dm: core: Add functions to obtain node's address/size cells

The of_n_addr_cells() and of_n_size_cells() functions are useful for
getting the size of addresses in a node, but in a few places U-Boot needs
to obtain the actual property value for a node without walking up the
stack. Add functions for this and just the existing code to use it.

Add a comment to the existing ofnode functions which do not do the right
thing with a flat tree.

This fixes a problem reading PCI addresses.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-on: Beaver, Jetson-TK1

1 files changed, 32 insertions, 0 deletions

diff --git a/include/dm/read.h b/include/dm/read.h
index cea1c16a006..6dd1634675b 100644
--- a/include/dm/read.h
+++ b/include/dm/read.h
@@ -231,6 +231,26 @@ int dev_read_addr_cells(struct udevice *dev);
 int dev_read_size_cells(struct udevice *dev);
 
 /**
+ * dev_read_addr_cells() - Get the address cells property in a node
+ *
+ * This function matches fdt_address_cells().
+ *
+ * @dev: devioe to check
+ * @return number of address cells this node uses
+ */
+int dev_read_simple_addr_cells(struct udevice *dev);
+
+/**
+ * dev_read_size_cells() - Get the size cells property in a node
+ *
+ * This function matches fdt_size_cells().
+ *
+ * @dev: devioe to check
+ * @return number of size cells this node uses
+ */
+int dev_read_simple_size_cells(struct udevice *dev);
+
+/**
  * dev_read_phandle() - Get the phandle from a device
  *
  * @dev: device to check
@@ -398,11 +418,23 @@ static inline int dev_read_phandle_with_args(struct udevice *dev,
 
 static inline int dev_read_addr_cells(struct udevice *dev)
 {
+	/* NOTE: this call should walk up the parent stack */
 	return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev));
 }
 
 static inline int dev_read_size_cells(struct udevice *dev)
 {
+	/* NOTE: this call should walk up the parent stack */
+	return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev));
+}
+
+static inline int dev_read_simple_addr_cells(struct udevice *dev)
+{
+	return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev));
+}
+
+static inline int dev_read_simple_size_cells(struct udevice *dev)
+{
 	return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev));
 }