atmel_lcdfb: wiring BGR to RGB color mode
Adds different wiring mode for the LCD screen.
The legacy atmel LCDC IP uses a non standard color mode, "BGR-555.1" instead
"RGB-565". The major part of graphic stacks for embedded systems uses only
"RGB-565". It is possible to swap LCD IOs instead of doing this bit swapping
by software (See application note AT91SAM9 LCD Controller
http://www.atmel.com/dyn/resources/prod_documents/doc6300.pdf)
This wire swapping is done on the at91sam9rl-ek board (board code
using this patch will come later).
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <avictor.za@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index 6fcf76c..5a31a7a 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -338,19 +338,35 @@
break;
case 15:
case 16:
- var->red.offset = 0;
+ if (sinfo->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
+ /* RGB:565 mode */
+ var->red.offset = 11;
+ var->blue.offset = 0;
+ var->green.length = 6;
+ } else {
+ /* BGR:555 mode */
+ var->red.offset = 0;
+ var->blue.offset = 10;
+ var->green.length = 5;
+ }
var->green.offset = 5;
- var->blue.offset = 10;
- var->red.length = var->green.length = var->blue.length = 5;
+ var->red.length = var->blue.length = 5;
break;
case 32:
var->transp.offset = 24;
var->transp.length = 8;
/* fall through */
case 24:
- var->red.offset = 0;
+ if (sinfo->lcd_wiring_mode == ATMEL_LCDC_WIRING_RGB) {
+ /* RGB:888 mode */
+ var->red.offset = 16;
+ var->blue.offset = 0;
+ } else {
+ /* BGR:888 mode */
+ var->red.offset = 0;
+ var->blue.offset = 16;
+ }
var->green.offset = 8;
- var->blue.offset = 16;
var->red.length = var->green.length = var->blue.length = 8;
break;
default:
@@ -697,6 +713,7 @@
sinfo->atmel_lcdfb_power_control = pdata_sinfo->atmel_lcdfb_power_control;
sinfo->guard_time = pdata_sinfo->guard_time;
sinfo->lcdcon_is_backlight = pdata_sinfo->lcdcon_is_backlight;
+ sinfo->lcd_wiring_mode = pdata_sinfo->lcd_wiring_mode;
} else {
dev_err(dev, "cannot get default configuration\n");
goto free_info;
diff --git a/include/video/atmel_lcdc.h b/include/video/atmel_lcdc.h
index 2fd9fad..ed64862 100644
--- a/include/video/atmel_lcdc.h
+++ b/include/video/atmel_lcdc.h
@@ -22,6 +22,15 @@
#ifndef __ATMEL_LCDC_H__
#define __ATMEL_LCDC_H__
+
+/* Way LCD wires are connected to the chip:
+ * Some Atmel chips use BGR color mode (instead of standard RGB)
+ * A swapped wiring onboard can bring to RGB mode.
+ */
+#define ATMEL_LCDC_WIRING_BGR 0
+#define ATMEL_LCDC_WIRING_RGB 1
+
+
/* LCD Controller info data structure, stored in device platform_data */
struct atmel_lcdfb_info {
spinlock_t lock;
@@ -42,6 +51,7 @@
u8 saved_lcdcon;
u8 default_bpp;
+ u8 lcd_wiring_mode;
unsigned int default_lcdcon2;
unsigned int default_dmacon;
void (*atmel_lcdfb_power_control)(int on);