edac: cpc925 MC platform device setup

Fix up the number of cells for the values of CPC925 Memory Controller,
and setup related platform device during system booting up, against
which CPC925 Memory Controller EDAC driver would be matched.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index ef6f649..a538824 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -1947,8 +1947,47 @@
 	prom_setprop(isa, name, "ranges",
 			isa_ranges, sizeof(isa_ranges));
 }
+
+#define CPC925_MC_START		0xf8000000
+#define CPC925_MC_LENGTH	0x1000000
+/* The values for memory-controller don't have right number of cells */
+static void __init fixup_device_tree_maple_memory_controller(void)
+{
+	phandle mc;
+	u32 mc_reg[4];
+	char *name = "/hostbridge@f8000000";
+	struct prom_t *_prom = &RELOC(prom);
+	u32 ac, sc;
+
+	mc = call_prom("finddevice", 1, 1, ADDR(name));
+	if (!PHANDLE_VALID(mc))
+		return;
+
+	if (prom_getproplen(mc, "reg") != 8)
+		return;
+
+	prom_getprop(_prom->root, "#address-cells", &ac, sizeof(ac));
+	prom_getprop(_prom->root, "#size-cells", &sc, sizeof(sc));
+	if ((ac != 2) || (sc != 2))
+		return;
+
+	if (prom_getprop(mc, "reg", mc_reg, sizeof(mc_reg)) == PROM_ERROR)
+		return;
+
+	if (mc_reg[0] != CPC925_MC_START || mc_reg[1] != CPC925_MC_LENGTH)
+		return;
+
+	prom_printf("Fixing up bogus hostbridge on Maple...\n");
+
+	mc_reg[0] = 0x0;
+	mc_reg[1] = CPC925_MC_START;
+	mc_reg[2] = 0x0;
+	mc_reg[3] = CPC925_MC_LENGTH;
+	prom_setprop(mc, name, "reg", mc_reg, sizeof(mc_reg));
+}
 #else
 #define fixup_device_tree_maple()
+#define fixup_device_tree_maple_memory_controller()
 #endif
 
 #ifdef CONFIG_PPC_CHRP
@@ -2189,6 +2228,7 @@
 static void __init fixup_device_tree(void)
 {
 	fixup_device_tree_maple();
+	fixup_device_tree_maple_memory_controller();
 	fixup_device_tree_chrp();
 	fixup_device_tree_pmac();
 	fixup_device_tree_efika();