Extend the Properties class with some functions to read a single integer
property. Add a new getprop_obj() function to return a Property object
instead of the raw data.
This suggested approach can be extended to handle other types, as well as
arrays.
Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx>
---
Changes in v4:
- Make the as_...() functions non-members of Property
- Drop getprop() and rename getprop_obj() to getprop()
Changes in v3:
- Rename the functions with an 'as_' prefix instead of 'to_'
pylibfdt/libfdt.i | 25 ++++++++++++++++++++++---
tests/pylibfdt_tests.py | 13 +++++++++++++
tests/run_tests.sh | 1 +
tests/test_props.dts | 11 +++++++++++
4 files changed, 47 insertions(+), 3 deletions(-)
create mode 100644 tests/test_props.dts
diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
index 170005f..0c13c5f 100644
--- a/pylibfdt/libfdt.i
+++ b/pylibfdt/libfdt.i
@@ -153,6 +153,24 @@ def check_err_null(val, quiet=()):
raise FdtException(val)
return val
+# Functions which convert a bytestring (as obtained by Fdt.getprop(), for
+# example. to various supported values
+def as_cell(bytes, fmt):
+ return struct.unpack('>' + fmt, bytes)[0]
+
+def as_uint32(bytes):
+ return as_cell(bytes, 'L')
+
+def as_int32(bytes):
+ return as_cell(bytes, 'l')
+
+def as_uint64(bytes):
+ return as_cell(bytes, 'Q')
+
+def as_int64(bytes):
+ return as_cell(bytes, 'q')
+
+
class Fdt:
"""Device tree class, supporting all operations
@@ -365,7 +383,9 @@ class Fdt:
quiet: Errors to ignore (empty to raise on all errors)
Returns:
- Value of property as a string of bytes, or -ve error number
+ Value of property as a Property object (which can be used as a
+ bytearray/string), or -ve error number. On failure, returns an
+ integer error
Raises:
FdtError if any error occurs (e.g. the property is not found)
@@ -374,8 +394,7 @@ class Fdt:
quiet)
if isinstance(pdata, (int)):
return pdata
- # Use bytes() rather than string(). This works on both Python 2 and 3
- return bytes(pdata[0])
+ return Property(prop_name, bytearray(pdata[0]))
def get_phandle(self, nodeoffset):
"""Get the phandle of a node
diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
index 343a1e4..c8c6da6 100644
--- a/tests/pylibfdt_tests.py
+++ b/tests/pylibfdt_tests.py
@@ -89,6 +89,7 @@ class PyLibfdtTests(unittest.TestCase):
def setUp(self):
"""Read in the device tree we use for testing"""
self.fdt = _ReadFdt('test_tree1.dtb')
+ self.fdt2 = _ReadFdt('test_props.dtb')
def GetPropList(self, node_path):
"""Read a list of properties from a node
@@ -330,6 +331,18 @@ class PyLibfdtTests(unittest.TestCase):
node2 = self.fdt.path_offset('/subnode@2/subsubnode@0')
self.assertEquals(node2, self.fdt.node_offset_by_phandle(0x2001))
+ def get_prop(self, name):
+ return self.fdt2.getprop(0, name)
+
+ def testGetIntProperties(self):
+ """Test that we can access properties as integers"""
+ self.assertEquals(0xdeadbeef,
+ libfdt.as_uint32(self.get_prop("prop-hex32")))
+ self.assertEquals(123, libfdt.as_uint32(self.get_prop("prop-uint32")))
+ self.assertEquals(-2, libfdt.as_int32(self.get_prop("prop-int32")))
+ self.assertEquals(9223372036854775807,
+ libfdt.as_uint64(self.get_prop("prop-uint64")))
+ self.assertEquals(-2, libfdt.as_int64(self.get_prop("prop-int64")))
if __name__ == "__main__":
unittest.main()
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index 28e528f..21b633e 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -888,6 +888,7 @@ fdtoverlay_tests() {
}
pylibfdt_tests () {
+ run_dtc_test -I dts -O dtb -o test_props.dtb test_props.dts
TMP=/tmp/tests.stderr.$$
python pylibfdt_tests.py -v 2> $TMP
diff --git a/tests/test_props.dts b/tests/test_props.dts
new file mode 100644
index 0000000..7e59bd1
--- /dev/null
+++ b/tests/test_props.dts
@@ -0,0 +1,11 @@
+/dts-v1/;
+
+/ {
+ compatible = "test_props";
+ prop-hex32 = <0xdeadbeef>;
+ prop-uint32 = <123>;
+ prop-int32 = <0xfffffffe>;
+ prop-hex64 = /bits/ 64 <0xdeadbeef01abcdef>;
+ prop-uint64 = /bits/ 64 <9223372036854775807>;
+ prop-int64 = /bits/ 64 <0xfffffffffffffffe>;
+};
--
2.17.1.1185.g55be947832-goog
--
To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
