[U-Boot] [RFC] fdt expert advice needed

[Matthias Fuchs <matthias.fuchs@esd-electronics.com>]

Hi Scott,

thanks for your hint. Please see my updated code below.
Do you think it's ok this way?

Matthias

---
 cpu/ppc4xx/fdt.c |   24 ++++++++++++++++++++++--
 1 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/cpu/ppc4xx/fdt.c b/cpu/ppc4xx/fdt.c
index c55e1cf..f9ff560 100644
--- a/cpu/ppc4xx/fdt.c
+++ b/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
+	 * Setup all UART clocks for CPU internal UARTs
+	 * (only these UARTs are definetely 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
-- 
1.5.6.3


> Scott Wood wrote:
> > Matthias Fuchs wrote:
> >> Now I want to replace the above code to only touch the ns16550 compatible nodes
> >> that are direct childs of /plb/opb. Not those under /plb/ebc and even not those under 
> >> /plb/opb/ebc. This is not easy to do with the fdt API. Below you find my first and dirty
> >> hack.
> >>
> >> Isn't there a more simple way to do so? Don't bother me about the printf, variable names etc.
> >> It's just for discussion.
> > 
> > Take the node that you want to search under (/plb/opb), and pass it to 
> > fdt_next_node(), with an initial depth of zero.  Continue until depth 
> > returns to zero (or less).
> 
> I just saw that you want to restrict it to direct children -- for that, 
> ignore any nodes where depth != 1.
> 
> -Scott