lcd: Add CONFIG_LCD_ALIGNMENT to select frame buffer alignment

The normal alignment is PAGE_SIZE, but if this is defined, we can support
other alignments.

The motivation for this change is to make the display section-aligned on
ARM so that we can easily turn off data caching for the frame buffer region
without resorting to level 2 page tables.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

diff --git a/README b/README
index afdf591c623f6cfa5c507d6918e738dea12b2c79..5c03be79187a09321abd5e618f2312e5e6fcb548 100644 (file)
--- a/README
+++ b/README
@@ -1469,6 +1469,16 @@ CBFS (Coreboot Filesystem) support
                Normally display is black on white background; define
                CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
 
+
+               CONFIG_LCD_ALIGNMENT
+
+               Normally the LCD is page-aligned (tyically 4KB). If this is
+               defined then the LCD will be aligned to this value instead.
+               For ARM it is sometimes useful to use MMU_SECTION_SIZE
+               here, since it is cheaper to change data cache settings on
+               a per-section basis.
+
+
 - Splash Screen Support: CONFIG_SPLASH_SCREEN
 
                If this option is set, the environment is checked for

diff --git a/common/lcd.c b/common/lcd.c
index b6be8002d201692535602677ae2d002b8618e088..37b03936f90106d7b12d96efa0d8d40fc728a397 100644 (file)
--- a/common/lcd.c
+++ b/common/lcd.c
@@ -72,6 +72,10 @@
 # endif
 #endif
 
+#ifndef CONFIG_LCD_ALIGNMENT
+#define CONFIG_LCD_ALIGNMENT PAGE_SIZE
+#endif
+
 DECLARE_GLOBAL_DATA_PTR;
 
 ulong lcd_setmem (ulong addr);
@@ -326,6 +330,12 @@ static void test_pattern(void)
 /* ** GENERIC Initialization Routines                                  */
 /************************************************************************/
 
+int lcd_get_size(int *line_length)
+{
+       *line_length = (panel_info.vl_col * NBITS(panel_info.vl_bpix)) / 8;
+       return *line_length * panel_info.vl_row;
+}
+
 int drv_lcd_init (void)
 {
        struct stdio_dev lcddev;
@@ -333,7 +343,7 @@ int drv_lcd_init (void)
 
        lcd_base = (void *)(gd->fb_base);
 
-       lcd_line_length = (panel_info.vl_col * NBITS (panel_info.vl_bpix)) / 8;
+       lcd_get_size(&lcd_line_length);
 
        lcd_init(lcd_base);             /* LCD initialization */
 
@@ -445,15 +455,16 @@ static int lcd_init(void *lcdbase)
 ulong lcd_setmem(ulong addr)
 {
        ulong size;
-       int line_length = (panel_info.vl_col * NBITS(panel_info.vl_bpix)) / 8;
+       int line_length;
 
        debug("LCD panel info: %d x %d, %d bit/pix\n", panel_info.vl_col,
                panel_info.vl_row, NBITS(panel_info.vl_bpix));
 
-       size = line_length * panel_info.vl_row;
+       size = lcd_get_size(&line_length);
 
-       /* Round up to nearest full page */
-       size = (size + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
+       /* Round up to nearest full page, or MMU section if defined */
+       size = ALIGN(size, CONFIG_LCD_ALIGNMENT);
+       addr = ALIGN(addr - CONFIG_LCD_ALIGNMENT + 1, CONFIG_LCD_ALIGNMENT);
 
        /* Allocate pages for the frame buffer. */
        addr -= size;

diff --git a/include/lcd.h b/include/lcd.h
index 42070d76366e8465a84baf3e90a7e95bff429a62..6a600eece4764d02606745ea4fa2274468fdced5 100644 (file)
--- a/include/lcd.h
+++ b/include/lcd.h
@@ -297,6 +297,9 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y);
 /* Allow boards to customize the information displayed */
 void lcd_show_board_info(void);
 
+/* Return the size of the LCD frame buffer, and the line length */
+int lcd_get_size(int *line_length);
+
 /************************************************************************/
 /* ** BITMAP DISPLAY SUPPORT                                           */
 /************************************************************************/