![Jani Nikula](/assets/img/avatar_default.png)
Now that the fbops member of struct fb_info is const, we can start making the ops const as well. This does not cover all drivers; some actually modify the fbops struct, for example to adjust for different configurations, and others do more involved things that I'd rather not touch in practically obsolete drivers. Mostly this is the low hanging fruit where we can add "const" and be done with it. v3: - un-constify atyfb, mb862xx, nvidia and uvesabf (0day) v2: - fix typo (Christophe de Dinechin) - use "static const" instead of "const static" in mx3fb.c - also constify smscufx.c Cc: linux-fbdev@vger.kernel.org Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/ce67f14435f3af498f2e8bf35ce4be11f7504132.1575390740.git.jani.nikula@intel.com
552 lines
13 KiB
C
552 lines
13 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/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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MODULE_PARM_DESC(videomemorysize, "RAM available to frame buffer (in bytes)");
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static char *mode_option = NULL;
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module_param(mode_option, charp, 0);
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MODULE_PARM_DESC(mode_option, "Preferred video mode (e.g. 640x480-8@60)");
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static const struct fb_videomode vfb_default = {
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.xres = 640,
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.yres = 480,
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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 = {
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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 bool vfb_enable __initdata = 0; /* disabled by default */
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module_param(vfb_enable, bool, 0);
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MODULE_PARM_DESC(vfb_enable, "Enable Virtual FB driver");
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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 const 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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switch (info->var.bits_per_pixel) {
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case 1:
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info->fix.visual = FB_VISUAL_MONO01;
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break;
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case 8:
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info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
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break;
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case 16:
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case 24:
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case 32:
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info->fix.visual = FB_VISUAL_TRUECOLOR;
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break;
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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 >= 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 + info->var.xres > info->var.xres_virtual ||
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var->yoffset + info->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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return remap_vmalloc_range(vma, (void *)info->fix.smem_start, vma->vm_pgoff);
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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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else
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mode_option = this_opt;
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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 vfb_probe(struct platform_device *dev)
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{
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struct fb_info *info;
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unsigned int size = PAGE_ALIGN(videomemorysize);
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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 = vmalloc_32_user(size)))
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return retval;
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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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if (!fb_find_mode(&info->var, info, mode_option,
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NULL, 0, &vfb_default, 8)){
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fb_err(info, "Unable to find usable video mode.\n");
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retval = -EINVAL;
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goto err1;
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}
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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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vfb_set_par(info);
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fb_info(info, "Virtual frame buffer device, using %ldK of video memory\n",
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videomemorysize >> 10);
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return 0;
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err2:
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fb_dealloc_cmap(&info->cmap);
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err1:
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framebuffer_release(info);
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err:
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vfree(videomemory);
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return retval;
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}
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static int vfb_remove(struct platform_device *dev)
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{
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struct fb_info *info = platform_get_drvdata(dev);
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if (info) {
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unregister_framebuffer(info);
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vfree(videomemory);
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fb_dealloc_cmap(&info->cmap);
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framebuffer_release(info);
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}
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return 0;
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}
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static struct platform_driver vfb_driver = {
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.probe = vfb_probe,
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.remove = vfb_remove,
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.driver = {
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.name = "vfb",
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},
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};
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static struct platform_device *vfb_device;
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static int __init vfb_init(void)
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{
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int ret = 0;
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|
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#ifndef MODULE
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char *option = NULL;
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|
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if (fb_get_options("vfb", &option))
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return -ENODEV;
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|
vfb_setup(option);
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#endif
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|
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if (!vfb_enable)
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return -ENXIO;
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|
|
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ret = platform_driver_register(&vfb_driver);
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|
|
|
if (!ret) {
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|
vfb_device = platform_device_alloc("vfb", 0);
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|
|
|
if (vfb_device)
|
|
ret = platform_device_add(vfb_device);
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|
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 */
|