612 lines
14 KiB
C
612 lines
14 KiB
C
/*
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* linux/drivers/video/vfb.c -- Virtual frame buffer device
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*
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* Copyright (C) 2002 James Simmons
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*
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* Copyright (C) 1997 Geert Uytterhoeven
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive for
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* more details.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/fb.h>
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#include <linux/init.h>
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/*
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* RAM we reserve for the frame buffer. This defines the maximum screen
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* size
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*
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* The default can be overridden if the driver is compiled as a module
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*/
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#define VIDEOMEMSIZE (1*1024*1024) /* 1 MB */
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static void *videomemory;
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static u_long videomemorysize = VIDEOMEMSIZE;
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module_param(videomemorysize, ulong, 0);
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/**********************************************************************
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*
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* Memory management
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*
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**********************************************************************/
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static void *rvmalloc(unsigned long size)
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{
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void *mem;
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unsigned long adr;
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size = PAGE_ALIGN(size);
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mem = vmalloc_32(size);
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if (!mem)
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return NULL;
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memset(mem, 0, size); /* Clear the ram out, no junk to the user */
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adr = (unsigned long) mem;
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while (size > 0) {
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SetPageReserved(vmalloc_to_page((void *)adr));
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adr += PAGE_SIZE;
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size -= PAGE_SIZE;
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}
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return mem;
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}
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static void rvfree(void *mem, unsigned long size)
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{
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unsigned long adr;
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if (!mem)
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return;
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adr = (unsigned long) mem;
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while ((long) size > 0) {
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ClearPageReserved(vmalloc_to_page((void *)adr));
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adr += PAGE_SIZE;
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size -= PAGE_SIZE;
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}
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vfree(mem);
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}
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static struct fb_var_screeninfo vfb_default __initdata = {
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.xres = 640,
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.yres = 480,
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.xres_virtual = 640,
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.yres_virtual = 480,
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.bits_per_pixel = 8,
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.red = { 0, 8, 0 },
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.green = { 0, 8, 0 },
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.blue = { 0, 8, 0 },
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.activate = FB_ACTIVATE_TEST,
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.height = -1,
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.width = -1,
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.pixclock = 20000,
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.left_margin = 64,
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.right_margin = 64,
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.upper_margin = 32,
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.lower_margin = 32,
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.hsync_len = 64,
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.vsync_len = 2,
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.vmode = FB_VMODE_NONINTERLACED,
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};
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static struct fb_fix_screeninfo vfb_fix __initdata = {
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.id = "Virtual FB",
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.type = FB_TYPE_PACKED_PIXELS,
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.visual = FB_VISUAL_PSEUDOCOLOR,
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.xpanstep = 1,
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.ypanstep = 1,
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.ywrapstep = 1,
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.accel = FB_ACCEL_NONE,
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};
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static int vfb_enable __initdata = 0; /* disabled by default */
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module_param(vfb_enable, bool, 0);
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static int vfb_check_var(struct fb_var_screeninfo *var,
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struct fb_info *info);
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static int vfb_set_par(struct fb_info *info);
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static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
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u_int transp, struct fb_info *info);
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static int vfb_pan_display(struct fb_var_screeninfo *var,
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struct fb_info *info);
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static int vfb_mmap(struct fb_info *info,
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struct vm_area_struct *vma);
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static struct fb_ops vfb_ops = {
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.fb_read = fb_sys_read,
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.fb_write = fb_sys_write,
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.fb_check_var = vfb_check_var,
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.fb_set_par = vfb_set_par,
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.fb_setcolreg = vfb_setcolreg,
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.fb_pan_display = vfb_pan_display,
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.fb_fillrect = sys_fillrect,
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.fb_copyarea = sys_copyarea,
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.fb_imageblit = sys_imageblit,
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.fb_mmap = vfb_mmap,
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};
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/*
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* Internal routines
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*/
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static u_long get_line_length(int xres_virtual, int bpp)
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{
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u_long length;
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length = xres_virtual * bpp;
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length = (length + 31) & ~31;
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length >>= 3;
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return (length);
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}
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/*
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* Setting the video mode has been split into two parts.
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* First part, xxxfb_check_var, must not write anything
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* to hardware, it should only verify and adjust var.
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* This means it doesn't alter par but it does use hardware
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* data from it to check this var.
