STM32LTDC: Rename ALLOW_2ND_LAYER to LTDC_USE_2ND_LAYER

boards/base/STM32F429i-Discovery/chibios/board_STM32LTDC.h

@@ -23,7 +23,7 @@ static const SPIConfig spi_cfg = {
 	((1 << 3) & SPI_CR1_BR) | SPI_CR1_SSM | SPI_CR1_SSI | SPI_CR1_MSTR
 };
 
-#define ALLOW_2ND_LAYER		GFXON
+#define LTDC_USE_2ND_LAYER		GFXON
 
 static const ltdcConfig driverCfg = {
 	240, 320,
@@ -47,7 +47,7 @@ static const ltdcConfig driverCfg = {
 		0xFF,								// alpha
 		LTDC_LEF_ENABLE						// flags
 	},
-#if ALLOW_2ND_LAYER
+#if LTDC_USE_2ND_LAYER
 	{										// Foreground layer config (if turned on)
 		(LLDCOLOR_TYPE *)(SDRAM_BANK_ADDR+(240 * 320 * LTDC_PIXELBYTES)), // Frame buffer address
 		240, 320,							// width, height

boards/base/STM32F439i-Eval/CubeHal/board_STM32LTDC.h

@@ -19,7 +19,7 @@
 #include "stm32f4xx_hal.h"
 #include "stm324x9i_eval_sdram.h"
 
-#define ALLOW_2ND_LAYER		GFXON
+#define LTDC_USE_2ND_LAYER		GFXON
 
 // Panel parameters
 // This panel is a AMPIRE640480 panel.
@@ -48,7 +48,7 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-#if ALLOW_2ND_LAYER
+#if LTDC_USE_2ND_LAYER
 	{										// Foreground layer config (if turned on)
 		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(640 * 480 * LTDC_PIXELBYTES)), // Frame buffer address
 		640, 480,							// Width, Height (pixels)

boards/base/STM32F746-Discovery/board_STM32LTDC.h

@@ -36,7 +36,7 @@
 	#define AFRH	AFR[1]
 #endif
 
-#define ALLOW_2ND_LAYER		GFXON
+#define LTDC_USE_2ND_LAYER		GFXON
 
 static const ltdcConfig driverCfg = {
 	480, 272,								// Width, Height (pixels)
@@ -62,7 +62,7 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-#if ALLOW_2ND_LAYER
+#if LTDC_USE_2ND_LAYER
 	{										// Foreground layer config (if turned on)
 		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(480 * 272 * LTDC_PIXELBYTES)), // Frame buffer address
 		480, 272,							// Width, Height (pixels)

drivers/gdisp/STM32LTDC/board_STM32LTDC_template.h

@@ -8,7 +8,7 @@
 #ifndef _GDISP_LLD_BOARD_H
 #define _GDISP_LLD_BOARD_H
 
-#define ALLOW_2ND_LAYER		GFXON
+#define LTDC_USE_2ND_LAYER		GFXON
 
 static const ltdcConfig driverCfg = {
 	480, 272,								// Width, Height (pixels)
@@ -34,7 +34,7 @@ static const ltdcConfig driverCfg = {
 		LTDC_LEF_ENABLE						// Layer configuration flags
 	},
 
-#if ALLOW_2ND_LAYER
+#if LTDC_USE_2ND_LAYER
 	{										// Foreground layer config (if turned on)
 		(LLDCOLOR_TYPE *)(SDRAM_DEVICE_ADDR+(480 * 272 * LTDC_PIXELBYTES)), // Frame buffer address
 		480, 272,							// Width, Height (pixels)

drivers/gdisp/STM32LTDC/gdisp_lld_STM32LTDC.c

@@ -23,9 +23,6 @@
 	#undef GDISP_SCREEN_HEIGHT
 #endif
 
-#ifndef LTDC_USE_DOUBLE_BUFFERING
-	#define LTDC_USE_DOUBLE_BUFFERING GFXOFF
-#endif
 #ifndef LTDC_USE_DMA2D
  	#define LTDC_USE_DMA2D 			GFXOFF
 #endif

drivers/gdisp/STM32LTDC/readme.md

@@ -0,0 +1,25 @@
+# Usage
+To use this driver:
+
+1. Add in your `gfxconf.h`:
+	a) `#define GFX_USE_GDISP		GFXON`
+
+2. To your makefile add the following lines:
+```
+	include $(GFXLIB)/gfx.mk
+	include $(GFXLIB)/drivers/gdisp/STM32LTDC/driver.mk
+```
+
+3. Add a `board_STM32LTDC.h` to you project directory (or board directory)
+	based on one of the templates.
+
+# 2nd layer
+Two things need to happen in order to use the 2nd LTDC layer:
+  - Set `LTDC_USE_2ND_LAYER` to `GFXON` in the board file.
+  - Set `GDISP_TOTAL_DISPLAYS` to `2` in `gfxconf.h`.
+
+The 2nd layer is exposed as a separate display. Use `gdispGetDisplay()` to retrieve the individual layers.
+
+For more information, see:
+  - https://wiki.ugfx.io/index.php/Multiple_displays#Example_-_Same_controller
+  - https://wiki.ugfx.io/index.php/Multiple_displays#Access_the_displays

drivers/gdisp/STM32LTDC/readme.txt

@@ -1,11 +0,0 @@
-To use this driver:
-
-1. Add in your gfxconf.h:
-	a) #define GFX_USE_GDISP		GFXON
-
-2. To your makefile add the following lines:
-	include $(GFXLIB)/gfx.mk
-	include $(GFXLIB)/drivers/gdisp/STM32LTDC/driver.mk
-
-3. Add a board_STM32LTDC.h to you project directory (or board directory)
-	based on one of the templates.