acornfb.c

Linux环境下视频显示卡设备的驱动程序源代码

	printk(KERN_DEBUG " Fsize            : 0x%08X\n", fsize);
#endif
}

/*
 * We have to take note of the VIDC20's 16-bit palette here.
 * The VIDC20 looks up a 16 bit pixel as follows:
 *
 *   bits   111111
 *          5432109876543210
 *   red            ++++++++  (8 bits,  7 to 0)
 *  green       ++++++++      (8 bits, 11 to 4)
 *   blue   ++++++++          (8 bits, 15 to 8)
 *
 * We use a pixel which looks like:
 *
 *   bits   111111
 *          5432109876543210
 *   red               +++++  (5 bits,  4 to  0)
 *  green         +++++       (5 bits,  9 to  5)
 *   blue    +++++            (5 bits, 14 to 10)
 */
static int
acornfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
		  u_int trans, struct fb_info *info)
{
	union palette pal;

	if (regno >= current_par.palette_size)
		return 1;

	if (regno < 16 && info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
		u32 pseudo_val;

		pseudo_val  = regno << info->var.red.offset;
		pseudo_val |= regno << info->var.green.offset;
		pseudo_val |= regno << info->var.blue.offset;

		((u32 *)info->pseudo_palette)[regno] = pseudo_val;
	}

	pal.p = 0;
	pal.vidc20.red   = red >> 8;
	pal.vidc20.green = green >> 8;
	pal.vidc20.blue  = blue >> 8;

	current_par.palette[regno] = pal;

	if (info->var.bits_per_pixel == 16) {
		int i;

		pal.p = 0;
		vidc_writel(0x10000000);
		for (i = 0; i < 256; i += 1) {
			pal.vidc20.red   = current_par.palette[ i       & 31].vidc20.red;
			pal.vidc20.green = current_par.palette[(i >> 1) & 31].vidc20.green;
			pal.vidc20.blue  = current_par.palette[(i >> 2) & 31].vidc20.blue;
			vidc_writel(pal.p);
			/* Palette register pointer auto-increments */
		}
	} else {
		vidc_writel(0x10000000 | regno);
		vidc_writel(pal.p);
	}

	return 0;
}
#endif

/*
 * Before selecting the timing parameters, adjust
 * the resolution to fit the rules.
 */
static int
acornfb_adjust_timing(struct fb_info *info, struct fb_var_screeninfo *var, u_int fontht)
{
	u_int font_line_len, sam_size, min_size, size, nr_y;

	/* xres must be even */
	var->xres = (var->xres + 1) & ~1;

	/*
	 * We don't allow xres_virtual to differ from xres
	 */
	var->xres_virtual = var->xres;
	var->xoffset = 0;

	if (current_par.using_vram)
		sam_size = current_par.vram_half_sam * 2;
	else
		sam_size = 16;

	/*
	 * Now, find a value for yres_virtual which allows
	 * us to do ywrap scrolling.  The value of
	 * yres_virtual must be such that the end of the
	 * displayable frame buffer must be aligned with
	 * the start of a font line.
	 */
	font_line_len = var->xres * var->bits_per_pixel * fontht / 8;
	min_size = var->xres * var->yres * var->bits_per_pixel / 8;

	/*
	 * If minimum screen size is greater than that we have
	 * available, reject it.
	 */
	if (min_size > info->fix.smem_len)
		return -EINVAL;

	/* Find int 'y', such that y * fll == s * sam < maxsize
	 * y = s * sam / fll; s = maxsize / sam
	 */
	for (size = info->fix.smem_len;
	     nr_y = size / font_line_len, min_size <= size;
	     size -= sam_size) {
		if (nr_y * font_line_len == size)
			break;
	}
	nr_y *= fontht;

	if (var->accel_flags & FB_ACCELF_TEXT) {
		if (min_size > size) {
			/*
			 * failed, use ypan
			 */
			size = info->fix.smem_len;
			var->yres_virtual = size / (font_line_len / fontht);
		} else
			var->yres_virtual = nr_y;
	} else if (var->yres_virtual > nr_y)
		var->yres_virtual = nr_y;

	current_par.screen_end = info->fix.smem_start + size;

	/*
	 * Fix yres & yoffset if needed.
	 */
	if (var->yres > var->yres_virtual)
		var->yres = var->yres_virtual;

	if (var->vmode & FB_VMODE_YWRAP) {
		if (var->yoffset > var->yres_virtual)
			var->yoffset = var->yres_virtual;
	} else {
		if (var->yoffset + var->yres > var->yres_virtual)
			var->yoffset = var->yres_virtual - var->yres;
	}

	/* hsync_len must be even */
	var->hsync_len = (var->hsync_len + 1) & ~1;

