lib/fonts: add font 6x8 for OLED display

This font is derived from lib/fonts/font_6x10.c and is useful for small
OLED displays
Signed-off-by: Sven Schneider <s.schneider@arkona-technologies.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200820082137.5907-1-s.hauer@pengutronix.de

include/linux/font.h

@@ -33,6 +33,7 @@ struct font_desc {
 #define	MINI4x6_IDX	9
 #define FONT6x10_IDX	10
 #define TER16x32_IDX	11
+#define FONT6x8_IDX	12
 
 extern const struct font_desc	font_vga_8x8,
 			font_vga_8x16,
@@ -45,7 +46,8 @@ extern const struct font_desc	font_vga_8x8,
 			font_acorn_8x8,
 			font_mini_4x6,
 			font_6x10,
-			font_ter_16x32;
+			font_ter_16x32,
+			font_6x8;
 
 /* Find a font with a specific name */
 

lib/fonts/Kconfig

@@ -119,6 +119,12 @@ config FONT_TER16x32
 	  This is the high resolution, large version for use with HiDPI screens.
 	  If the standard font is unreadable for you, say Y, otherwise say N.
 
+config FONT_6x8
+	bool "OLED 6x8 font" if FONTS
+	depends on FRAMEBUFFER_CONSOLE
+	help
+	  This font is useful for small displays (OLED).
+
 config FONT_AUTOSELECT
 	def_bool y
 	depends on !FONT_8x8
@@ -132,6 +138,7 @@ config FONT_AUTOSELECT
 	depends on !FONT_SUN12x22
 	depends on !FONT_10x18
 	depends on !FONT_TER16x32
+	depends on !FONT_6x8
 	select FONT_8x16
 
 endif # FONT_SUPPORT

lib/fonts/Makefile

@@ -15,6 +15,7 @@ font-objs-$(CONFIG_FONT_ACORN_8x8) += font_acorn_8x8.o
 font-objs-$(CONFIG_FONT_MINI_4x6)  += font_mini_4x6.o
 font-objs-$(CONFIG_FONT_6x10)      += font_6x10.o
 font-objs-$(CONFIG_FONT_TER16x32)  += font_ter16x32.o
+font-objs-$(CONFIG_FONT_6x8)       += font_6x8.o
 
 font-objs += $(font-objs-y)
 

lib/fonts/fonts.c

@@ -57,6 +57,9 @@ static const struct font_desc *fonts[] = {
 #ifdef CONFIG_FONT_TER16x32
 	&font_ter_16x32,
 #endif
+#ifdef CONFIG_FONT_6x8
+	&font_6x8,
+#endif
 };
 
 #define num_fonts ARRAY_SIZE(fonts)