[U-Boot] [PATCH v2 14/19] lcd: Add support for flushing LCD fb from dcache after update

Simon Glass
2012-06-13T16:19:50Z

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

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

common/cmd_echo.c | 3 ++-
common/lcd.c | 45 ++++++++++++++++++++++++++++++++++++++-------
include/lcd.h | 8 ++++++++
3 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/common/cmd_echo.c b/common/cmd_echo.c
index 43a6da5..12efbab 100644
--- a/common/cmd_echo.c
+++ b/common/cmd_echo.c
@@ -44,8 +44,9 @@ int do_echo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
}
}

+ /* Use puts() so that the LCD sees it as a new line */
if (putnl)
- putc('\n');
+ puts("\n");

return 0;
}
diff --git a/common/lcd.c b/common/lcd.c
index c915a49..758f158 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();
}
}

@@ -369,13 +397,6 @@ 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
@@ -417,6 +438,14 @@ 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(
@@ -611,6 +640,7 @@ void bitmap_plot (int x, int y)
}

WATCHDOG_RESET();
+ lcd_sync();
}
#endif /* CONFIG_LCD_LOGO */

@@ -809,6 +839,7 @@ 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 5016d6b..7c2dae2 100644
--- a/include/lcd.h
+++ b/include/lcd.h
@@ -56,6 +56,14 @@ extern void lcd_initcolregs (void);
/* gunzip_bmp used if CONFIG_VIDEO_BMP_GZIP */
extern struct bmp_image *gunzip_bmp(unsigned long addr, unsigned long *lenp);

+/**
+ * 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