pvr2fb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

			display->inverse = pvr2fb_inverse;
			switch (var->bits_per_pixel) {
#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);
		}
		if (con == currcon)
			pvr2_set_var(&display->var);
	}

	return 0;
}

/*
 * Pan or wrap the display.
 * This call looks only at xoffset, yoffset and the FB_VMODE_YRAP flag
 */

static int pvr2fb_pan_display(struct fb_var_screeninfo *var, int con,
                                struct fb_info *info)
{
	if (var->vmode & FB_VMODE_YWRAP) {
		if (var->yoffset<0 || var->yoffset >=
		    fb_display[con].var.yres_virtual || var->xoffset)
			return -EINVAL;
	 } else {
		if (var->xoffset+fb_display[con].var.xres >
		    fb_display[con].var.xres_virtual ||
		    var->yoffset+fb_display[con].var.yres >
		    fb_display[con].var.yres_virtual)
		    return -EINVAL;
	}
	if (con == currcon)
		pvr2_pan_var(var);
	fb_display[con].var.xoffset = var->xoffset;
	fb_display[con].var.yoffset = var->yoffset;
	if (var->vmode & FB_VMODE_YWRAP)
		fb_display[con].var.vmode |= FB_VMODE_YWRAP;
	else
		fb_display[con].var.vmode &= ~FB_VMODE_YWRAP;
			
	return 0;
}

/* Get the colormap */

static int pvr2fb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
                             struct fb_info *info)
{
	if (con == currcon) /* current console? */
		return fb_get_cmap(cmap, kspc, pvr2_getcolreg, info);
	else if (fb_display[con].cmap.len) /* non default colormap? */
		fb_copy_cmap(&fb_display[con].cmap, cmap, kspc ? 0 : 2);
	else
		fb_copy_cmap(fb_default_cmap(1<<fb_display[con].var.bits_per_pixel),
		             cmap, kspc ? 0 : 2);
	return 0;
}

/* Set the colormap */

static int pvr2fb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
	                     struct fb_info *info)
{
	int err;

	if (!fb_display[con].cmap.len) {        /* no colormap allocated? */
		if ((err = fb_alloc_cmap(&fb_display[con].cmap,
		                         1<<fb_display[con].var.bits_per_pixel,
					 0)))
			 return err;
	}
	if (con == currcon)                     /* current console? */
		return fb_set_cmap(cmap, kspc, pvr2_setcolreg, info);
	else
		fb_copy_cmap(cmap, &fb_display[con].cmap, kspc ? 0 : 1);

	return 0;
}

static int pvr2fbcon_switch(int con, struct fb_info *info)
{
	/* Do we have to save the colormap? */
	if (fb_display[currcon].cmap.len)
		fb_get_cmap(&fb_display[currcon].cmap, 1, pvr2_getcolreg, info);

	currcon = con;
	pvr2_set_var(&fb_display[con].var);
	/* Install new colormap */
	do_install_cmap(con, info);
	return 0;
}

static int pvr2fbcon_updatevar(int con, struct fb_info *info)
{
	pvr2_pan_var(&fb_display[con].var);
	return 0;
}

static void pvr2fbcon_blank(int blank, struct fb_info *info)
{
	do_blank = blank ? blank : -1;
}

/* Setup the colormap */

static void do_install_cmap(int con, struct fb_info *info)
{
	if (con != currcon)
		return;
	if (fb_display[con].cmap.len)
		fb_set_cmap(&fb_display[con].cmap, 1, pvr2_setcolreg, info);
	else
		fb_set_cmap(fb_default_cmap(1<<fb_display[con].var.bits_per_pixel),
                            1, pvr2_setcolreg, info);
}

static inline u_long get_line_length(int xres_virtual, int bpp)
{
	return (u_long)((((xres_virtual*bpp)+31)&~31) >> 3);
}

