Add items to Devicetree Source Format chapter

From: Frank Rowand <[email protected]>

Add items to Devicetree Source Format chapter

- Add naming convention for DTS files and DTS include files
- Add /include/ compiler directive
- Add ";" to end of node definition
- Add /delete-node/ and /delete-property/
- Add arithmetic, bitwise, logical, and ternary expressions

Note that cpp directives are not included in this patch, and are not yet specified in this appendix.

Signed-off-by Frank Rowand <[email protected]>

---

changes in v2
- arithmetic operators "and", "or" were incorrectly listed as as bitwise
- thus bitwise operators "and", "or" were incorrectly shown
- "exclusive or" operator added
- logical and arithmetic "not" operators added
- ternary operator added
- moved shift operators from arithmetic to bitwise

 source/source-language.rst |   70 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

Index: b/source/source-language.rst
===================================================================

source/source-language.rst +53 -1

@@ -9,6 +9,19 @@ devicetree in the form expected by the k
 not a formal syntax definition of DTS, but describes the basic
 constructs used to represent devicetrees.
 
+The name of DTS files should end with ".dts".
+
+Compiler directives
+-------------------
+
+Other source files can be included from a DTS file.  The name of include
+files should end with ".dtsi".  Included files can in turn include
+additional files.
+
+::
+
+    /include/ "FILE"
+
 Node and property definitions
 -----------------------------
 

@@ -21,11 +34,18 @@ preceded by a label.
     [label:] node-name[@unit-address] {
         [properties definitions]
         [child nodes]
-    }
+    };
 
 Nodes may contain property definitions and/or child node definitions. If
 both are present, properties shall come before child nodes.
 
+Previously defined nodes may be deleted.
+
+::
+
+    /delete-node/ node-name;
+    /delete-node/ &label;
+
 Property definitions are name value pairs in the form:
 
 ::

@@ -39,6 +59,12 @@ form:
 
         [label:] property-name;
 
+Previously defined properties may be deleted.
+
+::
+
+    /delete-property/ property-name;
+
 Property values may be defined as an array of 32-bit integer cells, as
 null-terminated strings, as bytestrings or a combination of these.
 

@@ -48,6 +74,48 @@ null-terminated strings, as bytestrings
 ::
 
         interrupts = <17 0xc>;
+-  values may be represented as arithmetic, bitwise, or logical expressions
+   within parenthesis.
+
+::
+
+    Arithmetic operators
+
+    +   add
+    -   subtract
+    *   multiply
+    /   divide
+
+::
+
+    Bitwise operators
+
+    &    and
+    |    or
+    ^    exclusive or
+    ~    not
+    <<  left shift
+    >>  right shift
+
+::
+
+    Logical operators

source/source-language.rst +5 -0

+::
+
+    Ternary operators
+
+    ?:   (condition ? value_if_true : value_if_false)
 
 -  A 64-bit value is represented with two 32-bit cells. Example:
 

Quoted 33 lines · Frank Rowand

From: Frank Rowand <[email protected]>

Add items to Devicetree Source Format chapter

- Add naming convention for DTS files and DTS include files
- Add /include/ compiler directive
- Add ";" to end of node definition
- Add /delete-node/ and /delete-property/
- Add arithmetic, bitwise, logical, and ternary expressions

Note that cpp directives are not included in this patch, and are not yet specified in this appendix.

Signed-off-by Frank Rowand <[email protected]>

---

changes in v2
- arithmetic operators "and", "or" were incorrectly listed as as bitwise
- thus bitwise operators "and", "or" were incorrectly shown
- "exclusive or" operator added
- logical and arithmetic "not" operators added
- ternary operator added
- moved shift operators from arithmetic to bitwise

 source/source-language.rst |   70 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

Index: b/source/source-language.rst
===================================================================

source/source-language.rst +0 -0

@@ -9,6 +9,19 @@ devicetree in the form expected by the k

source/source-language.rst null-terminated strings, as bytestrings · line 112

Quoted 11 lines

source/source-language.rst +11 -0

+    Logical operators
+
+    <    less than
+    >    greater than
+    <=   less than or equal
+    >=   greater than or equal
+    ==   equal
+    !=   not equal
+    &&   and
+    ||   or
+    !    not

Fwiw, I think &&, || and ! usually get classified as "logical operators" but <, > etc. get classified as "relational operators" rather than putting them in the same category.

Hrm.. given that you're listing them all here, I wonder if it would make sense to do so in precedence order (should be the same as for C).