cyber2000fb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

	}

	/*
	 * we should be able to remove this test once fbcon has been
	 * "improved" --rmk
	 */
	if (!err && con == cfb->currcon) {
		err = fb_set_cmap(cmap, kspc, cyber2000_setcolreg, &cfb->fb);
		dcmap = &cfb->fb.cmap;
	}

	if (!err)
		fb_copy_cmap(cmap, dcmap, kspc ? 0 : 1);

	return err;
}

static int
cyber2000fb_decode_crtc(struct par_info *hw, struct cfb_info *cfb,
			struct fb_var_screeninfo *var)
{
	u_int Htotal, Hblankend, Hsyncend;
	u_int Vtotal, Vdispend, Vblankstart, Vblankend, Vsyncstart, Vsyncend;
#define BIT(v,b1,m,b2) (((v >> b1) & m) << b2)

	hw->crtc[13] = hw->pitch;
	hw->crtc[17] = 0xe3;
	hw->crtc[14] = 0;
	hw->crtc[8]  = 0;

	Htotal      = var->xres + var->right_margin +
		      var->hsync_len + var->left_margin;

	if (Htotal > 2080)
		return -EINVAL;

	hw->crtc[0] = (Htotal >> 3) - 5;
	hw->crtc[1] = (var->xres >> 3) - 1;
	hw->crtc[2] = var->xres >> 3;
	hw->crtc[4] = (var->xres + var->right_margin) >> 3;

	Hblankend   = (Htotal - 4*8) >> 3;

	hw->crtc[3] = BIT(Hblankend,  0, 0x1f,  0) |
		      BIT(1,          0, 0x01,  7);

	Hsyncend    = (var->xres + var->right_margin + var->hsync_len) >> 3;

	hw->crtc[5] = BIT(Hsyncend,   0, 0x1f,  0) |
		      BIT(Hblankend,  5, 0x01,  7);

	Vdispend    = var->yres - 1;
	Vsyncstart  = var->yres + var->lower_margin;
	Vsyncend    = var->yres + var->lower_margin + var->vsync_len;
	Vtotal      = var->yres + var->lower_margin + var->vsync_len +
		      var->upper_margin - 2;

	if (Vtotal > 2047)
		return -EINVAL;

	Vblankstart = var->yres + 6;
	Vblankend   = Vtotal - 10;

	hw->crtc[6]  = Vtotal;
	hw->crtc[7]  = BIT(Vtotal,     8, 0x01,  0) |
			BIT(Vdispend,   8, 0x01,  1) |
			BIT(Vsyncstart, 8, 0x01,  2) |
			BIT(Vblankstart,8, 0x01,  3) |
			BIT(1,          0, 0x01,  4) |
	        	BIT(Vtotal,     9, 0x01,  5) |
			BIT(Vdispend,   9, 0x01,  6) |
			BIT(Vsyncstart, 9, 0x01,  7);
	hw->crtc[9]  = BIT(0,          0, 0x1f,  0) |
		        BIT(Vblankstart,9, 0x01,  5) |
			BIT(1,          0, 0x01,  6);
	hw->crtc[10] = Vsyncstart;
	hw->crtc[11] = BIT(Vsyncend,   0, 0x0f,  0) |
		       BIT(1,          0, 0x01,  7);
	hw->crtc[12] = Vdispend;
	hw->crtc[15] = Vblankstart;
	hw->crtc[16] = Vblankend;
	hw->crtc[18] = 0xff;

	/* overflow - graphics reg 0x11 */
	/* 0=VTOTAL:10 1=VDEND:10 2=VRSTART:10 3=VBSTART:10
	 * 4=LINECOMP:10 5-IVIDEO 6=FIXCNT
	 */
	hw->crtc_ofl =
		BIT(Vtotal,     10, 0x01,  0) |
		BIT(Vdispend,   10, 0x01,  1) |
		BIT(Vsyncstart, 10, 0x01,  2) |
		BIT(Vblankstart,10, 0x01,  3) |
		1 << 4;

