mga4xx.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

	for (i = 0; i < n; i++) {
		k = (2*i+1)*Meg;
		p[k] = 0;
		p[k] = i+1;
		*(mga->mmio + CACHEFLUSH) = 0;
		x[i] = p[k];
		trace("x[%d]=%d\n", i, x[i]);
	}
	for(i = 1; i < n; i++)
		if(x[i] != i+1)
			break;
	vga->vmz = mga->fbsize = 2*i*Meg;
	trace("probe found %d megabytes\n", 2*i);

	crtcextset(mga, 3, crtcext3, 0xff);

	ctlr->flag |= Fsnarf;
}

static void
options(Vga* vga, Ctlr* ctlr)
{
	if(vga->virtx & 127)
		vga->virtx = (vga->virtx+127)&~127;
	ctlr->flag |= Foptions;
}

/* ************************************************************ */

static void 
G450ApplyPFactor(Mga*, uchar ucP, ulong *pulFIn)
{
	if(!(ucP & 0x40))
	{
		*pulFIn = *pulFIn / (2L << (ucP & 3));
	}
}


static void 
G450RemovePFactor(Mga*, uchar ucP, ulong *pulFIn)
{
	if(!(ucP & 0x40))
	{
		*pulFIn = *pulFIn * (2L << (ucP & 3));
	}
}

static void 
G450CalculVCO(Mga*, ulong ulMNP, ulong *pulF)
{
	uchar ucM, ucN;

	ucM = (uchar)((ulMNP >> 16) & 0xff);
	ucN = (uchar)((ulMNP >>  8) & 0xff);

	*pulF = (27000 * (2 * (ucN + 2)) + ((ucM + 1) >> 1)) / (ucM + 1);
	trace("G450CalculVCO: ulMNP %lx, pulF %ld\n", ulMNP, *pulF);
}


static void 
G450CalculDeltaFreq(Mga*, ulong ulF1, ulong ulF2, ulong *pulDelta)
{
	if(ulF2 < ulF1)
	{
		*pulDelta = ((ulF1 - ulF2) * 1000) / ulF1;
	}
	else
	{
		*pulDelta = ((ulF2 - ulF1) * 1000) / ulF1;
	}
	trace("G450CalculDeltaFreq: ulF1 %ld, ulF2 %ld, pulDelta %ld\n", ulF1, ulF2, *pulDelta);
}

static void 
G450FindNextPLLParam(Mga* mga, ulong ulFout, ulong *pulPLLMNP)
{
	uchar ucM, ucN, ucP, ucS;
	ulong ulVCO, ulVCOMin;

	ucM = (uchar)((*pulPLLMNP >> 16) & 0xff);
	/* ucN = (uchar)((*pulPLLMNP >>  8) & 0xff); */
	ucP = (uchar)(*pulPLLMNP &  0x43);

	ulVCOMin = 256000;

	if(ulVCOMin >= (255L * 8000))
	{
		ulVCOMin = 230000;
	}

	if((ucM == 9) && (ucP & 0x40))
	{
		*pulPLLMNP = 0xffffffff;
	} else if (ucM == 9)
	{
		if(ucP)
		{
			ucP--;
		}
		else
		{
			ucP = 0x40;
		}
		ucM = 0;
	}
	else
	{
		ucM++;
	}

	ulVCO = ulFout;

	G450RemovePFactor(mga, ucP, &ulVCO);

	if(ulVCO < ulVCOMin)
	{
		*pulPLLMNP = 0xffffffff;
	}

	if(*pulPLLMNP != 0xffffffff)
	{
		ucN = (uchar)(((ulVCO * (ucM+1) + 27000)/(27000 * 2)) - 2);

		ucS = 5;
		if(ulVCO < 1300000) ucS = 4;
		if(ulVCO < 1100000) ucS = 3;
		if(ulVCO <  900000) ucS = 2;
		if(ulVCO <  700000) ucS = 1;
		if(ulVCO <  550000) ucS = 0;

		ucP |= (uchar)(ucS << 3);

		*pulPLLMNP &= 0xff000000;
		*pulPLLMNP |= (ulong)ucM << 16;
		*pulPLLMNP |= (ulong)ucN << 8;
		*pulPLLMNP |= (ulong)ucP;
	}
}

static void 
G450FindFirstPLLParam(Mga* mga, ulong ulFout, ulong *pulPLLMNP)
{
	uchar ucP;
	ulong ulVCO;
	ulong ulVCOMax;

