When updating existing nodes in a device tree merge operation, properties can be removed by setting the value to /undef-prop/.
if /undef-prop/ is assigned to a property that doesn't exist, the property is treated the same as if it had not been declared. Signed-off-by: John Bonesio <[email protected]> --- dtc-lexer.l | 14 ++++++++++---- dtc-parser.y | 6 ++++++ dtc.h | 7 +++++++ flattree.c | 3 +++ livetree.c | 38 +++++++++++++++++++++++++++++++++----- 5 files changed, 59 insertions(+), 9 deletions(-) diff --git a/dtc-lexer.l b/dtc-lexer.l index 216a3d2..efa89b4 100644 --- a/dtc-lexer.l +++ b/dtc-lexer.l @@ -102,6 +102,12 @@ static int pop_input_file(void); return DT_REMOVENODE; } +<*>"/undef-prop/" { + DPRINT("Keyword: /undef-prop/\n"); + BEGIN_DEFAULT(); + return DT_UNDEFINED; + } + <*>{LABEL}: { DPRINT("Label: %s\n", yytext); yylval.labelref = xstrdup(yytext); @@ -116,10 +122,10 @@ static int pop_input_file(void); } -<*>\&{LABEL} { /* label reference without the braces*/ - DPRINT("Ref: %s\n", yytext+1); - yylval.labelref = xstrdup(yytext+1); - return DT_REF; +<*>\&{LABEL} { /* label reference without the braces*/ + DPRINT("Ref: %s\n", yytext+1); + yylval.labelref = xstrdup(yytext+1); + return DT_REF; } <*>"&{"{LABEL}{PATHCHAR}*\} { /* label and/or path refererence with braces */ diff --git a/dtc-parser.y b/dtc-parser.y index 0a74c86..ac9cfd7 100644 --- a/dtc-parser.y +++ b/dtc-parser.y @@ -56,6 +56,7 @@ static unsigned long long eval_literal(const char *s, int base, int bits); %token DT_V1 %token DT_MEMRESERVE %token DT_REMOVENODE +%token DT_UNDEFINED %token <propnodename> DT_PROPNODENAME %token <literal> DT_LITERAL %token <cbase> DT_BASE @@ -178,6 +179,11 @@ propdef: { $$ = build_property($1, empty_data); } + | DT_PROPNODENAME '=' DT_UNDEFINED ';' + { + $$ = build_property($1, empty_data); + undefine_property($$) + } | DT_LABEL propdef { add_label(&$2->labels, $1); diff --git a/dtc.h b/dtc.h index a7f3667..b3fca6e 100644 --- a/dtc.h +++ b/dtc.h @@ -130,7 +130,12 @@ struct label { struct label *next; }; +#define PROP_DEFINED (0) +#define PROP_UNDEFINED (1) + struct property { + int undefined; /* if the property is set to undefined, this feild is + set to PROP_UNDEFINED */ char *name; struct data val; @@ -170,6 +175,7 @@ void add_label(struct label **labels, char *label); struct property *build_property(char *name, struct data val); struct property *chain_property(struct property *first, struct property *list); struct property *reverse_properties(struct property *first); +void undefine_property(struct property *prop); struct node *build_node(struct property *proplist, struct node *children); struct node *name_node(struct node *node, char *name); @@ -177,6 +183,7 @@ struct node *chain_node(struct node *first, struct node *list); struct node *merge_nodes(struct node *old_node, struct node *new_node); void add_property(struct node *node, struct property *prop); +void remove_property(struct node *node, struct property *prop); void add_child(struct node *parent, struct node *child); void remove_child(struct node *parent, struct node *child); diff --git a/flattree.c b/flattree.c index ead0332..00439e9 100644 --- a/flattree.c +++ b/flattree.c @@ -275,6 +275,9 @@ static void flatten_tree(struct node *tree, struct emitter *emit, for_each_property(tree, prop) { int nameoff; + if (prop->undefined) + continue; + if (streq(prop->name, "name")) seen_name_prop = 1; diff --git a/livetree.c b/livetree.c index bf8796b..2ef734d 100644 --- a/livetree.c +++ b/livetree.c @@ -51,6 +51,11 @@ struct property *build_property(char *name, struct data val) return new; } +void undefine_property(struct property *prop) +{ + prop->undefined = 1; +} + struct property *chain_property(struct property *first, struct property *list) { assert(first->next == NULL); @@ -121,11 +126,15 @@ struct node *merge_nodes(struct node *old_node, struct node *new_node) /* Look for a collision, set new value if there is */ for_each_property(old_node, old_prop) { if (streq(old_prop->name, new_prop->name)) { - /* Add new labels to old property */ - for_each_label(new_prop->labels, l) - add_label(&old_prop->labels, l->label); - - old_prop->val = new_prop->val; + if (new_prop->undefined) { + remove_property(old_node, old_prop); + } else { + /* Add new labels to old property */ + for_each_label(new_prop->labels, l) + add_label(&old_prop->labels, l->label); + + old_prop->val = new_prop->val; + } free(new_prop); new_prop = NULL; break; @@ -188,6 +197,25 @@ void add_property(struct node *node, struct property *prop) *p = prop; } +void remove_property(struct node *node, struct property *prop) +{ + struct property **p; + int found = 0; + + p = &node->proplist; + while (*p) { + if (*p == prop) { + *p = (*p)->next; + found = 1; + break; + } + p = &((*p)->next); + } + /* property not in the node? it's probably an error, so flag it. */ + assert(found); +} + + void add_child(struct node *parent, struct node *child) { struct node **p; _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
