diff options
Diffstat (limited to 'drivers/video/fbdev/vfb.c')
| -rw-r--r-- | drivers/video/fbdev/vfb.c | 610 | 
1 files changed, 610 insertions, 0 deletions
diff --git a/drivers/video/fbdev/vfb.c b/drivers/video/fbdev/vfb.c new file mode 100644 index 000000000000..70a897b1e458 --- /dev/null +++ b/drivers/video/fbdev/vfb.c @@ -0,0 +1,610 @@ +/* + *  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); + +/********************************************************************** + * + * Memory management + * + **********************************************************************/ +static void *rvmalloc(unsigned long size) +{ +	void *mem; +	unsigned long adr; + +	size = PAGE_ALIGN(size); +	mem = vmalloc_32(size); +	if (!mem) +		return NULL; + +	memset(mem, 0, size); /* Clear the ram out, no junk to the user */ +	adr = (unsigned long) mem; +	while (size > 0) { +		SetPageReserved(vmalloc_to_page((void *)adr)); +		adr += PAGE_SIZE; +		size -= PAGE_SIZE; +	} + +	return mem; +} + +static void rvfree(void *mem, unsigned long size) +{ +	unsigned long adr; + +	if (!mem) +		return; + +	adr = (unsigned long) mem; +	while ((long) size > 0) { +		ClearPageReserved(vmalloc_to_page((void *)adr)); +		adr += PAGE_SIZE; +		size -= PAGE_SIZE; +	} +	vfree(mem); +} + +static struct fb_var_screeninfo vfb_default = { +	.xres =		640, +	.yres =		480, +	.xres_virtual =	640, +	.yres_virtual =	480, +	.bits_per_pixel = 8, +	.red =		{ 0, 8, 0 }, +      	.green =	{ 0, 8, 0 }, +      	.blue =		{ 0, 8, 0 }, +      	.activate =	FB_ACTIVATE_TEST, +      	.height =	-1, +      	.width =	-1, +      	.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); + +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 struct fb_ops vfb_ops = { +	.fb_read        = fb_sys_read, +	.fb_write       = fb_sys_write, +	.fb_check_var	= vfb_check_var, +	.fb_set_par	= vfb_set_par, +	.fb_setcolreg	= vfb_setcolreg, +	.fb_pan_display	= vfb_pan_display, +	.fb_fillrect	= sys_fillrect, +	.fb_copyarea	= sys_copyarea, +	.fb_imageblit	= sys_imageblit, +	.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) +{ +	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) +{ +	unsigned long start = vma->vm_start; +	unsigned long size = vma->vm_end - vma->vm_start; +	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; +	unsigned long page, pos; + +	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) +		return -EINVAL; +	if (size > info->fix.smem_len) +		return -EINVAL; +	if (offset > info->fix.smem_len - size) +		return -EINVAL; + +	pos = (unsigned long)info->fix.smem_start + offset; + +	while (size > 0) { +		page = vmalloc_to_pfn((void *)pos); +		if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) { +			return -EAGAIN; +		} +		start += PAGE_SIZE; +		pos += PAGE_SIZE; +		if (size > PAGE_SIZE) +			size -= PAGE_SIZE; +		else +			size = 0; +	} + +	return 0; + +} + +#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; +	} +	return 1; +} +#endif  /*  MODULE  */ + +    /* +     *  Initialisation +     */ + +static int vfb_probe(struct platform_device *dev) +{ +	struct fb_info *info; +	int retval = -ENOMEM; + +	/* +	 * For real video cards we use ioremap. +	 */ +	if (!(videomemory = rvmalloc(videomemorysize))) +		return retval; + +	/* +	 * VFB must clear memory to prevent kernel info +	 * leakage into userspace +	 * VGA-based drivers MUST NOT clear memory if +	 * they want to be able to take over vgacon +	 */ +	memset(videomemory, 0, videomemorysize); + +	info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev); +	if (!info) +		goto err; + +	info->screen_base = (char __iomem *)videomemory; +	info->fbops = &vfb_ops; + +	retval = fb_find_mode(&info->var, info, NULL, +			      NULL, 0, NULL, 8); + +	if (!retval || (retval == 4)) +		info->var = vfb_default; +	vfb_fix.smem_start = (unsigned long) videomemory; +	vfb_fix.smem_len = videomemorysize; +	info->fix = vfb_fix; +	info->pseudo_palette = info->par; +	info->par = NULL; +	info->flags = FBINFO_FLAG_DEFAULT; + +	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); + +	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: +	rvfree(videomemory, videomemorysize); +	return retval; +} + +static int vfb_remove(struct platform_device *dev) +{ +	struct fb_info *info = platform_get_drvdata(dev); + +	if (info) { +		unregister_framebuffer(info); +		rvfree(videomemory, videomemorysize); +		fb_dealloc_cmap(&info->cmap); +		framebuffer_release(info); +	} +	return 0; +} + +static struct platform_driver vfb_driver = { +	.probe	= vfb_probe, +	.remove = vfb_remove, +	.driver = { +		.name	= "vfb", +	}, +}; + +static struct platform_device *vfb_device; + +static int __init vfb_init(void) +{ +	int ret = 0; + +#ifndef MODULE +	char *option = NULL; + +	if (fb_get_options("vfb", &option)) +		return -ENODEV; +	vfb_setup(option); +#endif + +	if (!vfb_enable) +		return -ENXIO; + +	ret = platform_driver_register(&vfb_driver); + +	if (!ret) { +		vfb_device = platform_device_alloc("vfb", 0); + +		if (vfb_device) +			ret = platform_device_add(vfb_device); +		else +			ret = -ENOMEM; + +		if (ret) { +			platform_device_put(vfb_device); +			platform_driver_unregister(&vfb_driver); +		} +	} + +	return ret; +} + +module_init(vfb_init); + +#ifdef MODULE +static void __exit vfb_exit(void) +{ +	platform_device_unregister(vfb_device); +	platform_driver_unregister(&vfb_driver); +} + +module_exit(vfb_exit); + +MODULE_LICENSE("GPL"); +#endif				/* MODULE */  | 

