VIDEO: Fix FFB DAC revision probing

[VIDEO] ffb: Fix two DAC handling bugs.

The determination of whether the DAC has inverted cursor logic is
broken, import the version checks the X.org driver uses to fix this.

Next, when we change the timing generator, borrow code from X.org that
does 10 NOP reads of the timing generator register afterwards to make
sure the video-enable transition occurs cleanly.

Finally, use macros for the DAC registers and fields in order to
provide documentation for the next person who reads this code.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/video/ffb.c

@@ -336,14 +336,30 @@ struct ffb_dac {
 	u32	value2;
 };
 
+#define FFB_DAC_UCTRL	0x1001 /* User Control */
+#define  FFB_DAC_UCTRL_MANREV	0x00000f00 /* 4-bit Manufacturing Revision */
+#define  FFB_DAC_UCTRL_MANREV_SHIFT 8
+#define FFB_DAC_TGEN	0x6000 /* Timing Generator */
+#define  FFB_DAC_TGEN_VIDE	0x00000001 /* Video Enable */
+#define FFB_DAC_DID	0x8000 /* Device Identification */
+#define  FFB_DAC_DID_PNUM	0x0ffff000 /* Device Part Number */
+#define  FFB_DAC_DID_PNUM_SHIFT 12
+#define  FFB_DAC_DID_REV	0xf0000000 /* Device Revision */
+#define  FFB_DAC_DID_REV_SHIFT 28
+
+#define FFB_DAC_CUR_CTRL	0x100
+#define  FFB_DAC_CUR_CTRL_P0	0x00000001
+#define  FFB_DAC_CUR_CTRL_P1	0x00000002
+
 struct ffb_par {
 	spinlock_t		lock;
 	struct ffb_fbc __iomem	*fbc;
 	struct ffb_dac __iomem	*dac;
 
 	u32			flags;
-#define FFB_FLAG_AFB		0x00000001
-#define FFB_FLAG_BLANKED	0x00000002
+#define FFB_FLAG_AFB		0x00000001 /* AFB m3 or m6 */
+#define FFB_FLAG_BLANKED	0x00000002 /* screen is blanked */
+#define FFB_FLAG_INVCURSOR	0x00000004 /* DAC has inverted cursor logic */
 
 	u32			fg_cache __attribute__((aligned (8)));
 	u32			bg_cache;
@@ -354,7 +370,6 @@ struct ffb_par {
 	unsigned long		physbase;
 	unsigned long		fbsize;
 
-	int			dac_rev;
 	int			board_type;
 };
 
@@ -426,11 +441,12 @@ static void ffb_switch_from_graph(struct ffb_par *par)
 	FFBWait(par);
 
 	/* Disable cursor.  */
-	upa_writel(0x100, &dac->type2);
-	if (par->dac_rev <= 2)
+	upa_writel(FFB_DAC_CUR_CTRL, &dac->type2);
+	if (par->flags & FFB_FLAG_INVCURSOR)
 		upa_writel(0, &dac->value2);
 	else
-		upa_writel(3, &dac->value2);
+		upa_writel((FFB_DAC_CUR_CTRL_P0 |
+			    FFB_DAC_CUR_CTRL_P1), &dac->value2);
 
 	spin_unlock_irqrestore(&par->lock, flags);
 }
@@ -664,18 +680,18 @@ ffb_blank(int blank, struct fb_info *info)
 	struct ffb_par *par = (struct ffb_par *) info->par;
 	struct ffb_dac __iomem *dac = par->dac;
 	unsigned long flags;
-	u32 tmp;
+	u32 val;
+	int i;
 
 	spin_lock_irqsave(&par->lock, flags);
 
 	FFBWait(par);
 
+	upa_writel(FFB_DAC_TGEN, &dac->type);
+	val = upa_readl(&dac->value);
 	switch (blank) {
 	case FB_BLANK_UNBLANK: /* Unblanking */
-		upa_writel(0x6000, &dac->type);
-		tmp = (upa_readl(&dac->value) | 0x1);
-		upa_writel(0x6000, &dac->type);
-		upa_writel(tmp, &dac->value);
+		val |= FFB_DAC_TGEN_VIDE;
 		par->flags &= ~FFB_FLAG_BLANKED;
 		break;
 