static void set_color_bitfields(struct fb_var_screeninfo *var)
{
	switch (var->bits_per_pixel) {
	    case 16:        /* RGB 565 */
		var->red.offset = 11;    var->red.length = 5;
		var->green.offset = 5;   var->green.length = 6;
		var->blue.offset = 0;    var->blue.length = 5;
		var->transp.offset = 0;  var->transp.length = 0;
		break;
	    case 24:        /* RGB 888 */
		var->red.offset = 16;    var->red.length = 8;
		var->green.offset = 8;   var->green.length = 8;
		var->blue.offset = 0;    var->blue.length = 8;
		var->transp.offset = 0;  var->transp.length = 0;
		break;
	    case 32:        /* ARGB 8888 */
		var->red.offset = 16;    var->red.length = 8;
		var->green.offset = 8;   var->green.length = 8;
		var->blue.offset = 0;    var->blue.length = 8;
		var->transp.offset = 24; var->transp.length = 8;
		break;
	}
}

static int pvr2_getcolreg(u_int regno, u_int *red, u_int *green, u_int *blue,
                            u_int *transp, struct fb_info *info)
{
	if (regno > 255)
	    return 1;
	
	*red = palette[regno].red;
	*green = palette[regno].green;
	*blue = palette[regno].blue;
	*transp = 0;
	return 0;
}
	
static int pvr2_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                            u_int transp, struct fb_info *info)
{
	if (regno > 255)
		return 1;

	palette[regno].red = red;
	palette[regno].green = green;
	palette[regno].blue = blue;

	if (regno < 16) {
		switch (currbpp) {
#ifdef FBCON_HAS_CFB16
		    case 16: /* RGB 565 */
			fbcon_cmap.cfb16[regno] = (red & 0xf800) |
			                          ((green & 0xfc00) >> 5) |
						  ((blue & 0xf800) >> 11);
			break;
#endif
#ifdef FBCON_HAS_CFB24
		    case 24: /* RGB 888 */
			red >>= 8; green >>= 8; blue >>= 8;
			fbcon_cmap.cfb24[regno] = (red << 16) | (green << 8) | blue;
			break;
#endif
#ifdef FBCON_HAS_CFB32
		    case 32: /* ARGB 8888 */
			red >>= 8; green >>= 8; blue >>= 8;
			fbcon_cmap.cfb32[regno] = (red << 16) | (green << 8) | blue;
			break;
#endif
		    default:
			DPRINTK("Invalid bit depth %d?!?\n", currbpp);
			return 1;
		}
	}

	return 0;
}


static int pvr2_encode_fix(struct fb_fix_screeninfo *fix,
                             struct pvr2fb_par *par)
{
	memset(fix, 0, sizeof(struct fb_fix_screeninfo));
	strcpy(fix->id, pvr2fb_name);
	fix->smem_start = videomemory;
	fix->smem_len = videomemorysize;
	fix->type = FB_TYPE_PACKED_PIXELS;
	fix->type_aux = 0;
	fix->visual = FB_VISUAL_TRUECOLOR;

	if (par->vmode & FB_VMODE_YWRAP) {
		fix->ywrapstep = 1;
		fix->xpanstep = fix->ypanstep = 0;
	} else {
		fix->ywrapstep = 0;
		fix->xpanstep = 1;
		fix->ypanstep = 1;
	}
	fix->line_length = par->next_line;

	return 0;
}

/*
 * Create a hardware video mode using the framebuffer values.  If a value needs
 * to be clipped or constrained it's done here.  This routine needs a bit more
 * work to make sure we're doing the right tests at the right time.
 */
static int pvr2_decode_var(struct fb_var_screeninfo *var,
                             struct pvr2fb_par *par)
{
	u_long line_length;
	u_short vtotal;

	if (var->pixclock != TV_CLK && var->pixclock != VGA_CLK) {
		DPRINTK("Invalid pixclock value %d\n", var->pixclock);
		return -EINVAL;
	}
	par->pixclock = var->pixclock;
	
	if ((par->xres = var->xres) < 320)
		par->xres = 320;
	if ((par->yres = var->yres) < 240)
		par->yres = 240;
	if ((par->vxres = var->xres_virtual) < par->xres)
		par->vxres = par->xres;
	if ((par->vyres = var->yres_virtual) < par->yres)
		par->vyres = par->yres;

	if ((par->bpp = var->bits_per_pixel) <= 16)
		par->bpp = 16;
	else if ((par->bpp = var->bits_per_pixel) <= 24)
		par->bpp = 24;
	else if ((par->bpp = var->bits_per_pixel) <= 32)
		par->bpp = 32;

	currbpp = par->bpp;

