There's typically a standard pinout for expansion boards on
platforms like raspberry pi, 96boards, C.H.I.P, etc. Introduce a
new syntax to describe these types of expansion boards in
devicetree.
In general, the resulting dtb format is very similar to the
/plugin/ style of overlays, except the 'target' property in the
fragment node is replaced with a 'target-alias' property that
contains a string instead of a phandle.
fragment@0 {
target-alias = "i2c_1";
};
instead of
fragment@0 {
target = <&i2c_1>;
};
Signed-off-by: Stephen Boyd <[email protected]>
---
checks.c | 2 +-
dtc-lexer.l | 6 ++++++
dtc-parser.y | 5 +++++
dtc.c | 3 +--
dtc.h | 1 +
livetree.c | 22 +++++++++++++++-------
6 files changed, 29 insertions(+), 10 deletions(-)
diff --git a/checks.c b/checks.c
index 3d18e45374c8..44101def69d5 100644
--- a/checks.c
+++ b/checks.c
@@ -487,7 +487,7 @@ static void fixup_phandle_references(struct check *c,
struct dt_info *dti,
refnode = get_node_by_ref(dt, m->ref);
if (! refnode) {
- if (!(dti->dtsflags & DTSF_PLUGIN))
+ if (!(dti->dtsflags & (DTSF_PLUGIN |
DTSF_EXPANSION)))
FAIL(c, "Reference to non-existent node
or "
"label \"%s\"\n",
m->ref);
else /* mark the entry as unresolved */
diff --git a/dtc-lexer.l b/dtc-lexer.l
index c600603044f3..c5683e0197ec 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l
@@ -126,6 +126,12 @@ static void lexical_error(const char *fmt, ...);
return DT_PLUGIN;
}
+<*>"/expansion/" {
+ DPRINT("Keyword: /expansion/\n");
+ return DT_EXPANSION;
+ }
+
+
<*>"/memreserve/" {
DPRINT("Keyword: /memreserve/\n");
BEGIN_DEFAULT();
diff --git a/dtc-parser.y b/dtc-parser.y
index 3d2ce372c286..28de8f6c1b61 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -60,6 +60,7 @@ extern bool treesource_error;
%token DT_V1
%token DT_PLUGIN
+%token DT_EXPANSION
%token DT_MEMRESERVE
%token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
%token DT_BITS
@@ -127,6 +128,10 @@ header:
{
$$ = DTSF_V1 | DTSF_PLUGIN;
}
+ | DT_V1 ';' DT_EXPANSION ';'
+ {
+ $$ = DTSF_V1 | DTSF_EXPANSION;
+ }
;
headers:
diff --git a/dtc.c b/dtc.c
index d52d6c77a8cd..8f0b47b53d8c 100644
--- a/dtc.c
+++ b/dtc.c
@@ -334,9 +334,8 @@ int main(int argc, char *argv[])
process_checks(force, dti);
/* on a plugin, generate by default */
- if (dti->dtsflags & DTSF_PLUGIN) {
+ if (dti->dtsflags & (DTSF_PLUGIN | DTSF_EXPANSION))
generate_fixups = 1;
- }
if (auto_label_aliases)
generate_label_tree(dti, "aliases", false);
diff --git a/dtc.h b/dtc.h
index be75aac1f185..f751757d63f6 100644
--- a/dtc.h
+++ b/dtc.h
@@ -264,6 +264,7 @@ struct dt_info {
/* DTS version flags definitions */
#define DTSF_V1 0x0001 /* /dts-v1/ */
#define DTSF_PLUGIN 0x0002 /* /plugin/ */
+#define DTSF_EXPANSION 0x0004 /* /expansion/ */
struct dt_info *build_dt_info(unsigned int dtsflags,
struct reserve_info *reservelist,
diff --git a/livetree.c b/livetree.c
index 798a87ed587e..f8abb875be8e 100644
--- a/livetree.c
+++ b/livetree.c
@@ -331,7 +331,8 @@ struct overlay *chain_overlay(struct overlay *first, struct
overlay *list)
return first;
}
-static void add_fragment(struct node *base, struct overlay *overlay)
+static void add_fragment(struct node *base, struct overlay *overlay,
+ bool expansion)
{
static unsigned int next_fragment = 0;
struct node *node;
@@ -343,11 +344,18 @@ static void add_fragment(struct node *base, struct
overlay *overlay)
die("Deletions not supported at runtime for %s\n",
overlay->target);
- /* Insert a target = <&phandle> property */
- d = data_add_marker(d, REF_PHANDLE, overlay->target);
- d = data_append_integer(d, 0xffffffff, 32);
+ if (expansion) {
+ /* Insert a target-alias = "<target>" property */
+ p = build_property("target-alias",
+ data_copy_mem(overlay->target,
+ strlen(overlay->target) + 1));
+ } else {
+ /* Insert a target = <&phandle> property */
+ d = data_add_marker(d, REF_PHANDLE, overlay->target);
+ d = data_append_integer(d, 0xffffffff, 32);
- p = build_property("target", d);
+ p = build_property("target", d);
+ }
xasprintf(&name, "fragment@%u", next_fragment++);
name_node(overlay->dt, "__overlay__");
@@ -363,8 +371,8 @@ void apply_overlay(struct node *base, struct overlay
*overlay,
struct node *target = get_node_by_ref(base, overlay->target);
if (!target) {
- if (dtsflags & DTSF_PLUGIN) {
- add_fragment(base, overlay);
+ if (dtsflags & (DTSF_PLUGIN | DTSF_EXPANSION)) {
+ add_fragment(base, overlay, dtsflags & DTSF_EXPANSION);
return;
} else
die("Couldn't find label or path %s for overlay\n",
--
2.10.0.297.gf6727b0