#ifdef HAS_VIDC
	/* left_margin must be odd */
	if ((var->left_margin & 1) == 0) {
		var->left_margin -= 1;
		var->right_margin += 1;
	}

	/* right_margin must be odd */
	var->right_margin |= 1;
#elif defined(HAS_VIDC20)
	/* left_margin must be even */
	if (var->left_margin & 1) {
		var->left_margin += 1;
		var->right_margin -= 1;
	}

	/* right_margin must be even */
	if (var->right_margin & 1)
		var->right_margin += 1;
#endif

	if (var->vsync_len < 1)
		var->vsync_len = 1;

	return 0;
}

static int
acornfb_validate_timing(struct fb_var_screeninfo *var,
			struct fb_monspecs *monspecs)
{
	unsigned long hs, vs;

	/*
	 * hs(Hz) = 10^12 / (pixclock * xtotal)
	 * vs(Hz) = hs(Hz) / ytotal
	 *
	 * No need to do long long divisions or anything
	 * like that if you factor it correctly
	 */
	hs = 1953125000 / var->pixclock;
	hs = hs * 512 /
	     (var->xres + var->left_margin + var->right_margin + var->hsync_len);
	vs = hs /
	     (var->yres + var->upper_margin + var->lower_margin + var->vsync_len);

	return (vs >= monspecs->vfmin && vs <= monspecs->vfmax &&
		hs >= monspecs->hfmin && hs <= monspecs->hfmax) ? 0 : -EINVAL;
}

static inline void
acornfb_update_dma(struct fb_info *info, struct fb_var_screeninfo *var)
{
	u_int off = var->yoffset * info->fix.line_length;

#if defined(HAS_MEMC)
	memc_write(VDMA_INIT, off >> 2);
#elif defined(HAS_IOMD)
	iomd_writel(info->fix.smem_start + off, IOMD_VIDINIT);
#endif
}

static int
acornfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	u_int fontht;
	int err;

	/*
	 * FIXME: Find the font height
	 */
	fontht = 8;

	var->red.msb_right = 0;
	var->green.msb_right = 0;
	var->blue.msb_right = 0;
	var->transp.msb_right = 0;

	switch (var->bits_per_pixel) {
	case 1:	case 2:	case 4:	case 8:
		var->red.offset    = 0;
		var->red.length    = var->bits_per_pixel;
		var->green         = var->red;
		var->blue          = var->red;
		var->transp.offset = 0;
		var->transp.length = 0;
		break;

#ifdef HAS_VIDC20
	case 16:
		var->red.offset    = 0;
		var->red.length    = 5;
		var->green.offset  = 5;
		var->green.length  = 5;
		var->blue.offset   = 10;
		var->blue.length   = 5;
		var->transp.offset = 15;
		var->transp.length = 1;
		break;

	case 32:
		var->red.offset    = 0;
		var->red.length    = 8;
		var->green.offset  = 8;
		var->green.length  = 8;
		var->blue.offset   = 16;
		var->blue.length   = 8;
		var->transp.offset = 24;
		var->transp.length = 4;
		break;
#endif
	default:
		return -EINVAL;
	}

	/*
	 * Check to see if the pixel rate is valid.
	 */
	if (!acornfb_valid_pixrate(var))
		return -EINVAL;

	/*
	 * Validate and adjust the resolution to
	 * match the video generator hardware.
	 */
	err = acornfb_adjust_timing(info, var, fontht);
	if (err)
		return err;

	/*
	 * Validate the timing against the
	 * monitor hardware.
	 */
	return acornfb_validate_timing(var, &info->monspecs);
}

static int acornfb_set_par(struct fb_info *info)
{
	switch (info->var.bits_per_pixel) {
	case 1:
		current_par.palette_size = 2;
		info->fix.visual = FB_VISUAL_MONO10;
		break;
	case 2:
		current_par.palette_size = 4;
		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
		break;
	case 4:
		current_par.palette_size = 16;
		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
		break;
	case 8:
		current_par.palette_size = VIDC_PALETTE_SIZE;
#ifdef HAS_VIDC
		info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
#else
		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
#endif
		break;
#ifdef HAS_VIDC20
	case 16:
		current_par.palette_size = 32;
		info->fix.visual = FB_VISUAL_DIRECTCOLOR;
		break;
	case 32:
		current_par.palette_size = VIDC_PALETTE_SIZE;
		info->fix.visual = FB_VISUAL_DIRECTCOLOR;
		break;
#endif
	default:
		BUG();
	}

	info->fix.line_length	= (info->var.xres * info->var.bits_per_pixel) / 8;