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*/
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static int vfb_check_var(struct fb_var_screeninfo *var,
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struct fb_info *info)
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{
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u_long line_length;
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/*
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* FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
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* as FB_VMODE_SMOOTH_XPAN is only used internally
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*/
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if (var->vmode & FB_VMODE_CONUPDATE) {
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var->vmode |= FB_VMODE_YWRAP;
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var->xoffset = info->var.xoffset;
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var->yoffset = info->var.yoffset;
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}
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/*
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* Some very basic checks
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*/
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if (!var->xres)
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var->xres = 1;
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if (!var->yres)
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var->yres = 1;
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if (var->xres > var->xres_virtual)
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var->xres_virtual = var->xres;
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if (var->yres > var->yres_virtual)
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var->yres_virtual = var->yres;
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if (var->bits_per_pixel <= 1)
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var->bits_per_pixel = 1;
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else if (var->bits_per_pixel <= 8)
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var->bits_per_pixel = 8;
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else if (var->bits_per_pixel <= 16)
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var->bits_per_pixel = 16;
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else if (var->bits_per_pixel <= 24)
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var->bits_per_pixel = 24;
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else if (var->bits_per_pixel <= 32)
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var->bits_per_pixel = 32;
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else
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return -EINVAL;
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if (var->xres_virtual < var->xoffset + var->xres)
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var->xres_virtual = var->xoffset + var->xres;
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if (var->yres_virtual < var->yoffset + var->yres)
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var->yres_virtual = var->yoffset + var->yres;
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/*
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* Memory limit
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*/
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line_length =
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get_line_length(var->xres_virtual, var->bits_per_pixel);
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if (line_length * var->yres_virtual > videomemorysize)
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return -ENOMEM;
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/*
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* Now that we checked it we alter var. The reason being is that the video
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* mode passed in might not work but slight changes to it might make it
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* work. This way we let the user know what is acceptable.
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*/
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switch (var->bits_per_pixel) {
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case 1:
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case 8:
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var->red.offset = 0;
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var->red.length = 8;
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var->green.offset = 0;
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var->green.length = 8;
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var->blue.offset = 0;
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var->blue.length = 8;
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var->transp.offset = 0;
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var->transp.length = 0;
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break;
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case 16: /* RGBA 5551 */
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if (var->transp.length) {
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var->red.offset = 0;
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var->red.length = 5;
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var->green.offset = 5;
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var->green.length = 5;
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var->blue.offset = 10;
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var->blue.length = 5;
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var->transp.offset = 15;
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var->transp.length = 1;
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} else { /* RGB 565 */
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var->red.offset = 0;
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var->red.length = 5;
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var->green.offset = 5;
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var->green.length = 6;
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var->blue.offset = 11;
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var->blue.length = 5;
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var->transp.offset = 0;
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var->transp.length = 0;
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}
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break;
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case 24: /* RGB 888 */
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var->red.offset = 0;
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var->red.length = 8;
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var->green.offset = 8;
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var->green.length = 8;
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var->blue.offset = 16;
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var->blue.length = 8;
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var->transp.offset = 0;
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var->transp.length = 0;
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break;
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case 32: /* RGBA 8888 */
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var->red.offset = 0;
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var->red.length = 8;
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var->green.offset = 8;
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var->green.length = 8;
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var->blue.offset = 16;
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var->blue.length = 8;
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var->transp.offset = 24;
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var->transp.length = 8;
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break;
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}
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var->red.msb_right = 0;
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var->green.msb_right = 0;
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var->blue.msb_right = 0;
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var->transp.msb_right = 0;
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return 0;
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}
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/* This routine actually sets the video mode. It's in here where we
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* the hardware state info->par and fix which can be affected by the
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* change in par. For this driver it doesn't do much.
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*/
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static int vfb_set_par(struct fb_info *info)
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{
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info->fix.line_length = get_line_length(info->var.xres_virtual,
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info->var.bits_per_pixel);
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return 0;
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}
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/*
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* Set a single color register. The values supplied are already
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* rounded down to the hardware's capabilities (according to the
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* entries in the var structure). Return != 0 for invalid regno.
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*/
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static int vfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
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u_int transp, struct fb_info *info)
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{
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if (regno >= 256) /* no. of hw registers */
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return 1;
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/*
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* Program hardware... do anything you want with transp
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*/
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/* grayscale works only partially under directcolor */
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if (info->var.grayscale) {
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/* grayscale = 0.30*R + 0.59*G + 0.11*B */
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red = green = blue =
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(red * 77 + green * 151 + blue * 28) >> 8;
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}
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/* Directcolor:
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* var->{color}.offset contains start of bitfield
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* var->{color}.length contains length of bitfield
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* {hardwarespecific} contains width of RAMDAC
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* cmap[X] is programmed to (X << red.offset) | (X << green.offset) | (X << blue.offset)
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* RAMDAC[X] is programmed to (red, green, blue)
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*
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* Pseudocolor:
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* var->{color}.offset is 0 unless the palette index takes less than
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* bits_per_pixel bits and is stored in the upper
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* bits of the pixel value
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* var->{color}.length is set so that 1 << length is the number of available
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* palette entries
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* cmap is not used
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* RAMDAC[X] is programmed to (red, green, blue)
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*
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* Truecolor:
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* does not use DAC. Usually 3 are present.
