ppc4xx/fdt/flash: Change fdt_fixup_nor_flash_node() to not rely on cs size

This patch changes the behaviour of the fdt_fixup_nor_flash_node()
function. Now it doesn't patch the size of the "reg" property with the
chip-select size, but with the size returned from the new function
flash_get_bank_size(). This function will return per weak default the
flash size of the bank (bank = chip-select numer) detected by the flash
driver. If this does not fit your needs, this function may be overridden
by a board specific one.

For this the parameters needed to be changed. So I intentionally squashed
the PPC4xx stuff using this routine into this patch. Otherwise it would
not be git-bisectable anymore.

The board specific function for the AMCC/APM Ebony eval board is now
included in this patch version.

Signed-off-by: Stefan Roese <sr@denx.de>
Tested-by: Detlev Zundel <dzu@denx.de>
Cc: Gerald Van Baren <vanbaren@cideas.com>
Cc: Wolfgang Denk <wd@denx.de>
diff --git a/board/amcc/ebony/flash.c b/board/amcc/ebony/flash.c
index 8fe3ba1..79d2c4c 100644
--- a/board/amcc/ebony/flash.c
+++ b/board/amcc/ebony/flash.c
@@ -34,6 +34,7 @@
 #include <common.h>
 #include <ppc4xx.h>
 #include <asm/processor.h>
+#include <asm/io.h>
 
 #undef DEBUG
 #ifdef DEBUG
@@ -71,6 +72,36 @@
  */
 static ulong flash_get_size(vu_long * addr, flash_info_t * info);
 
+/*
+ * Override the weak default mapping function with a board specific one
+ */
+u32 flash_get_bank_size(int cs, int idx)
+{
+	u8 reg = in_8((void *)CONFIG_SYS_FPGA_BASE);
+
+	if ((reg & BOOT_SMALL_FLASH) && !(reg & FLASH_ONBD_N)) {
+		/*
+		 * cs0: small flash (512KiB)
+		 * cs2: 2 * big flash (2 * 2MiB)
+		 */
+		if (cs == 0)
+			return flash_info[2].size;
+		if (cs == 2)
+			return flash_info[0].size + flash_info[1].size;
+	} else {
+		/*
+		 * cs0: 2 * big flash (2 * 2MiB)
+		 * cs2: small flash (512KiB)
+		 */
+		if (cs == 0)
+			return flash_info[0].size + flash_info[1].size;
+		if (cs == 2)
+			return flash_info[2].size;
+	}
+
+	return 0;
+}
+
 unsigned long flash_init(void)
 {
 	unsigned long total_b = 0;