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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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", },};
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 MODULEstatic void __exit vfb_exit(void){ platform_device_unregister(vfb_device); platform_driver_unregister(&vfb_driver);}
module_exit(vfb_exit);
MODULE_DESCRIPTION("Virtual Frame Buffer driver");MODULE_LICENSE("GPL");#endif /* MODULE */