linux/drivers/video/fbdev/vfb.c

/*
 *  linux/drivers/video/vfb.c -- Virtual frame buffer device
 *
 *      Copyright (C) 2002 James Simmons
 *
 *	Copyright (C) 1997 Geert Uytterhoeven
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>

#include <linux/fb.h>
#include <linux/init.h>

    /*
     *  RAM we reserve for the frame buffer. This defines the maximum screen
     *  size
     *
     *  The default can be overridden if the driver is compiled as a module
     */

#define VIDEOMEMSIZE …

static void *videomemory;
static u_long videomemorysize = …;
module_param(videomemorysize, ulong, 0);
MODULE_PARM_DESC(…) …;

static char *mode_option = …;
module_param(mode_option, charp, 0);
MODULE_PARM_DESC(…) …;

static const struct fb_videomode vfb_default = …;

static struct fb_fix_screeninfo vfb_fix = …;

static bool vfb_enable __initdata = …;	/* disabled by default */
module_param(vfb_enable, bool, 0);
MODULE_PARM_DESC(…) …;

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 = …;

    /*
     *  Internal routines
     */

static u_long get_line_length(int xres_virtual, int bpp)
{ … }

    /*
     *  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)
{ … }

/* 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)
{ … }

    /*
     *  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)
{ … }

    /*
     *  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)
{ … }

    /*
     *  Most drivers don't need their own mmap function
     */

static int vfb_mmap(struct fb_info *info,
		    struct vm_area_struct *vma)
{ … }

#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)
{ … }
#endif  /*  MODULE  */

    /*
     *  Initialisation
     */

static int vfb_probe(struct platform_device *dev)
{ … }

static void vfb_remove(struct platform_device *dev)
{ … }

static struct platform_driver vfb_driver = …;

static struct platform_device *vfb_device;

static int __init vfb_init(void)
{ … }

module_init(…) …;

#ifdef MODULE
static 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 */