[U-Boot] [PATCH V3 6/9] lcd: make 16bpp work

[Alessandro Rubini <rubini@unipv.it>]

Sorry for this late though about lcd issues.

> -				lcd_color_fg : lcd_color_bg;
> +				*d++ = (bits & 0x80) ? 0xffff : 0;

Here my patch uses hardwired 0 and ~0 for 16-bit pixels. Anatolij
suggested to use lcd_color_fg and lcd_color_bg as in the original
code, but unfortunately it doesn't work.

lcd_color_fg is set by common/lcd.c itself, using this function:

    static void lcd_setfgcolor (int color)
    {
    #ifdef CONFIG_ATMEL_LCD
    	lcd_color_fg = color;
    #else
    	lcd_color_fg = color & 0x0F;
    #endif
    }   

So, however white I declare my color, it turns out blue.  While I'd
understand a difference based on LCD_COLOR8 and LCD_COLOR16 (but even
in that case I'd request the caller to do the right thing avoiding
this late "fix"), I really can't tell why the atmel display is
different from other ones.

It's true that I can force lcd_color_fg to whatever I want, but only
after lcd_clear() is called. Moreover, if there's centralized I
wouldn't cowardly change it behind it's back.

This is one of the reasons why my original post was an RFC.
common/lcd.c is quite a mess and touching it is difficult.

At this point I still think forcing 0xffff and 0, ignoring
lcd_color_fg, is the right thing to do at least until atmel specifics
are removed from common/lcd.c.

BTW: I have a 9263ek an a 9261ek, so I might be able to try to propose
an atmel-related cleanup in the future, but not on short term,
unfortunately.

/alessandro