tgafb: TURBOchannel support

This is support for the TC variations of the TGA boards (properly known as
SFB+ or Smart Frame Buffer Plus boards).  The 8-plane SFB+ board uses the
Bt459 RAMDAC (unlike its PCI TGA counterpart, which uses the Bt485), so
bits have been added to support this chip as well.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: James Simmons <jsimmons@infradead.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/Kconfig

@@ -525,15 +525,25 @@ config FB_HP300
 	default y
 
 config FB_TGA
-	tristate "TGA framebuffer support"
-	depends on FB && ALPHA
+	tristate "TGA/SFB+ framebuffer support"
+	depends on FB && (ALPHA || TC)
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
 	select BITREVERSE
-	help
-	  This is the frame buffer device driver for generic TGA graphic
-	  cards. Say Y if you have one of those.
+	---help---
+	  This is the frame buffer device driver for generic TGA and SFB+
+	  graphic cards.  These include DEC ZLXp-E1, -E2 and -E3 PCI cards,
+	  also known as PBXGA-A, -B and -C, and DEC ZLX-E1, -E2 and -E3
+	  TURBOchannel cards, also known as PMAGD-A, -B and -C.
+
+	  Due to hardware limitations ZLX-E2 and E3 cards are not supported
+	  for DECstation 5000/200 systems.  Additionally due to firmware
+	  limitations these cards may cause troubles with booting DECstation
+	  5000/240 and /260 systems, but are fully supported under Linux if
+	  you manage to get it going. ;-)
+
+	  Say Y if you have one of those.
 
 config FB_VESA
 	bool "VESA VGA graphics support"

include/video/tgafb.h

@@ -39,6 +39,7 @@
 #define	TGA_RASTEROP_REG		0x0034
 #define	TGA_PIXELSHIFT_REG		0x0038
 #define	TGA_DEEP_REG			0x0050
+#define	TGA_START_REG			0x0054
 #define	TGA_PIXELMASK_REG		0x005c
 #define	TGA_CURSOR_BASE_REG		0x0060
 #define	TGA_HORIZ_REG			0x0064
@@ -140,7 +141,7 @@
 
 
 /*
- * Useful defines for managing the BT463 on the 24-plane TGAs
+ * Useful defines for managing the BT463 on the 24-plane TGAs/SFB+s
  */
 
 #define	BT463_ADDR_LO		0x0
@@ -167,13 +168,36 @@
 
 #define	BT463_WINDOW_TYPE_BASE	0x0300
 
+/*
+ * Useful defines for managing the BT459 on the 8-plane SFB+s
+ */
+
+#define	BT459_ADDR_LO		0x0
+#define	BT459_ADDR_HI		0x1
+#define	BT459_REG_ACC		0x2
+#define	BT459_PALETTE		0x3
+
+#define	BT459_CUR_CLR_1		0x0181
+#define	BT459_CUR_CLR_2		0x0182
+#define	BT459_CUR_CLR_3		0x0183
+
+#define	BT459_CMD_REG_0		0x0201
+#define	BT459_CMD_REG_1		0x0202
+#define	BT459_CMD_REG_2		0x0203
+
+#define	BT459_READ_MASK		0x0204
+
+#define	BT459_BLINK_MASK	0x0206
+
+#define	BT459_CUR_CMD_REG	0x0300
+
 /*
  * The framebuffer driver private data.
  */
 
 struct tga_par {
-	/* PCI device.  */
-	struct pci_dev *pdev;
+	/* PCI/TC device.  */
+	struct device *dev;
 
 	/* Device dependent information.  */
 	void __iomem *tga_mem_base;
@@ -235,4 +259,21 @@ BT463_WRITE(struct tga_par *par, u32 m, u16 a, u8 v)
 	TGA_WRITE_REG(par, m << 10 | v, TGA_RAMDAC_REG);
 }
 
+static inline void
+BT459_LOAD_ADDR(struct tga_par *par, u16 a)
+{
+	TGA_WRITE_REG(par, BT459_ADDR_LO << 2, TGA_RAMDAC_SETUP_REG);
+	TGA_WRITE_REG(par, a & 0xff, TGA_RAMDAC_REG);
+	TGA_WRITE_REG(par, BT459_ADDR_HI << 2, TGA_RAMDAC_SETUP_REG);
+	TGA_WRITE_REG(par, a >> 8, TGA_RAMDAC_REG);
+}
+
+static inline void
+BT459_WRITE(struct tga_par *par, u32 m, u16 a, u8 v)
+{
+	BT459_LOAD_ADDR(par, a);
+	TGA_WRITE_REG(par, m << 2, TGA_RAMDAC_SETUP_REG);
+	TGA_WRITE_REG(par, v, TGA_RAMDAC_REG);
+}
+
 #endif /* TGAFB_H */