mc68x328fb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

/*
 *  linux/drivers/video/mc68x328fb.c -- DragonBall frame buffer device
 *
 *	Copyright (C) 2003 Georges Menie
 *
 *  Support for the built in MC68x328 LCD Controller
 *
 *  This driver assumes an already configured controller (e.g. from crt0_fixed.s)
 *  Keep the code clean of board specific initialization.
 *
 *  This code has not been tested with colors, colormap management functions
 *  are minimal (no colormap data written to the 68328 registers...)
 *
 *  modified from :
 *
 *    linux/drivers/video/vfb.c -- Virtual frame buffer device
 *	  Copyright (C) 1997 Geert Uytterhoeven
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>
#include <linux/fb.h>
#include <linux/init.h>

#include <video/fbcon.h>
#include <video/fbcon-mfb.h>
#include <video/fbcon-cfb2.h>
#include <video/fbcon-cfb4.h>
#include <video/fbcon-cfb8.h>
#include <video/fbcon-cfb16.h>
#include <video/fbcon-cfb24.h>
#include <video/fbcon-cfb32.h>

#if defined(CONFIG_M68EZ328)
#include <asm/MC68EZ328.h>
#elif defined(CONFIG_M68VZ328)
#include <asm/MC68VZ328.h>
#else
#error wrong architecture for the MC68x328 Framebuffer Device
#endif

#if defined(CONFIG_FB_MC68X328_MONO01)
#define MC68X328FB_MONO_VISUAL FB_VISUAL_MONO01
#else
#define MC68X328FB_MONO_VISUAL FB_VISUAL_MONO10
#endif

static u_long videomemory, videomemorysize;
static int currcon = 0;
static struct display disp;
static struct fb_info fb_info;
static struct { u_char red, green, blue, pad; } palette[256];
static union {
#ifdef FBCON_HAS_CFB16
    u16 cfb16[16];
#endif
#ifdef FBCON_HAS_CFB24
    u32 cfb24[16];
#endif
#ifdef FBCON_HAS_CFB32
    u32 cfb32[16];
#endif
} fbcon_cmap;
static char mc68x328fb_name[16] = "DragonBall";

static struct fb_var_screeninfo mc68x328fb_default = {
    0, 0, 0, 0, 0, 0, 0, 0, /* some value are set by mc68x328fb_init() */
    {0, 8, 0}, {0, 8, 0}, {0, 8, 0}, {0, 0, 0},
    0, 0, -1, -1, 0, 20000, 64, 64, 32, 32, 64, 2,
    0, FB_VMODE_NONINTERLACED
};


    /*
     *  Interface used by the world
     */

int mc68x328fb_setup(char*);

static int mc68x328fb_get_fix(struct fb_fix_screeninfo *fix, int con,
		       struct fb_info *info);
static int mc68x328fb_get_var(struct fb_var_screeninfo *var, int con,
		       struct fb_info *info);
static int mc68x328fb_set_var(struct fb_var_screeninfo *var, int con,
		       struct fb_info *info);
static int mc68x328fb_pan_display(struct fb_var_screeninfo *var, int con,
			   struct fb_info *info);
static int mc68x328fb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
			struct fb_info *info);
static int mc68x328fb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
			struct fb_info *info);


    /*
     *  Interface to the low level console driver
     */

int mc68x328fb_init(void);
static int vfbcon_switch(int con, struct fb_info *info);
static int vfbcon_updatevar(int con, struct fb_info *info);
static void vfbcon_blank(int blank, struct fb_info *info);


    /*
     *  Internal routines
     */

static u_long get_line_length(int xres_virtual, int bpp);
static void mc68x328fb_encode_fix(struct fb_fix_screeninfo *fix,
			   struct fb_var_screeninfo *var);
static void set_color_bitfields(struct fb_var_screeninfo *var);
static int mc68x328fb_getcolreg(u_int regno, u_int *red, u_int *green, u_int *blue,
                         u_int *transp, struct fb_info *info);
static int mc68x328fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                         u_int transp, struct fb_info *info);
static void do_install_cmap(int con, struct fb_info *info);


static struct fb_ops mc68x328fb_ops = {
	owner:		THIS_MODULE,
	fb_get_fix:	mc68x328fb_get_fix,
	fb_get_var:	mc68x328fb_get_var,
	fb_set_var:	mc68x328fb_set_var,
	fb_get_cmap:	mc68x328fb_get_cmap,
	fb_set_cmap:	mc68x328fb_set_cmap,
	fb_pan_display:	mc68x328fb_pan_display,
};