	return 0;
}

/*
 * The following was discovered by a good monitor, bit twiddling, theorising
 * and but mostly luck.  Strangely, it looks like everyone elses' PLL!
 *
 * Clock registers:
 *   fclock = fpll / div2
 *   fpll   = fref * mult / div1
 * where:
 *   fref = 14.318MHz (69842ps)
 *   mult = reg0xb0.7:0
 *   div1 = (reg0xb1.5:0 + 1)
 *   div2 =  2^(reg0xb1.7:6)
 *   fpll should be between 115 and 260 MHz
 *  (8696ps and 3846ps)
 */
static int
cyber2000fb_decode_clock(struct par_info *hw, struct cfb_info *cfb,
			 struct fb_var_screeninfo *var)
{
	u_long pll_ps = var->pixclock;
	const u_long ref_ps = cfb->ref_ps;
	u_int div2, t_div1, best_div1, best_mult;
	int best_diff;
	int vco;

	/*
	 * Step 1:
	 *   find div2 such that 115MHz < fpll < 260MHz
	 *   and 0 <= div2 < 4
	 */
	for (div2 = 0; div2 < 4; div2++) {
		u_long new_pll;

		new_pll = pll_ps / cfb->divisors[div2];
		if (8696 > new_pll && new_pll > 3846) {
			pll_ps = new_pll;
			break;
		}
	}

	if (div2 == 4)
		return -EINVAL;

	/*
	 * Step 2:
	 *  Given pll_ps and ref_ps, find:
	 *    pll_ps * 0.995 < pll_ps_calc < pll_ps * 1.005
	 *  where { 1 < best_div1 < 32, 1 < best_mult < 256 }
	 *    pll_ps_calc = best_div1 / (ref_ps * best_mult)
	 */
	best_diff = 0x7fffffff;
	best_mult = 32;
	best_div1 = 255;
	for (t_div1 = 32; t_div1 > 1; t_div1 -= 1) {
		u_int rr, t_mult, t_pll_ps;
		int diff;

		/*
		 * Find the multiplier for this divisor
		 */
		rr = ref_ps * t_div1;
		t_mult = (rr + pll_ps / 2) / pll_ps;

		/*
		 * Is the multiplier within the correct range?
		 */
		if (t_mult > 256 || t_mult < 2)
			continue;

		/*
		 * Calculate the actual clock period from this multiplier
		 * and divisor, and estimate the error.
		 */
		t_pll_ps = (rr + t_mult / 2) / t_mult;
		diff = pll_ps - t_pll_ps;
		if (diff < 0)
			diff = -diff;

		if (diff < best_diff) {
			best_diff = diff;
			best_mult = t_mult;
			best_div1 = t_div1;
		}

		/*
		 * If we hit an exact value, there is no point in continuing.
		 */
		if (diff == 0)
			break;
	}

	/*
	 * Step 3:
	 *  combine values
	 */
	hw->clock_mult = best_mult - 1;
	hw->clock_div  = div2 << 6 | (best_div1 - 1);

	vco = ref_ps * best_div1 / best_mult;
	if ((ref_ps == 40690) && (vco < 5556))
		/* Set VFSEL when VCO > 180MHz (5.556 ps). */
		hw->clock_div |= DCLK_DIV_VFSEL;

	return 0;
}

/*
 * Decode the info required for the hardware.
 * This involves the PLL parameters for the dot clock,
 * CRTC registers, and accelerator settings.
 */
static int
cyber2000fb_decode_var(struct fb_var_screeninfo *var, struct cfb_info *cfb,
		       struct par_info *hw)
{
	int err;

	hw->width = var->xres_virtual;
	hw->palette_ctrl = 0x06;
	hw->vmode = var->vmode;

	switch (var->bits_per_pixel) {
#ifdef FBCON_HAS_CFB8
	case 8:	/* PSEUDOCOLOUR, 256 */
		hw->pixformat		= PIXFORMAT_8BPP;
		hw->visualid		= VISUALID_256;
		hw->pitch		= hw->width >> 3;
		break;
#endif
#ifdef FBCON_HAS_CFB16
	case 16:/* DIRECTCOLOUR, 64k */
#ifndef CFB16_IS_CFB15
		hw->pixformat		= PIXFORMAT_16BPP;
		hw->visualid		= VISUALID_64K;
		hw->pitch		= hw->width >> 2;
		hw->palette_ctrl	|= 0x10;
		break;
#endif
	case 15:/* DIRECTCOLOUR, 32k */
		hw->pixformat		= PIXFORMAT_16BPP;
		hw->visualid		= VISUALID_32K;
		hw->pitch		= hw->width >> 2;
		hw->palette_ctrl	|= 0x10;
		break;

