[U-Boot] [PATCH] fdt: add new fdt_fixup_display function to configure display

[Tim Harvey]

Add 'fdt_fixup_display' function to fixup device-tree for a specific
display. This is useful if a device-tree has configurations for multiple
display timings for undetectable displays.

Signed-off-by: Tim Harvey <tharvey at gateworks.com>
---
 common/fdt_support.c  | 31 +++++++++++++++++++++++++++++++
 include/fdt_support.h |  1 +
 2 files changed, 32 insertions(+)

diff --git a/common/fdt_support.c b/common/fdt_support.c
index 8266bca..60609e5 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -1560,3 +1560,34 @@ int fdt_setup_simplefb_node(void *fdt, int node, u64 base_address, u32 width,
 
 	return 0;
 }
+
+/*
+ * Update native-mode in display-timings from display environment variable.
+ * The node to update are specified by path.
+ */
+int fdt_fixup_display(void *blob, const char *path, const char *display)
+{
+	int off, toff;
+
+	if (!display || !path)
+		return -1;
+
+	toff = fdt_path_offset(blob, path);
+	if (toff >= 0)
+		toff = fdt_subnode_offset(blob, toff, "display-timings");
+	if (toff < 0)
+		return toff;
+
+	for (off = fdt_first_subnode(blob, toff);
+	     off >= 0;
+	     off = fdt_next_subnode(blob, off)) {
+		uint32_t handle = fdt_get_phandle(blob, off);
+		debug("%s:0x%x\n", fdt_get_name(blob, off, NULL),
+		      fdt32_to_cpu(handle));
+		if (strcasecmp(fdt_get_name(blob, off, NULL), display) == 0) {
+			fdt_setprop_u32(blob, toff, "native-mode", handle);
+			break;
+		}
+	}
+	return toff;
+}
diff --git a/include/fdt_support.h b/include/fdt_support.h
index ae5e8a3..98379d3 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -46,6 +46,7 @@ void fdt_fixup_ethernet(void *fdt);
 int fdt_find_and_setprop(void *fdt, const char *node, const char *prop,
 			 const void *val, int len, int create);
 void fdt_fixup_qe_firmware(void *fdt);
+int fdt_fixup_display(void *blob, const char *path, const char *display);
 
 #if defined(CONFIG_HAS_FSL_DR_USB) || defined(CONFIG_HAS_FSL_MPH_USB)
 void fdt_fixup_dr_usb(void *blob, bd_t *bd);
-- 
1.9.1