	/* Default value */
	ulVCOMax = 1300000;

	if(ulFout > (ulVCOMax/2))
	{
		ucP = 0x40;
		ulVCO = ulFout;
	}
	else
	{
		ucP = 3;
		ulVCO = ulFout;
		G450RemovePFactor(mga, ucP, &ulVCO);
		while(ucP && (ulVCO > ulVCOMax))
		{
			ucP--;
			ulVCO = ulFout;
			G450RemovePFactor(mga, ucP, &ulVCO);
		}
	}

	if(ulVCO > ulVCOMax)
	{
		*pulPLLMNP = 0xffffffff;
	}
	else
	{
		/* Pixel clock: 1 */
		*pulPLLMNP = (1 << 24) + 0xff0000 + ucP;
		G450FindNextPLLParam(mga, ulFout, pulPLLMNP);
	}
}


static void 
G450WriteMNP(Mga* mga, ulong ulMNP)
{
	if (0) trace("G450WriteMNP : 0x%lx\n", ulMNP);
	dacset(mga, Dac_Xpixpllcm, (uchar)(ulMNP >> 16), 0xff);
	dacset(mga, Dac_Xpixpllcn, (uchar)(ulMNP >>  8), 0xff);   
	dacset(mga, Dac_Xpixpllcp, (uchar)ulMNP, 0xff);   
}


static void 
G450CompareMNP(Mga* mga, ulong ulFout, ulong ulMNP1,
			    ulong ulMNP2, long *pulResult)
{
	ulong ulFreq, ulDelta1, ulDelta2;

	G450CalculVCO(mga, ulMNP1, &ulFreq);
	G450ApplyPFactor(mga, (uchar) ulMNP1, &ulFreq);
	G450CalculDeltaFreq(mga, ulFout, ulFreq, &ulDelta1);

	G450CalculVCO(mga, ulMNP2, &ulFreq);
	G450ApplyPFactor(mga, (uchar) ulMNP2, &ulFreq);
	G450CalculDeltaFreq(mga, ulFout, ulFreq, &ulDelta2);

	if(ulDelta1 < ulDelta2)
	{
		*pulResult = -1;
	}
	else if(ulDelta1 > ulDelta2)
	{
		*pulResult = 1;
	}
	else
	{
		*pulResult = 0;
	}

	if((ulDelta1 <= 5) && (ulDelta2 <= 5))
	{
		if((ulMNP1 & 0xff0000) < (ulMNP2 & 0xff0000))
		{
			*pulResult = -1;
		}
		else if((ulMNP1 & 0xff0000) > (ulMNP2 & 0xff0000))
		{
			*pulResult = 1;
		}
	}
}


static void 
G450IsPllLocked(Mga* mga, int *lpbLocked)
{
	ulong ulFallBackCounter, ulLockCount, ulCount;
	uchar  ucPLLStatus;

	/* Pixel PLL */
	mgawrite8(mga, 0x3c00, 0x4f);    
	ulFallBackCounter = 0;

	do 
	{
		ucPLLStatus = mgaread8(mga, 0x3c0a);
		if (0) trace("ucPLLStatus[1] : 0x%x\n", ucPLLStatus);
		ulFallBackCounter++;
	} while(!(ucPLLStatus & 0x40) && (ulFallBackCounter < 1000));

	ulLockCount = 0;
	if(ulFallBackCounter < 1000)
	{
		for(ulCount = 0; ulCount < 100; ulCount++)
		{
			ucPLLStatus = mgaread8(mga, 0x3c0a);
			if (0) trace("ucPLLStatus[2] : 0x%x\n", ucPLLStatus);
			if(ucPLLStatus & 0x40)
			{
				ulLockCount++;
			}
		}
	}

	*lpbLocked = ulLockCount >= 90;
}

static void 
G450SetPLLFreq(Mga* mga, long f_out) 
{
	int bFoundValidPLL;
	int bLocked;
	ulong ulMaxIndex;
	ulong ulMNP;
	ulong ulMNPTable[MNP_TABLE_SIZE];
	ulong ulIndex;
	ulong ulTryMNP;
	long lCompareResult;

	trace("f_out : %ld\n", f_out);

