common: convert compulab splash load code to common code

Move board/compulab/common/splash.c code to
common/splash_source.c to make it available for everybody. This move
renames cl_splash_screen_prepare() to splash_source_load(), and
the compilation of this code is conditional on CONFIG_SPLASH_SOURCE.

splash_source features:
* Provide a standardized way for declaring board specific splash screen
  locations
* Provide existing routines for auto loading the splash image from the
  locations as declared by the board
* Introduce the "splashsource" environment variable, which makes it
  possible to select the splash image source.

cm-t35 and cm-fx6 are updated to use the modified version.

Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Tom Rini <trini@ti.com>
Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Tom Rini <trini@ti.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
diff --git a/board/compulab/cm_fx6/cm_fx6.c b/board/compulab/cm_fx6/cm_fx6.c
index b5c3ea1..ae6945b 100644
--- a/board/compulab/cm_fx6/cm_fx6.c
+++ b/board/compulab/cm_fx6/cm_fx6.c
@@ -15,6 +15,7 @@
 #include <netdev.h>
 #include <fdt_support.h>
 #include <sata.h>
+#include <splash.h>
 #include <asm/arch/crm_regs.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/arch/iomux.h>
@@ -42,8 +43,8 @@
 
 int splash_screen_prepare(void)
 {
-	return cl_splash_screen_prepare(cm_fx6_splash_locations,
-					ARRAY_SIZE(cm_fx6_splash_locations));
+	return splash_source_load(cm_fx6_splash_locations,
+				  ARRAY_SIZE(cm_fx6_splash_locations));
 }
 #endif
 
diff --git a/board/compulab/cm_t35/cm_t35.c b/board/compulab/cm_t35/cm_t35.c
index 8143c05..c4ea8ea 100644
--- a/board/compulab/cm_t35/cm_t35.c
+++ b/board/compulab/cm_t35/cm_t35.c
@@ -19,6 +19,7 @@
 #include <i2c.h>
 #include <usb.h>
 #include <mmc.h>
+#include <splash.h>
 #include <twl4030.h>
 #include <linux/compiler.h>
 
@@ -69,8 +70,8 @@
 
 int splash_screen_prepare(void)
 {
-	return cl_splash_screen_prepare(splash_locations,
-					ARRAY_SIZE(splash_locations));
+	return splash_source_load(splash_locations,
+				  ARRAY_SIZE(splash_locations));
 }
 
 /*
diff --git a/board/compulab/common/Makefile b/board/compulab/common/Makefile
index dbf0009..286f327 100644
--- a/board/compulab/common/Makefile
+++ b/board/compulab/common/Makefile
@@ -9,5 +9,4 @@
 obj-y				+= common.o
 obj-$(CONFIG_SYS_I2C)		+= eeprom.o
 obj-$(CONFIG_LCD)		+= omap3_display.o
-obj-$(CONFIG_SPLASH_SCREEN)	+= splash.o
 obj-$(CONFIG_SMC911X)		+= omap3_smc911x.o
diff --git a/board/compulab/common/common.h b/board/compulab/common/common.h
index b992965..8f38b79 100644
--- a/board/compulab/common/common.h
+++ b/board/compulab/common/common.h
@@ -24,27 +24,6 @@
 static inline void cl_usb_hub_deinit(int gpio) {}
 #endif /* CONFIG_CMD_USB */
 
-enum splash_storage {
-	SPLASH_STORAGE_NAND,
-	SPLASH_STORAGE_SF,
-};
-
-struct splash_location {
-	char *name;
-	enum splash_storage storage;
-	u32 offset;	/* offset from start of storage */
-};
-
-#ifdef CONFIG_SPLASH_SCREEN
-int cl_splash_screen_prepare(struct splash_location *locations, uint size);
-#else /* !CONFIG_SPLASH_SCREEN */
-static inline int cl_splash_screen_prepare(struct splash_location *locations,
-					   uint size)
-{
-	return -ENOSYS;
-}
-#endif /* CONFIG_SPLASH_SCREEN */
-
 #ifdef CONFIG_SMC911X
 int cl_omap3_smc911x_init(int id, int cs, u32 base_addr,
 			  int (*reset)(int), int rst_gpio);
diff --git a/common/Makefile b/common/Makefile
index 94554f2..0f1416d 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -196,6 +196,7 @@
 obj-$(CONFIG_I2C_EDID) += edid.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-y += splash.o
+obj-$(CONFIG_SPLASH_SOURCE) += splash_source.o
 obj-$(CONFIG_LCD) += lcd.o lcd_console.o
 obj-$(CONFIG_LYNXKDI) += lynxkdi.o
 obj-$(CONFIG_MENU) += menu.o
diff --git a/board/compulab/common/splash.c b/common/splash_source.c
similarity index 86%
rename from board/compulab/common/splash.c
rename to common/splash_source.c
index 16c315c..d1bb5a4 100644
--- a/board/compulab/common/splash.c
+++ b/common/splash_source.c
@@ -9,10 +9,10 @@
 #include <common.h>
 #include <nand.h>
 #include <errno.h>
+#include <splash.h>
 #include <spi_flash.h>
 #include <spi.h>
 #include <bmp_layout.h>
-#include "common.h"
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -98,8 +98,7 @@
 	return splash_storage_read(location, bmp_load_addr, bmp_size);
 
