/* * 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/tty.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <asm/uaccess.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); static struct fb_var_screeninfo vfb_default __initdata = { .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 __initdata = { .id = "Virtual FB", .type = FB_TYPE_PACKED_PIXELS, .visual = FB_VISUAL_PSEUDOCOLOR, .xpanstep = 1, .ypanstep = 1, .ywrapstep = 1, .accel = FB_ACCEL_NONE, }; static int 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 file *file, struct vm_area_struct *vma); static struct fb_ops vfb_ops = { .fb_check_var = vfb_check_var, .fb_set_par = vfb_set_par, .fb_setcolreg = vfb_setcolreg, .fb_pan_display = vfb_pan_display, .fb_fillrect = cfb_fillrect, .fb_copyarea = cfb_copyarea, .fb_imageblit = cfb_imageblit, .fb_cursor = soft_cursor, .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: * uses offset = 0 && length = RAMDAC register width. * var->{color}.offset is 0 * var->{color}.length contains widht of DAC * 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 < 0 || var->yoffset >= info->var.yres_virtual || var->xoffset) return -EINVAL; } else { if (var->xoffset + var->xres > info->var.xres_virtual || var->yoffset + 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 file *file, struct vm_area_struct *vma) { return -EINVAL; } #ifndef MODULE static int __init vfb_setup(char *options) { char *this_opt; vfb_enable = 1; if (!options || !*options) return 1; while ((this_opt = strsep(&options, ",")) != NULL) { if (!*this_opt) continue; if (!strncmp(this_opt, "disable", 7)) vfb_enable = 0; } return 1; } #endif /* MODULE */ /* * Initialisation */ static void vfb_platform_release(struct device *device) { // This is called when the reference count goes to zero. } static int __init vfb_probe(struct device *device) { struct platform_device *dev = to_platform_device(device); struct fb_info *info; int retval = -ENOMEM; /* * For real video cards we use ioremap. */ if (!(videomemory = vmalloc(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; 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; dev_set_drvdata(&dev->dev, info); printk(KERN_INFO "fb%d: Virtual frame buffer device, using %ldK of video memory\n", info->node, videomemorysize >> 10); return 0; err2: fb_dealloc_cmap(&info->cmap); err1: framebuffer_release(info); err: vfree(videomemory); return retval; } static int vfb_remove(struct device *device) { struct fb_info *info = dev_get_drvdata(device); if (info) { unregister_framebuffer(info); vfree(videomemory); framebuffer_release(info); } return 0; } static struct device_driver vfb_driver = { .name = "vfb", .bus = &platform_bus_type, .probe = vfb_probe, .remove = vfb_remove, }; static struct platform_device vfb_device = { .name = "vfb", .id = 0, .dev = { .release = vfb_platform_release, } }; 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 = driver_register(&vfb_driver); if (!ret) { ret = platform_device_register(&vfb_device); if (ret) driver_unregister(&vfb_driver); } return ret; } module_init(vfb_init); #ifdef MODULE static void __exit vfb_exit(void) { platform_device_unregister(&vfb_device); driver_unregister(&vfb_driver); } module_exit(vfb_exit); MODULE_LICENSE("GPL"); #endif /* MODULE */