reset: Add reset_control_get_count()

Currently the reset core has internal support for counting the number of
resets for a device described in DT.  Generalize this to devices using
lookup resets, and export it for public use.

This will be used by generic drivers that need to be sure a device is
controlled by a single, dedicated reset line (e.g. vfio-platform).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
[p.zabel@pengutronix.de: fixed a typo in reset_control_get_count comment]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/reset.h b/include/linux/reset.h
index 76690cf2e3e0..c1901b61ca30 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -32,6 +32,8 @@ struct reset_control *devm_reset_control_array_get(struct device *dev,
 struct reset_control *of_reset_control_array_get(struct device_node *np,
                                                  bool shared, bool optional);
 
+int reset_control_get_count(struct device *dev);
+
 #else
 
 static inline int reset_control_reset(struct reset_control *rstc)
@@ -97,6 +99,11 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional)
         return optional ? NULL : ERR_PTR(-ENOTSUPP);
 }
 
+static inline int reset_control_get_count(struct device *dev)
+{
+        return -ENOENT;
+}
+
 #endif /* CONFIG_RESET_CONTROLLER */
 
 static inline int __must_check device_reset(struct device *dev)