 splash_address_too_high:
-	printf("Error: splashimage address too high. Data overwrites U-Boot "
-		"and/or placed beyond DRAM boundaries.\n");
+	printf("Error: splashimage address too high. Data overwrites U-Boot and/or placed beyond DRAM boundaries.\n");
 
 	return -EFAULT;
 }
@@ -141,7 +140,19 @@
 	return NULL;
 }
 
-int cl_splash_screen_prepare(struct splash_location *locations, uint size)
+/**
+ * splash_source_load - load splash image from a supported location.
+ *
+ * Select a splash image location based on the value of splashsource environment
+ * variable and the board supported splash source locations, and load a
+ * splashimage to the address pointed to by splashimage environment variable.
+ *
+ * @locations:		An array of supported splash locations.
+ * @size:		Size of splash_locations array.
+ *
+ * @return: 0 on success, negative value on failure.
+ */
+int splash_source_load(struct splash_location *locations, uint size)
 {
 	struct splash_location *splash_location;
 	char *env_splashimage_value;
diff --git a/doc/README.splashprepare b/doc/README.splashprepare
index 61b4ec5..a0f0f3c 100644
--- a/doc/README.splashprepare
+++ b/doc/README.splashprepare
@@ -6,3 +6,16 @@
 sequence. It gives the board an opportunity to prepare the splash
 image data before it is processed and sent to the frame buffer by
 U-Boot.  Define your own version to use this feature.
+
+CONFIG_SPLASH_SOURCE
+
+Use the splash_source.c library. This library provides facilities to declare
+board specific splash image locations, routines for loading splash image from
+supported locations, and a way of controlling the selected splash location
+using the "splashsource" environment variable.
+
+splashsource works as follows:
+- If splashsource is set to a supported location name as defined by board code,
+  use that splash location.
+- If splashsource is undefined, use the first splash location as default.
+- If splashsource is set to an unsupported value, do not load a splash screen.
diff --git a/include/configs/cm_fx6.h b/include/configs/cm_fx6.h
index b92ba97..1f64495 100644
--- a/include/configs/cm_fx6.h
+++ b/include/configs/cm_fx6.h
@@ -313,6 +313,7 @@
 #define CONFIG_VIDEO_SW_CURSOR
 
 #define CONFIG_SPLASH_SCREEN
+#define CONFIG_SPLASH_SOURCE
 #define CONFIG_CMD_BMP
 #define CONFIG_VIDEO_BMP_RLE8
 
diff --git a/include/configs/cm_t35.h b/include/configs/cm_t35.h
index 9767512..b2a9f35 100644
--- a/include/configs/cm_t35.h
+++ b/include/configs/cm_t35.h
@@ -310,6 +310,7 @@
 
 #define CONFIG_LCD
 #define CONFIG_SPLASH_SCREEN
+#define CONFIG_SPLASH_SOURCE
 #define CONFIG_CMD_BMP
 #define CONFIG_BMP_16BPP
 #define CONFIG_SCF0403_LCD
diff --git a/include/splash.h b/include/splash.h
index 89ee7b2..a60e895 100644
--- a/include/splash.h
+++ b/include/splash.h
@@ -22,7 +22,18 @@
 #ifndef _SPLASH_H_
 #define _SPLASH_H_
 
+enum splash_storage {
+	SPLASH_STORAGE_NAND,
+	SPLASH_STORAGE_SF,
+};
+
+struct splash_location {
+	char *name;
+	enum splash_storage storage;
+	u32 offset;	/* offset from start of storage */
+};
 
+int splash_source_load(struct splash_location *locations, uint size);
 int splash_screen_prepare(void);
 
 #ifdef CONFIG_SPLASH_SCREEN_ALIGN