Current qemu_fdt_getprop exits if the property is not found. It is
sometimes needed to read an optional property, in which case we do
not wish to exit but simply returns a null value.
This patch converts qemu_fdt_getprop to accept an Error **, and existing
users are converted to pass &error_fatal. This preserves the existing
behaviour. Then to use the API with your optional semantic a null
parameter can be conveyed.
Signed-off-by: Eric Auger <eric.au...@linaro.org>
---
v1 -> v2:
- add a doc comment in the header file
RFC -> v1:
- get rid of qemu_fdt_getprop_optional and implement Peter's suggestion
that consists in using the error API
Signed-off-by: Eric Auger <eric.au...@linaro.org>
---
device_tree.c | 11 ++++++-----
include/sysemu/device_tree.h | 15 ++++++++++++++-
2 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/device_tree.c b/device_tree.c
index 8441e01..6ecc9da 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -321,18 +321,18 @@ int qemu_fdt_setprop_string(void *fdt, const char
*node_path,
}
const void *qemu_fdt_getprop(void *fdt, const char *node_path,
- const char *property, int *lenp)
+ const char *property, int *lenp, Error **errp)
{
int len;
const void *r;
+
if (!lenp) {
lenp = &len;
}
r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp);
if (!r) {
- error_report("%s: Couldn't get %s/%s: %s", __func__,
- node_path, property, fdt_strerror(*lenp));
- exit(1);
+ error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__,
+ node_path, property, fdt_strerror(*lenp));
}
return r;
}
@@ -341,7 +341,8 @@ uint32_t qemu_fdt_getprop_cell(void *fdt, const char
*node_path,
const char *property)
{
int len;
- const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len);
+ const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len,
+ &error_fatal);
if (len != 4) {
error_report("%s: %s/%s not 4 bytes long (not a cell?)",
__func__, node_path, property);
diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h
index 269cb1c..4d7cbb9 100644
--- a/include/sysemu/device_tree.h
+++ b/include/sysemu/device_tree.h
@@ -45,8 +45,21 @@ int qemu_fdt_setprop_string(void *fdt, const char *node_path,
int qemu_fdt_setprop_phandle(void *fdt, const char *node_path,
const char *property,
const char *target_node_path);
+/**
+ * qemu_fdt_getprop: retrieve the value of a given 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 length of the property on success
+ * @errp: handle to an error object
+ *
+ * returns a pointer to the property on success and NULL on failure
+ * in case errp is set to &error_fatal, the function auto-asserts
+ * on error (legacy behavior)
+ */
const void *qemu_fdt_getprop(void *fdt, const char *node_path,
- const char *property, int *lenp);
+ const char *property, int *lenp,
+ Error **errp);
uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path,
const char *property);
uint32_t qemu_fdt_get_phandle(void *fdt, const char *path);
--
1.9.1
