[PATCH 04/16] deps: dtc: introduce new (virtual) property no-dependencies
From: Alexander Holler <hidden>
Date: 2015-08-26 12:30:05
Also in:
linux-devicetree, lkml
Subsystem:
open firmware and flattened device tree, the rest · Maintainers:
Rob Herring, Saravana Kannan, Linus Torvalds
In some cases it makes sense to handle some phandles not as dependencies.
This is escpecially true for 'remote-endpoint' properties, because these
otherwise introducing dependency cycles into the graph. To avoid these,
one end of each remote-endpoint pairs has not to be handled as a
dependency.
The syntax is like
foo {
remote-endpoint = <&bar>;
};
bar {
remote-endpoint = <&foo>;
no-dependencies = <&foo>;
};
Without that 'no-dependencies' property dtc would automatically add a
dependency to foo to the property 'dependencies' of the node bar.
But with that 'no-dependencies' it will not automatically add the
listed dependencies.
The property 'no-dependencies' is virtual property and will not be added
to any output file.
Signed-off-by: Alexander Holler <redacted>
---
scripts/dtc/dependencies.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/scripts/dtc/dependencies.c b/scripts/dtc/dependencies.c
index 2c1e0d4..76e4d91 100644
--- a/scripts/dtc/dependencies.c
+++ b/scripts/dtc/dependencies.c@@ -44,6 +44,23 @@ static bool is_parent_of(struct node *node1, struct node *node2) } +static bool is_no_dependency(struct node *dt, struct property *prop, cell_t ph) +{ + struct node *node; + unsigned i; + cell_t *cell = (cell_t *)(prop->val.val); + + for (i = 0; i < prop->val.len/4; ++i) { + node = get_node_by_phandle(dt, cpu_to_fdt32(*cell++)); + if (node) { + node = find_compatible_not_disabled(node); + if (node && get_node_phandle(dt, node) == ph) + return true; + } + } + return false; +} + static void add_deps(struct node *dt, struct node *node, struct property *prop) { struct marker *m = prop->val.markers;
@@ -73,6 +90,10 @@ static void add_deps(struct node *dt, struct node *node, struct property *prop) is_parent_of(target, source)) continue; phandle = get_node_phandle(dt, target); + prop_deps = get_property(node, "no-dependencies"); + if (prop_deps && is_no_dependency(dt, prop_deps, phandle)) + /* avoid adding non-dependencies */ + continue; prop_deps = get_property(source, "dependencies"); if (!prop_deps) { add_property(source,
@@ -102,9 +123,21 @@ static void process_nodes_props(struct node *dt, struct node *node) process_nodes_props(dt, child); } +static void del_prop_no_dependencies(struct node *node) +{ + struct node *child; + + if (!node) + return; + delete_property_by_name(node, "no-dependencies"); + for_each_child(node, child) + del_prop_no_dependencies(child); +} + void add_dependencies(struct boot_info *bi) { process_nodes_props(bi->dt, bi->dt); + del_prop_no_dependencies(bi->dt); } /*
--
2.1.0