#endif
#ifdef FBCON_HAS_CFB24
	case 24:/* TRUECOLOUR, 16m */
		hw->pixformat		= PIXFORMAT_24BPP;
		hw->visualid		= VISUALID_16M;
		hw->width		*= 3;
		hw->pitch		= hw->width >> 3;
		hw->palette_ctrl	|= 0x10;
		break;
#endif
#ifdef FBCON_HAS_CFB32
	case 32:/* TRUECOLOUR, 16m */
		hw->pixformat		= PIXFORMAT_32BPP;
		hw->visualid		= VISUALID_16M_32;
		hw->pitch		= hw->width >> 1;
		hw->palette_ctrl	|= 0x10;
		break;
#endif
	default:
		return -EINVAL;
	}

	err = cyber2000fb_decode_clock(hw, cfb, var);
	if (err)
		return err;

	err = cyber2000fb_decode_crtc(hw, cfb, var);
	if (err)
		return err;

	hw->width -= 1;
	hw->fetch = hw->pitch;
	if (!(cfb->mem_ctl2 & MEM_CTL2_64BIT))
		hw->fetch <<= 1;
	hw->fetch += 1;

	return 0;
}

/*
 *    Set the User Defined Part of the Display
 */
static int
cyber2000fb_set_var(struct fb_var_screeninfo *var, int con,
		    struct fb_info *info)
{
	struct cfb_info *cfb = (struct cfb_info *)info;
	struct display *display;
	struct par_info hw;
	int err, chgvar = 0;

	/*
	 * CONUPDATE and SMOOTH_XPAN are equal.  However,
	 * SMOOTH_XPAN is only used internally by fbcon.
	 */
	if (var->vmode & FB_VMODE_CONUPDATE) {
		var->vmode |= FB_VMODE_YWRAP;
		var->xoffset = cfb->fb.var.xoffset;
		var->yoffset = cfb->fb.var.yoffset;
	}

	err = cyber2000fb_decode_var(var, (struct cfb_info *)info, &hw);
	if (err)
		return err;

	if (var->activate & FB_ACTIVATE_TEST)
		return 0;

	if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
		return -EINVAL;

	if (cfb->fb.var.xres != var->xres)
		chgvar = 1;
	if (cfb->fb.var.yres != var->yres)
		chgvar = 1;
	if (cfb->fb.var.xres_virtual != var->xres_virtual)
		chgvar = 1;
	if (cfb->fb.var.yres_virtual != var->yres_virtual)
		chgvar = 1;
	if (cfb->fb.var.bits_per_pixel != var->bits_per_pixel)
		chgvar = 1;

	if (con < 0) {
		display = cfb->fb.disp;
		chgvar = 0;
	} else {
		display = fb_display + con;
	}

	var->red.msb_right	= 0;
	var->green.msb_right	= 0;
	var->blue.msb_right	= 0;

	switch (var->bits_per_pixel) {
#ifdef FBCON_HAS_CFB8
	case 8:	/* PSEUDOCOLOUR, 256 */
		var->red.offset		= 0;
		var->red.length		= 8;
		var->green.offset	= 0;
		var->green.length	= 8;
		var->blue.offset	= 0;
		var->blue.length	= 8;

		cfb->fb.fix.visual	= FB_VISUAL_PSEUDOCOLOR;
		cfb->dispsw		= &fbcon_cfb8;
		display->dispsw_data	= NULL;
		display->next_line	= var->xres_virtual;
		break;
#endif
#ifdef FBCON_HAS_CFB16
	case 16:/* DIRECTCOLOUR, 64k */
#ifndef CFB16_IS_CFB15
		var->red.offset		= 11;
		var->red.length		= 5;
		var->green.offset	= 5;
		var->green.length	= 6;
		var->blue.offset	= 0;
		var->blue.length	= 5;

