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/* *  linux/drivers/video/vfb.c -- Virtual frame buffer device * *      Copyright (C) 2002 James Simmons * *	Copyright (C) 1997 Geert Uytterhoeven * *  This file is subject to the terms and conditions of the GNU General Public *  License. See the file COPYING in the main directory of this archive for *  more details. */ #include <linux/module.h>#include <linux/kernel.h>#include <linux/errno.h>#include <linux/string.h>#include <linux/mm.h>#include <linux/vmalloc.h>#include <linux/delay.h>#include <linux/interrupt.h>#include <linux/platform_device.h> #include <linux/fb.h>#include <linux/init.h>     /*     *  RAM we reserve for the frame buffer. This defines the maximum screen     *  size     *     *  The default can be overridden if the driver is compiled as a module     */ #define VIDEOMEMSIZE	(1*1024*1024)	/* 1 MB */ static void *videomemory;static u_long videomemorysize = VIDEOMEMSIZE;module_param(videomemorysize, ulong, 0);MODULE_PARM_DESC(videomemorysize, "RAM available to frame buffer (in bytes)"); static char *mode_option = NULL;module_param(mode_option, charp, 0);MODULE_PARM_DESC(mode_option, "Preferred video mode (e.g. 640x480-8@60)"); static const struct fb_videomode vfb_default = {	.xres =		640,	.yres =		480,	.pixclock =	20000,	.left_margin =	64,	.right_margin =	64,	.upper_margin =	32,	.lower_margin =	32,	.hsync_len =	64,	.vsync_len =	2,	.vmode =	FB_VMODE_NONINTERLACED,}; static struct fb_fix_screeninfo vfb_fix = {	.id =		"Virtual FB",	.type =		FB_TYPE_PACKED_PIXELS,	.visual =	FB_VISUAL_PSEUDOCOLOR,	.xpanstep =	1,	.ypanstep =	1,	.ywrapstep =	1,	.accel =	FB_ACCEL_NONE,}; static bool vfb_enable __initdata = 0;	/* disabled by default */module_param(vfb_enable, bool, 0);MODULE_PARM_DESC(vfb_enable, "Enable Virtual FB driver"); static int vfb_check_var(struct fb_var_screeninfo *var,			 struct fb_info *info);static int vfb_set_par(struct fb_info *info);static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,			 u_int transp, struct fb_info *info);static int vfb_pan_display(struct fb_var_screeninfo *var,			   struct fb_info *info);static int vfb_mmap(struct fb_info *info,		    struct vm_area_struct *vma); static const struct fb_ops vfb_ops = {	.owner		= THIS_MODULE,	__FB_DEFAULT_SYSMEM_OPS_RDWR,	.fb_check_var	= vfb_check_var,	.fb_set_par	= vfb_set_par,	.fb_setcolreg	= vfb_setcolreg,	.fb_pan_display	= vfb_pan_display,	__FB_DEFAULT_SYSMEM_OPS_DRAW,	.fb_mmap	= vfb_mmap,};     /*     *  Internal routines     */ static u_long get_line_length(int xres_virtual, int bpp){	u_long length; 	length = xres_virtual * bpp;	length = (length + 31) & ~31;	length >>= 3;	return (length);}     /*     *  Setting the video mode has been split into two parts.     *  First part, xxxfb_check_var, must not write anything     *  to hardware, it should only verify and adjust var.     *  This means it doesn't alter par but it does use hardware     *  data from it to check this var.     */ static int vfb_check_var(struct fb_var_screeninfo *var,			 struct fb_info *info){	u_long line_length; 	/*	 *  FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!	 *  as FB_VMODE_SMOOTH_XPAN is only used internally	 */ 	if (var->vmode & FB_VMODE_CONUPDATE) {		var->vmode |= FB_VMODE_YWRAP;		var->xoffset = info->var.xoffset;		var->yoffset = info->var.yoffset;	} 	/*	 *  Some very basic checks	 */	if (!var->xres)		var->xres = 1;	if (!var->yres)		var->yres = 1;	if (var->xres > var->xres_virtual)		var->xres_virtual = var->xres;	if (var->yres > var->yres_virtual)		var->yres_virtual = var->yres;	if (var->bits_per_pixel <= 1)		var->bits_per_pixel = 1;	else if (var->bits_per_pixel <= 8)		var->bits_per_pixel = 8;	else if (var->bits_per_pixel <= 16)		var->bits_per_pixel = 16;	else if (var->bits_per_pixel <= 24)		var->bits_per_pixel = 24;	else if (var->bits_per_pixel <= 32)		var->bits_per_pixel = 32;	else		return -EINVAL; 	if (var->xres_virtual < var->xoffset + var->xres)		var->xres_virtual = var->xoffset + var->xres;	if (var->yres_virtual < var->yoffset + var->yres)		var->yres_virtual = var->yoffset + var->yres; 	/*	 *  Memory limit	 */	line_length =	    get_line_length(var->xres_virtual, var->bits_per_pixel);	if (line_length * var->yres_virtual > videomemorysize)		return -ENOMEM; 	/*	 * Now that we checked it we alter var. The reason being is that the video	 * mode passed in might not work but slight changes to it might make it	 * work. This way we let the user know what is acceptable.	 */	switch (var->bits_per_pixel) {	case 1:	case 8:		var->red.offset = 0;		var->red.length = 8;		var->green.offset = 0;		var->green.length = 8;		var->blue.offset = 0;		var->blue.length = 8;		var->transp.offset = 0;		var->transp.length = 0;		break;	case 16:		/* RGBA 5551 */		if (var->transp.length) {			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;		} else {	/* RGB 565 */			var->red.offset = 0;			var->red.length = 5;			var->green.offset = 5;			var->green.length = 6;			var->blue.offset = 11;			var->blue.length = 5;			var->transp.offset = 0;			var->transp.length = 0;		}		break;	case 24:		/* RGB 888 */		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 = 0;		var->transp.length = 0;		break;	case 32:		/* RGBA 8888 */		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 = 8;		break;	}	var->red.msb_right = 0;	var->green.msb_right = 0;	var->blue.msb_right = 0;	var->transp.msb_right = 0; 	return 0;} /* This routine actually sets the video mode. It's in here where we * the hardware state info->par and fix which can be affected by the * change in par. For this driver it doesn't do much. */static int vfb_set_par(struct fb_info *info){	switch (info->var.bits_per_pixel) {	case 1:		info->fix.visual = FB_VISUAL_MONO01;		break;	case 8:		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;		break;	case 16:	case 24:	case 32:		info->fix.visual = FB_VISUAL_TRUECOLOR;		break;	} 	info->fix.line_length = get_line_length(info->var.xres_virtual,						info->var.bits_per_pixel); 	return 0;}     /*     *  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.     */ static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,			 u_int transp, struct fb_info *info){	if (regno >= 256)	/* no. of hw registers */		return 1;	/*	 * Program hardware... do anything you want with transp	 */ 	/* grayscale works only partially under directcolor */	if (info->var.grayscale) {		/* grayscale = 0.30*R + 0.59*G + 0.11*B */		red = green = blue =		    (red * 77 + green * 151 + blue * 28) >> 8;	} 	/* Directcolor:	 *   var->{color}.offset contains start of bitfield	 *   var->{color}.length contains length of bitfield	 *   {hardwarespecific} contains width of RAMDAC	 *   cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)	 *   RAMDAC[X] is programmed to (red, green, blue)	 *	 * Pseudocolor:	 *    var->{color}.offset is 0 unless the palette index takes less than	 *                        bits_per_pixel bits and is stored in the upper	 *                        bits of the pixel value	 *    var->{color}.length is set so that 1 << length is the number of available	 *                        palette entries	 *    cmap is not used	 *    RAMDAC[X] is programmed to (red, green, blue)	 *	 * Truecolor:	 *    does not use DAC. Usually 3 are present.	 *    var->{color}.offset contains start of bitfield	 *    var->{color}.length contains length of bitfield	 *    cmap is programmed to (red << red.offset) | (green << green.offset) |	 *                      (blue << blue.offset) | (transp << transp.offset)	 *    RAMDAC does not exist	 */#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)	switch (info->fix.visual) {	case FB_VISUAL_TRUECOLOR:	case FB_VISUAL_PSEUDOCOLOR:		red = CNVT_TOHW(red, info->var.red.length);		green = CNVT_TOHW(green, info->var.green.length);		blue = CNVT_TOHW(blue, info->var.blue.length);		transp = CNVT_TOHW(transp, info->var.transp.length);		break;	case FB_VISUAL_DIRECTCOLOR:		red = CNVT_TOHW(red, 8);	/* expect 8 bit DAC */		green = CNVT_TOHW(green, 8);		blue = CNVT_TOHW(blue, 8);		/* hey, there is bug in transp handling... */		transp = CNVT_TOHW(transp, 8);		break;	}#undef CNVT_TOHW	/* Truecolor has hardware independent palette */	if (info->fix.visual == FB_VISUAL_TRUECOLOR) {		u32 v; 		if (regno >= 16)			return 1; 		v = (red << info->var.red.offset) |		    (green << info->var.green.offset) |		    (blue << info->var.blue.offset) |		    (transp << info->var.transp.offset);		switch (info->var.bits_per_pixel) {		case 8:			break;		case 16:			((u32 *) (info->pseudo_palette))[regno] = v;			break;		case 24:		case 32:			((u32 *) (info->pseudo_palette))[regno] = v;			break;		}		return 0;	}	return 0;}     /*     *  Pan or Wrap the Display     *     *  This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag     */ static int vfb_pan_display(struct fb_var_screeninfo *var,			   struct fb_info *info){	if (var->vmode & FB_VMODE_YWRAP) {		if (var->yoffset >= info->var.yres_virtual ||		    var->xoffset)			return -EINVAL;	} else {		if (var->xoffset + info->var.xres > info->var.xres_virtual ||		    var->yoffset + info->var.yres > info->var.yres_virtual)			return -EINVAL;	}	info->var.xoffset = var->xoffset;	info->var.yoffset = var->yoffset;	if (var->vmode & FB_VMODE_YWRAP)		info->var.vmode |= FB_VMODE_YWRAP;	else		info->var.vmode &= ~FB_VMODE_YWRAP;	return 0;}     /*     *  Most drivers don't need their own mmap function     */ static int vfb_mmap(struct fb_info *info,		    struct vm_area_struct *vma){	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); 	return remap_vmalloc_range(vma, (void *)info->fix.smem_start, vma->vm_pgoff);} #ifndef MODULE/* * The virtual framebuffer driver is only enabled if explicitly * requested by passing 'video=vfb:' (or any actual options). */static int __init vfb_setup(char *options){	char *this_opt; 	vfb_enable = 0; 	if (!options)		return 1; 	vfb_enable = 1; 	if (!*options)		return 1; 	while ((this_opt = strsep(&options, ",")) != NULL) {		if (!*this_opt)			continue;		/* Test disable for backwards compatibility */		if (!strcmp(this_opt, "disable"))			vfb_enable = 0;		else			mode_option = this_opt;	}	return 1;}#endif  /*  MODULE  */     /*     *  Initialisation     */ static int vfb_probe(struct platform_device *dev){	struct fb_info *info;	unsigned int size = PAGE_ALIGN(videomemorysize);	int retval = -ENOMEM; 	/*	 * For real video cards we use ioremap.	 */	if (!(videomemory = vmalloc_32_user(size)))		return retval; 	info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);	if (!info)		goto err; 	info->flags |= FBINFO_VIRTFB;	info->screen_buffer = videomemory;	info->fbops = &vfb_ops; 	if (!fb_find_mode(&info->var, info, mode_option,			  NULL, 0, &vfb_default, 8)){		fb_err(info, "Unable to find usable video mode.\n");		retval = -EINVAL;		goto err1;	} 	vfb_fix.smem_start = (unsigned long) videomemory;	vfb_fix.smem_len = videomemorysize;	info->fix = vfb_fix;	info->pseudo_palette = info->par;	info->par = NULL; 	retval = fb_alloc_cmap(&info->cmap, 256, 0);	if (retval < 0)		goto err1; 	retval = register_framebuffer(info);	if (retval < 0)		goto err2;	platform_set_drvdata(dev, info); 	vfb_set_par(info); 	fb_info(info, "Virtual frame buffer device, using %ldK of video memory\n",		videomemorysize >> 10);	return 0;err2:	fb_dealloc_cmap(&info->cmap);err1:	framebuffer_release(info);err:	vfree(videomemory);	return retval;} static void vfb_remove(struct platform_device *dev){	struct fb_info *info = platform_get_drvdata(dev); 	if (info) {		unregister_framebuffer(info);		vfree(videomemory);		fb_dealloc_cmap(&info->cmap);		framebuffer_release(info);	}} static struct platform_driver vfb_driver = {	.probe	= vfb_probe,	.remove = vfb_remove,	.driver = {		.name	= "vfb",	},};

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