LCD_WINCTRL0_A
val = lcd->window[plane].winctrl0 & ~(LCD_WINCTRL0_A);
val |= ((pdata->alpha_color << 2) & LCD_WINCTRL0_A);
pdata->alpha_color = (lcd->window[plane].winctrl0 & LCD_WINCTRL0_A) >> 2;
winctrl0 &= (LCD_WINCTRL0_A | LCD_WINCTRL0_AEN);