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>

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>
Simon Glass · Tom Warren
1 parent 0dde7f5379
Showing 3 changed files with 29 additions and 5 deletions Side-by-side Diff
README
common/lcd.c
include/lcd.h
@@ -1469,6 +1469,16 @@
 		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
@@ -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 @@
 /* ** 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 @@
  
 	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 @@
 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;
@@ -297,6 +297,9 @@
 /* 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						*/
 /************************************************************************/
...	...	@@ -1469,6 +1469,16 @@
1469	1469	Normally display is black on white background; define
1470	1470	CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1471	1471
	1472	+
	1473	+ CONFIG_LCD_ALIGNMENT
	1474	+
	1475	+ Normally the LCD is page-aligned (tyically 4KB). If this is
	1476	+ defined then the LCD will be aligned to this value instead.
	1477	+ For ARM it is sometimes useful to use MMU_SECTION_SIZE
	1478	+ here, since it is cheaper to change data cache settings on
	1479	+ a per-section basis.
	1480	+
	1481	+
1472	1482	- Splash Screen Support: CONFIG_SPLASH_SCREEN
1473	1483
1474	1484	If this option is set, the environment is checked for
...	...	@@ -72,6 +72,10 @@
72	72	# endif
73	73	#endif
74	74
	75	+#ifndef CONFIG_LCD_ALIGNMENT
	76	+#define CONFIG_LCD_ALIGNMENT PAGE_SIZE
	77	+#endif
	78	+
75	79	DECLARE_GLOBAL_DATA_PTR;
76	80
77	81	ulong lcd_setmem (ulong addr);
...	...	@@ -326,6 +330,12 @@
326	330	/* ** GENERIC Initialization Routines */
327	331	/************************************************************************/
328	332
	333	+int lcd_get_size(int *line_length)
	334	+{
	335	+ line_length = (panel_info.vl_col NBITS(panel_info.vl_bpix)) / 8;
	336	+ return line_length panel_info.vl_row;
	337	+}
	338	+
329	339	int drv_lcd_init (void)
330	340	{
331	341	struct stdio_dev lcddev;
...	...	@@ -333,7 +343,7 @@
333	343
334	344	lcd_base = (void *)(gd->fb_base);
335	345
336		- lcd_line_length = (panel_info.vl_col * NBITS (panel_info.vl_bpix)) / 8;
	346	+ lcd_get_size(&lcd_line_length);
337	347
338	348	lcd_init(lcd_base); /* LCD initialization */
339	349
340	350
341	351
...	...	@@ -445,15 +455,16 @@
445	455	ulong lcd_setmem(ulong addr)
446	456	{
447	457	ulong size;
448		- int line_length = (panel_info.vl_col * NBITS(panel_info.vl_bpix)) / 8;
	458	+ int line_length;
449	459
450	460	debug("LCD panel info: %d x %d, %d bit/pix\n", panel_info.vl_col,
451	461	panel_info.vl_row, NBITS(panel_info.vl_bpix));
452	462
453		- size = line_length * panel_info.vl_row;
	463	+ size = lcd_get_size(&line_length);
454	464
455		- /* Round up to nearest full page */
456		- size = (size + (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
	465	+ /* Round up to nearest full page, or MMU section if defined */
	466	+ size = ALIGN(size, CONFIG_LCD_ALIGNMENT);
	467	+ addr = ALIGN(addr - CONFIG_LCD_ALIGNMENT + 1, CONFIG_LCD_ALIGNMENT);
457	468
458	469	/* Allocate pages for the frame buffer. */
459	470	addr -= size;
...	...	@@ -297,6 +297,9 @@
297	297	/* Allow boards to customize the information displayed */
298	298	void lcd_show_board_info(void);
299	299
	300	+/* Return the size of the LCD frame buffer, and the line length */
	301	+int lcd_get_size(int *line_length);
	302	+
300	303	/************************************************************************/
301	304	/* ** BITMAP DISPLAY SUPPORT */
302	305	/************************************************************************/