[RFC 01/19] device property: Introduce fwnode_property_get_reference_args

Sakari Ailus
2017-07-18T19:04:03Z

The new fwnode_property_get_reference_args() interface amends the fwnode
property API with the functionality of both of_parse_phandle_with_args()
and __acpi_node_get_property_reference().

The semantics is slightly different: the cells property is ignored on ACPI
as the number of arguments can be explicitly obtained from the firmware
interface.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/acpi/property.c | 27 +++++++++++++++++++++++++++
drivers/base/property.c | 12 ++++++++++++
drivers/of/property.c | 31 +++++++++++++++++++++++++++++++
include/linux/fwnode.h | 19 +++++++++++++++++++
include/linux/property.h | 4 ++++
5 files changed, 93 insertions(+)

diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index f8d60051efb8..b39497cd3f7f 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -1195,6 +1195,32 @@ acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
return NULL;
}

+static int
+acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
+ const char *prop, const char *nargs_prop,
+ unsigned int args_count, unsigned int index,
+ struct fwnode_reference_args *args)
+{
+ struct acpi_reference_args acpi_args;
+ unsigned int i;
+ int ret;
+
+ ret = __acpi_node_get_property_reference(fwnode, prop, index,
+ args_count, &acpi_args);
+ if (ret < 0)
+ return ret;
+ if (!args)
+ return 0;
+
+ args->nargs = acpi_args.nargs;
+ args->fwnode = acpi_fwnode_handle(acpi_args.adev);
+
+ for (i = 0; i < NR_OF_FWNODE_REFERENCE_ARGS; i++)
+ args->args[i] = i < acpi_args.nargs ? acpi_args.args[i] : 0;
+
+ return 0;
+}
+
static struct fwnode_handle *
acpi_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
struct fwnode_handle *prev)
@@ -1248,6 +1274,7 @@ static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
.get_parent = acpi_node_get_parent, \
.get_next_child_node = acpi_get_next_subnode, \
.get_named_child_node = acpi_fwnode_get_named_child_node, \
+ .get_reference_args = acpi_fwnode_get_reference_args, \
.graph_get_next_endpoint = \
acpi_fwnode_graph_get_next_endpoint, \
.graph_get_remote_endpoint = \
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 673e2353a2fb..369b5471198f 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -665,6 +665,18 @@ int fwnode_property_match_string(const struct fwnode_handle *fwnode,
}
EXPORT_SYMBOL_GPL(fwnode_property_match_string);

+/**
+ */
+int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
+ const char *prop, const char *nargs_prop,
+ unsigned int nargs, unsigned int index,
+ struct fwnode_reference_args *args)
+{
+ return fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
+ nargs, index, args);
+}
+EXPORT_SYMBOL_GPL(fwnode_property_get_reference_args);
+
static int property_copy_string_array(struct property_entry *dst,
const struct property_entry *src)
{
diff --git a/drivers/of/property.c b/drivers/of/property.c
index ae46a6f0ea36..2350103f8be6 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -891,6 +891,36 @@ of_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
return NULL;
}

+static int
+of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
+ const char *prop, const char *nargs_prop,
+ unsigned int nargs, unsigned int index,
+ struct fwnode_reference_args *args)
+{
+ struct of_phandle_args of_args;
+ unsigned int i;
+ int ret;
+
+ if (nargs_prop)
+ ret = of_parse_phandle_with_args(to_of_node(fwnode), prop,
+ nargs_prop, index, &of_args);
+ else
+ ret = of_parse_phandle_with_fixed_args(to_of_node(fwnode), prop,
+ nargs, index, &of_args);
+ if (ret < 0)
+ return ret;
+ if (!args)
+ return 0;
+
+ args->nargs = of_args.args_count;
+ args->fwnode = of_fwnode_handle(of_args.np);
+
+ for (i = 0; i < NR_OF_FWNODE_REFERENCE_ARGS; i++)
+ args->args[i] = i < of_args.args_count ? of_args.args[i] : 0;
+
+ return 0;
+}
+
static struct fwnode_handle *
of_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
struct fwnode_handle *prev)
@@ -949,6 +979,7 @@ const struct fwnode_operations of_fwnode_ops = {
.get_parent = of_fwnode_get_parent,
.get_next_child_node = of_fwnode_get_next_child_node,
.get_named_child_node = of_fwnode_get_named_child_node,
+ .get_reference_args = of_fwnode_get_reference_args,
.graph_get_next_endpoint = of_fwnode_graph_get_next_endpoint,
.graph_get_remote_endpoint = of_fwnode_graph_get_remote_endpoint,
.graph_get_port_parent = of_fwnode_graph_get_port_parent,
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 7b50ee4edcfc..218fe03544c9 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -33,6 +33,20 @@ struct fwnode_endpoint {
const struct fwnode_handle *local_fwnode;
};

+#define NR_OF_FWNODE_REFERENCE_ARGS 8
+
+/**
+ * struct fwnode_reference_args - Fwnode reference with additional arguments
+ * @fwnode:- A reference to the base fwnode
+ * @nargs: Number of elements in @args array
+ * @args: Integer arguments on the fwnode
+ */
+struct fwnode_reference_args {
+ struct fwnode_handle *fwnode;
+ unsigned int nargs;
+ unsigned int args[NR_OF_FWNODE_REFERENCE_ARGS];
+};
+
/**
* struct fwnode_operations - Operations for fwnode interface
* @get: Get a reference to an fwnode.
@@ -46,6 +60,7 @@ struct fwnode_endpoint {
* @get_parent: Return the parent of an fwnode.
* @get_next_child_node: Return the next child node in an iteration.
* @get_named_child_node: Return a child node with a given name.
+ * @get_reference_args: Return a reference pointed to by a property, with args
* @graph_get_next_endpoint: Return an endpoint node in an iteration.
* @graph_get_remote_endpoint: Return the remote endpoint node of a local
* endpoint node.
@@ -73,6 +88,10 @@ struct fwnode_operations {
struct fwnode_handle *
(*get_named_child_node)(const struct fwnode_handle *fwnode,
const char *name);
+ int (*get_reference_args)(const struct fwnode_handle *fwnode,
+ const char *prop, const char *nargs_prop,
+ unsigned int nargs, unsigned int index,
+ struct fwnode_reference_args *args);
struct fwnode_handle *
(*graph_get_next_endpoint)(const struct fwnode_handle *fwnode,
struct fwnode_handle *prev);
diff --git a/include/linux/property.h b/include/linux/property.h
index edff3f89e755..6bebee13c5e0 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -73,6 +73,10 @@ int fwnode_property_read_string(const struct fwnode_handle *fwnode,
const char *propname, const char **val);
int fwnode_property_match_string(const struct fwnode_handle *fwnode,
const char *propname, const char *string);
+int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
+ const char *prop, const char *nargs_prop,
+ unsigned int nargs, unsigned int index,
+ struct fwnode_reference_args *args);

struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
struct fwnode_handle *fwnode_get_next_parent(
--
2.11.0