		cfb->fb.fix.visual	= FB_VISUAL_DIRECTCOLOR;
		cfb->dispsw		= &fbcon_cfb16;
		display->dispsw_data	= cfb->fb.pseudo_palette;
		display->next_line	= var->xres_virtual * 2;
		break;
#endif
	case 15:/* DIRECTCOLOUR, 32k */
		var->bits_per_pixel	= 15;
		var->red.offset		= 10;
		var->red.length		= 5;
		var->green.offset	= 5;
		var->green.length	= 5;
		var->blue.offset	= 0;
		var->blue.length	= 5;

		cfb->fb.fix.visual	= FB_VISUAL_DIRECTCOLOR;
		cfb->dispsw		= &fbcon_cfb16;
		display->dispsw_data	= cfb->fb.pseudo_palette;
		display->next_line	= var->xres_virtual * 2;
		break;
#endif
#ifdef FBCON_HAS_CFB24
	case 24:/* TRUECOLOUR, 16m */
		var->red.offset		= 16;
		var->red.length		= 8;
		var->green.offset	= 8;
		var->green.length	= 8;
		var->blue.offset	= 0;
		var->blue.length	= 8;

		cfb->fb.fix.visual	= FB_VISUAL_TRUECOLOR;
		cfb->dispsw		= &fbcon_cfb24;
		display->dispsw_data	= cfb->fb.pseudo_palette;
		display->next_line	= var->xres_virtual * 3;
		break;
#endif
#ifdef FBCON_HAS_CFB32
	case 32:/* TRUECOLOUR, 16m */
		var->transp.offset	= 24;
		var->transp.length	= 8;
		var->red.offset		= 16;
		var->red.length		= 8;
		var->green.offset	= 8;
		var->green.length	= 8;
		var->blue.offset	= 0;
		var->blue.length	= 8;

		cfb->fb.fix.visual	= FB_VISUAL_TRUECOLOR;
		cfb->dispsw		= &fbcon_cfb32;
		display->dispsw_data	= cfb->fb.pseudo_palette;
		display->next_line	= var->xres_virtual * 4;
		break;
#endif
	default:/* in theory this should never happen */
		printk(KERN_WARNING "%s: no support for %dbpp\n",
		       cfb->fb.fix.id, var->bits_per_pixel);
		cfb->dispsw = &fbcon_dummy;
		break;
	}

	if (var->accel_flags & FB_ACCELF_TEXT && cfb->dispsw != &fbcon_dummy)
		display->dispsw = &fbcon_cyber_accel;
	else
		display->dispsw = cfb->dispsw;

	cfb->fb.fix.line_length	= display->next_line;

	display->screen_base	= cfb->fb.screen_base;
	display->line_length	= cfb->fb.fix.line_length;
	display->visual		= cfb->fb.fix.visual;
	display->type		= cfb->fb.fix.type;
	display->type_aux	= cfb->fb.fix.type_aux;
	display->ypanstep	= cfb->fb.fix.ypanstep;
	display->ywrapstep	= cfb->fb.fix.ywrapstep;
	display->can_soft_blank = 1;
	display->inverse	= 0;

	cfb->fb.var = *var;
	cfb->fb.var.activate &= ~FB_ACTIVATE_ALL;

	/*
	 * Update the old var.  The fbcon drivers still use this.
	 * Once they are using cfb->fb.var, this can be dropped.
	 *					--rmk
	 */
	display->var = cfb->fb.var;

