pylibfdt: Add functions to update properties

Allow updating and creating properties, including special methods for
integers.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

3 files changed, 110 insertions, 0 deletions

diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index 79e4d82..c99d28f 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -1345,10 +1345,13 @@ static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
 	fdt64_t tmp = cpu_to_fdt64(val);
 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
 }
+
+#ifndef SWIG /* Not available in Python */
 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
 {
 	return fdt_property_u32(fdt, name, val);
 }
+#endif
 
 /**
  * fdt_property_placeholder - add a new property and return a ptr to its value
diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
index da32148..3abcf32 100644
--- a/pylibfdt/libfdt.i
+++ b/pylibfdt/libfdt.i
@@ -528,6 +528,60 @@ class Fdt:
         """
         return check_err(fdt_parent_offset(self._fdt, nodeoffset), quiet)
 
+    def setprop(self, nodeoffset, prop_name, val, quiet=()):
+        """Set the value of a property
+
+        Args:
+            nodeoffset: Node offset containing the property to create/update
+            prop_name: Name of property
+            val: Value to write (string or bytearray)
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            Error code, or 0 if OK
+
+        Raises:
+            FdtException if no parent found or other error occurs
+        """
+        return check_err(fdt_setprop(self._fdt, nodeoffset, prop_name, val,
+                                     len(val)), quiet)
+
+    def setprop_u32(self, nodeoffset, prop_name, val, quiet=()):
+        """Set the value of a property
+
+        Args:
+            nodeoffset: Node offset containing the property to create/update
+            prop_name: Name of property
+            val: Value to write (integer)
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            Error code, or 0 if OK
+
+        Raises:
+            FdtException if no parent found or other error occurs
+        """
+        return check_err(fdt_setprop_u32(self._fdt, nodeoffset, prop_name, val),
+                         quiet)
+
+    def setprop_u64(self, nodeoffset, prop_name, val, quiet=()):
+        """Set the value of a property
+
+        Args:
+            nodeoffset: Node offset containing the property to create/update
+            prop_name: Name of property
+            val: Value to write (integer)
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            Error code, or 0 if OK
+
+        Raises:
+            FdtException if no parent found or other error occurs
+        """
+        return check_err(fdt_setprop_u64(self._fdt, nodeoffset, prop_name, val),
+                         quiet)
+
     def delprop(self, nodeoffset, prop_name):
         """Delete a property from a node
 
@@ -625,6 +679,11 @@ typedef int fdt32_t;
 		$result = Py_BuildValue("s#", $1, *arg4);
 }
 
+/* typemap used for fdt_setprop() */
+%typemap(in) (const void *val) {
+    $1 = PyString_AsString($input);   /* char *str */
+}
+
 /* typemaps used for fdt_next_node() */
 %typemap(in, numinputs=1) int *depth (int depth) {
    depth = (int) PyInt_AsLong($input);
diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
index ea38b78..08c4f57 100644
--- a/tests/pylibfdt_tests.py
+++ b/tests/pylibfdt_tests.py
@@ -49,6 +49,7 @@
 #     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #
 
+import struct
 import sys
 import types
 import unittest
@@ -57,6 +58,18 @@ sys.path.insert(0, '../pylibfdt')
 import libfdt
 from libfdt import Fdt, FdtException, QUIET_NOTFOUND, QUIET_ALL
 
+small_size = 160
+full_size = 1024
+
+TEST_VALUE_1 = 0xdeadbeef
+
+TEST_VALUE64_1H = 0xdeadbeef
+TEST_VALUE64_1L = 0x01abcdef
+TEST_VALUE64_1 = (TEST_VALUE64_1H << 32) | TEST_VALUE64_1L
+
+TEST_STRING_1 = 'hello world'
+
+
 def get_err(err_code):
     """Convert an error code into an error message
 
@@ -380,6 +393,41 @@ class PyLibfdtTests(unittest.TestCase):
         fdt.pack()
         self.assertTrue(fdt.totalsize() < 128)
 
+    def testSetProp(self):
+        """Test that we can update and create properties"""
+        node = self.fdt.path_offset('/subnode@1')
+        self.fdt.setprop(node, 'compatible', TEST_STRING_1)
+        self.assertEquals(TEST_STRING_1, self.fdt.getprop(node, 'compatible'))
+
+        # Check that this property is missing, and that we don't have space to
+        # add it
+        self.assertEquals(-libfdt.NOTFOUND,
+                          self.fdt.getprop(node, 'missing', QUIET_NOTFOUND))
+        self.assertEquals(-libfdt.NOSPACE,
+                          self.fdt.setprop(node, 'missing', TEST_STRING_1,
+                                           quiet=(libfdt.NOSPACE,)))
+
+        # Expand the device tree so we now have room
+        self.fdt.resize(self.fdt.totalsize() + 50)
+        self.fdt.setprop(node, 'missing', TEST_STRING_1)
+        self.assertEquals(TEST_STRING_1, self.fdt.getprop(node, 'missing'))
+
+    def testSetPropU32(self):
+        """Test that we can update and create integer properties"""
+        node = 0
+        prop = 'prop-int'
+        self.fdt.setprop_u32(node, prop, TEST_VALUE_1)
+        self.assertEquals(struct.pack('>I', TEST_VALUE_1),
+                          self.fdt.getprop(node, prop))
+
+    def testSetPropU64(self):
+        """Test that we can update and create integer properties"""
+        node = 0
+        prop = 'prop-int64'
+        self.fdt.setprop_u64(node, prop, TEST_VALUE64_1)
+        self.assertEquals(struct.pack('>Q', TEST_VALUE64_1),
+                          self.fdt.getprop(node, prop))
+
 
 if __name__ == "__main__":
     unittest.main()