[PATCH] fbcon: Console Rotation - Add support to rotate font bitmap

Add support to rotate the font bitmap.  To save on processing time, the entire
fontdata will be rotated on a console switch, then stored in a buffer private
to fbcon.  To further save on processing, the fontdata will only be rotated if
the font has changed or if the angle of rotation has changed.  Only a single
copy of the rotated fontdata will be kept.

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, 105 insertions, 0 deletions

diff --git a/drivers/video/console/fbcon_rotate.c b/drivers/video/console/fbcon_rotate.c
new file mode 100644
index 00000000000..6a969318480
--- /dev/null
+++ b/drivers/video/console/fbcon_rotate.c
@@ -0,0 +1,105 @@
+/*
+ *  linux/drivers/video/console/fbcon_rotate.c -- Software Rotation
+ *
+ *      Copyright (C) 2005 Antonino Daplas <adaplas @pol.net>
+ *
+ *  This file is subject to the terms and conditions of the GNU General Public
+ *  License.  See the file COPYING in the main directory of this archive for
+ *  more details.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fb.h>
+#include <linux/vt_kern.h>
+#include <linux/console.h>
+#include <asm/types.h>
+#include "fbcon.h"
+#include "fbcon_rotate.h"
+
+static int fbcon_rotate_font(struct fb_info *info, struct vc_data *vc,
+			     struct display *p)
+{
+	struct fbcon_ops *ops = info->fbcon_par;
+	int len, err = 0;
+	int s_cellsize, d_cellsize, i;
+	const u8 *src;
+	u8 *dst;
+
+	if (vc->vc_font.data == ops->fontdata &&
+	    p->con_rotate == ops->cur_rotate)
+		goto finished;
+
+	src = ops->fontdata = vc->vc_font.data;
+	ops->cur_rotate = p->con_rotate;
+	len = (!p->userfont) ? 256 : FNTCHARCNT(src);
+	s_cellsize = ((vc->vc_font.width + 7)/8) *
+		vc->vc_font.height;
+	d_cellsize = s_cellsize;
+
+	if (ops->rotate == FB_ROTATE_CW ||
+	    ops->rotate == FB_ROTATE_CCW)
+		d_cellsize = ((vc->vc_font.height + 7)/8) *
+			vc->vc_font.width;
+
+	if (info->fbops->fb_sync)
+		info->fbops->fb_sync(info);
+
+	if (ops->fd_size < d_cellsize * len) {
+		dst = kmalloc(d_cellsize * len, GFP_KERNEL);
+
+		if (dst == NULL) {
+			err = -ENOMEM;
+			goto finished;
+		}
+
+		ops->fd_size = d_cellsize * len;
+		kfree(ops->fontbuffer);
+		ops->fontbuffer = dst;
+	}
+
+	dst = ops->fontbuffer;
+	memset(dst, 0, ops->fd_size);
+
+	switch (ops->rotate) {
+	case FB_ROTATE_UD:
+		for (i = len; i--; ) {
+			rotate_ud(src, dst, vc->vc_font.width,
+				  vc->vc_font.height);
+
+			src += s_cellsize;
+			dst += d_cellsize;
+		}
+		break;
+	case FB_ROTATE_CW:
+		for (i = len; i--; ) {
+			rotate_cw(src, dst, vc->vc_font.width,
+				  vc->vc_font.height);
+			src += s_cellsize;
+			dst += d_cellsize;
+		}
+		break;
+	case FB_ROTATE_CCW:
+		for (i = len; i--; ) {
+			rotate_ccw(src, dst, vc->vc_font.width,
+				   vc->vc_font.height);
+			src += s_cellsize;
+			dst += d_cellsize;
+		}
+		break;
+	}
+
+finished:
+	return err;
+}
+
+void fbcon_set_rotate(struct fbcon_ops *ops)
+{
+	ops->rotate_font = fbcon_rotate_font;
+}
+EXPORT_SYMBOL(fbcon_set_rotate);
+
+MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
+MODULE_DESCRIPTION("Console Rotation Support");
+MODULE_LICENSE("GPL");