There are lot of drivers using of_get_child_by_name() followed by
of_device_is_available() to find the available child node by name for a
given parent. Provide a helper for these users to simplify the code.
Suggested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
---
v1->v2:
* Updated commit description.
* Updated kerneldoc comment block
* Avoided code duplication by using of_get_child_by_name().
Note:
grep showed the below files will be the users for this new API.
I will be updating these drivers once this patch is in mainline.
drivers/net/dsa/rzn1_a5psw.c
drivers/net/can/rcar/rcar_canfd.c
drivers/net/ethernet/mediatek/mtk_star_emac.c
drivers/net/dsa/mt7530.c
drivers/net/dsa/sja1105/sja1105_mdio.c
drivers/net/dsa/qca/qca8k-8xxx.c
drivers/net/wireless/mediatek/mt76/mac80211.c
drivers/net/ethernet/ibm/emac/core.c
drivers/net/ethernet/ti/am65-cpsw-nuss.c
drivers/net/ethernet/actions/owl-emac.c
drivers/net/ethernet/mediatek/mtk_eth_soc.c
drivers/media/platform/samsung/exynos4-is/media-dev.h
drivers/gpu/drm/tegra/rgb.c
drivers/gpu/drm/msm/adreno/adreno_gpu.c
drivers/clk/davinci/pll.c
---
drivers/of/base.c | 27 +++++++++++++++++++++++++++
include/linux/of.h | 9 +++++++++
2 files changed, 36 insertions(+)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index af6c68bbb427..e37b088f1fad 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -824,6 +824,33 @@ struct device_node *of_get_child_by_name(const struct device_node *node,
}
EXPORT_SYMBOL(of_get_child_by_name);
+/**
+ * of_get_available_child_by_name - Find the available child node by name for a given parent
+ * @node: parent node
+ * @name: child name to look for.
+ *
+ * This function looks for child node for given matching name and checks the
+ * device's availability for use.
+ *
+ * Return: A node pointer if found, with refcount incremented, use
+ * of_node_put() on it when done.
+ * Returns NULL if node is not found.
+ */
+struct device_node *of_get_available_child_by_name(const struct device_node *node,
+ const char *name)
+{
+ struct device_node *child;
+
+ child = of_get_child_by_name(node, name);
+ if (child && !of_device_is_available(child)) {
+ of_node_put(child);
+ return NULL;
+ }
+
+ return child;
+}
+EXPORT_SYMBOL(of_get_available_child_by_name);
+
struct device_node *__of_find_node_by_path(const struct device_node *parent,
const char *path)
{
diff --git a/include/linux/of.h b/include/linux/of.h
index eaf0e2a2b75c..9d6b8a61607f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -301,6 +301,8 @@ extern struct device_node *of_get_compatible_child(const struct device_node *par
const char *compatible);
extern struct device_node *of_get_child_by_name(const struct device_node *node,
const char *name);
+extern struct device_node *of_get_available_child_by_name(const struct device_node *node,
+ const char *name);
/* cache lookup */
extern struct device_node *of_find_next_cache_node(const struct device_node *);
@@ -578,6 +580,13 @@ static inline struct device_node *of_get_child_by_name(
return NULL;
}
+static inline struct device_node *of_get_available_child_by_name(
+ const struct device_node *node,
+ const char *name)
+{
+ return NULL;
+}
+
static inline int of_device_is_compatible(const struct device_node *device,
const char *name)
{
--
2.43.0