#if defined(HAS_MEMC)
	{
		unsigned long size = info->fix.smem_len - VDMA_XFERSIZE;

		memc_write(VDMA_START, 0);
		memc_write(VDMA_END, size >> 2);
	}
#elif defined(HAS_IOMD)
	{
		unsigned long start, size;
		u_int control;

		start = info->fix.smem_start;
		size  = current_par.screen_end;

		if (current_par.using_vram) {
			size -= current_par.vram_half_sam;
			control = DMA_CR_E | (current_par.vram_half_sam / 256);
		} else {
			size -= 16;
			control = DMA_CR_E | DMA_CR_D | 16;
		}

		iomd_writel(start,   IOMD_VIDSTART);
		iomd_writel(size,    IOMD_VIDEND);
		iomd_writel(control, IOMD_VIDCR);
	}
#endif

	acornfb_update_dma(info, &info->var);
	acornfb_set_timing(info);

	return 0;
}

static int
acornfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
	u_int y_bottom = var->yoffset;

	if (!(var->vmode & FB_VMODE_YWRAP))
		y_bottom += var->yres;

	BUG_ON(y_bottom > var->yres_virtual);

	acornfb_update_dma(info, var);

	return 0;
}

/*
 * Note that we are entered with the kernel locked.
 */
static int
acornfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
	unsigned long off, start;
	u32 len;

	off = vma->vm_pgoff << PAGE_SHIFT;

	start = info->fix.smem_start;
	len = PAGE_ALIGN(start & ~PAGE_MASK) + info->fix.smem_len;
	start &= PAGE_MASK;
	if ((vma->vm_end - vma->vm_start + off) > len)
		return -EINVAL;
	off += start;
	vma->vm_pgoff = off >> PAGE_SHIFT;

	/* This is an IO map - tell maydump to skip this VMA */
	vma->vm_flags |= VM_IO;

	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);

	/*
	 * Don't alter the page protection flags; we want to keep the area
	 * cached for better performance.  This does mean that we may miss
	 * some updates to the screen occasionally, but process switches
	 * should cause the caches and buffers to be flushed often enough.
	 */
	if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
				vma->vm_end - vma->vm_start,
				vma->vm_page_prot))
		return -EAGAIN;
	return 0;
}

static struct fb_ops acornfb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= acornfb_check_var,
	.fb_set_par	= acornfb_set_par,
	.fb_setcolreg	= acornfb_setcolreg,
	.fb_pan_display	= acornfb_pan_display,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
	.fb_mmap	= acornfb_mmap,
};

/*
 * Everything after here is initialisation!!!
 */
static struct fb_videomode modedb[] __initdata = {
	{	/* 320x256 @ 50Hz */
		NULL, 50,  320,  256, 125000,  92,  62,  35, 19,  38, 2,
		FB_SYNC_COMP_HIGH_ACT,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x250 @ 50Hz, 15.6 kHz hsync */
		NULL, 50,  640,  250,  62500, 185, 123,  38, 21,  76, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x256 @ 50Hz, 15.6 kHz hsync */
		NULL, 50,  640,  256,  62500, 185, 123,  35, 18,  76, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x512 @ 50Hz, 26.8 kHz hsync */
		NULL, 50,  640,  512,  41667, 113,  87,  18,  1,  56, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x250 @ 70Hz, 31.5 kHz hsync */
		NULL, 70,  640,  250,  39722,  48,  16, 109, 88,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x256 @ 70Hz, 31.5 kHz hsync */
		NULL, 70,  640,  256,  39722,  48,  16, 106, 85,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x352 @ 70Hz, 31.5 kHz hsync */
		NULL, 70,  640,  352,  39722,  48,  16,  58, 37,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 640x480 @ 60Hz, 31.5 kHz hsync */
		NULL, 60,  640,  480,  39722,  48,  16,  32, 11,  96, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 800x600 @ 56Hz, 35.2 kHz hsync */
		NULL, 56,  800,  600,  27778, 101,  23,  22,  1, 100, 2,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 896x352 @ 60Hz, 21.8 kHz hsync */
		NULL, 60,  896,  352,  41667,  59,  27,   9,  0, 118, 3,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 1024x 768 @ 60Hz, 48.4 kHz hsync */
		NULL, 60, 1024,  768,  15385, 160,  24,  29,  3, 136, 6,
		0,
		FB_VMODE_NONINTERLACED
	}, {	/* 1280x1024 @ 60Hz, 63.8 kHz hsync */
		NULL, 60, 1280, 1024,   9090, 186,  96,  38,  1, 160, 3,
		0,
		FB_VMODE_NONINTERLACED
	}
};

static struct fb_videomode __initdata
acornfb_default_mode = {
	.name =		NULL,
	.refresh =	60,
	.xres =		640,