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* var->{color}.offset contains start of bitfield
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* var->{color}.length contains length of bitfield
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* cmap is programmed to (red << red.offset) | (green << green.offset) |
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* (blue << blue.offset) | (transp << transp.offset)
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* RAMDAC does not exist
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*/
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#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
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switch (info->fix.visual) {
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case FB_VISUAL_TRUECOLOR:
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case FB_VISUAL_PSEUDOCOLOR:
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red = CNVT_TOHW(red, info->var.red.length);
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green = CNVT_TOHW(green, info->var.green.length);
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blue = CNVT_TOHW(blue, info->var.blue.length);
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transp = CNVT_TOHW(transp, info->var.transp.length);
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break;
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case FB_VISUAL_DIRECTCOLOR:
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red = CNVT_TOHW(red, 8); /* expect 8 bit DAC */
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green = CNVT_TOHW(green, 8);
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blue = CNVT_TOHW(blue, 8);
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/* hey, there is bug in transp handling... */
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transp = CNVT_TOHW(transp, 8);
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break;
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}
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#undef CNVT_TOHW
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/* Truecolor has hardware independent palette */
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if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
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u32 v;
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if (regno >= 16)
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return 1;
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v = (red << info->var.red.offset) |
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(green << info->var.green.offset) |
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(blue << info->var.blue.offset) |
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(transp << info->var.transp.offset);
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switch (info->var.bits_per_pixel) {
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case 8:
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break;
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case 16:
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((u32 *) (info->pseudo_palette))[regno] = v;
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break;
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case 24:
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case 32:
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((u32 *) (info->pseudo_palette))[regno] = v;
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break;
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}
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return 0;
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}
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return 0;
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}
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/*
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* Pan or Wrap the Display
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*
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* This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
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*/
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static int vfb_pan_display(struct fb_var_screeninfo *var,
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struct fb_info *info)
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{
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if (var->vmode & FB_VMODE_YWRAP) {
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if (var->yoffset < 0
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|| var->yoffset >= info->var.yres_virtual
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|| var->xoffset)
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return -EINVAL;
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} else {
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if (var->xoffset + var->xres > info->var.xres_virtual ||
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var->yoffset + var->yres > info->var.yres_virtual)
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return -EINVAL;
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}
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info->var.xoffset = var->xoffset;
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info->var.yoffset = var->yoffset;
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if (var->vmode & FB_VMODE_YWRAP)
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info->var.vmode |= FB_VMODE_YWRAP;
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else
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info->var.vmode &= ~FB_VMODE_YWRAP;
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return 0;
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}
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/*
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* Most drivers don't need their own mmap function
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*/
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static int vfb_mmap(struct fb_info *info,
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struct vm_area_struct *vma)
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{
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unsigned long start = vma->vm_start;
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unsigned long size = vma->vm_end - vma->vm_start;
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unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
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unsigned long page, pos;
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if (offset + size > info->fix.smem_len) {
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return -EINVAL;
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}
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pos = (unsigned long)info->fix.smem_start + offset;
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while (size > 0) {
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page = vmalloc_to_pfn((void *)pos);
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if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) {
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return -EAGAIN;
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}
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start += PAGE_SIZE;
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pos += PAGE_SIZE;
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if (size > PAGE_SIZE)
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size -= PAGE_SIZE;
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else
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size = 0;
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}
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vma->vm_flags |= VM_RESERVED; /* avoid to swap out this VMA */
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return 0;
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}
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#ifndef MODULE
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/*
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* The virtual framebuffer driver is only enabled if explicitly
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* requested by passing 'video=vfb:' (or any actual options).
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*/
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static int __init vfb_setup(char *options)
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{
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char *this_opt;
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vfb_enable = 0;
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if (!options)
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return 1;
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vfb_enable = 1;
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if (!*options)
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return 1;
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while ((this_opt = strsep(&options, ",")) != NULL) {
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if (!*this_opt)
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continue;
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/* Test disable for backwards compatibility */
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if (!strcmp(this_opt, "disable"))
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vfb_enable = 0;
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}
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return 1;
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}
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#endif /* MODULE */
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/*
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* Initialisation
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*/
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static int __init vfb_probe(struct platform_device *dev)
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{
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struct fb_info *info;
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int retval = -ENOMEM;
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/*
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* For real video cards we use ioremap.
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*/
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if (!(videomemory = rvmalloc(videomemorysize)))
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return retval;
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/*
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* VFB must clear memory to prevent kernel info
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* leakage into userspace
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* VGA-based drivers MUST NOT clear memory if
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* they want to be able to take over vgacon
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*/
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memset(videomemory, 0, videomemorysize);
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info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);
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if (!info)
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goto err;
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info->screen_base = (char __iomem *)videomemory;
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info->fbops = &vfb_ops;
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retval = fb_find_mode(&info->var, info, NULL,
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NULL, 0, NULL, 8);
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if (!retval || (retval == 4))
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info->var = vfb_default;
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vfb_fix.smem_start = (unsigned long) videomemory;
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vfb_fix.smem_len = videomemorysize;
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info->fix = vfb_fix;
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info->pseudo_palette = info->par;
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info->par = NULL;
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info->flags = FBINFO_FLAG_DEFAULT;
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retval = fb_alloc_cmap(&info->cmap, 256, 0);
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if (retval < 0)
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goto err1;
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retval = register_framebuffer(info);
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if (retval < 0)
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goto err2;
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platform_set_drvdata(dev, info);
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printk(KERN_INFO
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"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:
|
|
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 */
|