	G450FindFirstPLLParam(mga, f_out, &ulMNP);
	ulMNPTable[0] = ulMNP;
	G450FindNextPLLParam(mga, f_out, &ulMNP);
	ulMaxIndex = 1;
	while(ulMNP != 0xffffffff)
	{
		int ulIndex;
		int bSkipValue;

		bSkipValue = FALSE;
		if(ulMaxIndex == MNP_TABLE_SIZE)
		{
			G450CompareMNP(mga, f_out, ulMNP, ulMNPTable[MNP_TABLE_SIZE - 1],
				       &lCompareResult);

			if(lCompareResult > 0)
			{
				bSkipValue = TRUE;
			}
			else
			{
				ulMaxIndex--;
			}
		}

		if(!bSkipValue)
		{
			for(ulIndex = ulMaxIndex; !bSkipValue && (ulIndex > 0); ulIndex--)
			{
				G450CompareMNP(mga, f_out, ulMNP, ulMNPTable[ulIndex - 1],
					       &lCompareResult);

				if(lCompareResult < 0)
				{
					ulMNPTable[ulIndex] = ulMNPTable[ulIndex - 1];
				}
				else
				{
					break;
				}
			}
			ulMNPTable[ulIndex] = ulMNP;
			ulMaxIndex++;
		}

		G450FindNextPLLParam(mga, f_out, &ulMNP);
	}

	bFoundValidPLL = FALSE;
	ulMNP = 0;

	for(ulIndex = 0; !bFoundValidPLL && (ulIndex < ulMaxIndex); ulIndex++)
	{
		ulTryMNP = ulMNPTable[ulIndex];

		{
			bLocked = TRUE;
			if((ulMNPTable[ulIndex] & 0xff00) < 0x300 ||
			   (ulMNPTable[ulIndex] & 0xff00) > 0x7a00)
			{
				bLocked = FALSE;
			}

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP - 0x300);
				G450IsPllLocked(mga, &bLocked);
			}     

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP + 0x300);
				G450IsPllLocked(mga, &bLocked);
			}     

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP - 0x200);
				G450IsPllLocked(mga, &bLocked);
			}     

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP + 0x200);
				G450IsPllLocked(mga, &bLocked);
			}     

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP - 0x100);
				G450IsPllLocked(mga, &bLocked);
			}     

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP + 0x100);
				G450IsPllLocked(mga, &bLocked);
			}     

			if(bLocked)
			{
				G450WriteMNP(mga, ulTryMNP);
				G450IsPllLocked(mga, &bLocked);
			}     
			else if(!ulMNP)
			{
				G450WriteMNP(mga, ulTryMNP);
				G450IsPllLocked(mga, &bLocked);
				if(bLocked)
				{
					ulMNP = ulMNPTable[ulIndex]; 
				}
				bLocked = FALSE;
			}

			if(bLocked)
			{
				bFoundValidPLL = TRUE;
			}
		}
	}

	if(!bFoundValidPLL)
	{
		if(ulMNP)
		{
			G450WriteMNP(mga, ulMNP);
		}
		else
		{
			G450WriteMNP(mga, ulMNPTable[0]);
		}
	}
}


/* ************************************************************ */

/*
	calcclock - Calculate the PLL settings (m, n, p, s).
*/
static double
g400_calcclock(Mga* mga, long Fneeded)
{
	double	Fpll;
	double	Fvco;
	double 	Fref;
	int		pixpll_m_min;
	int		pixpll_m_max;
	int		pixpll_n_min;
	int		pixpll_n_max;
	int		pixpll_p_max;
	double 	Ferr, Fcalc;
	int		m, n, p;
	
	if (mga->devid == MGA4XX || mga->devid == MGA550) {
		/* These values are taken from Matrox G400 Specification - p 4-91 */
		Fref     		= 27000000.0;
		pixpll_n_min 	= 7;
		pixpll_n_max 	= 127;
		pixpll_m_min	= 1;
		pixpll_m_max	= 31;
		pixpll_p_max 	= 7;
	} else { 				/* MGA200 */
		/* These values are taken from Matrox G200 Specification - p 4-77 */
		//Fref     		= 14318180.0;
		Fref     		= 27050500.0;
		pixpll_n_min 	= 7;
		pixpll_n_max 	= 127;
		pixpll_m_min	= 1;
		pixpll_m_max	= 6;
		pixpll_p_max 	= 7;
	}

