lcd: add option for board specific splash screen preparation

Currently there is no logical place to put the code that prepares the
splash image data. The splash image data should be ready in memory
before bmp_display() is called, and after the environment is ready
(since lcd.c looks for the splash image in an address specified by
the environment variable "splashimage").

Our window of opportunity in board_init_r() is therefore: between
env_relocate() and bmp_display(), and from the available options
only the lcd related functions in drv_lcd_init() seem appropriate
for such lcd oriented code.

Add the option to prepare the splash image data in lcd_logo() right
before it is sent to be displayed.

Cc: Anatolij Gustschin <agust@denx.de>
Cc: Jeroen Hofstee <jeroen@myspectrum.nl>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>

README

@@ -1550,6 +1550,14 @@ CBFS (Coreboot Filesystem) support
 			=> vertically centered image
 			   at x = dspWidth - bmpWidth - 9
 
+		CONFIG_SPLASH_SCREEN_PREPARE
+
+		If this option is set then the board_splash_screen_prepare()
+		function, which must be defined in your code, is called as part
+		of the splash screen display sequence. It gives the board an
+		opportunity to prepare the splash image data before it is
+		processed and sent to the frame buffer by U-Boot.
+
 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
 
 		If this option is set, additionally to standard BMP

common/lcd.c

@@ -1034,6 +1034,18 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
 }
 #endif
 
+#ifdef CONFIG_SPLASH_SCREEN_PREPARE
+static inline int splash_screen_prepare(void)
+{
+	return board_splash_screen_prepare();
+}
+#else
+static inline int splash_screen_prepare(void)
+{
+	return 0;
+}
+#endif
+
 static void *lcd_logo(void)
 {
 #ifdef CONFIG_SPLASH_SCREEN
@@ -1045,6 +1057,9 @@ static void *lcd_logo(void)
 		int x = 0, y = 0;
 		do_splash = 0;
 
+		if (splash_screen_prepare())
+			return (void *)gd->fb_base;
+
 		addr = simple_strtoul (s, NULL, 16);
 #ifdef CONFIG_SPLASH_SCREEN_ALIGN
 		s = getenv("splashpos");

include/lcd.h

@@ -47,6 +47,7 @@ extern struct vidinfo panel_info;
 
 extern void lcd_ctrl_init (void *lcdbase);
 extern void lcd_enable (void);
+extern int board_splash_screen_prepare(void);
 
 /* setcolreg used in 8bpp/16bpp; initcolregs used in monochrome */
 extern void lcd_setcolreg (ushort regno,