@@ -683,13 +699,16 @@ ffb_blank(int blank, struct fb_info *info)
 	case FB_BLANK_VSYNC_SUSPEND: /* VESA blank (vsync off) */
 	case FB_BLANK_HSYNC_SUSPEND: /* VESA blank (hsync off) */
 	case FB_BLANK_POWERDOWN: /* Poweroff */
-		upa_writel(0x6000, &dac->type);
-		tmp = (upa_readl(&dac->value) & ~0x1);
-		upa_writel(0x6000, &dac->type);
-		upa_writel(tmp, &dac->value);
+		val &= ~FFB_DAC_TGEN_VIDE;
 		par->flags |= FFB_FLAG_BLANKED;
 		break;
 	}
+	upa_writel(FFB_DAC_TGEN, &dac->type);
+	upa_writel(val, &dac->value);
+	for (i = 0; i < 10; i++) {
+		upa_writel(FFB_DAC_TGEN, &dac->type);
+		upa_readl(&dac->value);
+	}
 
 	spin_unlock_irqrestore(&par->lock, flags);
 
@@ -894,6 +913,7 @@ static int ffb_init_one(struct of_device *op)
 	struct ffb_dac __iomem *dac;
 	struct all_info *all;
 	int err;
+	u32 dac_pnum, dac_rev, dac_mrev;
 
 	all = kzalloc(sizeof(*all), GFP_KERNEL);
 	if (!all)
@@ -948,17 +968,31 @@ static int ffb_init_one(struct of_device *op)
 	if ((upa_readl(&fbc->ucsr) & FFB_UCSR_ALL_ERRORS) != 0)
 		upa_writel(FFB_UCSR_ALL_ERRORS, &fbc->ucsr);
 
-	ffb_switch_from_graph(&all->par);
-
 	dac = all->par.dac;
-	upa_writel(0x8000, &dac->type);
-	all->par.dac_rev = upa_readl(&dac->value) >> 0x1c;
+	upa_writel(FFB_DAC_DID, &dac->type);
+	dac_pnum = upa_readl(&dac->value);
+	dac_rev = (dac_pnum & FFB_DAC_DID_REV) >> FFB_DAC_DID_REV_SHIFT;
+	dac_pnum = (dac_pnum & FFB_DAC_DID_PNUM) >> FFB_DAC_DID_PNUM_SHIFT;
+
+	upa_writel(FFB_DAC_UCTRL, &dac->type);
+	dac_mrev = upa_readl(&dac->value);
+	dac_mrev = (dac_mrev & FFB_DAC_UCTRL_MANREV) >>
+		FFB_DAC_UCTRL_MANREV_SHIFT;
 
 	/* Elite3D has different DAC revision numbering, and no DAC revisions
-	 * have the reversed meaning of cursor enable.
+	 * have the reversed meaning of cursor enable.  Otherwise, Pacifica 1
+	 * ramdacs with manufacturing revision less than 3 have inverted
+	 * cursor logic.  We identify Pacifica 1 as not Pacifica 2, the
+	 * latter having a part number value of 0x236e.
 	 */
-	if (all->par.flags & FFB_FLAG_AFB)
-		all->par.dac_rev = 10;
+	if ((all->par.flags & FFB_FLAG_AFB) || dac_pnum == 0x236e) {
+		all->par.flags &= ~FFB_FLAG_INVCURSOR;
+	} else {
+		if (dac_mrev < 3)
+			all->par.flags |= FFB_FLAG_INVCURSOR;
+	}
+
+	ffb_switch_from_graph(&all->par);
 
 	/* Unblank it just to be sure.  When there are multiple
 	 * FFB/AFB cards in the system, or it is not the OBP
@@ -993,10 +1027,12 @@ static int ffb_init_one(struct of_device *op)
 
 	dev_set_drvdata(&op->dev, all);
 
-	printk("%s: %s at %016lx, type %d, DAC revision %d\n",
+	printk("%s: %s at %016lx, type %d, "
+	       "DAC pnum[%x] rev[%d] manuf_rev[%d]\n",
 	       dp->full_name,
 	       ((all->par.flags & FFB_FLAG_AFB) ? "AFB" : "FFB"),
-	       all->par.physbase, all->par.board_type, all->par.dac_rev);
+	       all->par.physbase, all->par.board_type,
+	       dac_pnum, dac_rev, dac_mrev);
 
 	return 0;
 }