[PATCH] fbdev driver for S3 Trio/Virge

Add a driver for S3 Trio / S3 Virge.  Driver is tested with most versions
of S3 Trio and with S3 Virge/DX, on i386.

(akpm: We kind-of have support for this hardware already, but...

virgefb.c
  - amiga/zorro specific,
  - broken (according to Kconfig),
  - uses obsolete/nonexistent interface (struct display_switch)
  - recent Adrian Bunk's patch removes this driver

S3triofb.c
  - ppc/openfirmware specific
  - minimal functionality
  - broken (according to Kconfig),
  - uses obsolete/nonexistent interface (struct display_switch)
)

Signed-off-by: Ondrej Zajicek <[email protected]>
Cc: James Simmons <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Documentation/fb/s3fb.txt

@@ -0,0 +1,78 @@
+
+	s3fb - fbdev driver for S3 Trio/Virge chips
+	===========================================
+
+
+Supported Hardware
+==================
+
+	S3 Trio32
+	S3 Trio64 (and variants V+, UV+, V2/DX, V2/GX)
+	S3 Virge  (and variants VX, DX, GX and GX2+)
+	S3 Plato/PX		(completely untested)
+	S3 Aurora64V+		(completely untested)
+
+	- only PCI bus supported
+	- only BIOS initialized VGA devices supported
+	- probably not working on big endian
+
+I tested s3fb on Trio64 (plain, V+ and V2/DX) and Virge (plain, VX, DX),
+all on i386.
+
+
+Supported Features
+==================
+
+	*  4 bpp pseudocolor modes (with 18bit palette, two variants)
+	*  8 bpp pseudocolor mode (with 18bit palette)
+	* 16 bpp truecolor modes (RGB 555 and RGB 565)
+	* 24 bpp truecolor mode (RGB 888) on (only on Virge VX)
+	* 32 bpp truecolor mode (RGB 888) on (not on Virge VX)
+	* text mode (activated by bpp = 0)
+	* interlaced mode variant (not available in text mode)
+	* doublescan mode variant (not available in text mode)
+	* panning in both directions
+	* suspend/resume support
+	* DPMS support
+
+Text mode is supported even in higher resolutions, but there is limitation
+to lower pixclocks (maximum between 50-60 MHz, depending on specific hardware).
+This limitation is not enforced by driver. Text mode supports 8bit wide fonts
+only (hardware limitation) and 16bit tall fonts (driver limitation).
+
+There are two 4 bpp modes. First mode (selected if nonstd == 0) is mode with
+packed pixels, high nibble first. Second mode (selected if nonstd == 1) is mode
+with interleaved planes (1 byte interleave), MSB first. Both modes support
+8bit wide fonts only (driver limitation).
+
+Suspend/resume works on systems that initialize video card during resume and
+if device is active (for example used by fbcon).
+
+
+Missing Features
+================
+(alias TODO list)
+
+	* secondary (not initialized by BIOS) device support
+   	* big endian support
+	* Zorro bus support
+	* MMIO support
+	* 24 bpp mode support on more cards
+	* support for fontwidths != 8 in 4 bpp modes
+	* support for fontheight != 16 in text mode
+	* composite and external sync (is anyone able to test this?)
+	* hardware cursor
+	* video overlay support
+	* vsync synchronization
+	* feature connector support
+	* acceleration support (8514-like 2D, Virge 3D, busmaster transfers)
+	* better values for some magic registers (performance issues)
+
+
+Known bugs
+==========
+
+	* cursor disable in text mode doesn't work
+
+--
+Ondrej Zajicek <[email protected]>

drivers/video/Kconfig

@@ -85,6 +85,14 @@ config FB_CFB_IMAGEBLIT
 	  blitting. This is used by drivers that don't provide their own
 	  (accelerated) version.
 
+config FB_SVGALIB
+	tristate
+	depends on FB
+	default n
+	---help---
+	  Common utility functions useful to fbdev drivers of VGA-based
+	  cards.
+
 config FB_MACMODES
        tristate
        depends on FB
@@ -1147,6 +1155,17 @@ config FB_S3TRIO
 	help
 	  If you have a S3 Trio say Y. Say N for S3 Virge.
 
+config FB_S3
+	tristate "S3 Trio/Virge support"
+	depends on FB && PCI
+	select FB_CFB_FILLRECT
+	select FB_CFB_COPYAREA
+	select FB_CFB_IMAGEBLIT
+	select FB_TILEBLITTING
+	select FB_SVGALIB
+	---help---
+	  Driver for graphics boards with S3 Trio / S3 Virge chip.
+
 config FB_SAVAGE
 	tristate "S3 Savage support"
 	depends on FB && PCI && EXPERIMENTAL

drivers/video/Makefile

@@ -17,6 +17,7 @@ obj-$(CONFIG_SYSFS)		  += backlight/
 obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
 obj-$(CONFIG_FB_CFB_COPYAREA)  += cfbcopyarea.o
 obj-$(CONFIG_FB_CFB_IMAGEBLIT) += cfbimgblt.o
+obj-$(CONFIG_FB_SVGALIB)       += svgalib.o
 obj-$(CONFIG_FB_MACMODES)      += macmodes.o
 obj-$(CONFIG_FB_DDC)           += fb_ddc.o
 
@@ -54,6 +55,7 @@ obj-$(CONFIG_FB_S3TRIO)           += S3triofb.o
 obj-$(CONFIG_FB_FM2)              += fm2fb.o
 obj-$(CONFIG_FB_CYBLA)            += cyblafb.o
 obj-$(CONFIG_FB_TRIDENT)          += tridentfb.o
+obj-$(CONFIG_FB_S3)               += s3fb.o vgastate.o
 obj-$(CONFIG_FB_STI)              += stifb.o
 obj-$(CONFIG_FB_FFB)              += ffb.o sbuslib.o
 obj-$(CONFIG_FB_CG6)              += cg6.o sbuslib.o