	/*
	 * XXX: It's possible that a user could use a VGA box, change the cable
	 * type in hardware (i.e. switch from VGA<->composite), then change modes
	 * (i.e. switching to another VT).  If that happens we should automagically
	 * change the output format to cope, but currently I don't have a VGA box
	 * to make sure this works properly.
	 */
	cable_type = pvr2_init_cable();
	if (cable_type == CT_VGA && video_output != VO_VGA)
		video_output = VO_VGA;

	par->vmode = var->vmode & FB_VMODE_MASK;
	if (par->vmode & FB_VMODE_INTERLACED && video_output != VO_VGA)
		par->is_interlaced = 1;
	/* 
	 * XXX: Need to be more creative with this (i.e. allow doublecan for
	 * PAL/NTSC output).
	 */
	par->is_doublescan = (par->yres < 480 && video_output == VO_VGA);
	
	par->hsync_total = var->left_margin + var->xres + var->right_margin +
	                   var->hsync_len;
	par->vsync_total = var->upper_margin + var->yres + var->lower_margin +
	                   var->vsync_len;

	if (var->sync & FB_SYNC_BROADCAST) {
		vtotal = par->vsync_total;
		if (par->is_interlaced)
			vtotal /= 2;
		if (vtotal > (PAL_VTOTAL + NTSC_VTOTAL)/2) {
			/* PAL video output */
			/* XXX: Should be using a range here ... ? */
			if (par->hsync_total != PAL_HTOTAL) {
				DPRINTK("invalid hsync total for PAL\n");
				return -EINVAL;
			}
			/* XXX: Check for start values here... */
			/* XXX: Check hardware for PAL-compatibility */
			par->borderstart_h = 116;
			par->borderstart_v = 44;
		} else {
			/* NTSC video output */
			if (par->hsync_total != NTSC_HTOTAL) {
				DPRINTK("invalid hsync total for NTSC\n");
				return -EINVAL;
			}
			par->borderstart_h = 126;
			par->borderstart_v = 18;
		}
	} else {
		/* VGA mode */
		/* XXX: What else needs to be checked? */
		/* 
		 * XXX: We have a little freedom in VGA modes, what ranges should
		 * be here (i.e. hsync/vsync totals, etc.)?
		 */
		par->borderstart_h = 126;
		par->borderstart_v = 40;
	}

	/* Calculate the remainding offsets */
	par->borderstop_h = par->borderstart_h + par->hsync_total -
	                    var->hsync_len;
	par->borderstop_v = par->borderstart_v + par->vsync_total -
	                    var->vsync_len;
	par->diwstart_h = par->borderstart_h + var->left_margin;
	par->diwstart_v = par->borderstart_v + var->upper_margin;
	if (!par->is_interlaced)
		par->borderstop_v /= 2;

	if (par->xres < 640)
		par->is_lowres = 1;

	/* XXX: Needs testing. */
	if (!((par->vmode ^ var->vmode) & FB_VMODE_YWRAP)) {
		par->xoffset = var->xoffset;
		par->yoffset = var->yoffset;
		if (par->vmode & FB_VMODE_YWRAP) {
			if (par->xoffset || par->yoffset < 0 || par->yoffset >=
			    par->vyres)
				par->xoffset = par->yoffset = 0;
		} else {
			if (par->xoffset < 0 || par->xoffset > par->vxres-par->xres ||
			    par->yoffset < 0 || par->yoffset > par->vyres-par->yres)
				par->xoffset = par->yoffset = 0;
		}
	} else
		par->xoffset = par->yoffset = 0;

	/* Check memory sizes */
	line_length = get_line_length(var->xres_virtual, var->bits_per_pixel);
	if (line_length * var->yres_virtual > videomemorysize)
		return -ENOMEM;
	par->disp_start = videomemory + (get_line_length(par->vxres, par->bpp) *
	                  par->yoffset) * get_line_length(par->xoffset, par->bpp);
	par->next_line = line_length;
	
	return 0;
}

static int pvr2_encode_var(struct fb_var_screeninfo *var,
                             struct pvr2fb_par *par)
{
	memset(var, 0, sizeof(struct fb_var_screeninfo));

	var->xres = par->xres;
	var->yres = par->yres;