	/*
	 * If we are setting all the virtual consoles, also set the
	 * defaults used to create new consoles.
	 */
	if (var->activate & FB_ACTIVATE_ALL)
		cfb->fb.disp->var = cfb->fb.var;

	if (chgvar && info && cfb->fb.changevar)
		cfb->fb.changevar(con);

	cyber2000fb_update_start(cfb, var);
	cyber2000fb_set_timing(cfb, &hw);
	fb_set_cmap(&cfb->fb.cmap, 1, cyber2000_setcolreg, &cfb->fb);

	return 0;
}


/*
 *    Pan or Wrap the Display
 */
static int
cyber2000fb_pan_display(struct fb_var_screeninfo *var, int con,
			struct fb_info *info)
{
	struct cfb_info *cfb = (struct cfb_info *)info;
	u_int y_bottom;

	y_bottom = var->yoffset;

	if (!(var->vmode & FB_VMODE_YWRAP))
		y_bottom += var->yres;

	if (var->xoffset > (var->xres_virtual - var->xres))
		return -EINVAL;
	if (y_bottom > cfb->fb.var.yres_virtual)
		return -EINVAL;

	if (cyber2000fb_update_start(cfb, var))
		return -EINVAL;

	cfb->fb.var.xoffset = var->xoffset;
	cfb->fb.var.yoffset = var->yoffset;
	if (var->vmode & FB_VMODE_YWRAP) {
		cfb->fb.var.vmode |= FB_VMODE_YWRAP;
	} else {
		cfb->fb.var.vmode &= ~FB_VMODE_YWRAP;
	}

	return 0;
}


/*
 *    Update the `var' structure (called by fbcon.c)
 *
 *    This call looks only at yoffset and the FB_VMODE_YWRAP flag in `var'.
 *    Since it's called by a kernel driver, no range checking is done.
 */
static int cyber2000fb_updatevar(int con, struct fb_info *info)
{
	struct cfb_info *cfb = (struct cfb_info *)info;

	return cyber2000fb_update_start(cfb, &fb_display[con].var);
}

static int cyber2000fb_switch(int con, struct fb_info *info)
{
	struct cfb_info *cfb = (struct cfb_info *)info;
	struct display *disp;
	struct fb_cmap *cmap;

	if (cfb->currcon >= 0) {
		disp = fb_display + cfb->currcon;

		/*
		 * Save the old colormap and video mode.
		 */
		disp->var = cfb->fb.var;
		if (disp->cmap.len)
			fb_copy_cmap(&cfb->fb.cmap, &disp->cmap, 0);
	}

	cfb->currcon = con;
	disp = fb_display + con;

	/*
	 * Install the new colormap and change the video mode.  By default,
	 * fbcon sets all the colormaps and video modes to the default
	 * values at bootup.
	 *
	 * Really, we want to set the colourmap size depending on the
	 * depth of the new video mode.  For now, we leave it at its
	 * default 256 entry.
	 */
	if (disp->cmap.len)
		cmap = &disp->cmap;
	else
		cmap = fb_default_cmap(1 << disp->var.bits_per_pixel);

	fb_copy_cmap(cmap, &cfb->fb.cmap, 0);

	cfb->fb.var = disp->var;
	cfb->fb.var.activate = FB_ACTIVATE_NOW;

	cyber2000fb_set_var(&cfb->fb.var, con, &cfb->fb);

	return 0;
}

/*
 *    (Un)Blank the display.
 */
static void cyber2000fb_blank(int blank, struct fb_info *info)
{
	struct cfb_info *cfb = (struct cfb_info *)info;
	int i;

	/*
	 *  Blank the screen if blank_mode != 0, else unblank. If
	 *  blank == NULL then the caller blanks by setting the CLUT
	 *  (Color Look Up Table) to all black. Return 0 if blanking
	 *  succeeded, != 0 if un-/blanking failed due to e.g. a
	 *  video mode which doesn't support it. Implements VESA
	 *  suspend and powerdown modes on hardware that supports
	 *  disabling hsync/vsync:
	 *    blank_mode == 2: suspend vsync
	 *    blank_mode == 3: suspend hsync
	 *    blank_mode == 4: powerdown
	 *
	 *  wms...Enable VESA DMPS compatible powerdown mode
	 *  run "setterm -powersave powerdown" to take advantage
	 */
     
	switch (blank) {
	case 4:	/* powerdown - both sync lines down */
    		cyber2000_grphw(0x16, 0x05, cfb);
		break;	
	case 3:	/* hsync off */
    		cyber2000_grphw(0x16, 0x01, cfb);
		break;	
	case 2:	/* vsync off */
    		cyber2000_grphw(0x16, 0x04, cfb);