Count number of reset phandles available with the device node
to know the resets a given device has.
Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
---
Changes since v1:
- Handling the error path by returning error code for failures
and ENODEV for count equal to 0.
- Moved the function to drivers instead of putting in the includes.
drivers/reset/core.c | 22 ++++++++++++++++++++++
include/linux/reset.h | 6 ++++++
2 files changed, 28 insertions(+)
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index f1e5e65388bb..66db061165cb 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -455,3 +455,25 @@ int device_reset(struct device *dev)
return ret;
}
EXPORT_SYMBOL_GPL(device_reset);
+
+/**
+ * of_reset_control_get_count - Count number of resets available with a device
+ *
+ * @node: device node that contains 'resets'.
+ *
+ * Returns positive reset count on success, or error number on failure and
+ * on count being zero.
+ */
+int of_reset_control_get_count(struct device_node *node)
+{
+ int count;
+
+ count = of_count_phandle_with_args(node, "resets", "#reset-cells");
+ if (count < 0)
+ return count;
+ if (count == 0)
+ return -ENODEV;
+
+ return count;
+}
+EXPORT_SYMBOL_GPL(of_reset_control_get_count);
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 96fb139bdd08..d89556412ccc 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -21,6 +21,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
bool optional);
int __must_check device_reset(struct device *dev);
+int of_reset_control_get_count(struct device_node *node);
static inline int device_reset_optional(struct device *dev)
{
@@ -79,6 +80,11 @@ static inline struct reset_control *__devm_reset_control_get(
return optional ? NULL : ERR_PTR(-ENOTSUPP);
}
+static inline int of_reset_control_get_count(struct device_node *node);
+{
+ return -ENOTSUPP;
+}
+
#endif /* CONFIG_RESET_CONTROLLER */
/**
--
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