[PATCH] fbdev: Add Tile Blitting support

Hopefully, this patch fixes one last major regression for one particular
driver, namely matroxfb.  This drier has 2 versions, one for the kernel and
another as a '2.4 backport' patch.

This patch adds a tileblitting extension to fbcon.  This extension, in
summary, is basically a forward-port of the 2.4 fbdev/fbcon framework to 2.6
but without the fbcon dependency.  Tile blitting is similar to bitblit, except
that the basic unit is a tile (a bitmap of x-by-y dimensions).  The display,
instead of being described in terms of pixels and scanlines, are described as
a region further subdivided into rectangular sections.  In fbcon parlance, a
tile is a character.

Besides a possible fix for matroxfb, tileblitting can be advantageous for
hardware that supports some kind of fontcaching mechanism.  Also, in the
unlikely chance that the console begins supporting multicolored fonts,
tileblitting is probably more optimal than bitblitting because bitblitting
will need to push more data through the bus.

To enable support for this extension, a driver needs to:

- enable CONFIG_FB_TILEBLITTING
- set FBINFO_MISC_TILEBLITTING in info->flags
- set the required function pointers in struct fb_tileops.  The required
  operations are:

  - void (*fb_settile)(struct fb_info *info, struct fb_tilemap *map);

    tells driver about the tile characteristics (dimensions, bitdepth) and
    about the tilemap which is an array of bitmaps: display->fontdata

  - void (*fb_tilecopy)(struct fb_info *info, struct fb_tilearea *area);

    move a rectangular section of tiles (bmove)

  - void (*fb_tilefill)(struct fb_info *info, struct fb_tilerect *rect);

    fill a rectangular section with a tile (clear)

  - void (*fb_tileblit)(struct fb_info *info, struct fb_tileblit *blit);

    copy an array of tiles to a rectangular section (putcs)

  - void (*fb_tilecursor)(struct fb_info *info, struct fb_tilecursor *cursor);

    cursor function

Changes:

Addition of this extension necessitates cleanup of fbcon.c.  The basic drawing
functions in fbcon are bmove, clear, putcs and cursor (the fbcon_* set).  The
fbcon_* set are just wrappers to accel_* set.  However, usage is not
consistent, some functions call the fbcon_* set, others call the accel_* set.

With this patch, a new fbcon-specific structure (struct fbcon_ops) is created.
 Depending on the setting of the hardware, this struct contains pointers to
either the tileblitting set or the bitblitting set (formerly the accel_* set).
 The tileblitting set is new in this patch.

The vast majority of functions in fbcon will need to only call the fbcon_*
set.  In turn, it calls functions in struct fbcon_ops.  Knowledge of the
blitting type is not required.

The accel_* set is renamed to bit_* and is moved into a separate file,
bitblit.c.  The tile blitting set is in tileblit.c.

In my case at least, the cleanup did produce an unexpected but beneficial
side effect, a little more speedup.  Not much, < 5%.

Petr, if you have comments, suggestions, or you think this is a bad idea,
let me know.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 82 insertions, 1 deletions

diff --git a/include/linux/fb.h b/include/linux/fb.h
index 478c73665d3c..a09f31d7c6ee 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -318,6 +318,7 @@ struct fb_cursor {
 	struct fbcurpos hot;	/* cursor hot spot */
 	struct fb_image	image;	/* Cursor image */
 /* all fields below are for fbcon use only */
+	int   flash;            /* cursor blink */
 	char  *data;             /* copy of bitmap */
 };
 
@@ -555,6 +556,82 @@ struct fb_ops {
 	int (*fb_mmap)(struct fb_info *info, struct file *file, struct vm_area_struct *vma);
 };
 
