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/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/common/splash_source.c b/common/splash_source.c
new file mode 100644
index 0000000..d1bb5a4
--- /dev/null
+++ b/common/splash_source.c
@@ -0,0 +1,176 @@
+/*
+ * (C) Copyright 2014 CompuLab, Ltd. <www.compulab.co.il>
+ *
+ * Authors: Igor Grinberg <grinberg@compulab.co.il>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <nand.h>
+#include <errno.h>
+#include <splash.h>
+#include <spi_flash.h>
+#include <spi.h>
+#include <bmp_layout.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifdef CONFIG_SPI_FLASH
+static struct spi_flash *sf;
+static int splash_sf_read(u32 bmp_load_addr, int offset, size_t read_size)
+{
+	if (!sf) {
+		sf = spi_flash_probe(CONFIG_SF_DEFAULT_BUS,
+				     CONFIG_SF_DEFAULT_CS,
+				     CONFIG_SF_DEFAULT_SPEED,
+				     CONFIG_SF_DEFAULT_MODE);
+		if (!sf)
+			return -ENODEV;
+	}
+
+	return spi_flash_read(sf, offset, read_size, (void *)bmp_load_addr);
+}
+#else
+static int splash_sf_read(u32 bmp_load_addr, int offset, size_t read_size)
+{
+	debug("%s: sf support not available\n", __func__);
+	return -ENOSYS;
+}
+#endif
+
+#ifdef CONFIG_CMD_NAND
+static int splash_nand_read(u32 bmp_load_addr, int offset, size_t read_size)
+{
+	return nand_read_skip_bad(&nand_info[nand_curr_device], offset,
+				  &read_size, NULL,
+				  nand_info[nand_curr_device].size,
+				  (u_char *)bmp_load_addr);
+}
+#else
+static int splash_nand_read(u32 bmp_load_addr, int offset, size_t read_size)
+{
+	debug("%s: nand support not available\n", __func__);
+	return -ENOSYS;
+}
+#endif
+
+static int splash_storage_read(struct splash_location *location,
+			       u32 bmp_load_addr, size_t read_size)
+{
+	u32 offset;
+
+	if (!location)
+		return -EINVAL;
+
+	offset = location->offset;
+	switch (location->storage) {
+	case SPLASH_STORAGE_NAND:
+		return splash_nand_read(bmp_load_addr, offset, read_size);
+	case SPLASH_STORAGE_SF:
+		return splash_sf_read(bmp_load_addr, offset, read_size);
+	default:
+		printf("Unknown splash location\n");
+	}
+
+	return -EINVAL;
+}
+
+static int splash_load_raw(struct splash_location *location, u32 bmp_load_addr)
+{
+	struct bmp_header *bmp_hdr;
+	int res;
+	size_t bmp_size, bmp_header_size = sizeof(struct bmp_header);
+
+	if (bmp_load_addr + bmp_header_size >= gd->start_addr_sp)
+		goto splash_address_too_high;
+
+	res = splash_storage_read(location, bmp_load_addr, bmp_header_size);
+	if (res < 0)
+		return res;
+
+	bmp_hdr = (struct bmp_header *)bmp_load_addr;
+	bmp_size = le32_to_cpu(bmp_hdr->file_size);
+
+	if (bmp_load_addr + bmp_size >= gd->start_addr_sp)
+		goto splash_address_too_high;
+
+	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");
+
+	return -EFAULT;
+}
+
+/**
+ * select_splash_location - return the splash location based on board support
+ *			    and env variable "splashsource".
+ *
+ * @locations:		An array of supported splash locations.
+ * @size:		Size of splash_locations array.
+ *
+ * @return: If a null set of splash locations is given, or
+ *	    splashsource env variable is set to unsupported value
+ *			return NULL.
+ *	    If splashsource env variable is not defined
+ *			return the first entry in splash_locations as default.
+ *	    If splashsource env variable contains a supported value
+ *			return the location selected by splashsource.
+ */
+static struct splash_location *select_splash_location(
+			    struct splash_location *locations, uint size)
+{
+	int i;
+	char *env_splashsource;
+
+	if (!locations || size == 0)
+		return NULL;
+
+	env_splashsource = getenv("splashsource");
+	if (env_splashsource == NULL)
+		return &locations[0];
+
+	for (i = 0; i < size; i++) {
+		if (!strcmp(locations[i].name, env_splashsource))
+			return &locations[i];
+	}
+
+	printf("splashsource env variable set to unsupported value\n");
+	return NULL;
+}
+
+/**
+ * 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;
+	u32 bmp_load_addr;
+
+	env_splashimage_value = getenv("splashimage");
+	if (env_splashimage_value == NULL)
+		return -ENOENT;
+
+	bmp_load_addr = simple_strtoul(env_splashimage_value, 0, 16);
+	if (bmp_load_addr == 0) {
+		printf("Error: bad splashimage address specified\n");
+		return -EFAULT;
+	}
+
+	splash_location = select_splash_location(locations, size);
+	if (!splash_location)
+		return -EINVAL;
+
+	return splash_load_raw(splash_location, bmp_load_addr);
+}