font: fbconsole: add custom font supports

Signed-off-by: Du Huanpeng <u74147@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers/video/fbconsole.c

@@ -84,7 +84,7 @@ static struct rgb colors[] = {
 	{ 255, 255, 255 },
 };
 
-static void drawchar(struct fbc_priv *priv, int x, int y, char c)
+static void drawchar(struct fbc_priv *priv, int x, int y, int c)
 {
 	void *buf;
 	int bpp = priv->fb->bits_per_pixel >> 3;
@@ -97,7 +97,8 @@ static void drawchar(struct fbc_priv *priv, int x, int y, char c)
 
 	buf = gui_screen_render_buffer(priv->sc);
 
-	inbuf = priv->font->data + c * priv->font->height;
+	i = find_font_index(priv->font, c);
+	inbuf = priv->font->data + i;
 
 	line_length = priv->fb->line_length;
 

include/linux/font.h

@@ -12,17 +12,25 @@
 #define _VIDEO_FONT_H
 
 #include <param.h>
+#include <wchar.h>
 
+struct font_index {
+	wchar_t wc;	/* code of the char. */
+	short index;	/* offset of the char in the bitmap. */
+};
 struct font_desc {
 	const char *name;
 	int width, height;
+	struct font_index *index;
 	const void *data;
+	int num_chars;
 	struct list_head list;
 };
 
 /* Max. length for the name of a predefined font */
 #define MAX_FONT_NAME	32
 
+extern int find_font_index(const struct font_desc *font, int ch);
 extern const struct font_desc *find_font_enum(int n);
 extern struct param_d *add_param_font(struct device_d *dev,
 		int (*set)(struct param_d *p, void *priv),

lib/fonts/Kconfig

@@ -20,6 +20,11 @@ config FONT_7x14
 config FONT_MINI_4x6
 	bool "Mini 4x6 font"
 
+config FONT_CUSTOM_16X
+	bool "Custom 16x16 font"
+	help
+	  This font is useful for Chinese and other non ascii chars.
+
 config FONT_AUTOSELECT
 	def_bool y
 	depends on !FONT_MINI_4x6

lib/fonts/Makefile

@@ -5,6 +5,7 @@ font-objs := fonts.o
 font-objs-$(CONFIG_FONT_8x16)      += font_8x16.o
 font-objs-$(CONFIG_FONT_7x14)      += font_7x14.o
 font-objs-$(CONFIG_FONT_MINI_4x6)  += font_mini_4x6.o
+font-objs-$(CONFIG_FONT_CUSTOM_16X)+= font_custom_16x.o
 
 font-objs += $(font-objs-y)
 

lib/fonts/font_custom_16x.c

@@ -0,0 +1,50 @@
+/*
+ * by Du Huanpeng <u74147@gmail.com>
+ */
+
+#include <init.h>
+#include <module.h>
+#include <linux/font.h>
+#include <common.h>
+
+/* place real font data here or set fontdata_custom_16x points to
+ * the address of font data and also setup the index.
+ */
+
+static const unsigned char fontdata_custom_16x[] = {
+	0xFF, 0xFF,	/*OOOOOOOOOOOOOOOO*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0x80, 0x01,	/*O______________O*/
+	0xFF, 0xFF,	/*OOOOOOOOOOOOOOOO*/
+};
+
+static struct font_index fontdata_custom_16x_index[] = {
+	{ 0x0000, 0x0000 },
+};
+
+static struct font_desc font_custom_16x = {
+	.name	= "CUSTOM-16x",
+	.width	= 16,
+	.height	= 16,
+	.data	= fontdata_custom_16x,
+	.index	= fontdata_custom_16x_index,
+	.num_chars = ARRAY_SIZE(fontdata_custom_16x_index),
+};
+
+static int font_custom_16x_register(void)
+{
+	return font_register(&font_custom_16x);
+}
+postcore_initcall(font_custom_16x_register);

lib/fonts/fonts.c

@@ -31,6 +31,29 @@ int font_register(struct font_desc *font)
 
 	return 0;
 }
+int find_font_index(const struct font_desc *font, int ch)
+{
+	int index;
+	if (font->index == NULL) {
+		index  = font->width + 7;
+		index /= 8;
+		index *= font->height;
+		index *= ch;
+	} else {
+		/*
+		* FIXME: use binary search instead!
+		*/
+		index = font->num_chars - 1;
+
+		while (index && font->index[index].wc != ch)
+			index--;
+
+		/* return 0 if not found. */
+		index = font->index->index;
+	}
+
+	return index;
+}
 
 const struct font_desc *find_font_enum(int n)
 {