device_tree: qemu_fdt_getprop_cell converted to use the error API

This patch aligns the prototype with qemu_fdt_getprop. The caller
can choose whether the function self-asserts on error (passing
&error_fatal as Error ** argument, corresponding to the legacy behavior),
or behaves differently such as simply output a message.

In this later case the caller can use the new lenp parameter to interpret
the error if any.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h
index 48bf3b5..705650a 100644
--- a/include/sysemu/device_tree.h
+++ b/include/sysemu/device_tree.h
@@ -67,8 +67,20 @@ int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
 const void *qemu_fdt_getprop(void *fdt, const char *node_path,
                              const char *property, int *lenp,
                              Error **errp);
+/**
+ * qemu_fdt_getprop_cell: retrieve the value of a given 4 byte property
+ * @fdt: pointer to the device tree blob
+ * @node_path: node path
+ * @property: name of the property to find
+ * @lenp: fdt error if any or -EINVAL if the property size is different from
+ *        4 bytes, or 4 (expected length of the property) upon success.
+ * @errp: handle to an error object
+ *
+ * returns the property value on success
+ */
 uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
-                               const char *property);
+                               const char *property, int *lenp,
+                               Error **errp);
 uint32_t qemu_fdt_get_phandle(void *fdt, const char *path);
 uint32_t qemu_fdt_alloc_phandle(void *fdt);
 int qemu_fdt_nop_node(void *fdt, const char *node_path);