ppc4xx: Only fixup opb attached UARTs

This patch updates the fdt UART clock fixup code to
only touch CPU internal UARTs on 4xx systems.
Only these UARTs are definitely clocked by gd->uart_clk.

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>
Signed-off-by: Stefan Roese <sr@denx.de>

cpu/ppc4xx/fdt.c

@@ -113,6 +113,7 @@ void fdt_pcie_setup(void *blob)
 void ft_cpu_setup(void *blob, bd_t *bd)
 {
 	sys_info_t sys_info;
+	int off, ndepth = 0;
 
 	get_sys_info(&sys_info);
 
@@ -133,9 +134,28 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 	fdt_fixup_memory(blob, (u64)bd->bi_memstart, (u64)bd->bi_memsize);
 
 	/*
-	 * Setup all baudrates for the UARTs
+	 * Fixup all UART clocks for CPU internal UARTs
+	 * (only these UARTs are definitely clocked by gd->uart_clk)
+	 *
+	 * These UARTs are direct childs of /plb/opb. This code
+	 * does not touch any UARTs that are connected to the ebc.
 	 */
-	do_fixup_by_compat_u32(blob, "ns16550", "clock-frequency", gd->uart_clk, 1);
+	off = fdt_path_offset(blob, "/plb/opb");
+	while ((off = fdt_next_node(blob, off, &ndepth)) >= 0) {
+		/*
+		 * process all sub nodes and stop when we are back
+		 * at the starting depth
+		 */
+		if (ndepth <= 0)
+			break;
+
+		/* only update direct childs */
+		if ((ndepth == 1) &&
+		    (fdt_node_check_compatible(blob, off, "ns16550") == 0))
+			fdt_setprop(blob, off,
+				    "clock-frequency",
+				    (void*)&(gd->uart_clk), 4);
+	}
 
 	/*
 	 * Fixup all ethernet nodes