This provides an option for the LCD to flush the dcache after each update
(puts, scroll or clear).

Signed-off-by: Simon Glass <s...@chromium.org>
---
Changes in v2:
- Put the LCD cache flush logic into lcd_putc() instead of lcd_puts()

Changes in v3:
- Put the LCD cache flush logic back into lcd_puts()

 common/lcd.c  |   46 +++++++++++++++++++++++++++++++++++++++-------
 include/lcd.h |    8 ++++++++
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/common/lcd.c b/common/lcd.c
index 18525a7..f7514a4 100644
--- a/common/lcd.c
+++ b/common/lcd.c
@@ -97,6 +97,9 @@ static void lcd_setbgcolor (int color);
 
 char lcd_is_enabled = 0;
 
+static char lcd_flush_dcache;  /* 1 to flush dcache after each lcd update */
+
+
 #ifdef NOT_USED_SO_FAR
 static void lcd_getcolreg (ushort regno,
                                ushort *red, ushort *green, ushort *blue);
@@ -105,6 +108,28 @@ static int lcd_getfgcolor (void);
 
 /************************************************************************/
 
+/* Flush LCD activity to the caches */
+void lcd_sync(void)
+{
+       /*
+        * flush_dcache_range() is declared in common.h but it seems that some
+        * architectures do not actually implement it. Is there a way to find
+        * out whether it exists? For now, ARM is safe.
+        */
+#ifdef CONFIG_ARM
+       int line_length;
+
+       if (lcd_flush_dcache)
+               flush_dcache_range((u32)lcd_base,
+                       (u32)(lcd_base + lcd_get_size(&line_length)));
+#endif
+}
+
+void lcd_set_flush_dcache(int flush)
+{
+       lcd_flush_dcache = (flush != 0);
+}
+
 /*----------------------------------------------------------------------*/
 
 static void console_scrollup (void)
@@ -114,6 +139,7 @@ static void console_scrollup (void)
 
        /* Clear the last one */
        memset (CONSOLE_ROW_LAST, COLOR_MASK(lcd_color_bg), CONSOLE_ROW_SIZE);
+       lcd_sync();
 }
 
 /*----------------------------------------------------------------------*/
@@ -144,6 +170,8 @@ static inline void console_newline (void)
                /* Scroll everything up */
                console_scrollup () ;
                --console_row;
+       } else {
+               lcd_sync();
        }
 }
 
@@ -198,6 +226,7 @@ void lcd_puts (const char *s)
        while (*s) {
                lcd_putc (*s++);
        }
+       lcd_sync();
 }
 
 /*----------------------------------------------------------------------*/
@@ -365,13 +394,6 @@ int drv_lcd_init (void)
 }
 
 /*----------------------------------------------------------------------*/
-static
-int do_lcd_clear(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
-{
-       lcd_clear();
-       return 0;
-}
-
 void lcd_clear(void)
 {
 #if LCD_BPP == LCD_MONOCHROME
@@ -413,6 +435,14 @@ void lcd_clear(void)
 
        console_col = 0;
        console_row = 0;
+       lcd_sync();
+}
+
+static int do_lcd_clear(cmd_tbl_t *cmdtp, int flag, int argc,
+                       char *const argv[])
+{
+       lcd_clear();
+       return 0;
 }
 
 U_BOOT_CMD(
@@ -607,6 +637,7 @@ void bitmap_plot (int x, int y)
        }
 
        WATCHDOG_RESET();
+       lcd_sync();
 }
 #else
 static inline void bitmap_plot(int x, int y) {}
@@ -820,6 +851,7 @@ int lcd_display_bitmap(ulong bmp_image, int x, int y)
                break;
        };
 
+       lcd_sync();
        return (0);
 }
 #endif
diff --git a/include/lcd.h b/include/lcd.h
index 26f6d83..4363131 100644
--- a/include/lcd.h
+++ b/include/lcd.h
@@ -57,6 +57,14 @@ extern void lcd_initcolregs (void);
 extern struct bmp_image *gunzip_bmp(unsigned long addr, unsigned long *lenp);
 extern int bmp_display(ulong addr, int x, int y);
 
+/**
+ * Set whether we need to flush the dcache when changing the LCD image. This
+ * defaults to off.
+ *
+ * @param flush                non-zero to flush cache after update, 0 to skip
+ */
+void lcd_set_flush_dcache(int flush);
+
 #if defined CONFIG_MPC823
 /*
  * LCD controller stucture for MPC823 CPU
-- 
1.7.7.3

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