    /*
     *  Get the Fixed Part of the Display
     */

static int mc68x328fb_get_fix(struct fb_fix_screeninfo *fix, int con,
		       struct fb_info *info)
{
    struct fb_var_screeninfo *var;

    if (con == -1)
	var = &mc68x328fb_default;
    else
	var = &fb_display[con].var;
    mc68x328fb_encode_fix(fix, var);
    return 0;
}


    /*
     *  Get the User Defined Part of the Display
     */

static int mc68x328fb_get_var(struct fb_var_screeninfo *var, int con,
		       struct fb_info *info)
{
    if (con == -1)
	*var = mc68x328fb_default;
    else
	*var = fb_display[con].var;
    set_color_bitfields(var);
    return 0;
}


    /*
     *  Set the User Defined Part of the Display
     */

static int mc68x328fb_set_var(struct fb_var_screeninfo *var, int con,
		       struct fb_info *info)
{
    int err, activate = var->activate;
    int oldxres, oldyres, oldvxres, oldvyres, oldbpp;
    u_long line_length;

    struct display *display;
    if (con >= 0)
	display = &fb_display[con];
    else
	display = &disp;	/* used during initialization */

    /*
     *  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 = display->var.xoffset;
	var->yoffset = display->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;
#if 0
    /* fbcon doesn't support this (yet) */
    else if (var->bits_per_pixel <= 24)
	var->bits_per_pixel = 24;
    else if (var->bits_per_pixel <= 32)
	var->bits_per_pixel = 32;
#endif
    else
	return -EINVAL;

    /*
     *  Memory limit
     */
    line_length = get_line_length(var->xres_virtual, var->bits_per_pixel);
    if (line_length*var->yres_virtual > videomemorysize)
	return -ENOMEM;

    set_color_bitfields(var);

    if ((activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) {
	oldxres = display->var.xres;
	oldyres = display->var.yres;
	oldvxres = display->var.xres_virtual;
	oldvyres = display->var.yres_virtual;
	oldbpp = display->var.bits_per_pixel;
	display->var = *var;
	if (oldxres != var->xres || oldyres != var->yres ||
	    oldvxres != var->xres_virtual || oldvyres != var->yres_virtual ||
	    oldbpp != var->bits_per_pixel) {
	    struct fb_fix_screeninfo fix;

	    mc68x328fb_encode_fix(&fix, var);
	    display->screen_base = (char *)videomemory;
	    display->visual = fix.visual;
	    display->type = fix.type;
	    display->type_aux = fix.type_aux;
	    display->ypanstep = fix.ypanstep;
	    display->ywrapstep = fix.ywrapstep;
	    display->line_length = fix.line_length;
	    display->can_soft_blank = 1;
	    display->inverse = 0;
	    switch (var->bits_per_pixel) {
#ifdef FBCON_HAS_MFB
		case 1:
		    display->dispsw = &fbcon_mfb;
		    break;
#endif
#ifdef FBCON_HAS_CFB2
		case 2:
		    display->dispsw = &fbcon_cfb2;
		    break;
#endif
#ifdef FBCON_HAS_CFB4
		case 4:
		    display->dispsw = &fbcon_cfb4;
		    break;
#endif
#ifdef FBCON_HAS_CFB8
		case 8:
		    display->dispsw = &fbcon_cfb8;
		    break;
#endif
#ifdef FBCON_HAS_CFB16
		case 16:
		    display->dispsw = &fbcon_cfb16;
		    display->dispsw_data = fbcon_cmap.cfb16;
		    break;
#endif
#ifdef FBCON_HAS_CFB24
		case 24:
		    display->dispsw = &fbcon_cfb24;
		    display->dispsw_data = fbcon_cmap.cfb24;
		    break;
#endif
#ifdef FBCON_HAS_CFB32
		case 32:
		    display->dispsw = &fbcon_cfb32;
		    display->dispsw_data = fbcon_cmap.cfb32;
		    break;
#endif
		default:
		    display->dispsw = &fbcon_dummy;
		    break;
	    }
	    if (fb_info.changevar)
		(*fb_info.changevar)(con);
	}
	if (oldbpp != var->bits_per_pixel) {
	    if ((err = fb_alloc_cmap(&display->cmap, 0, 0)))
		return err;
	    do_install_cmap(con, info);
	}
    }
    return 0;
}


    /*