	Fvco = ( double ) Fneeded;
	for (p = 0;  p <= pixpll_p_max && Fvco < mga->maxpclk; p = p * 2 + 1, Fvco *= 2.0)
		;
	mga->pixpll_p = p;

	Ferr = Fneeded;
	for ( m = pixpll_m_min ; m <= pixpll_m_max ; m++ )
		for ( n = pixpll_n_min; n <= pixpll_n_max; n++ )
		{ 
			Fcalc = Fref * (n + 1) / (m + 1) ;

			/*
			 * Pick the closest frequency.
			 */
			if ( labs(Fcalc - Fvco) < Ferr ) {
				Ferr = abs(Fcalc - Fvco);
				mga->pixpll_m = m;
				mga->pixpll_n = n;
			}
		}
	
	Fvco = Fref * (mga->pixpll_n + 1) / (mga->pixpll_m + 1);

	if (mga->devid == MGA4XX || mga->devid == MGA550) {
		if ( (50000000.0 <= Fvco) && (Fvco < 110000000.0) )
			mga->pixpll_p |= 0;	
		if ( (110000000.0 <= Fvco) && (Fvco < 170000000.0) )
			mga->pixpll_p |= (1<<3);	
		if ( (170000000.0 <= Fvco) && (Fvco < 240000000.0) )
			mga->pixpll_p |= (2<<3);	
		if ( (300000000.0 <= Fvco) )
			mga->pixpll_p |= (3<<3);	
	} else {
		if ( (50000000.0 <= Fvco) && (Fvco < 100000000.0) )
			mga->pixpll_p |= 0;	
		if ( (100000000.0 <= Fvco) && (Fvco < 140000000.0) )
			mga->pixpll_p |= (1<<3);	
		if ( (140000000.0 <= Fvco) && (Fvco < 180000000.0) )
			mga->pixpll_p |= (2<<3);	
		if ( (250000000.0 <= Fvco) )
			mga->pixpll_p |= (3<<3);	
	}
	
	Fpll = Fvco / (p + 1);

	return Fpll;
}

/* ************************************************************ */

static void
init(Vga* vga, Ctlr* ctlr)
{
	Mode*	mode;
	Mga*	mga;
	double	Fpll;
	Ctlr*	c;
	int	i;
	ulong	t;
	int     bppShift;

	mga = vga->private;
	mode = vga->mode;

	trace("mga mmio at %#p\n", mga->mmio);

	ctlr->flag |= Ulinear;

	/*
	 * Set the right bppShitf based on depth
	 */

	switch(mode->z) {
	case 8: 
		bppShift = 0;
		break;
	case 16:
		bppShift = 1;
		break;
	case 24:
		bppShift = 0;
		break;
	case 32:
		bppShift = 2;
		break;
	default:
		bppShift = 0;
		error("depth %d not supported !\n", mode->z);
	}

	if (mode->interlace)
		error("interlaced mode not supported !\n");

	trace("%s: Initializing mode %dx%dx%d on %s\n", ctlr->name, mode->x, mode->y, mode->z, mode->type);
	trace("%s: Suggested Dot Clock : %d\n", 	ctlr->name, mode->frequency);
	trace("%s: Horizontal Total = %d\n", 		ctlr->name, mode->ht);
	trace("%s: Start Horizontal Blank = %d\n", ctlr->name, mode->shb);
	trace("%s: End Horizontal Blank = %d\n", 	ctlr->name, mode->ehb);
	trace("%s: Vertical Total = %d\n", 		ctlr->name, mode->vt);
	trace("%s: Vertical Retrace Start = %d\n", 	ctlr->name, mode->vrs);
	trace("%s: Vertical Retrace End = %d\n", 	ctlr->name, mode->vre);
	trace("%s: Start Horizontal Sync = %d\n", 	ctlr->name, mode->shs);
	trace("%s: End Horizontal Sync = %d\n", 	ctlr->name, mode->ehs);