > size_remap)
			size_remap = h;
	}
	size_remap *= 2;

	/*
	 *   size_vmode -- that is the amount of memory needed for the
	 *                 used video mode, i.e. the minimum amount of
	 *                 memory we need.
	 */
	if (mode != NULL) {
		size_vmode = info->var.yres * mode->bytes_per_scan_line;
	} else {
		size_vmode = info->var.yres * info->var.xres *
			     ((info->var.bits_per_pixel + 7) >> 3);
	}

	/*
	 *   size_total -- all video memory we have. Used for mtrr
	 *                 entries, resource allocation and bounds
	 *                 checking.
	 */
	size_total = par->vbe_ib.total_memory * 65536;
	if (vram_total)
		size_total = vram_total * 1024 * 1024;
	if (size_total < size_vmode)
		size_total = size_vmode;

	/*
	 *   size_remap -- the amount of video memory we are going to
	 *                 use for vesafb.  With modern cards it is no
	 *                 option to simply use size_total as th
	 *                 wastes plenty of kernel address space.
	 */
	if (vram_remap)
		size_remap = vram_remap * 1024 * 1024;
	if (size_remap < size_vmode)
		size_remap = size_vmode;
	if (size_remap > size_total)
		size_remap = size_total;

	info->fix.smem_len = size_remap;
	info->fix.smem_start = mode->phys_base_ptr;

	/*
	 * We have to set yres_virtual here because when setup_var() was
	 * called, smem_len wasn't defined yet.
	 */
	info->var.yres_virtual = info->fix.smem_len /
				 mode->bytes_per_scan_line;

	if (par->ypan && info->var.yres_virtual > info->var.yres) {
		printk(KERN_INFO "uvesafb: scrolling: %s "
			"using protected mode interface, "
			"yres_virtual=%d\n",
			(par->ypan > 1) ? "ywrap" : "ypan",
			info->var.yres_virtual);
	} else {
		printk(KERN_INFO "uvesafb: scrolling: redraw\n");
		info->var.yres_virtual = info->var.yres;
		par->ypan = 0;
	}

	info->flags = FBINFO_FLAG_DEFAULT |
			(par->ypan) ? FBINFO_HWACCEL_YPAN : 0;

	if (!par->ypan)
		info->fbops->fb_pan_display = NULL;
}