+#ifdef CONFIG_FB_TILEBLITTING
+
+#define FB_TILE_CURSOR_NONE        0
+#define FB_TILE_CURSOR_UNDERLINE   1
+#define FB_TILE_CURSOR_LOWER_THIRD 2
+#define FB_TILE_CURSOR_LOWER_HALF  3
+#define FB_TILE_CURSOR_TWO_THIRDS  4
+#define FB_TILE_CURSOR_BLOCK       5
+
+struct fb_tilemap {
+	__u32 width;                /* width of each tile in pixels */
+	__u32 height;               /* height of each tile in scanlines */
+	__u32 depth;                /* color depth of each tile */
+	__u32 length;               /* number of tiles in the map */
+	__u8  *data;                /* actual tile map: a bitmap array, packed
+				       to the nearest byte */
+};
+
+struct fb_tilerect {
+	__u32 sx;                   /* origin in the x-axis */
+	__u32 sy;                   /* origin in the y-axis */
+	__u32 width;                /* number of tiles in the x-axis */
+	__u32 height;               /* number of tiles in the y-axis */
+	__u32 index;                /* what tile to use: index to tile map */
+	__u32 fg;                   /* foreground color */
+	__u32 bg;                   /* background color */
+	__u32 rop;                  /* raster operation */
+};
+
+struct fb_tilearea {
+	__u32 sx;                   /* source origin in the x-axis */
+	__u32 sy;                   /* source origin in the y-axis */
+	__u32 dx;                   /* destination origin in the x-axis */
+	__u32 dy;                   /* destination origin in the y-axis */
+	__u32 width;                /* number of tiles in the x-axis */
+	__u32 height;               /* number of tiles in the y-axis */
+};
+
+struct fb_tileblit {
+	__u32 sx;                   /* origin in the x-axis */
+	__u32 sy;                   /* origin in the y-axis */
+	__u32 width;                /* number of tiles in the x-axis */
+	__u32 height;               /* number of tiles in the y-axis */
+	__u32 fg;                   /* foreground color */
+	__u32 bg;                   /* background color */
+	__u32 length;               /* number of tiles to draw */
+	__u32 *indices;             /* array of indices to tile map */
+};
+
+struct fb_tilecursor {
+	__u32 sx;                   /* cursor position in the x-axis */
+	__u32 sy;                   /* cursor position in the y-axis */
+	__u32 mode;                 /* 0 = erase, 1 = draw */
+	__u32 shape;                /* see FB_TILE_CURSOR_* */
+	__u32 fg;                   /* foreground color */
+	__u32 bg;                   /* background color */
+};
+
+struct fb_tile_ops {
+	/* set tile characteristics */
+	void (*fb_settile)(struct fb_info *info, struct fb_tilemap *map);
+
+	/* all dimensions from hereon are in terms of tiles */
+
+	/* move a rectangular region of tiles from one area to another*/
+	void (*fb_tilecopy)(struct fb_info *info, struct fb_tilearea *area);
+	/* fill a rectangular region with a tile */
+	void (*fb_tilefill)(struct fb_info *info, struct fb_tilerect *rect);
+	/* copy an array of tiles */
+	void (*fb_tileblit)(struct fb_info *info, struct fb_tileblit *blit);
+	/* cursor */
+	void (*fb_tilecursor)(struct fb_info *info,
+			      struct fb_tilecursor *cursor);
+};
+#endif /* CONFIG_FB_TILEBLITTING */
+
 /* FBINFO_* = fb_info.flags bit flags */
 #define FBINFO_MODULE		0x0001	/* Low-level driver is a module */
 #define FBINFO_HWACCEL_DISABLED	0x0002
@@ -586,6 +663,7 @@ struct fb_ops {
 						  from userspace */
 #define FBINFO_MISC_MODESWITCH         0x20000 /* mode switch */
 #define FBINFO_MISC_MODESWITCHLATE     0x40000 /* init hardware later */
+#define FBINFO_MISC_TILEBLITTING       0x80000 /* use tile blitting */
 
 struct fb_info {
 	int node;
@@ -602,6 +680,9 @@ struct fb_info {
 	struct list_head modelist;      /* mode list */
 	struct fb_ops *fbops;
 	struct device *device;
+#ifdef CONFIG_FB_TILEBLITTING
+	struct fb_tile_ops *tileops;    /* Tile Blitting */
+#endif
 	char __iomem *screen_base;	/* Virtual address */
 	unsigned long screen_size;	/* Amount of ioremapped VRAM or 0 */ 
 	int currcon;			/* Current VC. */
@@ -609,7 +690,7 @@ struct fb_info {
 #define FBINFO_STATE_RUNNING	0
 #define FBINFO_STATE_SUSPENDED	1
 	u32 state;			/* Hardware state i.e suspend */
-
+	void *fbcon_par;                /* fbcon use-only private area */
 	/* From here on everything is device dependent */
 	void *par;	
 };