On 6/9/2016 5:13 PM, Adam Thomson wrote:
For device nodes in both DT and ACPI, it possible to have named
child nodes which contain properties (an existing example being
gpio-leds). This adds a function to find a named child node for
a device which can be used by drivers for property retrieval.
For ACPI data node name matching, a helper function is also added
which returns false if CONFIG_ACPI is not set, otherwise it
performs a string comparison on the data node name. This avoids
using the acpi_data_node struct for non CONFIG_ACPI builds,
which would otherwise cause a build failure.
Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
Tested-by: Sathyanarayana Nujella <sathyanarayana.nujella@xxxxxxxxx>
For some reason that didn't make it into the linux-acpi list, or at
least I can't see it there.
---
Changes in v2:
- Rebase to v4.7-rc1
drivers/base/property.c | 28 ++++++++++++++++++++++++++++
include/acpi/acpi_bus.h | 7 +++++++
include/linux/acpi.h | 6 ++++++
include/linux/property.h | 3 +++
4 files changed, 44 insertions(+)
diff --git a/drivers/base/property.c b/drivers/base/property.c
index f38c21d..573b361 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -888,6 +888,34 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev,
EXPORT_SYMBOL_GPL(device_get_next_child_node);
/**
+ * device_get_named_child_node - Return first matching named child node handle
+ * @dev: Device to find the named child node for.
+ * @childname: String to match child node name against.
+ */
+struct fwnode_handle *device_get_named_child_node(struct device *dev,
+ const char *childname)
+{
+ struct fwnode_handle *child;
+
+ /*
+ * Find first matching named child node of this device.
+ * For ACPI this will be a data only sub-node.
+ */
+ device_for_each_child_node(dev, child) {
+ if (is_of_node(child)) {
+ if (!strcasecmp(to_of_node(child)->name, childname))
Why do you use strcasecmp() here?
+ return child;
+ } else if (is_acpi_data_node(child)) {
+ if (acpi_data_node_match(child, childname))
+ return child;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(device_get_named_child_node);
+
+/**
* fwnode_handle_put - Drop reference to a device node
* @fwnode: Pointer to the device node to drop the reference to.
*
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 788c6c3..993bdd0 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -420,6 +420,13 @@ static inline struct acpi_data_node *to_acpi_data_node(struct fwnode_handle *fwn
container_of(fwnode, struct acpi_data_node, fwnode) : NULL;
}
+static inline bool acpi_data_node_match(struct fwnode_handle *fwnode,
+ const char *name)
+{
+ return is_acpi_data_node(fwnode) ?
+ (!strcasecmp(to_acpi_data_node(fwnode)->name, name)) : false;
+}
Is there any particular reason to introduce this function instead of
doing the test in device_get_named_child_node() directly?
+
static inline struct fwnode_handle *acpi_fwnode_handle(struct acpi_device *adev)
{
return &adev->fwnode;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 288fac5..03039c4 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -568,6 +568,12 @@ static inline struct acpi_data_node *to_acpi_data_node(struct fwnode_handle *fwn
return NULL;
}
+static inline bool acpi_data_node_match(struct fwnode_handle *fwnode,
+ const char *name)
+{
+ return false;
+}
+
static inline struct fwnode_handle *acpi_fwnode_handle(struct acpi_device *adev)
{
return NULL;
diff --git a/include/linux/property.h b/include/linux/property.h
index ecab11e..3a2f9ae 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -77,6 +77,9 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev,
for (child = device_get_next_child_node(dev, NULL); child; \
child = device_get_next_child_node(dev, child))
+struct fwnode_handle *device_get_named_child_node(struct device *dev,
+ const char *childname);
+
void fwnode_handle_put(struct fwnode_handle *fwnode);
unsigned int device_get_child_node_count(struct device *dev);
--
Mika, Heikki, Andy, any feedback on this one?
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